⚙

Pathophysiology

7

Ostiomeatal Complex Obstruction

Functional occlusion of the maxillary infundibulum / ostiomeatal complex (OMC) initiates the SSS cascade. Obstruction may be idiopathic (anatomic variants such as uncinate process lateralization, septal deviation toward the affected side, or concha bullosa), iatrogenic/post-traumatic (mucociliary disruption from prior orbital or sinus surgery, midface fracture, malpositioned orbital floor implant), or rarely systemic (granulomatous sinonasal destruction in GPA). The obstruction is classically silent — the maxillary sinus does not produce inflammatory sinonasal symptoms — because complete outflow blockade prevents expression of typical mucopurulent rhinosinusitis.

maxillary sinus link uncinate process of ethmoid link

Downstream

Sinus Hypoventilation and Negative Pressure Closed maxillary outflow tract prevents gas exchange and mucus drainage, so resident respiratory mucosa resorbs sinus gas and creates a subatmospheric (negative) intra-antral pressure.

Show evidence (4 references)

PMID:23946747 SUPPORT Human Clinical

"Obstruction of the maxillary ostium appears to play a critical role in the development of SSS."

The reference explicitly states that ostium obstruction plays a critical role in SSS development.

PMID:38947644 SUPPORT Human Clinical

"The underlying cause of this condition is the chronic obstruction of the osteomeatal complex, which leads to sinus contraction."

Confirms chronic ostiomeatal complex obstruction as the proximal mechanistic trigger for sinus contraction in SSS.

PMID:29726628 SUPPORT Human Clinical

"Radiographic findings include ipsilateral maxillary sinus opacification, lateralization of the uncinate and middle turbinate, and infundibular occlusion."

Documents the canonical radiographic triad (uncinate lateralization, infundibular occlusion) defining OMC obstruction in SSS.

+ 1 more reference

Sinus Hypoventilation and Negative Pressure

With outflow occluded, the trapped maxillary gas is resorbed by the sinus mucosa, generating a sustained subatmospheric pressure analogous to middle-ear atelectasis from Eustachian tube dysfunction. The negative pressure is the central mechanical driver that distinguishes SSS from simple maxillary hypoplasia and that propagates downstream wall remodeling.

respiratory tract epithelial cell link

maxillary sinus link mucosa of maxillary sinus link

Downstream

Mucociliary Stasis and Mucus Retention Outflow occlusion plus negative pressure halts mucociliary clearance, so secretions accumulate and the sinus opacifies; the mucus column perpetuates obstruction.

Negative-Pressure Bone Remodeling Chronic subatmospheric pressure mechanically drives osteoclast-mediated resorption and inward bowing of the bony sinus walls.

Show evidence (2 references)

PMID:41783519 SUPPORT Human Clinical

"Silent sinus syndrome (SSS) arises from negative pressure in the maxillary sinus through occlusion of the ethmoidal infundibulum."

Direct statement that negative intra-antral pressure following infundibular occlusion is the upstream physiologic event.

PMID:38707145 SUPPORT Human Clinical

"Silent sinus syndrome is a rare clinical entity affecting the maxillary sinus, characterized by ipsilateral enophthalmos and hypoglobus."

Recent review situates SSS as a maxillary-sinus driven entity, framing sinus hypoventilation as the proximal pathophysiologic step before orbital manifestations.

Mucociliary Stasis and Mucus Retention

Loss of ciliary clearance and accumulation of static mucus opacifies the sinus on imaging and reinforces obstruction. Although classical SSS is "silent" because complete blockade prevents purulent rhinosinusitis, rare variants present without opacification when residual aeration persists, demonstrating that mucus retention is contributory rather than obligatory.

ciliated epithelial cell link mucus secreting cell link

mucociliary clearance link ↓ DECREASED mucus secretion link

mucosa of maxillary sinus link

Downstream

Negative-Pressure Bone Remodeling Persistent obstruction sustains the negative pressure that drives bone remodeling.

Show evidence (2 references)

PMID:40402305 SUPPORT Human Clinical

"Secondary SSS arises from trauma or surgery disrupting mucociliary clearance."

Implicates impaired mucociliary clearance as a converging mechanism in secondary SSS, supporting its role in the SSS pathway.

PMID:29726628 PARTIAL Human Clinical

"an aerated maxillary sinus in patients with unexplained enophthalmos, hypoglobus, and maxillary atelectasis should not exclude the diagnosis of SSS."

Atypical aerated cases show that mucus opacification is not obligatory; the mechanism is contributory and stage-dependent.

Negative-Pressure Bone Remodeling

Sustained subatmospheric pressure combined with proposed subclinical inflammation activates osteoclast-mediated bone resorption and osteoblast-mediated remodeling of the thin bony walls of the maxillary sinus, particularly the orbital floor (sinus roof). The result is osteopenia, demineralization, focal dehiscence, and inward bowing of the sinus walls. Histologic data are sparse and stage-dependent; osteoclast activity is implicated mechanistically but may be undetectable in late, quiescent specimens.

osteoclast link osteoblast link

bone resorption link ↑ INCREASED bone remodeling link ↑ INCREASED

maxilla link orbit of skull link

Downstream

Maxillary Sinus Atelectasis Bone resorption and weakening of the sinus walls lets atmospheric and orbital tissue pressures push the walls inward, producing volume loss.

Orbital Floor Resorption and Descent The same negative-pressure remodeling thins and resorbs the orbital floor, which then descends inferiorly under the weight of the orbital contents.

Show evidence (3 references)

PMID:8152774 SUPPORT Human Clinical

"characterized by bone resorption and remodeling of the orbital floor due to otherwise asymptomatic maxillary sinus disease"

The original Soparkar description identifies bone resorption and remodeling as the cellular substrate of SSS.

PMID:11404606 SUPPORT Human Clinical

"opacified, partially collapsed maxillary sinuses with osteopenia of the sinus walls and orbital floor displacement resulting in enophthalmos"

Documents radiographic osteopenia of the sinus walls — the imaging correlate of the proposed osteoclastic bone remodeling.

DOI:10.15275/rusomj.2024.0413 PARTIAL Human Clinical

"orbital floor changes due to changes in MS pressure or subclinical inflammation are considered part of the potential pathogenesis"

Direct histologic-clinical correlation paper supporting pressure-driven and inflammation-mediated remodeling of the orbital floor as the bony substrate of SSS.

Maxillary Sinus Atelectasis

Progressive volume loss and concentric inward bowing of all four maxillary sinus walls — anterior (canine fossa), posterolateral (towards the pterygopalatine fossa), medial (towards the nasal cavity), and superior (orbital floor). Volumetric studies show roughly a third reduction in maxillary sinus volume relative to the contralateral side (mean 8.9 mL difference; ~29% volume loss in opacification-negative cases). Wall retraction enlarges adjacent compartments, including the pterygopalatine fossa and tuber maxillae.

maxillary sinus link maxilla link

Downstream

Orbital Floor Resorption and Descent Chronic negative pressure and sinus wall collapse causes the orbital floor (maxillary sinus roof) to descend into the atelectatic sinus.

Pterygopalatine Fossa Expansion Posterolateral wall retraction enlarges the adjacent pterygopalatine fossa and elevates the tuber maxillae.

Show evidence (5 references)

PMID:23946747 SUPPORT Human Clinical

"The silent sinus syndrome (SSS) involves painless facial asymmetry and enophthalmos, which is the result of chronic maxillary sinus atelectasis."

This reference directly states that SSS is the result of chronic maxillary sinus atelectasis, confirming the pathophysiological mechanism.

PMID:11404606 SUPPORT Human Clinical

"progressive enophthalmos secondary to maxillary collapse resulting from maxillary sinus hypoventilation"

This reference describes the progressive collapse mechanism due to sinus hypoventilation.

PMID:28573375 SUPPORT Human Clinical

"rare clinical entities characterized by an implosion of the maxillary sinus that may or may not be associated with sinonasal symptoms, and are complicated by ipsilateral enophthalmos"

Frames CMA/SSS as a spectrum of maxillary sinus implosion, supporting atelectasis as the central anatomic event.

+ 2 more references

Pterygopalatine Fossa Expansion

Posterolateral retraction of the maxillary sinus enlarges the adjacent pterygopalatine fossa and elevates the tuber maxillae, an under-recognised secondary anatomic consequence of SSS that is relevant for surgical planning because the surgeon may inadvertently enter these expanded spaces during endoscopic dissection.

maxilla link

Show evidence (1 reference)

PMID:41783519 SUPPORT Human Clinical

"The extension of the pterygopalatine fossa and the height of the tuber maxillae were significantly larger on the affected side"

Direct quantitative measurement of pterygopalatine fossa enlargement and tuber maxillae elevation as secondary effects of SSS.

Orbital Floor Resorption and Descent

The weakened and retracting maxillary sinus roof (which forms the orbital floor) progressively descends into the atelectatic sinus, often with focal dehiscence. Bone resorption and remodeling increase orbital volume and allow the orbital fat and inferior rectus to herniate inferiorly. The resulting expansion of the bony orbit is the immediate cause of the cardinal phenotypes of SSS — enophthalmos, hypoglobus, and superior sulcus deepening — and is the proximal target of orbital reconstruction. Dynamic studies show the orbital floor can re-elevate after sinus re-aeration, supporting causal coupling to negative pressure.

osteoclast link

bone resorption link ↑ INCREASED

orbit of skull link maxilla link

Show evidence (5 references)

PMID:8152774 SUPPORT Human Clinical

"characterized by bone resorption and remodeling of the orbital floor due to otherwise asymptomatic maxillary sinus disease"

The original description of SSS confirms bone resorption and remodeling of the orbital floor as a key mechanism.

PMID:11404606 SUPPORT Human Clinical

"opacified, partially collapsed maxillary sinuses with osteopenia of the sinus walls and orbital floor displacement resulting in enophthalmos"

This case series confirms osteopenia and orbital floor displacement secondary to maxillary sinus collapse.

PMID:30712438 SUPPORT Human Clinical

"Silent sinus syndrome (SSS) is defined as spontaneous, painless enophthalmos, hypoglobus with orbital floor resorption and maxillary sinus collapse on the ipsilateral side."

Modern definitional statement directly linking orbital floor resorption to the SSS phenotype.

+ 2 more references

⬡

Pathograph

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●

Phenotypes

9

Eye 3

Enophthalmos VERY_FREQUENT Deeply set eye (HP:0000490)

Show evidence (5 references)

PMID:8152774 SUPPORT Human Clinical

"Spontaneous enophthalmos and hypoglobus, in the absence of other symptoms and unrelated to trauma or surgery"

The original 1994 paper describes spontaneous enophthalmos as the cardinal presenting feature, unrelated to trauma.

PMID:23946747 SUPPORT Human Clinical

"The silent sinus syndrome (SSS) involves painless facial asymmetry and enophthalmos, which is the result of chronic maxillary sinus atelectasis."

Confirms enophthalmos as a defining feature of SSS.

PMID:11404606 SUPPORT Human Clinical

"Four patients with enophthalmos and asymptomatic maxillary sinus disease were identified."

Case series confirms enophthalmos as the presenting feature with asymptomatic sinus disease.

+ 2 more references

Diplopia OCCASIONAL Diplopia (HP:0000651)

Show evidence (2 references)

PMID:40929629 SUPPORT Human Clinical

"The most common presenting signs were enophthalmos (48.5%), hypoglobus (37.1%), and diplopia (11.4%)."

Diplopia present in 11.4% of mixed primary/secondary SSS cohort, supporting "occasional" frequency in idiopathic disease.

PMID:40402305 SUPPORT Human Clinical

"All patients presented with unilateral enophthalmos or hypoglobus; eight reported diplopia."

In secondary post-traumatic/iatrogenic SSS, diplopia was reported by 8/9 patients, far higher than in idiopathic primary disease.

Ptosis OCCASIONAL Ptosis (HP:0000508)

Show evidence (1 reference)

PMID:38707145 PARTIAL Human Clinical

"Silent sinus syndrome is a rare clinical entity affecting the maxillary sinus, characterized by ipsilateral enophthalmos and hypoglobus."

Tousidonis 2024 review enumerates ptosis among atypical SSS findings; the abstract quote anchors the disease context (ptosis itself is mentioned in the body but not the abstract; supports: PARTIAL).

Head and Neck 2

Facial Asymmetry FREQUENT Facial asymmetry (HP:0000324)

Show evidence (1 reference)

PMID:23946747 SUPPORT Human Clinical

"The silent sinus syndrome (SSS) involves painless facial asymmetry and enophthalmos, which is the result of chronic maxillary sinus atelectasis."

Facial asymmetry is listed as a defining clinical feature of SSS.

Malar Flattening OCCASIONAL Malar flattening (HP:0000272)

Show evidence (1 reference)

PMID:34597532 SUPPORT Human Clinical

"SSS is usually diagnosed when facial asymmetry or vision problems occur."

Malar flattening contributes to the facial asymmetry that prompts diagnosis; supportive but indirect for malar-specific frequency.

Other 4

Hypoglobus FREQUENT Vertical orbital dystopia (HP:0030867)

Show evidence (3 references)

PMID:8152774 SUPPORT Human Clinical

"Spontaneous enophthalmos and hypoglobus, in the absence of other symptoms and unrelated to trauma or surgery"

Hypoglobus is described alongside enophthalmos as a presenting feature in the original description.

PMID:40929629 SUPPORT Human Clinical

"The most common presenting signs were enophthalmos (48.5%), hypoglobus (37.1%), and diplopia (11.4%)."

Quantifies hypoglobus frequency at 37.1% of presenting cases in a 35-patient cohort, supporting "frequent" classification.

PMID:39600263 SUPPORT Human Clinical

"Silent sinus syndrome (SSS) is a rare condition involving idiopathic maxillary sinus underdevelopment, orbital floor resorption, enophthalmos, and hypoglobus."

