Radiology · patient case question
What is Patient A's finding?
Patient case: Two findings that should be recognised and left alone — or investigated
Patient: Two patients
Chief Complaint: Both attend for routine examination.
Background: A, 55-year-old male: asymptomatic. An identical finding is visible on a panoramic taken eleven years ago and has not changed. B, 30-year-old female: several extractions performed three years ago.
Findings: A: a well-defined, densely CORTICATED radiolucency at the angle of the mandible lying BELOW the mandibular canal, between the canal and the inferior border. B: the extraction sockets remain clearly visible as dense sclerotic outlines that have not remodelled into the surrounding trabecular pattern.
Show answer and explanation
Correct answer: C. Stafne defect
- A. A residual cyst requires a previous extraction of a non-vital tooth and sits within the alveolus, above the canal, not beneath it.
- B. A traumatic bone cyst lies ABOVE the mandibular canal in the alveolar bone, characteristically scalloping upward between the roots of vital teeth, and occurs typically in younger patients.
- C. CORRECT. The STAFNE DEFECT — also called the static bone cavity or lingual mandibular salivary gland depression — is a developmental concavity on the LINGUAL surface of the mandible containing normal SUBMANDIBULAR salivary gland tissue or fat. Its defining features are exactly those described: located BELOW the mandibular canal between the canal and the inferior border, at the angle or molar region, well-defined and densely corticated, entirely asymptomatic, and UNCHANGING over years. It requires NO treatment. Recognising it and leaving it alone is the whole of management; where the appearance is atypical, CBCT demonstrates the lingual concavity and settles it.
- D. Ameloblastoma is expansile and multilocular, and would not sit unchanged below the canal for eleven years.
Note: Two variants are worth knowing beyond the classic posterior one: an ANTERIOR variant lingual to the premolars, related to the SUBLINGUAL gland, which is easier to mistake for pathology because it sits among the roots; and a rare superior variant near the ramus. The single most useful feature in all of them is stability across serial radiographs.