Radiology · patient case with 1 question
A dome on the floor of the sinus
Patient: Male, 41 years old
Chief Complaint: Attends for assessment before an implant to replace #14.
Background: Healthy, non-smoker. No nasal obstruction, no facial pain, no discharge, no history of sinus disease.
Vital Signs: BP 124/76 mmHg · HR 70 bpm · afebrile
Findings: The panoramic radiograph shows a smooth, well-defined, DOME-SHAPED radiopacity rising from the FLOOR of the right maxillary sinus. The remaining sinus is well aerated. All adjacent teeth respond normally to cold and have intact lamina dura.
Question 1
What is this, and what does it require?
Show answer and explanation
Correct answer: C. An antral mucous retention pseudocyst — no treatment
- A. An antral malignancy destroys the bony walls of the sinus, has ill-defined margins, and produces symptoms — paraesthesia, epistaxis, nasal obstruction, loosening teeth or facial swelling. A smooth dome on an intact sinus floor is not that.
- B. A periapical cyst projecting into the antrum would be CONTINUOUS with the apex of a NON-VITAL tooth and would show loss of the lamina dura at that apex. Every adjacent tooth here is vital with intact lamina dura, which excludes it.
- C. CORRECT. The ANTRAL MUCOUS RETENTION PSEUDOCYST — also called an antral pseudocyst or mucosal antral cyst — is among the commonest incidental panoramic findings, reported in roughly 2–10% of patients. It is an accumulation of inflammatory exudate lifting the sinus lining, and it is a PSEUDOcyst because it has NO EPITHELIAL LINING. Its features are exactly those described: smooth, well-defined, DOME-SHAPED, rising from the FLOOR of the antrum, asymptomatic, and frequently changing in size or resolving spontaneously on later films. It requires NO treatment.
- D. Odontogenic sinusitis produces generalised mucosal thickening or an air-fluid level, together with symptoms — facial pain, nasal discharge, congestion — and an identifiable odontogenic source. This patient has a well-aerated sinus and no symptoms at all.
Note: Two practical points for this patient. The pseudocyst does NOT preclude implant placement or a sinus lift, but a large one may warrant ENT opinion beforehand, because grafting can displace it and obstruct the ostium. And distinguish it from a true MUCOCELE of the sinus, which is an entirely different problem — it fills and EXPANDS the whole sinus, thins and displaces the bony walls, and does require surgical management.