Confirms hypoglobus as a defining feature, including in pediatric presentations.

Superior Sulcus Deformity FREQUENT

Opacified Maxillary Sinus FREQUENT Opacified paranasal sinuses (HP:0034494)

Show evidence (2 references)

PMID:11404606 SUPPORT Human Clinical

"On computed tomography, all four of the patients had opacified, partially collapsed maxillary sinuses with osteopenia of the sinus walls and orbital floor displacement resulting in enophthalmos."

Confirms opacification as a typical CT finding in SSS.

PMID:29726628 PARTIAL Human Clinical

"We present a case series of three patients with clinical and radiographic evidence of SSS but without maxillary sinus opacification."

Establishes that opacification is not an obligatory finding — important diagnostic caveat.

Maxillary Sinus Hypoplasia VERY_FREQUENT Paranasal sinus hypoplasia (HP:0006784)

Show evidence (2 references)

PMID:41783519 SUPPORT Human Clinical

"the syndrome reduces the volume of the affected maxillary sinus (mean difference = 8.885 mL; P < .01)"

Quantitative volumetric documentation of the maxillary sinus under-development that defines SSS radiographically.

PMID:36939460 SUPPORT Human Clinical

"the mean volume of the diseased maxillary sinus significantly increased by 9.82%, from 6.37 to 7.00 cm3"

Pre-treatment maxillary sinus volume of 6.37 cm³ documents the hypoplastic appearance of the SSS-affected sinus.

🧬

Genetic Associations

1

Familial Clustering (no causal gene identified) (Possible heritable predisposition)

Show evidence (1 reference)

PMID:39912025 PARTIAL Human Clinical

"The familial clustering of these cases suggests a possible genetic or hereditary component to the development of CMA and SSS, an aspect not commonly explored in the existing literature."

A single three-member familial cluster suggests but does not establish a heritable contribution.

💊

Treatments

2

Functional Endoscopic Sinus Surgery

Action: endoscopic sinus surgery Ontology label: Endoscopic Sinus Surgery NCIT:C157836

Endoscopic uncinectomy and maxillary antrostomy to restore sinus ventilation and equalize pressure. This addresses the underlying cause by relieving ostial obstruction.

Show evidence (2 references)

PMID:23946747 SUPPORT Human Clinical

"Treatment involves functional endoscopic surgery."

FESS is identified as the primary treatment for SSS.

PMID:11404606 SUPPORT Human Clinical

"All four underwent successful functional endoscopic sinus surgery and transconjunctival orbital floor repair."

Case series confirms successful treatment with functional endoscopic sinus surgery.

Orbital Floor Reconstruction

Action: orbital floor reconstruction Ontology label: Eye Socket Reconstruction NCIT:C157849

Surgical repair of the orbital floor using implants or grafts to correct enophthalmos when spontaneous resolution does not occur after sinus surgery. May be performed simultaneously with or staged after FESS.

Show evidence (1 reference)

PMID:11404606 SUPPORT Human Clinical

"All four underwent successful functional endoscopic sinus surgery and transconjunctival orbital floor repair."

Transconjunctival orbital floor repair is described as part of the successful treatment approach.

🌍

Environmental Factors

3

Prior Maxillofacial Trauma

Midface trauma (orbital floor fracture, blowout fracture) can disrupt mucociliary clearance and predispose to secondary SSS. Time from trauma to clinical SSS onset ranges 1-36 months (median 3 months in post-traumatic series). Some authors have proposed reclassifying post-traumatic cases as a separate entity (CDR / post-traumatic sinus syndrome).

Show evidence (2 references)

PMID:40402305 SUPPORT Human Clinical

"The time from trauma or surgery to SSS onset ranged from one to thirty-six months, with a median of three months in the posttraumatic group."

Quantifies the latent interval between maxillofacial trauma and development of secondary SSS.

PMID:38440537 SUPPORT Human Clinical

"the post-traumatic/surgery SSS are more frequent than the idiopathic ones"

Systematic review concludes secondary (post-traumatic/surgery) SSS may now outnumber idiopathic cases in the literature.

Prior Sinus or Orbital Surgery

Iatrogenic disruption of the ostiomeatal complex or orbital floor — including malpositioned orbital floor implants, prior orbital decompression for thyroid eye disease, and sinus surgery affecting the inferomedial strut — is a recognized precipitant of secondary SSS.

Show evidence (2 references)

PMID:40478163 SUPPORT Human Clinical

"orbital pathology may cause OMC occlusion, which may lead to maxillary sinus atelectasis"

Documents orbital surgical complications (malpositioned implants, mucoceles after decompression) as a precipitant of OMC occlusion and subsequent SSS-pattern atelectasis.

PMID:40402305 SUPPORT Human Clinical

"Secondary SSS arises from trauma or surgery disrupting mucociliary clearance."

Prior surgery is a defining trigger of secondary SSS via mucociliary disruption.

Granulomatosis with Polyangiitis (GPA)

Rarely, systemic ANCA-associated vasculitis (granulomatosis with polyangiitis) produces destructive sinonasal inflammation that obstructs the ostiomeatal complex and triggers an SSS phenotype. Only one such case has been reported.

Show evidence (1 reference)

PMID:38947644 SUPPORT Human Clinical

"This case is particularly noteworthy as it is the first reported instance of GPA causing SSS."

First-reported case linking GPA to SSS through destructive sinonasal inflammation and OMC obstruction.

🔀

Differential Diagnoses

4

Conditions with similar clinical presentations that must be differentiated from Silent Sinus Syndrome:

Maxillary Sinus Hypoplasia

Overlapping Features Congenital underdevelopment of the maxillary sinus. Distinguished from SSS by the absence of progressive orbital floor descent and by a typically aerated, non-opacified sinus without inward bowing of the walls. SSS is sometimes considered the advanced (type III) end of the chronic maxillary atelectasis spectrum.

Post-Traumatic Enophthalmos

Overlapping Features Enophthalmos following acute orbital floor fracture. Distinguished by history of trauma and absence of progressive maxillary sinus collapse, although delayed-onset post-traumatic SSS can mimic this presentation.

Orbital Mass / Pulsatile Enophthalmos

Overlapping Features Orbital varix, neurofibromatosis type 1, or sphenoid wing dysplasia can produce enophthalmos without maxillary sinus collapse.

Granulomatosis with Polyangiitis

Overlapping Features ANCA vasculitis causing destructive sinonasal disease can present with SSS-like findings. Suspect when accompanied by epistaxis, saddle-nose deformity, ANCA positivity, or renal disease.

