A 40-year-old male patient was referred to a private clinic for endodontic treatment of teeth with a periapical lesion in his premolar region of mandible that was discovered during routine radiographic examination. Panoramic radiography revealed a unilocular periapical radiolucency below the apex of the mandibular left canine extending to the second premolar (Figure ). On the periapical radiograph, the lesion mimicked a radicular cyst; however, the teeth were asymptomatic and the periodontal ligament space and lamina dura were intact. The teeth also gave a positive response to the sensibility tests. The patient had no history of trauma to the jaw. Clinical examination revealed no facial asymmetry and no lymphadenopathy. The most likely diagnosis was a nonodontogenic cyst.\nIt was decided to examine the lesion by CBCT to evaluate the relationship of the lesion with its surrounding structures and reach a definite diagnosis. CBCT images were taken by NewTom CBCT system (NewTom VG) with the exposure settings of 110 kVp, 59.62 mA, 4.3 seconds exposure time, 5 × 5 cm field of view, and 14-bits gray scale. The CBCT scans revealed a well-defined lingual defect in the canine to second premolar region with no connection to the base of the mandible and a cyst-like appearance. Evaluation of axial, coronal, and sagittal sections confirmed a lingual wall defect; the buccal wall was intact and there was no expansion. The mental foramen was clearly demarcated from the radiolucency by cortical bone and was not part of the lesion. The root apices of the first and second premolars directly contacted the lesion with no sign of resorption (Figure ).\nFor more evaluation of the internal contents of the defect, we used the software's ability to determine the gray scale value. The gray scale value of the main contents of the defect in the middle section was approximately in the range of −78 to 202 with a mean (± standard deviation) of 108 (±31). The mean gray scale value for the adjacent lingual soft tissue was 108 (±52). The lesion was clearly related to the adjacent lingual soft tissue, which could be the anatomical location of sublingual gland with approximately similar gray scale value (Figure ). Thus, this defect could be classified into the group with range of soft tissues.\nConsidering the dental and clinical history of the patient and the radiographic features, the defect was diagnosed as a premolar region variant of lingual bone depression and regular follow-ups were scheduled for the patient.
A 45-year-old man referred to the Department of Periodontology, School of Dentistry, Isfahan University of Medical Sciences for routine dental and periodontal examinations. The patient's medical history was not significant. He was not a smoker and revealed no history of trauma or jaw surgery. On extraoral examination, he had a normal appearance. On intraoral examination, the patient had neither any pain nor swelling on the buccal and lingual aspects of the mandible. The radiographic images showed a well-defined unilocular radiolucency below the apices of the left lateral incisor and left canine teeth [].\nFurthermore, deep caries was observed in the left lateral incisor. The clinician suspected a periapical lesion of endodontic origin, but unfortunately, the vitality test of the tooth was not done. To rule out any possible existing pathology in anterior mandible, a diagnostic excision biopsy was planned. The surgical exploration revealed the lingual cortex had been destroyed. Further, the gross examination indicated a soft, relatively firm, brownish, gray mass with granular surface measuring approximately 20 mm × 10 mm × 20 mm. Moreover, histopathologic examination showed a normal salivary gland tissue, with many mucous acini and ducts, which was consistent with normal sublingual gland []. The sections from few other areas revealed inflammatory cells, muscle tissue, fat tissue, blood vessels, and nerve bundles []. Thus, based on the clinical, radiographical, and histopathological findings, the final diagnosis of SBC with ectopic salivary gland tissue was made. Clinical and radiographic controls were performed during 3 months of follow-up. No changes in the zone have been detected.