A 17-year-old male patient attended the oral and maxillofacial surgery clinic in King Saud University requesting extraction of all third molars. The patient’s medical history was unremarkable; he was a non-smoker and revealed no history of previous facial trauma or surgery. There was neither pain nor swelling of the buccal and lingual sulci of the mandible and no cervical lymphadenopathy. Initial dental examination revealed a minimally restored permanent dentition with good oral hygiene. A panoramic radiograph showed that all third molars were present and impacted except on the upper right side where the tooth was missing, with the lower third molars in close proximity to the inferior alveolar canals (Figure ). The radiograph was otherwise unremarkable with no signs of pathology or abnormality.\nA CBCT of the mandible was requested for further assessment of the relation and proximity of the roots to the inferior alveolar canal. A survey of the CBCT sections of the mandibular body revealed bilateral sublingual depressions inferior to the premolars and first molars extending to the inferior border of the mandible that was not seen on the panoramic radiograph.\nTo assess the depth and width of these depressions, the CBCT images were reconstructed in planes aligned with the axes of the right and left mandibular second premolars in the mesiodistal dimension, buccolingual dimension, and the coronoapical dimension. Then, linear measurements representing the width of the depressions were made along a line drawn a tangent to the heights of contours (crest of curvatures) of the lingual surfaces of the mandible superior and inferior to the bilateral depression. The superoinferior width of the depressions was found to be 2.1 cm on the right side and 2.9 cm on the left side. Linear measurements representing the buccolingual depth of the depressions were made along a line drawn perpendicular to the above-mentioned width line to the deepest point of the depression; it measured 0.59 cm on the left side and 0.6 cm on the right side. The buccolingual thickness of the remaining mandible was 0.42 cm on the left side and 0.45 cm on the right side (Figures -).\nThe diagnosis was concluded to be bilateral sublingual depressions of the mandible. It is considered a normal anatomical variation that does not require any further investigation or intervention. The incidental finding was documented in the patient dental record for future implications in case an implant placement was needed.
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.