{ }

Source YAML

click to show

name: Silent Sinus Syndrome
creation_date: '2026-01-28T13:19:56Z'
updated_date: '2026-05-02T12:00:00Z'
category: Complex
disease_term:
  preferred_term: silent sinus syndrome
  term:
    id: MONDO:0019108
    label: silent sinus syndrome
parents:
- Maxillary Sinus Disease
- Orbital Disease
synonyms:
- Imploding antrum syndrome
- Chronic maxillary atelectasis
- Maxillary sinus atelectasis
pathophysiology:
- name: Ostiomeatal Complex Obstruction
  description: >-
    Functional occlusion of the maxillary infundibulum / ostiomeatal complex
    (OMC) initiates the SSS cascade. Obstruction may be idiopathic (anatomic
    variants such as uncinate process lateralization, septal deviation toward
    the affected side, or concha bullosa), iatrogenic/post-traumatic
    (mucociliary disruption from prior orbital or sinus surgery, midface
    fracture, malpositioned orbital floor implant), or rarely systemic
    (granulomatous sinonasal destruction in GPA). The obstruction is
    classically silent — the maxillary sinus does not produce inflammatory
    sinonasal symptoms — because complete outflow blockade prevents
    expression of typical mucopurulent rhinosinusitis.
  locations:
  - preferred_term: maxillary sinus
    term:
      id: UBERON:0001764
      label: maxillary sinus
  - preferred_term: uncinate process of ethmoid
    term:
      id: UBERON:0010372
      label: uncinate process of ethmoid
  evidence:
  - reference: PMID:23946747
    reference_title: "The silent sinus syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Obstruction of the maxillary ostium appears to play a critical role
      in the development of SSS.
    explanation: >-
      The reference explicitly states that ostium obstruction plays a
      critical role in SSS development.
  - reference: PMID:38947644
    reference_title: "Granulomatosis With Polyangiitis as an Etiology of Silent Sinus Syndrome: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The underlying cause of this condition is the chronic obstruction of
      the osteomeatal complex, which leads to sinus contraction.
    explanation: >-
      Confirms chronic ostiomeatal complex obstruction as the proximal
      mechanistic trigger for sinus contraction in SSS.
  - reference: PMID:29726628
    reference_title: "Silent sinus syndrome without opacification of ipsilateral maxillary sinus."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Radiographic findings include ipsilateral maxillary sinus
      opacification, lateralization of the uncinate and middle turbinate,
      and infundibular occlusion.
    explanation: >-
      Documents the canonical radiographic triad (uncinate lateralization,
      infundibular occlusion) defining OMC obstruction in SSS.
  - reference: PMID:34236252
    reference_title: "Prevalence of Maxillary Sinus Hypoplasia and Silent Sinus Syndrome: A Radiological Cross-Sectional Retrospective Cohort Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Lateralization of the uncinate process was detected in about 50% of
      MSH patients, while a septal deviation towards the affected sinus was
      detected in 21.82%.
    explanation: >-
      Quantifies the anatomic predisposing variants (uncinate lateralization,
      ipsilateral septal deviation) that precede ostiomeatal obstruction.
  downstream:
  - target: Sinus Hypoventilation and Negative Pressure
    description: >-
      Closed maxillary outflow tract prevents gas exchange and mucus drainage,
      so resident respiratory mucosa resorbs sinus gas and creates a
      subatmospheric (negative) intra-antral pressure.
- name: Sinus Hypoventilation and Negative Pressure
  description: >-
    With outflow occluded, the trapped maxillary gas is resorbed by the
    sinus mucosa, generating a sustained subatmospheric pressure analogous
    to middle-ear atelectasis from Eustachian tube dysfunction. The negative
    pressure is the central mechanical driver that distinguishes SSS from
    simple maxillary hypoplasia and that propagates downstream wall
    remodeling.
  cell_types:
  - preferred_term: respiratory tract epithelial cell
    term:
      id: CL:0002368
      label: respiratory tract epithelial cell
  locations:
  - preferred_term: maxillary sinus
    term:
      id: UBERON:0001764
      label: maxillary sinus
  - preferred_term: mucosa of maxillary sinus
    term:
      id: UBERON:0005028
      label: mucosa of maxillary sinus
  evidence:
  - reference: PMID:41783519
    reference_title: "Radioanatomy of the Silent Sinus Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Silent sinus syndrome (SSS) arises from negative pressure in the
      maxillary sinus through occlusion of the ethmoidal infundibulum.
    explanation: >-
      Direct statement that negative intra-antral pressure following
      infundibular occlusion is the upstream physiologic event.
  - reference: PMID:38707145
    reference_title: "Contemporary Treatment of Silent Sinus Syndrome: A Case Report and Literature Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Silent sinus syndrome is a rare clinical entity affecting the maxillary
      sinus, characterized by ipsilateral enophthalmos and hypoglobus.
    explanation: >-
      Recent review situates SSS as a maxillary-sinus driven entity, framing
      sinus hypoventilation as the proximal pathophysiologic step before
      orbital manifestations.
  downstream:
  - target: Mucociliary Stasis and Mucus Retention
    description: >-
      Outflow occlusion plus negative pressure halts mucociliary clearance,
      so secretions accumulate and the sinus opacifies; the mucus column
      perpetuates obstruction.
  - target: Negative-Pressure Bone Remodeling
    description: >-
      Chronic subatmospheric pressure mechanically drives osteoclast-mediated
      resorption and inward bowing of the bony sinus walls.
- name: Mucociliary Stasis and Mucus Retention
  description: >-
    Loss of ciliary clearance and accumulation of static mucus opacifies the
    sinus on imaging and reinforces obstruction. Although classical SSS is
    "silent" because complete blockade prevents purulent rhinosinusitis,
    rare variants present without opacification when residual aeration
    persists, demonstrating that mucus retention is contributory rather
    than obligatory.
  cell_types:
  - preferred_term: ciliated epithelial cell
    term:
      id: CL:0000067
      label: ciliated epithelial cell
  - preferred_term: mucus secreting cell
    term:
      id: CL:0000319
      label: mucus secreting cell
  biological_processes:
  - preferred_term: mucociliary clearance
    term:
      id: GO:0120197
      label: mucociliary clearance
    modifier: DECREASED
  - preferred_term: mucus secretion
    term:
      id: GO:0070254
      label: mucus secretion
  locations:
  - preferred_term: mucosa of maxillary sinus
    term:
      id: UBERON:0005028
      label: mucosa of maxillary sinus
  evidence:
  - reference: PMID:40402305
    reference_title: "Post-traumatic and iatrogenic silent sinus syndrome: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Secondary SSS arises from trauma or surgery disrupting mucociliary
      clearance.
    explanation: >-
      Implicates impaired mucociliary clearance as a converging mechanism in
      secondary SSS, supporting its role in the SSS pathway.
  - reference: PMID:29726628
    reference_title: "Silent sinus syndrome without opacification of ipsilateral maxillary sinus."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      an aerated maxillary sinus in patients with unexplained enophthalmos,
      hypoglobus, and maxillary atelectasis should not exclude the diagnosis
      of SSS.
    explanation: >-
      Atypical aerated cases show that mucus opacification is not obligatory;
      the mechanism is contributory and stage-dependent.
  downstream:
  - target: Negative-Pressure Bone Remodeling
    description: >-
      Persistent obstruction sustains the negative pressure that drives bone
      remodeling.
- name: Negative-Pressure Bone Remodeling
  description: >-
    Sustained subatmospheric pressure combined with proposed subclinical
    inflammation activates osteoclast-mediated bone resorption and
    osteoblast-mediated remodeling of the thin bony walls of the maxillary
    sinus, particularly the orbital floor (sinus roof). The result is
    osteopenia, demineralization, focal dehiscence, and inward bowing of
    the sinus walls. Histologic data are sparse and stage-dependent;
    osteoclast activity is implicated mechanistically but may be undetectable
    in late, quiescent specimens.
  cell_types:
  - preferred_term: osteoclast
    term:
      id: CL:0000092
      label: osteoclast
  - preferred_term: osteoblast
    term:
      id: CL:0000062
      label: osteoblast
  biological_processes:
  - preferred_term: bone resorption
    term:
      id: GO:0045453
      label: bone resorption
    modifier: INCREASED
  - preferred_term: bone remodeling
    term:
      id: GO:0046849
      label: bone remodeling
    modifier: INCREASED
  locations:
  - preferred_term: maxilla
    term:
      id: UBERON:0002397
      label: maxilla
  - preferred_term: orbit of skull
    term:
      id: UBERON:0001697
      label: orbit of skull
  evidence:
  - reference: PMID:8152774
    reference_title: "The silent sinus syndrome. A cause of spontaneous enophthalmos."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      characterized by bone resorption and remodeling of the orbital floor
      due to otherwise asymptomatic maxillary sinus disease
    explanation: >-
      The original Soparkar description identifies bone resorption and
      remodeling as the cellular substrate of SSS.
  - reference: PMID:11404606
    reference_title: "The silent sinus syndrome: a case series and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      opacified, partially collapsed maxillary sinuses with osteopenia of
      the sinus walls and orbital floor displacement resulting in
      enophthalmos
    explanation: >-
      Documents radiographic osteopenia of the sinus walls — the imaging
      correlate of the proposed osteoclastic bone remodeling.
  - reference: DOI:10.15275/rusomj.2024.0413
    reference_title: "Clinical and morphological features of the orbital floor in a patient with silent sinus syndrome: A clinical case report"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      orbital floor changes due to changes in MS pressure or subclinical
      inflammation are considered part of the potential pathogenesis
    explanation: >-
      Direct histologic-clinical correlation paper supporting pressure-driven
      and inflammation-mediated remodeling of the orbital floor as the bony
      substrate of SSS.
  downstream:
  - target: Maxillary Sinus Atelectasis
    description: >-
      Bone resorption and weakening of the sinus walls lets atmospheric and
      orbital tissue pressures push the walls inward, producing volume loss.
  - target: Orbital Floor Resorption and Descent
    description: >-
      The same negative-pressure remodeling thins and resorbs the orbital
      floor, which then descends inferiorly under the weight of the orbital
      contents.
- name: Maxillary Sinus Atelectasis
  description: >-
    Progressive volume loss and concentric inward bowing of all four
    maxillary sinus walls — anterior (canine fossa), posterolateral
    (towards the pterygopalatine fossa), medial (towards the nasal cavity),
    and superior (orbital floor). Volumetric studies show roughly a third
    reduction in maxillary sinus volume relative to the contralateral side
    (mean 8.9 mL difference; ~29% volume loss in opacification-negative
    cases). Wall retraction enlarges adjacent compartments, including the
    pterygopalatine fossa and tuber maxillae.
  locations:
  - preferred_term: maxillary sinus
    term:
      id: UBERON:0001764
      label: maxillary sinus
  - preferred_term: maxilla
    term:
      id: UBERON:0002397
      label: maxilla
  evidence:
  - reference: PMID:23946747
    reference_title: "The silent sinus syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The silent sinus syndrome (SSS) involves painless facial asymmetry
      and enophthalmos, which is the result of chronic maxillary sinus
      atelectasis.
    explanation: >-
      This reference directly states that SSS is the result of chronic
      maxillary sinus atelectasis, confirming the pathophysiological
      mechanism.
  - reference: PMID:11404606
    reference_title: "The silent sinus syndrome: a case series and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      progressive enophthalmos secondary to maxillary collapse resulting
      from maxillary sinus hypoventilation
    explanation: >-
      This reference describes the progressive collapse mechanism due to
      sinus hypoventilation.
  - reference: PMID:28573375
    reference_title: "Chronic maxillary atelectasis and silent sinus syndrome: two faces of the same clinical entity."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      rare clinical entities characterized by an implosion of the maxillary
      sinus that may or may not be associated with sinonasal symptoms, and
      are complicated by ipsilateral enophthalmos
    explanation: >-
      Frames CMA/SSS as a spectrum of maxillary sinus implosion, supporting
      atelectasis as the central anatomic event.
  - reference: PMID:41783519
    reference_title: "Radioanatomy of the Silent Sinus Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the syndrome reduces the volume of the affected maxillary sinus (mean
      difference = 8.885 mL; P < .01)
    explanation: >-
      Quantitative volumetric evidence confirming sinus volume loss as the
      defining anatomic consequence of atelectasis.
  - reference: PMID:29726628
    reference_title: "Silent sinus syndrome without opacification of ipsilateral maxillary sinus."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Silent sinus syndrome (SSS) is a rare disease characterized by
      spontaneous enophthalmos and hypoglobus secondary to collapse of the
      orbital floor in patients with asymptomatic maxillary sinusitis.
    explanation: >-
      Confirms that atelectatic collapse — even without opacification —
      drives orbital floor descent in SSS.
  downstream:
  - target: Orbital Floor Resorption and Descent
    description: >-
      Chronic negative pressure and sinus wall collapse causes the orbital
      floor (maxillary sinus roof) to descend into the atelectatic sinus.
  - target: Pterygopalatine Fossa Expansion
    description: >-
      Posterolateral wall retraction enlarges the adjacent pterygopalatine
      fossa and elevates the tuber maxillae.
- name: Pterygopalatine Fossa Expansion
  description: >-
    Posterolateral retraction of the maxillary sinus enlarges the adjacent
    pterygopalatine fossa and elevates the tuber maxillae, an under-recognised
    secondary anatomic consequence of SSS that is relevant for surgical
    planning because the surgeon may inadvertently enter these expanded
    spaces during endoscopic dissection.
  locations:
  - preferred_term: maxilla
    term:
      id: UBERON:0002397
      label: maxilla
  evidence:
  - reference: PMID:41783519
    reference_title: "Radioanatomy of the Silent Sinus Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The extension of the pterygopalatine fossa and the height of the tuber
      maxillae were significantly larger on the affected side
    explanation: >-
      Direct quantitative measurement of pterygopalatine fossa enlargement
      and tuber maxillae elevation as secondary effects of SSS.
- name: Orbital Floor Resorption and Descent
  description: >-
    The weakened and retracting maxillary sinus roof (which forms the orbital
    floor) progressively descends into the atelectatic sinus, often with
    focal dehiscence. Bone resorption and remodeling increase orbital
    volume and allow the orbital fat and inferior rectus to herniate
    inferiorly. The resulting expansion of the bony orbit is the immediate
    cause of the cardinal phenotypes of SSS — enophthalmos, hypoglobus, and
    superior sulcus deepening — and is the proximal target of orbital
    reconstruction. Dynamic studies show the orbital floor can re-elevate
    after sinus re-aeration, supporting causal coupling to negative
    pressure.
  cell_types:
  - preferred_term: osteoclast
    term:
      id: CL:0000092
      label: osteoclast
  biological_processes:
  - preferred_term: bone resorption
    term:
      id: GO:0045453
      label: bone resorption
    modifier: INCREASED
  locations:
  - preferred_term: orbit of skull
    term:
      id: UBERON:0001697
      label: orbit of skull
  - preferred_term: maxilla
    term:
      id: UBERON:0002397
      label: maxilla
  evidence:
  - reference: PMID:8152774
    reference_title: "The silent sinus syndrome. A cause of spontaneous enophthalmos."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      characterized by bone resorption and remodeling of the orbital floor
      due to otherwise asymptomatic maxillary sinus disease
    explanation: >-
      The original description of SSS confirms bone resorption and
      remodeling of the orbital floor as a key mechanism.
  - reference: PMID:11404606
    reference_title: "The silent sinus syndrome: a case series and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      opacified, partially collapsed maxillary sinuses with osteopenia of
      the sinus walls and orbital floor displacement resulting in
      enophthalmos
    explanation: >-
      This case series confirms osteopenia and orbital floor displacement
      secondary to maxillary sinus collapse.
  - reference: PMID:30712438
    reference_title: "Silent sinus syndrome: combined sinus surgery and orbital reconstruction - report of 15 cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Silent sinus syndrome (SSS) is defined as spontaneous, painless
      enophthalmos, hypoglobus with orbital floor resorption and maxillary
      sinus collapse on the ipsilateral side.
    explanation: >-
      Modern definitional statement directly linking orbital floor resorption
      to the SSS phenotype.
  - reference: PMID:21835074
    reference_title: "Silent sinus syndrome: dynamic changes in the position of the orbital floor after restoration of normal sinus pressure."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      dynamic changes in orbital floor position can occur after sinus
      re-ventilation
    explanation: >-
      Demonstrates that orbital floor descent is mechanically coupled to
      sinus pressure: re-aeration reverses descent, confirming the causal
      pathway.
  - reference: PMID:36939460
    reference_title: "Volumetric Analysis of the Sinus and Orbit in Silent Sinus Syndrome After Endoscopic Sinus Surgery."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      All patients had resolution of clinical or radiographic enophthalmos
      and orbital displacement with ESS alone.
    explanation: >-
      Volumetric data showing orbital displacement reverses with sinus
      ventilation, supporting orbital floor descent as the proximate cause
      of enophthalmos.
phenotypes:
- name: Enophthalmos
  category: Ophthalmologic
  frequency: VERY_FREQUENT
  diagnostic: true
  description: >-
    Posterior displacement of the globe within the orbit due to increased
    orbital volume from orbital floor descent. This is the hallmark
    presenting feature of silent sinus syndrome. Reported magnitudes are
    typically 2–5 mm of recession, with case-series means around 2.6 mm.
    Enophthalmos is dynamic — re-aeration of the maxillary sinus with FESS
    can reverse globe position even without orbital floor reconstruction.
  phenotype_term:
    preferred_term: Enophthalmos
    term:
      id: HP:0000490
      label: Deeply set eye
  evidence:
  - reference: PMID:8152774
    reference_title: "The silent sinus syndrome. A cause of spontaneous enophthalmos."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Spontaneous enophthalmos and hypoglobus, in the absence of other
      symptoms and unrelated to trauma or surgery
    explanation: >-
      The original 1994 paper describes spontaneous enophthalmos as the
      cardinal presenting feature, unrelated to trauma.
  - reference: PMID:23946747
    reference_title: "The silent sinus syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The silent sinus syndrome (SSS) involves painless facial asymmetry
      and enophthalmos, which is the result of chronic maxillary sinus
      atelectasis.
    explanation: >-
      Confirms enophthalmos as a defining feature of SSS.
  - reference: PMID:11404606
    reference_title: "The silent sinus syndrome: a case series and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Four patients with enophthalmos and asymptomatic maxillary sinus
      disease were identified.
    explanation: >-
      Case series confirms enophthalmos as the presenting feature with
      asymptomatic sinus disease.
  - reference: PMID:40929629
    reference_title: "Outcomes of Sinus Surgery and Orbital Reconstruction in Silent Sinus Syndrome: A Retrospective Cohort Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The most common presenting signs were enophthalmos (48.5%), hypoglobus
      (37.1%), and diplopia (11.4%).
    explanation: >-
      Cohort of 35 SSS patients quantifying enophthalmos as the most common
      presenting sign.
  - reference: PMID:30712438
    reference_title: "Silent sinus syndrome: combined sinus surgery and orbital reconstruction - report of 15 cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      On affected side, mean enophthalmos was 2.6 mm and hypoglobus 2.7 mm.
    explanation: >-
      Provides quantitative magnitude of globe displacement in a 15-patient
      series.
- name: Hypoglobus
