A 52-year-old female patient presented with facial injury suspicious for nasal bone fracture. During facial bone computed tomography (CT), a well-circumscribed cystic lesion was discovered incidentally on right side of the mandible (). The patient did not complain of any discomfort, pain, or numbness of the lower face. She also denied any trauma to the chin or significant surgical history.\nLateral radiographs showed a well-defined, radiolucent, ovoid lesion anterior to the right mandibular angle (). The coronal and sagittal CT images demonstrated a deficiency in the mandibular defect containing the soft tissue lesion in continuity with the submandibular gland (). Based on the radiological findings, the patient was diagnosed with a Stafne bone cavity, and regular observation was recommended.
A 52-year-old African-American male patient was referred to the emergency clinic of the Department of Oral Medicine at the University of Pennsylvania School of Dental Medicine by a private dentist for possible extractions of the maxillary left first molar, mandibular left third molar, and second premolar due to severe periodontal bone loss and pain.\nA comprehensive intraoral and extraoral exam was completed. The patient was well developed and well nourished. Tooth vitality tests were performed; the dental complaint of pain was odontogenic in nature, and was limited to the maxillary left first molar, mandibular left third molar, and second premolar. There was no evidence for suppuration or swelling. Bilateral mandibular tori were noted. The temporomandibular joint (TMJ) exhibited a full range of motion, and neither crepitus nor clicking were noted. The patient denied any history of pain associated with the TMJ or myofascial pain related to the muscles of mastication. Cranial nerves II through XII were grossly intact. Submandibular lymph nodes were palpable, non-tender, and mobile. The patient's vital signs were within the normal limits. The patient denied taking any medications other than a course of antibiotics prescribed for the periodontal infection by his general dentist.\nA panoramic radiograph, taken after the initial examination, revealed that the maxillary left first molar exhibited severe vertical bone loss, the mandibular left third molar was symptomatic with an apical rarefying osteitis in relation to the mesiobuccal root, and the mandibular left second premolar was symptomatic with irreversible pulpitis (based on vitality tests) and appeared to be non-restorable. The panoramic examination also revealed an atypical bone cavity that presented as an ovoid radiolucency with well-defined, corticated borders at the superior region of the ascending left ramus (). The area was asymptomatic and appeared to have no relationship with the chief dental complaint. The area appeared to be non-odontogenic in nature. The patient denied any active medical conditions or knowledge of mandibular atypia prior to the dental examination at our clinic.\nCBCT was recommended to visualize the lesion 3-dimensionally. A medium-volume CBCT scan was performed at a voxel resolution of 200 µm (CS 9300, Carestream, Atlanta, GA, USA). The depression was a round, well-circumscribed radiolucency, corticated, and its maximal dimensions were 5.4×10×6.3 mm in the coronal, sagittal, and axial multi-planar reconstruction images (, , ). presents a panoramic reconstruction of the CBCT volume showing the depression. In the axial cross sections, the well-defined lytic area was located on the posterior border of the ascending ramus on the lingual aspect ().\nBased on the clinical and radiographic features of the lesion, a provisional diagnosis of a developmental salivary gland depression of the left ramus was made. The differential diagnosis included a static bone cavity, or a simple bone cyst, a benign tumor of salivary gland or fatty origin. Although we did not expect the defect to change in size over time, a clinical and radiographic follow-up was recommended to the patient. The patient was cleared for the extractions and was scheduled for annual follow-up.