  category: Ophthalmologic
  frequency: FREQUENT
  description: >-
    Inferior displacement of the globe due to descent of the orbital floor
    into the collapsed maxillary sinus. Magnitude is typically 2–6 mm of
    vertical drop. The HPO does not have a dedicated hypoglobus term;
    "Vertical orbital dystopia" (HP:0030867) is used as the closest
    canonical equivalent.
  phenotype_term:
    preferred_term: Hypoglobus
    term:
      id: HP:0030867
      label: Vertical orbital dystopia
  evidence:
  - reference: PMID:8152774
    reference_title: "The silent sinus syndrome. A cause of spontaneous enophthalmos."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Spontaneous enophthalmos and hypoglobus, in the absence of other
      symptoms and unrelated to trauma or surgery
    explanation: >-
      Hypoglobus is described alongside enophthalmos as a presenting
      feature in the original description.
  - reference: PMID:40929629
    reference_title: "Outcomes of Sinus Surgery and Orbital Reconstruction in Silent Sinus Syndrome: A Retrospective Cohort Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The most common presenting signs were enophthalmos (48.5%), hypoglobus
      (37.1%), and diplopia (11.4%).
    explanation: >-
      Quantifies hypoglobus frequency at 37.1% of presenting cases in a
      35-patient cohort, supporting "frequent" classification.
  - reference: PMID:39600263
    reference_title: "Pediatric Silent Sinus Syndrome: A Case Report and Literature Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Silent sinus syndrome (SSS) is a rare condition involving idiopathic
      maxillary sinus underdevelopment, orbital floor resorption,
      enophthalmos, and hypoglobus.
    explanation: >-
      Confirms hypoglobus as a defining feature, including in pediatric
      presentations.
- name: Facial Asymmetry
  category: Craniofacial
  frequency: FREQUENT
  description: >-
    Visible asymmetry of the midface due to cheek flattening from maxillary
    sinus collapse and malar depression.
  phenotype_term:
    preferred_term: Facial asymmetry
    term:
      id: HP:0000324
      label: Facial asymmetry
  evidence:
  - reference: PMID:23946747
    reference_title: "The silent sinus syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The silent sinus syndrome (SSS) involves painless facial asymmetry
      and enophthalmos, which is the result of chronic maxillary sinus
      atelectasis.
    explanation: >-
      Facial asymmetry is listed as a defining clinical feature of SSS.
- name: Diplopia
  category: Ophthalmologic
  frequency: OCCASIONAL
  description: >-
    Double vision from altered globe position affecting binocular alignment.
    Frequency is bimodal: uncommon in idiopathic primary SSS (~11% in mixed
    cohorts) but present in the majority of secondary (post-traumatic /
    iatrogenic) SSS, where 8 of 9 patients reported diplopia in a recent
    series.
  phenotype_term:
    preferred_term: Diplopia
    term:
      id: HP:0000651
      label: Diplopia
  evidence:
  - reference: PMID:40929629
    reference_title: "Outcomes of Sinus Surgery and Orbital Reconstruction in Silent Sinus Syndrome: A Retrospective Cohort Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The most common presenting signs were enophthalmos (48.5%), hypoglobus
      (37.1%), and diplopia (11.4%).
    explanation: >-
      Diplopia present in 11.4% of mixed primary/secondary SSS cohort,
      supporting "occasional" frequency in idiopathic disease.
  - reference: PMID:40402305
    reference_title: "Post-traumatic and iatrogenic silent sinus syndrome: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      All patients presented with unilateral enophthalmos or hypoglobus;
      eight reported diplopia.
    explanation: >-
      In secondary post-traumatic/iatrogenic SSS, diplopia was reported by
      8/9 patients, far higher than in idiopathic primary disease.
- name: Superior Sulcus Deformity
  category: Ophthalmologic
  frequency: FREQUENT
  description: >-
    Deepening of the upper eyelid sulcus due to enophthalmos, giving a
    hollowed appearance to the upper eyelid. Often the cosmetic complaint
    that prompts ophthalmology referral. There is no dedicated HPO term;
    captured here without a term binding.
- name: Malar Flattening
  category: Craniofacial
  frequency: OCCASIONAL
  description: >-
    Diminished malar (cheek) projection from anterior wall retraction of the
    atelectatic maxillary sinus, contributing to the visible facial
    asymmetry.
  phenotype_term:
    preferred_term: Malar flattening
    term:
      id: HP:0000272
      label: Malar flattening
  evidence:
  - reference: PMID:34597532
    reference_title: "Etiology, Early Diagnosis and Proper Treatment of Silent Sinus Syndrome Based on Review of the Literature and Own Experience."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      SSS is usually diagnosed when facial asymmetry or vision problems
      occur.
    explanation: >-
      Malar flattening contributes to the facial asymmetry that prompts
      diagnosis; supportive but indirect for malar-specific frequency.
- name: Opacified Maxillary Sinus
  category: Imaging
  frequency: FREQUENT
  diagnostic: true
  description: >-
    Partial or complete opacification of the affected maxillary sinus on CT,
    reflecting mucus retention behind the obstructed ostium. Not obligate —
    a minority of SSS cases have a partially aerated atelectatic sinus.
  phenotype_term:
    preferred_term: Opacified paranasal sinuses
    term:
      id: HP:0034494
      label: Opacified paranasal sinuses
  evidence:
  - reference: PMID:11404606
    reference_title: "The silent sinus syndrome: a case series and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      On computed tomography, all four of the patients had opacified,
      partially collapsed maxillary sinuses with osteopenia of the sinus
      walls and orbital floor displacement resulting in enophthalmos.
    explanation: >-
      Confirms opacification as a typical CT finding in SSS.
  - reference: PMID:29726628
    reference_title: "Silent sinus syndrome without opacification of ipsilateral maxillary sinus."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We present a case series of three patients with clinical and
      radiographic evidence of SSS but without maxillary sinus opacification.
    explanation: >-
      Establishes that opacification is not an obligatory finding —
      important diagnostic caveat.
- name: Maxillary Sinus Hypoplasia
  category: Imaging
  frequency: VERY_FREQUENT
  diagnostic: true
  description: >-
    Reduced maxillary sinus volume from inward bowing of all four walls.
    Volumetric studies show ~9 mL mean reduction relative to the
    contralateral side; in opacification-negative SSS the affected sinus
    averaged 29% volume loss.
  phenotype_term:
    preferred_term: Paranasal sinus hypoplasia
    term:
      id: HP:0006784
      label: Paranasal sinus hypoplasia
  evidence:
  - reference: PMID:41783519
    reference_title: "Radioanatomy of the Silent Sinus Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the syndrome reduces the volume of the affected maxillary sinus (mean
      difference = 8.885 mL; P < .01)
    explanation: >-
      Quantitative volumetric documentation of the maxillary sinus
      under-development that defines SSS radiographically.
  - reference: PMID:36939460
    reference_title: "Volumetric Analysis of the Sinus and Orbit in Silent Sinus Syndrome After Endoscopic Sinus Surgery."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the mean volume of the diseased maxillary sinus significantly
      increased by 9.82%, from 6.37 to 7.00 cm3
    explanation: >-
      Pre-treatment maxillary sinus volume of 6.37 cm³ documents the
      hypoplastic appearance of the SSS-affected sinus.
- name: Ptosis
  category: Ophthalmologic
  frequency: OCCASIONAL
  description: >-
    Atypical secondary upper eyelid ptosis from inferior globe descent and
    altered upper lid position. Reported as a less typical presenting
    feature in modern reviews.
  phenotype_term:
    preferred_term: Ptosis
    term:
      id: HP:0000508
      label: Ptosis
  evidence:
  - reference: PMID:38707145
    reference_title: "Contemporary Treatment of Silent Sinus Syndrome: A Case Report and Literature Review."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Silent sinus syndrome is a rare clinical entity affecting the maxillary
      sinus, characterized by ipsilateral enophthalmos and hypoglobus.
    explanation: >-
      Tousidonis 2024 review enumerates ptosis among atypical SSS findings;
      the abstract quote anchors the disease context (ptosis itself is
      mentioned in the body but not the abstract; supports: PARTIAL).
diagnosis:
- name: CT Scan of Paranasal Sinuses
  description: >-
    Shows opacified and contracted maxillary sinus with inward bowing of
    sinus walls, particularly the orbital floor. Characteristic imaging
    features include maxillary sinus outlet obstruction, sinus opacification,
    and sinus volume loss.
  diagnosis_term:
    preferred_term: computed tomography procedure
    term:
      id: MAXO:0000571
      label: computed tomography procedure
  evidence:
  - reference: PMID:23946747
    reference_title: "The silent sinus syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In most cases, it is diagnosed clinically, however, using the
      characteristic imaging features including maxillary sinus outlet
      obstruction, sinus opacification, and sinus volume loss caused by
      inward retraction of the sinus walls.
    explanation: >-
      CT imaging features are described as key diagnostic criteria for SSS.
  - reference: PMID:11404606
    reference_title: "The silent sinus syndrome: a case series and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      On computed tomography, all four of the patients had opacified,
      partially collapsed maxillary sinuses with osteopenia of the sinus
      walls and orbital floor displacement resulting in enophthalmos.
    explanation: >-
      Confirms the characteristic CT imaging findings in a case series.
- name: Ophthalmologic Examination
  description: >-
    Documents enophthalmos, hypoglobus, and superior sulcus deformity.
    Exophthalmometry quantifies the degree of globe recession; orthoptic
    testing (e.g., Hess-Lancaster) characterizes diplopia in cases with
    motility involvement.
- name: Nasal Endoscopy
  description: >-
    Direct visualization of the middle meatus and ostiomeatal complex,
    typically showing a laterally displaced uncinate process and an
    obstructed/absent maxillary infundibulum on the affected side.
  diagnosis_term:
    preferred_term: nasal endoscopy
    term:
      id: MAXO:0035089
      label: nasal endoscopy
  evidence:
  - reference: PMID:29726628
    reference_title: "Silent sinus syndrome without opacification of ipsilateral maxillary sinus."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Radiographic findings include ipsilateral maxillary sinus
      opacification, lateralization of the uncinate and middle turbinate,
      and infundibular occlusion.
    explanation: >-
      Endoscopic and imaging correlate of the lateralized uncinate / occluded
      infundibulum used for diagnosis.
treatments:
- name: Functional Endoscopic Sinus Surgery
  description: >-
    Endoscopic uncinectomy and maxillary antrostomy to restore sinus
    ventilation and equalize pressure. This addresses the underlying cause
    by relieving ostial obstruction.
  treatment_term:
    preferred_term: endoscopic sinus surgery
    term:
      id: NCIT:C157836
      label: Endoscopic Sinus Surgery
  evidence:
  - reference: PMID:23946747
    reference_title: "The silent sinus syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Treatment involves functional endoscopic surgery.
    explanation: >-
      FESS is identified as the primary treatment for SSS.
  - reference: PMID:11404606
    reference_title: "The silent sinus syndrome: a case series and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      All four underwent successful functional endoscopic sinus surgery
      and transconjunctival orbital floor repair.
    explanation: >-
      Case series confirms successful treatment with functional endoscopic
      sinus surgery.
- name: Orbital Floor Reconstruction
  description: >-
    Surgical repair of the orbital floor using implants or grafts to correct
    enophthalmos when spontaneous resolution does not occur after sinus
    surgery. May be performed simultaneously with or staged after FESS.
  treatment_term:
    preferred_term: orbital floor reconstruction
    term:
      id: NCIT:C157849
      label: Eye Socket Reconstruction
  evidence:
  - reference: PMID:11404606
    reference_title: "The silent sinus syndrome: a case series and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      All four underwent successful functional endoscopic sinus surgery
      and transconjunctival orbital floor repair.
    explanation: >-
      Transconjunctival orbital floor repair is described as part of the
      successful treatment approach.
environmental:
- name: Prior Maxillofacial Trauma
  description: >-
    Midface trauma (orbital floor fracture, blowout fracture) can disrupt
    mucociliary clearance and predispose to secondary SSS. Time from trauma
    to clinical SSS onset ranges 1-36 months (median 3 months in
    post-traumatic series). Some authors have proposed reclassifying
    post-traumatic cases as a separate entity (CDR / post-traumatic sinus
    syndrome).
  effect: Predisposing
  evidence:
  - reference: PMID:40402305
    reference_title: "Post-traumatic and iatrogenic silent sinus syndrome: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The time from trauma or surgery to SSS onset ranged from one to
      thirty-six months, with a median of three months in the posttraumatic
      group.
    explanation: >-
      Quantifies the latent interval between maxillofacial trauma and
      development of secondary SSS.
  - reference: PMID:38440537
    reference_title: "Post-traumatic Sinus Syndrome, Proposal for a New Clinical Entity (CDR Syndrome) as Variant of the Silent Sinus Syndrome: Systematic Review and Case Series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the post-traumatic/surgery SSS are more frequent than the idiopathic
      ones
    explanation: >-
      Systematic review concludes secondary (post-traumatic/surgery) SSS may
      now outnumber idiopathic cases in the literature.
- name: Prior Sinus or Orbital Surgery
  description: >-
    Iatrogenic disruption of the ostiomeatal complex or orbital floor —
    including malpositioned orbital floor implants, prior orbital
    decompression for thyroid eye disease, and sinus surgery affecting the
    inferomedial strut — is a recognized precipitant of secondary SSS.
  effect: Predisposing
  evidence:
  - reference: PMID:40478163
    reference_title: "Orbital Causes of Ostiomeatal Complex Occlusion."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      orbital pathology may cause OMC occlusion, which may lead to maxillary
      sinus atelectasis
    explanation: >-
      Documents orbital surgical complications (malpositioned implants,
      mucoceles after decompression) as a precipitant of OMC occlusion and
      subsequent SSS-pattern atelectasis.
  - reference: PMID:40402305
    reference_title: "Post-traumatic and iatrogenic silent sinus syndrome: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Secondary SSS arises from trauma or surgery disrupting mucociliary
      clearance.
    explanation: >-
      Prior surgery is a defining trigger of secondary SSS via mucociliary
      disruption.
- name: Granulomatosis with Polyangiitis (GPA)
  description: >-
    Rarely, systemic ANCA-associated vasculitis (granulomatosis with
    polyangiitis) produces destructive sinonasal inflammation that
    obstructs the ostiomeatal complex and triggers an SSS phenotype. Only
    one such case has been reported.
  effect: Predisposing
  evidence:
  - reference: PMID:38947644
    reference_title: "Granulomatosis With Polyangiitis as an Etiology of Silent Sinus Syndrome: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This case is particularly noteworthy as it is the first reported
      instance of GPA causing SSS.
    explanation: >-
      First-reported case linking GPA to SSS through destructive sinonasal
      inflammation and OMC obstruction.
genetic:
- name: Familial Clustering (no causal gene identified)
  association: Possible heritable predisposition
  relationship_type: SUSCEPTIBILITY
  notes: >-
    A familial occurrence of chronic maxillary atelectasis and SSS in three
    male family members has been reported, suggesting a possible heritable
    predisposition. No causal gene has been identified, and SSS is not
    classically considered Mendelian; this represents a hypothesis based on
    a single kindred.
  evidence:
  - reference: PMID:39912025
    reference_title: "Unveiling the Silent Sinus Syndrome: A Familial Case Series Exploring Chronic Maxillary Atelectasis."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The familial clustering of these cases suggests a possible genetic or
      hereditary component to the development of CMA and SSS, an aspect not
      commonly explored in the existing literature.
    explanation: >-
      A single three-member familial cluster suggests but does not establish
      a heritable contribution.
prevalence:
- population: adults undergoing head CT
  percentage: 0.56
  notes: >-
    Radiologic cross-sectional cohort estimate of SSS prevalence in adults
    without prior maxillofacial trauma or surgery. Companion radiologic
    studies report a chronic maxillary atelectasis prevalence of ~0.92%,
    with SSS at the advanced end of the CMA spectrum. Roughly 100 SSS
    cases had been reported in the world literature as of 2024.
  evidence:
  - reference: PMID:34236252
    reference_title: "Prevalence of Maxillary Sinus Hypoplasia and Silent Sinus Syndrome: A Radiological Cross-Sectional Retrospective Cohort Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      MSH and SSS prevalences were 6.17% (n = 55) and 0,56% (n = 5)
    explanation: >-
      Cross-sectional radiologic study estimating SSS prevalence at ~0.56%
      in adults undergoing head CT.
  - reference: PMID:35000660
    reference_title: "Prevalence of chronic maxillary atelectasis: a radiological study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Fifty-four patients were diagnosed with chronic maxillary atelectasis;
      its prevalence was 0.92 per cent.
    explanation: >-
      Independent radiologic estimate of CMA prevalence (~0.92%) in a
      paranasal CT cohort.
progression:
- phase: Asymptomatic / subclinical
  notes: >-
    Early SSS is silent; gas resorption, mucociliary stasis, and progressive
    bone remodeling proceed without symptoms over months to years.
  evidence:
  - reference: PMID:34597532
    reference_title: "Etiology, Early Diagnosis and Proper Treatment of Silent Sinus Syndrome Based on Review of the Literature and Own Experience."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      SSS is usually diagnosed when facial asymmetry or vision problems
      occur.
    explanation: >-
      Diagnosis is typically made only after late cosmetic or visual
      manifestations appear, confirming a long preceding asymptomatic
      phase.
- phase: Symptomatic enophthalmos / hypoglobus
  notes: >-
    Patients present after months to years of subclinical progression with
    enophthalmos, hypoglobus, superior sulcus deepening, and (less
    commonly) diplopia. Reversible globe-position changes can occur after
    FESS-mediated re-aeration.
  evidence:
  - reference: PMID:21835074
    reference_title: "Silent sinus syndrome: dynamic changes in the position of the orbital floor after restoration of normal sinus pressure."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Twenty-two of the 23 patients had either complete or partial
      resolution.
    explanation: >-
      In a 23-patient series, FESS alone produced full or partial resolution
      in 22 cases, demonstrating reversibility of late-stage SSS.
differential_diagnoses:
- name: Maxillary Sinus Hypoplasia
  description: >-
    Congenital underdevelopment of the maxillary sinus. Distinguished from
    SSS by the absence of progressive orbital floor descent and by a
    typically aerated, non-opacified sinus without inward bowing of the
    walls. SSS is sometimes considered the advanced (type III) end of the
    chronic maxillary atelectasis spectrum.
- name: Post-Traumatic Enophthalmos
  description: >-
    Enophthalmos following acute orbital floor fracture. Distinguished by
    history of trauma and absence of progressive maxillary sinus collapse,
    although delayed-onset post-traumatic SSS can mimic this presentation.
- name: Orbital Mass / Pulsatile Enophthalmos
  description: >-
    Orbital varix, neurofibromatosis type 1, or sphenoid wing dysplasia can
    produce enophthalmos without maxillary sinus collapse.
- name: Granulomatosis with Polyangiitis
  description: >-
    ANCA vasculitis causing destructive sinonasal disease can present with
    SSS-like findings. Suspect when accompanied by epistaxis, saddle-nose
    deformity, ANCA positivity, or renal disease.
notes: >-
  Silent sinus syndrome is characterized by the insidious, painless development
  of enophthalmos without prior history of sinus symptoms. The "silent" nature
  refers to the absence of typical sinonasal complaints (nasal obstruction,
  discharge, facial pain) despite significant maxillary sinus pathology. Most
  cases are unilateral and affect individuals in the third to fifth decade of
  life. The condition was first described by Soparkar et al. in 1994.

  The dominant mechanistic model is: ostiomeatal complex obstruction → sinus
  hypoventilation and gas resorption with negative intra-antral pressure →
  mucociliary stasis with mucus retention → osteoclast-mediated bone resorption
  and remodeling of the thin maxillary walls → atelectatic collapse and
  inferior descent of the orbital floor → enophthalmos, hypoglobus, and
  superior sulcus deformity. Dynamic studies (Sivasubramaniam 2011, Amin 2023)
  show this cascade is partially reversible: re-aeration with FESS alone can
  resolve enophthalmos in many cases.

  SSS is now recognized as a spectrum entity with chronic maxillary atelectasis
  (CMA), with classical SSS representing the advanced (type III) end of the
  spectrum. Secondary SSS — driven by post-traumatic or iatrogenic
  mucociliary disruption — may now outnumber idiopathic cases in the modern
  literature. A single familial cluster has been reported, suggesting (but
  not proving) heritable predisposition. Population prevalence is rare
  (~0.5–0.9% on radiologic cohorts), and radiologists frequently
  underdiagnose the entity.

📚

References & Deep Research

Deep Research

1

Falcon ▸

Disease Characteristics Research Template

Edison Scientific Literature 44 citations 2026-04-30T20:39:59.282467

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

Disease Name: Silent Sinus Syndrome
MONDO ID: MONDO:0019108 (if available)
Category: Complex

Research Objectives

Please provide a comprehensive research report on Silent Sinus Syndrome covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

What is the disease? Provide a concise overview.
What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
What are the common synonyms and alternative names?
Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
Risk Factors:

Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases
Genetic risk factors (causal variants, susceptibility loci, modifier genes)
Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
Protective Factors:

Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases
Genetic protective factors (protective variants, modifier alleles)
Environmental protective factors (diet, lifestyle, exposures that reduce risk)
Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene
Pathogenic Variants:
Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
Variant type/class (missense, frameshift, nonsense, splice-site, structural)
Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
Functional consequences (loss of function, gain of function, dominant negative)
Modifier Genes: Genes that modify disease severity or expression
Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth
Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases
Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

Search first: CDC databases, WHO, PubMed, NHANES
Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc
Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

Search first: Gene Ontology (GO), Reactome, KEGG, PubMed
Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold
Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA
Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

Search first: ImmPort, Immunome Database, IEDB, Gene Ontology
Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

Search first: PubMed, Gene Ontology, Reactome
Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

Search first: BRENDA, UniProt, KEGG, OMIM, PubMed
Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth
Molecular Profiling (if available):
Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
Advanced Technologies (if applicable):
Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

Organ Level:
Primary organs directly affected
Secondary organ involvement (complications, secondary effects)
Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT
Tissue and Cell Level:
Specific tissue types affected (epithelial, connective, muscle, nervous)
Specific cell populations targeted (with Cell Ontology terms)

Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB
Subcellular Level:
Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas
Localization:
Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

Onset:
Typical age of onset (congenital, pediatric, adult, geriatric)
Onset pattern (acute, subacute, chronic, insidious)

Search first: OMIM, Orphanet, HPO, PubMed
Progression:
Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
Progression rate (rapid, slow, variable)
Disease course pattern (episodic, relapsing-remitting, progressive, stable)
Disease duration (self-limited, chronic lifelong)

Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM
Patterns:
Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

Epidemiology:
Prevalence (cases per 100,000 at given time)
Incidence (new cases per 100,000 per year)

Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries
For Genetic Etiology:
Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
Population Demographics:
Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
Geographic distribution of specific variants
Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

Clinical Tests:
Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
Genetic Testing:

Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen
Overview of recommended genetic testing approach
Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
FISH > Search first: ClinVar, cytogenetics databases, PubMed
Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
Omics-Based Diagnostics (if applicable):
RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
Clinical Criteria:
Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
Screening:
Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

Survival and Mortality:
Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
Morbidity and Function:
Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
Disease Course:
Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
Prediction:
Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

Pharmacotherapy:
Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
Advanced Therapeutics:
Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
Surgical and Interventional:
Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
Supportive and Rehabilitative:
Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
Experimental:
Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
Treatment Outcomes:
Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
Treatment Strategy:
Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest MAXO (Medical Action Ontology) terms where applicable.

13. Prevention

Prevention Levels:
Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
Immunization: Vaccine strategies (if applicable)

Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database
Screening and Early Detection:
Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
Behavioral Interventions: Lifestyle modifications to reduce risk

Search first: CDC, WHO, behavioral intervention databases, Cochrane Library
Counseling: Genetic counseling (risk assessment, family planning guidance)

Search first: NSGC resources, ACMG guidelines, GeneReviews
Public Health:
Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
Prophylaxis: Preventive medications or procedures

Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

Taxonomy: Species affected (with NCBI Taxon identifiers)

Search first: NCBI Taxonomy
Breed: Specific breeds affected (with VBO identifiers if applicable)

Search first: VBO (Vertebrate Breed Ontology)
Gene: Orthologous genes in other species (with NCBI Gene IDs)

Search first: NCBI Gene
Natural Disease:
Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
Comparative Biology:
Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
Transmission (if applicable):
Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

Model Types:
Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
Genetic Models:
Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
Model Characteristics:
Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
Applications:
Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
Resources:
Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

Cite primary literature (PMID preferred) for all mechanistic and clinical claims
Prioritize recent reviews and landmark papers
Include direct quotes from abstracts where possible to support key statements
Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, MAXO, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Silent Sinus Syndrome (SSS) — Comprehensive Disease Characteristics Report

Target disease

Disease name: Silent sinus syndrome (SSS)
MONDO ID: MONDO:0019108 (provided by user)
Category: Complex (acquired/anatomic-mechanistic syndrome)

1. Disease information

1.1 Concise overview (current understanding)

Silent sinus syndrome (SSS) is a rare clinical-radiologic entity characterized by progressive collapse (atelectasis) of the maxillary sinus with associated inferior displacement (descent) of the orbital floor, producing painless, progressive ipsilateral enophthalmos and/or hypoglobus, often with minimal sinonasal symptoms. Representative definitions include: - “Spontaneous, painless enophthalmos, hypoglobus with orbital floor resorption and maxillary sinus collapse on the ipsilateral side.” (Clarós 2019; URL: https://doi.org/10.1080/00016489.2018.1542161) (claros2019silentsinussyndrome pages 1-3) - Diagnostic criteria summarized by de Dorlodot 2017 (attributed to Soparkar et al.) include “modification of facial appearance, enophthalmos and/or hypoglobus, a reduction of maxillary sinus volume on computed tomography (CT) scan, and the absence of sinonasal symptoms.” (de Dorlodot 2017; URL: https://doi.org/10.1007/s00405-017-4622-8) (dorlodot2017chronicmaxillaryatelectasis pages 1-2)

SSS is widely considered within the spectrum of chronic maxillary atelectasis (CMA), sometimes described as an advanced form (e.g., type 3 CMA in some classification systems). (claros2019silentsinussyndrome pages 1-3, dorlodot2017chronicmaxillaryatelectasis pages 1-2)

1.2 Key identifiers

MONDO: MONDO:0019108 (user-provided)
ICD-10 / ICD-11, MeSH, Orphanet, OMIM: Not retrievable using the provided toolchain in this run; therefore not reported here to avoid introducing uncited identifiers.

1.3 Common synonyms / alternative names

Evidence-supported synonyms and closely related terms: - Chronic maxillary atelectasis (CMA) (spectrum entity including SSS) (dorlodot2017chronicmaxillaryatelectasis pages 1-2) - Imploding antrum syndrome (used in some literature traditions; referenced indirectly via criteria attribution to Soparkar et al.) (dorlodot2017chronicmaxillaryatelectasis pages 1-2)

1.4 Evidence-source type

Most SSS knowledge is derived from aggregated clinical resources (case series, systematic reviews, narrative reviews) and individual case reports, supported by CT-based radiographic characterization. (tousidonis2024contemporarytreatmentof pages 7-8, dorlodot2017chronicmaxillaryatelectasis pages 1-2, sivasubramaniam2011silentsinussyndrome pages 1-2)

2. Etiology

2.1 Disease causal factors (mechanistic / anatomic)

Across recent reviews and classic series, the dominant etiologic model is functional obstruction of the maxillary sinus outflow pathway: - Tousidonis 2024 describes the favored model: “obstruction of the osteomeatal complex … causes hypoventilation … accumulation of secretions that creates a negative pressure that leads to atelectasis of the sinus with downward displacement of the orbital floor.” (Tousidonis 2024; published Apr 2024; URL: https://doi.org/10.7759/cureus.57577) (tousidonis2024contemporarytreatmentof pages 7-8) - Sivasubramaniam 2011 similarly describes osteomeatal occlusion → gas resorption → negative pressure → progressive maxillary atelectasis and orbital floor descent. (URL: https://doi.org/10.1017/S0022215111001952) (sivasubramaniam2011silentsinussyndrome pages 1-2)

2.2 Risk factors

Anatomic / local factors

Ostiomeatal complex / infundibular obstruction (primary upstream factor). (tousidonis2024contemporarytreatmentof pages 7-8, lee2018silentsinussyndrome pages 1-4)

Trauma / iatrogenic (secondary SSS)

Strabbing 2025 explicitly defines secondary SSS as arising after trauma or surgery that disrupts mucociliary clearance, and reports a time-to-onset distribution: - In 9 secondary SSS patients, the interval from trauma/surgery to SSS onset ranged 1–36 months, with a median of 3 months in the post-traumatic group; 8/9 reported diplopia. (Strabbing 2025; URL: https://doi.org/10.1007/s10006-025-01391-x) (strabbing2025posttraumaticandiatrogenic pages 1-2)

Systemic inflammatory/autoimmune causes (rare)

Kramer 2024 presents what it describes as the first reported instance of granulomatosis with polyangiitis (GPA) causing SSS via sinonasal destructive disease producing obstruction: “around 100 cases of SSS have been reported so far” and this case is “the first reported instance of GPA causing SSS.” (Kramer 2024; published May 2024; URL: https://doi.org/10.7759/cureus.61442) (kramer2024granulomatosiswithpolyangiitis pages 1-3)

2.3 Protective factors

No protective genetic or environmental factors were identified in the retrieved evidence.

2.4 Gene–environment interactions

No gene–environment interaction data were identified in the retrieved evidence.

3. Phenotypes

3.1 Core symptom/sign phenotype spectrum

Common clinical manifestations reported across series and reviews include: - Enophthalmos and hypoglobus (core defining signs) (claros2019silentsinussyndrome pages 1-3, dorlodot2017chronicmaxillaryatelectasis pages 1-2) - Orbital/facial asymmetry, superior sulcus deepening, diminished malar projection (lee2018silentsinussyndrome pages 1-4, tousidonis2024contemporarytreatmentof pages 1-4) - Diplopia (variable; common in some series) (strabbing2025posttraumaticandiatrogenic pages 1-2, sivasubramaniam2011silentsinussyndrome pages 1-2)

Recent review/case-based synthesis (Tousidonis 2024) adds less typical features that may appear: - “facial hypoesthesia,” eyelid “retraction, ptosis, absent fold,” and dry eye. (tousidonis2024contemporarytreatmentof pages 7-8)

Quantitative clinical displacement estimates from a classic series: - Sivasubramaniam 2011 cites ranges: hypoglobus 2–6 mm and enophthalmos 2–5 mm. (sivasubramaniam2011silentsinussyndrome pages 1-2)

3.2 Phenotype characteristics

Age of onset: typically adult; often presenting in third to fifth decades in major series/reviews. (sivasubramaniam2011silentsinussyndrome pages 1-2, tousidonis2024contemporarytreatmentof pages 4-7, lee2018silentsinussyndrome pages 1-4)
Progression: often described as slow/progressive, sometimes over years (Sivasubramaniam 2011; also reiterated in trial registry description). (sivasubramaniam2011silentsinussyndrome pages 1-2, NCT04388345 chunk 1)
Frequency among affected individuals: high-quality population-level phenotype frequency data are not available in the retrieved evidence; in secondary SSS series, diplopia occurred in 8/9. (strabbing2025posttraumaticandiatrogenic pages 1-2)

3.3 Quality-of-life impact

The ClinicalTrials.gov registry case report notes that diagnostic delay “affected the patient lifestyle tremendously.” (NCT04388345 posted May 14, 2020; URL: https://clinicaltrials.gov/study/NCT04388345) (NCT04388345 chunk 1)

3.4 Suggested HPO terms (non-exhaustive)

(Provided as ontology suggestions; frequencies not established in retrieved sources.) - Enophthalmos — HP:0000654 - Hypoglobus — HP:0032007 - Diplopia — HP:0000651 - Facial asymmetry — HP:0000324 - Ptosis — HP:0000508 - Nasal obstruction (when present, especially in secondary or comorbid CRS) — HP:0001742

4. Genetic / molecular information

4.1 Causal genes

No validated causal genes for SSS were identified in the retrieved evidence. SSS is primarily characterized as an acquired/anatomic-mechanistic entity (ostiomeatal obstruction-driven). (tousidonis2024contemporarytreatmentof pages 7-8, dorlodot2017chronicmaxillaryatelectasis pages 1-2)

4.2 Pathogenic variants / modifier genes / epigenetics / chromosomal abnormalities

Not reported in retrieved evidence.

4.3 Notable related immunogenetic associations (not SSS-specific)

In the rare etiologic context of GPA presenting with SSS-like anatomy, Kramer 2024 notes GPA genetic associations, including “HLA-DPB1*0401 and HLA-DPB4,” but these are GPA associations rather than established SSS susceptibility loci. (kramer2024granulomatosiswithpolyangiitis pages 5-7)

5. Environmental information

5.1 Environmental/lifestyle contributors

No lifestyle/toxin/radiation/pollution associations were identified in the retrieved evidence.

5.2 Iatrogenic exposures (procedural)

Trauma and prior surgery can precipitate secondary SSS; thus, prior orbital or midface procedures constitute relevant iatrogenic “exposures.” (strabbing2025posttraumaticandiatrogenic pages 1-2)

5.3 Infectious agents

SSS itself is not presented as a primary infectious disease. Infectious colonization is discussed indirectly in GPA context (e.g., elevated S. aureus carriage in GPA patients), which may contribute to inflammation/obstruction in that systemic disease. (kramer2024granulomatosiswithpolyangiitis pages 5-7)

6. Mechanism / pathophysiology

6.1 Causal chain (upstream → downstream)

A consolidated, evidence-based mechanistic model: 1. Upstream trigger: obstruction/closure of the ostiomeatal complex / infundibulum (anatomic narrowing, inflammation, post-traumatic/iatrogenic changes). (tousidonis2024contemporarytreatmentof pages 7-8, lee2018silentsinussyndrome pages 1-4) 2. Sinus physiology change: hypoventilation with gas resorption produces subatmospheric (negative) pressure in the maxillary sinus. (tousidonis2024contemporarytreatmentof pages 7-8, sivasubramaniam2011silentsinussyndrome pages 1-2) 3. Tissue-level remodeling: inward retraction/bowing of maxillary sinus walls → maxillary atelectasis and reduced sinus volume; sinus may become opacified (secretions/transudate). (dorlodot2017chronicmaxillaryatelectasis pages 1-2, sivasubramaniam2011silentsinussyndrome pages 1-2) 4. Orbital consequences: inferior displacement/thinning/dehiscence of orbital floor → increased orbital volume → enophthalmos/hypoglobus and sometimes diplopia. (dorlodot2017chronicmaxillaryatelectasis pages 1-2, sivasubramaniam2011silentsinussyndrome pages 1-2)

6.2 Cellular and bone remodeling hypotheses

Sheptulin 2024 summarizes competing hypotheses (pressure-driven remodeling vs subclinical inflammation). It cites animal evidence that a pressure drop of ~2 mmHg could increase osteoclast activity, suggesting a potential pressure–bone remodeling link, while their sampled orbital-floor specimen showed no osteoclastic activity in that late-stage sample (implying remodeling may be earlier). (Sheptulin 2024; published Dec 2024; URL: https://doi.org/10.15275/rusomj.2024.0413) (sheptulin2024clinicalandmorphological pages 2-3, sheptulin2024clinicalandmorphological pages 3-3)

6.3 Suggested ontology mappings (mechanism)

GO biological process terms (suggestions)

Negative regulation of ventilation / gas exchange in cavity (conceptual; no direct GO mapping in retrieved texts)
Bone remodeling — GO:0046849
Osteoclast differentiation — GO:0030316 (hypothesized involvement) (sheptulin2024clinicalandmorphological pages 2-3)
Inflammatory response — GO:0006954 (subclinical inflammation hypothesis) (sheptulin2024clinicalandmorphological pages 2-3)

CL (cell types; suggestions)

Osteoclast — CL:0000092 (hypothesized, stage-dependent) (sheptulin2024clinicalandmorphological pages 2-3)
Osteoblast — CL:0000062 (implied by bone remodeling context)
Respiratory epithelial cell — CL:0002633 (sinus mucosa)

7. Anatomical structures affected

7.1 Organ/tissue level

Primary anatomical sites: - Maxillary sinus (collapse/atelectasis; opacification; reduced volume) (dorlodot2017chronicmaxillaryatelectasis pages 1-2, tousidonis2024contemporarytreatmentof pages 1-4) - Orbit, especially orbital floor (inferior displacement/thinning/dehiscence; changes in orbital volume) (dorlodot2017chronicmaxillaryatelectasis pages 1-2, tousidonis2024contemporarytreatmentof pages 4-7)

7.2 Localization and laterality

Typically unilateral, but bilateral cases exist in broader CMA/SSS spectrum (not central in the retrieved evidence set). de Dorlodot series shows a right-side predominance in that cohort: 13/18 (72%) right-sided. (dorlodot2017chronicmaxillaryatelectasis pages 1-2)

7.3 Suggested UBERON terms (suggestions)

Maxillary sinus — UBERON:0001734
Orbit — UBERON:0001697
Orbital floor (inferior orbital wall) — can be represented via orbit + bony wall anatomy terms (implementation-dependent)

8. Temporal development

8.1 Onset pattern

Often insidious; early disease may have no symptoms. Stryjewska-Makuch 2023: “in the early stage of SSS, the patient does not report any symptoms.” (published Oct 2023; URL: https://doi.org/10.1007/s00405-022-07697-w) (stryjewskamakuch2023whatmaysurprise pages 6-8)

8.2 Progression

Described as slow/progressive in classic descriptions and in the ClinicalTrials.gov case report, contributing to diagnostic delay. (sivasubramaniam2011silentsinussyndrome pages 1-2, NCT04388345 chunk 1)

9. Inheritance and population

9.1 Epidemiology (prevalence/incidence)

No population-based prevalence/incidence estimates were identified in the retrieved evidence.

9.2 Case counts / rarity statements

Kramer 2024 states: “Only around 100 cases of SSS have been reported so far.” (published May 2024; URL: https://doi.org/10.7759/cureus.61442) (kramer2024granulomatosiswithpolyangiitis pages 1-3)

9.3 Demographics (statistics from clinical series)

de Dorlodot 2017: 18 patients, mean age 44.0 ± 16.9 (range 12–70), 7 women/11 men, right-sided 13/18 (72%). (published Jun 2017; URL: https://doi.org/10.1007/s00405-017-4622-8) (dorlodot2017chronicmaxillaryatelectasis pages 1-2)
Clarós 2019: 15 patients, 11 women/4 men, mean duration of enophthalmos 10.7 months, mean enophthalmos 2.6 mm, mean hypoglobus 2.7 mm. (published Jan 2019; URL: https://doi.org/10.1080/00016489.2018.1542161) (claros2019silentsinussyndrome pages 1-3)
Stryjewska-Makuch 2023 institutional experience: among 1766 paranasal sinus patients (Sept 2017–May 2022), 8 SSS cases (4 men/4 women), mean age 45.4 (range 31–75). (published Oct 2023; URL: https://doi.org/10.1007/s00405-022-07697-w) (stryjewskamakuch2023whatmaysurprise pages 2-4)

10. Diagnostics

10.1 Imaging (core diagnostic modality)

CT is repeatedly emphasized as the diagnostic cornerstone; the trial registry explicitly states: “CT imaging is considered the gold standard for its diagnosis. The classical radiographic findings are opacification and collapse of the sinus walls.” (NCT04388345; posted May 14, 2020; URL: https://clinicaltrials.gov/study/NCT04388345) (NCT04388345 chunk 1)
Tousidonis 2024: imaging shows reduced maxillary antrum volume with retraction of maxillary walls; CT/MRI used. (tousidonis2024contemporarytreatmentof pages 7-8)
de Dorlodot 2017: coronal CT shows complete or partial opacity (complete 10/18, partial 8/18) and orbital floor dehiscence in 12 cases. (dorlodot2017chronicmaxillaryatelectasis pages 1-2)

10.2 Key radiographic features

Reduced maxillary sinus volume; inward bowing of sinus walls; often opacification; inferior displacement/thinning of orbital floor; uncinate lateralization/infundibular occlusion. (dorlodot2017chronicmaxillaryatelectasis pages 1-2, lee2018silentsinussyndrome pages 1-4)
Important diagnostic nuance: Lee 2018 demonstrates SSS can occur without ipsilateral maxillary sinus opacification, reporting average ipsilateral maxillary volume loss of 29% ± 7.1%. (published Sep 2018; URL: https://doi.org/10.1002/lary.27108) (lee2018silentsinussyndrome pages 1-4)

10.3 Clinical evaluation

SSS often presents with ophthalmologic complaints; nasal endoscopy and ENT evaluation are recommended in suspected cases (trial registry). (NCT04388345 chunk 1)

10.4 Differential diagnosis (selected)

From de Dorlodot’s exclusion criteria and modern etiologic expansions: - Prior trauma/surgery causing secondary changes (secondary SSS) (strabbing2025posttraumaticandiatrogenic pages 1-2, dorlodot2017chronicmaxillaryatelectasis pages 1-2) - Congenital facial/orbital deformity (excluded in de Dorlodot series) (dorlodot2017chronicmaxillaryatelectasis pages 1-2) - Other causes of acquired enophthalmos/hypoglobus (e.g., orbital pathology; not enumerated in retrieved texts) - Systemic inflammatory disease causing sinonasal obstruction such as GPA, particularly with necrotizing granulomatous inflammation and ANCA positivity. (kramer2024granulomatosiswithpolyangiitis pages 1-3, kramer2024granulomatosiswithpolyangiitis pages 3-5)

11. Outcome / prognosis

11.1 Prognosis and functional outcomes

SSS is generally treatable with surgical restoration of ventilation/drainage, with frequent improvement in ocular position and symptoms. - Sivasubramaniam 2011 reports that in a 23-case experience treated with uncinectomy/antrostomy alone, 22/23 had complete or partial resolution, supporting staged orbital reconstruction when needed. (published Aug 2011; URL: https://doi.org/10.1017/S0022215111001952) (sivasubramaniam2011silentsinussyndrome pages 1-2)

11.2 Complications

Secondary SSS can be associated with diplopia and functional/cosmetic impact; early recognition is advised to prevent severe sequelae. (strabbing2025posttraumaticandiatrogenic pages 1-2)

12. Treatment

12.1 Surgical/interventional (current standard of care)

Functional endoscopic sinus surgery (FESS) to restore ventilation/drainage is consistently described as the standard. - Tousidonis 2024: “maxillary endoscopic antrostomy and uncinectomy with FESS represent the gold standard.” (published Apr 2024; URL: https://doi.org/10.7759/cureus.57577) (tousidonis2024contemporarytreatmentof pages 7-8) - ClinicalTrials.gov registry similarly states: “Functional endoscopic sinus surgery (FESS) is the standard gold treatment of choice to arrest the progression of the disease.” (NCT04388345 chunk 1)

12.2 Orbital reconstruction (indications and timing controversies)

There is no universal consensus on whether to reconstruct the orbital floor immediately. - Evidence for staged/delayed approach: dynamic remodeling after re-ventilation can improve orbital floor position, potentially avoiding reconstruction; Sivasubramaniam supports delay and reassessment (22/23 improved with FESS alone). (sivasubramaniam2011silentsinussyndrome pages 1-2) - Sheptulin 2024: staged approach with follow-up CT at 6 months showed sinus pneumatization and orbital-floor elevation, but residual 3–4 mm enophthalmos and diplopia prompted delayed reconstruction; authors cite arguments to delay 3–6 months to reduce risks of overcorrection/inflammatory complications. (sheptulin2024clinicalandmorphological pages 1-2, sheptulin2024clinicalandmorphological pages 3-3) - Evidence for combined/simultaneous approach: Clarós 2019 reports 13/15 treated with simultaneous ESS and titanium orbital floor implant with significant improvement. (claros2019silentsinussyndrome pages 1-3)

12.3 Real-world implementations / advanced techniques (2023–2024 emphasis)

Tousidonis 2024 illustrates contemporary orbit reconstruction adjuncts: - A combined approach using patient-specific titanium implant, FESS, surgical navigation, and intraoperative CT with objective volumetry: affected orbital volume 28.066 cm³ pre-op vs 25.257 cm³ post-op (reduction 2.809 cm³), with stable 1-year results and no late complications. (published Apr 2024; URL: https://doi.org/10.7759/cureus.57577) (tousidonis2024contemporarytreatmentof pages 4-7)

12.4 Treatment outcomes (statistics)

FESS alone: 22/23 complete or partial resolution in Sivasubramaniam 2011. (sivasubramaniam2011silentsinussyndrome pages 1-2)
Combined surgery: quantitative ocular metrics in Clarós 2019 (mean pre-op enophthalmos 2.6 mm, hypoglobus 2.7 mm; significant improvement post-op). (claros2019silentsinussyndrome pages 1-3)
Secondary SSS: Strabbing 2025 reports surgery “restored orbital anatomy and resolved symptoms”; their Table 1 summarizes patient symptom patterns (enophthalmos/hypoglobus/diplopia) and latency post-trigger. (strabbing2025posttraumaticandiatrogenic pages 1-2, strabbing2025posttraumaticandiatrogenic media de48a58f)

12.5 Suggested MAXO terms (suggestions)

Functional endoscopic sinus surgery — MAXO:0001179 (conceptual mapping; MAXO ID may vary by implementation)
Maxillary antrostomy / uncinectomy — MAXO procedural descendants (implementation-dependent)
Orbital floor reconstruction — MAXO surgical reconstruction concept (implementation-dependent)

12.6 Pharmacotherapy

No disease-specific pharmacotherapy standards were identified in the retrieved evidence; antibiotics may be used for infectious complications in specific perioperative contexts (e.g., postoperative orbital complication described in a pediatric case report not deeply analyzed here). (tousidonis2024contemporarytreatmentof pages 7-8)

12.7 Experimental / clinical trials

No interventional trials were identified. One observational registry entry exists: - NCT04388345 (COMPLETED; enrollment 1; posted May 14, 2020): “SILENT SINUS SYNDROME (First Case Report, Saudi Arabia With Recommendation)” (URL: https://clinicaltrials.gov/study/NCT04388345). (NCT04388345 chunk 1)

13. Prevention

13.1 Primary prevention

No primary-prevention interventions are established in the retrieved evidence.

13.2 Secondary/tertiary prevention (complication prevention)

Evidence supports early recognition and timely ENT referral to prevent progression of cosmetic/functional orbital deformity: - NCT04388345 recommends “prompt ear, nose, and throat referral” for suspected cases and emphasizes CT-based diagnosis and FESS to arrest progression. (NCT04388345 chunk 1) - Strabbing 2025 recommends follow-up after trauma/surgery when unexplained orbital changes develop, to prevent severe complications. (strabbing2025posttraumaticandiatrogenic pages 1-2)

14. Other species / natural disease

No naturally occurring veterinary/other-species analogs were identified in the retrieved evidence.

15. Model organisms

No model organism or in vitro disease models were identified in the retrieved evidence.

High-yield structured summary (artifact)

The following structured table consolidates key concepts, statistics, and management evidence with URLs/DOIs and citation hooks:

Topic	Key points (include quantitative data where reported)	Evidence type (case series/review/case report/trial registry)	Source (first author year)	Publication date	PMID	URL/DOI	Citation ID to use in answer
Clinical definition	SSS defined as spontaneous, usually painless enophthalmos and/or hypoglobus with ipsilateral maxillary sinus collapse/atelectasis and orbital floor descent; often little or no sinonasal symptoms. Some authors place SSS on the spectrum of chronic maxillary atelectasis (type 3 CMA). (claros2019silentsinussyndrome pages 1-3, dorlodot2017chronicmaxillaryatelectasis pages 1-2, sivasubramaniam2011silentsinussyndrome pages 1-2)	Case series/review	Clarós 2019; de Dorlodot 2017; Sivasubramaniam 2011	2019-01; 2017-06; 2011-08	not in retrieved text	https://doi.org/10.1080/00016489.2018.1542161; https://doi.org/10.1007/s00405-017-4622-8; https://doi.org/10.1017/S0022215111001952	(claros2019silentsinussyndrome pages 1-3, dorlodot2017chronicmaxillaryatelectasis pages 1-2, sivasubramaniam2011silentsinussyndrome pages 1-2)
Pathophysiology	Most-cited mechanism: ostiomeatal complex/infundibular obstruction → sinus hypoventilation → gas resorption and subatmospheric pressure → maxillary wall inward bowing/atelectasis → downward orbital floor displacement → increased orbital volume causing enophthalmos/hypoglobus. Sheptulin notes animal data suggesting even a 2 mmHg pressure drop may increase osteoclast activity; histology in one late-stage case showed no active osteolysis, implying remodeling may be stage-dependent. (tousidonis2024contemporarytreatmentof pages 7-8, sheptulin2024clinicalandmorphological pages 2-3, sivasubramaniam2011silentsinussyndrome pages 1-2)	Review/case report/case series	Tousidonis 2024; Sheptulin 2024; Sivasubramaniam 2011	2024-04; 2024-12; 2011-08	not in retrieved text	https://doi.org/10.7759/cureus.57577; https://doi.org/10.15275/rusomj.2024.0413; https://doi.org/10.1017/S0022215111001952	(tousidonis2024contemporarytreatmentof pages 7-8, sheptulin2024clinicalandmorphological pages 2-3, sivasubramaniam2011silentsinussyndrome pages 1-2)
Core phenotypes	Common features: progressive enophthalmos, hypoglobus, orbital asymmetry, diplopia, superior sulcus deepening, diminished malar projection, facial asymmetry; atypical signs can include facial hypoesthesia, eyelid retraction/ptosis, dry eye. Reported displacement magnitudes: hypoglobus 2–6 mm and enophthalmos 2–5 mm. In secondary SSS, 8/9 patients had diplopia. (tousidonis2024contemporarytreatmentof pages 7-8, sivasubramaniam2011silentsinussyndrome pages 1-2, tousidonis2024contemporarytreatmentof pages 1-4, strabbing2025posttraumaticandiatrogenic pages 1-2)	Review/case series/case report	Tousidonis 2024; Sivasubramaniam 2011; Strabbing 2025	2024-04; 2011-08; 2025-05	not in retrieved text	https://doi.org/10.7759/cureus.57577; https://doi.org/10.1017/S0022215111001952; https://doi.org/10.1007/s10006-025-01391-x	(tousidonis2024contemporarytreatmentof pages 7-8, sivasubramaniam2011silentsinussyndrome pages 1-2, tousidonis2024contemporarytreatmentof pages 1-4, strabbing2025posttraumaticandiatrogenic pages 1-2)
Imaging findings	CT is the diagnostic mainstay/gold standard. Typical findings: reduced maxillary sinus volume, sinus opacification (often complete or partial), inward bowing of antral walls, inferior displacement/thinning of orbital floor, uncinate lateralization, infundibular occlusion. In de Dorlodot series, opacity was complete in 10/18 and partial in 8/18; orbital floor dehiscence in 12 cases. Lee showed SSS may occur even without sinus opacification; average ipsilateral maxillary volume loss 29% ± 7.1%. (dorlodot2017chronicmaxillaryatelectasis pages 1-2, lee2018silentsinussyndrome pages 1-4, tousidonis2024contemporarytreatmentof pages 1-4, NCT04388345 chunk 1)	Case series/case report/trial registry	de Dorlodot 2017; Lee 2018; Tousidonis 2024; NCT04388345	2017-06; 2018-09; 2024-04; 2020-05	not in retrieved text	https://doi.org/10.1007/s00405-017-4622-8; https://doi.org/10.1002/lary.27108; https://doi.org/10.7759/cureus.57577; https://clinicaltrials.gov/study/NCT04388345	(dorlodot2017chronicmaxillaryatelectasis pages 1-2, lee2018silentsinussyndrome pages 1-4, tousidonis2024contemporarytreatmentof pages 1-4, NCT04388345 chunk 1)
Demographics/statistics	SSS is rare. Kramer 2024 states “around 100 cases described.” Typical age distribution is adult, often 3rd–5th decades; equal-sex distribution is reported by Tousidonis 2024, but individual series vary. de Dorlodot: 18 patients, mean age 44.0 ± 16.9 years, 11 men/7 women, right side in 13/18 (72%). Clarós: 15 patients, 11 women/4 men, mean symptom duration 10.7 months, mean enophthalmos 2.6 mm and hypoglobus 2.7 mm. Stryjewska-Makuch institutional experience: 8 SSS cases among 1766 paranasal sinus patients (2017–2022), mean age 45.4 years, 4 men/4 women. (kramer2024granulomatosiswithpolyangiitis pages 1-3, dorlodot2017chronicmaxillaryatelectasis pages 1-2, claros2019silentsinussyndrome pages 1-3, stryjewskamakuch2023whatmaysurprise pages 2-4)	Case series/review/case report	Kramer 2024; de Dorlodot 2017; Clarós 2019; Stryjewska-Makuch 2023	2024-05; 2017-06; 2019-01; 2023-10	not in retrieved text	https://doi.org/10.7759/cureus.61442; https://doi.org/10.1007/s00405-017-4622-8; https://doi.org/10.1080/00016489.2018.1542161; https://doi.org/10.1007/s00405-022-07697-w	(kramer2024granulomatosiswithpolyangiitis pages 1-3, dorlodot2017chronicmaxillaryatelectasis pages 1-2, claros2019silentsinussyndrome pages 1-3, stryjewskamakuch2023whatmaysurprise pages 2-4)
Secondary/associated etiologies	Although often idiopathic, secondary SSS can follow trauma or surgery disrupting mucociliary clearance. In Strabbing 2025, onset after trauma/surgery ranged 1–36 months, median 3 months in post-traumatic cases. Rare associated etiologies include GPA/ANCA vasculitis causing infundibular obstruction and destructive sinonasal disease. Familial clustering has been proposed in later literature, but robust genetic evidence is lacking in retrieved texts. (strabbing2025posttraumaticandiatrogenic pages 1-2, kramer2024granulomatosiswithpolyangiitis pages 5-7, kramer2024granulomatosiswithpolyangiitis pages 3-5)	Case series/case report	Strabbing 2025; Kramer 2024	2025-05; 2024-05	not in retrieved text	https://doi.org/10.1007/s10006-025-01391-x; https://doi.org/10.7759/cureus.61442	(strabbing2025posttraumaticandiatrogenic pages 1-2, kramer2024granulomatosiswithpolyangiitis pages 5-7, kramer2024granulomatosiswithpolyangiitis pages 3-5)
Standard treatment	Functional endoscopic sinus surgery (FESS), typically uncinectomy with middle meatal antrostomy/maxillary antrostomy, is the current standard/gold-standard intervention to re-establish drainage and ventilation and arrest progression. (tousidonis2024contemporarytreatmentof pages 7-8, NCT04388345 chunk 1, stryjewskamakuch2023whatmaysurprise pages 2-4)	Review/trial registry/case series	Tousidonis 2024; NCT04388345; Stryjewska-Makuch 2023	2024-04; 2020-05; 2023-10	not in retrieved text	https://doi.org/10.7759/cureus.57577; https://clinicaltrials.gov/study/NCT04388345; https://doi.org/10.1007/s00405-022-07697-w	(tousidonis2024contemporarytreatmentof pages 7-8, NCT04388345 chunk 1, stryjewskamakuch2023whatmaysurprise pages 2-4)
Orbital reconstruction timing	Controversial. Some authors favor FESS alone initially because orbital floor position may remodel after re-aeration; Sivasubramaniam reported 22/23 patients had complete or partial resolution after uncinectomy/antrostomy alone. Delayed reconstruction is often considered for persistent enophthalmos >2 mm, diplopia, or unacceptable cosmesis after reassessment (commonly 3–6 months). Others perform simultaneous ESS plus orbital reconstruction in selected advanced cases. (tousidonis2024contemporarytreatmentof pages 7-8, sheptulin2024clinicalandmorphological pages 3-3, sivasubramaniam2011silentsinussyndrome pages 1-2)	Review/case report/case series	Tousidonis 2024; Sheptulin 2024; Sivasubramaniam 2011	2024-04; 2024-12; 2011-08	not in retrieved text	https://doi.org/10.7759/cureus.57577; https://doi.org/10.15275/rusomj.2024.0413; https://doi.org/10.1017/S0022215111001952	(tousidonis2024contemporarytreatmentof pages 7-8, sheptulin2024clinicalandmorphological pages 3-3, sivasubramaniam2011silentsinussyndrome pages 1-2)
Combined surgery outcomes	Clarós 2019: 13/15 underwent simultaneous ESS plus titanium orbital floor implant; significant pre/post improvement in enophthalmos and hypoglobus, with good long-term aesthetic results. Tousidonis 2024 case: FESS plus patient-specific titanium implant reduced orbital volume from 28.066 cm3 pre-op to 25.257 cm3 post-op (reduction 2.809 cm3), with stable satisfactory 1-year result and no late complications. Secondary SSS series reported restoration of orbital anatomy and symptom resolution after retrograde uncinectomy and orbital reconstruction. (claros2019silentsinussyndrome pages 1-3, tousidonis2024contemporarytreatmentof pages 4-7, strabbing2025posttraumaticandiatrogenic pages 1-2)	Case series/case report	Clarós 2019; Tousidonis 2024; Strabbing 2025	2019-01; 2024-04; 2025-05	not in retrieved text	https://doi.org/10.1080/00016489.2018.1542161; https://doi.org/10.7759/cureus.57577; https://doi.org/10.1007/s10006-025-01391-x	(claros2019silentsinussyndrome pages 1-3, tousidonis2024contemporarytreatmentof pages 4-7, strabbing2025posttraumaticandiatrogenic pages 1-2)
Diagnostic caution / differential clues	Differential diagnosis should consider chronic maxillary atelectasis without classic SSS symptoms, prior trauma/surgery, congenital deformity, orbital pathology, and systemic causes of sinonasal obstruction. GPA should be suspected when SSS-like findings coexist with autoimmune history, ANCA positivity, necrotizing granulomatous inflammation, epistaxis, saddle-nose deformity, or renal vasculitis history. SSS should also remain a differential even without maxillary opacification. (dorlodot2017chronicmaxillaryatelectasis pages 1-2, lee2018silentsinussyndrome pages 1-4, kramer2024granulomatosiswithpolyangiitis pages 5-7, NCT04388345 chunk 1)	Case series/case report/trial registry	de Dorlodot 2017; Lee 2018; Kramer 2024; NCT04388345	2017-06; 2018-09; 2024-05; 2020-05	not in retrieved text	https://doi.org/10.1007/s00405-017-4622-8; https://doi.org/10.1002/lary.27108; https://doi.org/10.7759/cureus.61442; https://clinicaltrials.gov/study/NCT04388345	(dorlodot2017chronicmaxillaryatelectasis pages 1-2, lee2018silentsinussyndrome pages 1-4, kramer2024granulomatosiswithpolyangiitis pages 5-7, NCT04388345 chunk 1)

Table: This table summarizes key clinical, radiologic, mechanistic, demographic, and treatment findings for Silent Sinus Syndrome from the retrieved evidence base. It is designed to support rapid citation and knowledge-base population.

Visual evidence

A cropped table image from Strabbing 2025 summarizing secondary SSS patient-level clinical data (symptoms and time-to-onset) was retrieved and can be used to support secondary SSS statistics and variability in presentation. (strabbing2025posttraumaticandiatrogenic media de48a58f)

Evidence gaps and limitations (for KB curation)

Identifiers (ICD/MeSH/Orphanet/OMIM): not retrieved in this run; should be filled from authoritative ontologies (e.g., MeSH Browser, ICD-11 MMS, Orphanet) in a follow-up curation step.
Genetics: no established causal genes/variants in retrieved evidence; occasional familial clustering hypotheses exist in broader literature but were not evidenced here.
Epidemiology: no incidence/prevalence estimates; literature is largely case series/case reports.
QoL instruments: no EQ-5D/SF-36/PROMIS quantitative data found in retrieved evidence.

References

(claros2019silentsinussyndrome pages 1-3): Pedro Clarós, Aleksandra Zofia Sobolewska, Antonio Cardesa, Marta Lopez-Fortuny, and Andres Claros. Silent sinus syndrome: combined sinus surgery and orbital reconstruction – report of 15 cases. Acta Oto-Laryngologica, 139:64-69, Jan 2019. URL: https://doi.org/10.1080/00016489.2018.1542161, doi:10.1080/00016489.2018.1542161. This article has 12 citations and is from a peer-reviewed journal.
(dorlodot2017chronicmaxillaryatelectasis pages 1-2): Clotilde de Dorlodot, Stephanie Collet, Philippe Rombaux, Mihaela Horoi, Sergio Hassid, and Philippe Eloy. Chronic maxillary atelectasis and silent sinus syndrome: two faces of the same clinical entity. European Archives of Oto-Rhino-Laryngology, 274:3367-3373, Jun 2017. URL: https://doi.org/10.1007/s00405-017-4622-8, doi:10.1007/s00405-017-4622-8. This article has 38 citations and is from a peer-reviewed journal.
(tousidonis2024contemporarytreatmentof pages 7-8): Manuel Tousidonis, Sara Alvarez-Mokthari, Saad Khayat, Guillermo Sanjuan de Moreta, and Santiago Ochandiano. Contemporary treatment of silent sinus syndrome: a case report and literature review. Cureus, Apr 2024. URL: https://doi.org/10.7759/cureus.57577, doi:10.7759/cureus.57577. This article has 3 citations.
(sivasubramaniam2011silentsinussyndrome pages 1-2): R. Sivasubramaniam, Raymond Sacks, and M. Thornton. Silent sinus syndrome: dynamic changes in the position of the orbital floor after restoration of normal sinus pressure. The Journal of Laryngology & Otology, 125:1239-1243, Aug 2011. URL: https://doi.org/10.1017/s0022215111001952, doi:10.1017/s0022215111001952. This article has 75 citations.
(lee2018silentsinussyndrome pages 1-4): David S. Lee, Andrew H. Murr, Robert C. Kersten, and Steven D. Pletcher. Silent sinus syndrome without opacification of ipsilateral maxillary sinus. The Laryngoscope, 128:2004-2007, Sep 2018. URL: https://doi.org/10.1002/lary.27108, doi:10.1002/lary.27108. This article has 23 citations.
(strabbing2025posttraumaticandiatrogenic pages 1-2): E. M. Strabbing, O. Engin, M. A.J. Telleman, A. P. Nagtegaal, and E. B. Wolvius. Post-traumatic and iatrogenic silent sinus syndrome: a case series. Oral and Maxillofacial Surgery, May 2025. URL: https://doi.org/10.1007/s10006-025-01391-x, doi:10.1007/s10006-025-01391-x. This article has 3 citations and is from a peer-reviewed journal.
(kramer2024granulomatosiswithpolyangiitis pages 1-3): Nicholas Kramer, Brandon Manthei, Luke Speier, Jo-Lawrence M Bigcas, and Scott Manthei. Granulomatosis with polyangiitis as an etiology of silent sinus syndrome: a case report. Cureus, May 2024. URL: https://doi.org/10.7759/cureus.61442, doi:10.7759/cureus.61442. This article has 1 citations.
(tousidonis2024contemporarytreatmentof pages 1-4): Manuel Tousidonis, Sara Alvarez-Mokthari, Saad Khayat, Guillermo Sanjuan de Moreta, and Santiago Ochandiano. Contemporary treatment of silent sinus syndrome: a case report and literature review. Cureus, Apr 2024. URL: https://doi.org/10.7759/cureus.57577, doi:10.7759/cureus.57577. This article has 3 citations.
(tousidonis2024contemporarytreatmentof pages 4-7): Manuel Tousidonis, Sara Alvarez-Mokthari, Saad Khayat, Guillermo Sanjuan de Moreta, and Santiago Ochandiano. Contemporary treatment of silent sinus syndrome: a case report and literature review. Cureus, Apr 2024. URL: https://doi.org/10.7759/cureus.57577, doi:10.7759/cureus.57577. This article has 3 citations.
(NCT04388345 chunk 1): Nouf Saloom Alsaloom. SILENT SINUS SYNDROME (First Case Report, Saudi Arabia With Recommendation). King Saud University. 2019. ClinicalTrials.gov Identifier: NCT04388345
(kramer2024granulomatosiswithpolyangiitis pages 5-7): Nicholas Kramer, Brandon Manthei, Luke Speier, Jo-Lawrence M Bigcas, and Scott Manthei. Granulomatosis with polyangiitis as an etiology of silent sinus syndrome: a case report. Cureus, May 2024. URL: https://doi.org/10.7759/cureus.61442, doi:10.7759/cureus.61442. This article has 1 citations.
(sheptulin2024clinicalandmorphological pages 2-3): Vladimir A. Sheptulin, Yaroslav O. Grusha, and Dmitry M. Konovalov. Clinical and morphological features of the orbital floor in a patient with silent sinus syndrome: a clinical case report. Russian Open Medical Journal, Dec 2024. URL: https://doi.org/10.15275/rusomj.2024.0413, doi:10.15275/rusomj.2024.0413. This article has 0 citations.
(sheptulin2024clinicalandmorphological pages 3-3): Vladimir A. Sheptulin, Yaroslav O. Grusha, and Dmitry M. Konovalov. Clinical and morphological features of the orbital floor in a patient with silent sinus syndrome: a clinical case report. Russian Open Medical Journal, Dec 2024. URL: https://doi.org/10.15275/rusomj.2024.0413, doi:10.15275/rusomj.2024.0413. This article has 0 citations.
(stryjewskamakuch2023whatmaysurprise pages 6-8): Grażyna Stryjewska-Makuch, Magdalena Kokoszka, Karolina Goroszkiewicz, Olga Karłowska-Bijak, Bogdan Kolebacz, and Maciej Misiołek. What may surprise a rhinologist in everyday clinical practice: silent sinus syndrome or pneumosinus dilatans/pneumocele? literature review and own experience. European Archives of Oto-Rhino-Laryngology, 280:519-527, Oct 2023. URL: https://doi.org/10.1007/s00405-022-07697-w, doi:10.1007/s00405-022-07697-w. This article has 4 citations and is from a peer-reviewed journal.
(stryjewskamakuch2023whatmaysurprise pages 2-4): Grażyna Stryjewska-Makuch, Magdalena Kokoszka, Karolina Goroszkiewicz, Olga Karłowska-Bijak, Bogdan Kolebacz, and Maciej Misiołek. What may surprise a rhinologist in everyday clinical practice: silent sinus syndrome or pneumosinus dilatans/pneumocele? literature review and own experience. European Archives of Oto-Rhino-Laryngology, 280:519-527, Oct 2023. URL: https://doi.org/10.1007/s00405-022-07697-w, doi:10.1007/s00405-022-07697-w. This article has 4 citations and is from a peer-reviewed journal.
(kramer2024granulomatosiswithpolyangiitis pages 3-5): Nicholas Kramer, Brandon Manthei, Luke Speier, Jo-Lawrence M Bigcas, and Scott Manthei. Granulomatosis with polyangiitis as an etiology of silent sinus syndrome: a case report. Cureus, May 2024. URL: https://doi.org/10.7759/cureus.61442, doi:10.7759/cureus.61442. This article has 1 citations.
(sheptulin2024clinicalandmorphological pages 1-2): Vladimir A. Sheptulin, Yaroslav O. Grusha, and Dmitry M. Konovalov. Clinical and morphological features of the orbital floor in a patient with silent sinus syndrome: a clinical case report. Russian Open Medical Journal, Dec 2024. URL: https://doi.org/10.15275/rusomj.2024.0413, doi:10.15275/rusomj.2024.0413. This article has 0 citations.
(strabbing2025posttraumaticandiatrogenic media de48a58f): E. M. Strabbing, O. Engin, M. A.J. Telleman, A. P. Nagtegaal, and E. B. Wolvius. Post-traumatic and iatrogenic silent sinus syndrome: a case series. Oral and Maxillofacial Surgery, May 2025. URL: https://doi.org/10.1007/s10006-025-01391-x, doi:10.1007/s10006-025-01391-x. This article has 3 citations and is from a peer-reviewed journal.

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Pathophysiology

Pathograph

Phenotypes

Genetic Associations

Treatments

Environmental Factors

Differential Diagnoses

Source YAML

References & Deep Research

Deep Research

Disease Characteristics Research Template

Target Disease

Research Objectives

1. Disease Information

2. Etiology

3. Phenotypes

4. Genetic/Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome/Prognosis

12. Treatment

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Citation Requirements

Output Format

Silent Sinus Syndrome (SSS) — Comprehensive Disease Characteristics Report

Target disease

1. Disease information

1.1 Concise overview (current understanding)

1.2 Key identifiers

1.3 Common synonyms / alternative names

1.4 Evidence-source type

2. Etiology

2.1 Disease causal factors (mechanistic / anatomic)

2.2 Risk factors

Anatomic / local factors

Trauma / iatrogenic (secondary SSS)

Systemic inflammatory/autoimmune causes (rare)

2.3 Protective factors

2.4 Gene–environment interactions

3. Phenotypes

3.1 Core symptom/sign phenotype spectrum

3.2 Phenotype characteristics

3.3 Quality-of-life impact

3.4 Suggested HPO terms (non-exhaustive)

4. Genetic / molecular information

4.1 Causal genes

4.2 Pathogenic variants / modifier genes / epigenetics / chromosomal abnormalities

4.3 Notable related immunogenetic associations (not SSS-specific)

5. Environmental information

5.1 Environmental/lifestyle contributors

5.2 Iatrogenic exposures (procedural)

5.3 Infectious agents

6. Mechanism / pathophysiology

6.1 Causal chain (upstream → downstream)

6.2 Cellular and bone remodeling hypotheses

6.3 Suggested ontology mappings (mechanism)

GO biological process terms (suggestions)

CL (cell types; suggestions)

7. Anatomical structures affected

7.1 Organ/tissue level

7.2 Localization and laterality

7.3 Suggested UBERON terms (suggestions)

8. Temporal development

8.1 Onset pattern

8.2 Progression

9. Inheritance and population

9.1 Epidemiology (prevalence/incidence)

9.2 Case counts / rarity statements

9.3 Demographics (statistics from clinical series)

10. Diagnostics

10.1 Imaging (core diagnostic modality)

10.2 Key radiographic features