A rare case of odontoma

OBJECTIVES. The aim of this study is to report a rare localization of a compound odontoma in the mandible, discovered accidentally on an orthopantomogram (OPT). MATERIALS AND METHODS. We report the case of a 22 years-old male patient referred to our department and presenting with impaction of lower third molars. OPT exam confirmed the suspect of compound odontoma surrounding the apexes of teeth 3.4 and 3.5, which is an unusual site of presentation for compound odontomas. CT exam revealed the boundaries of the lesion and its close contact with IAN (Inferior Alveolar Nerve). The surgical procedure can be described as follows: 1) regional anesthesia and triangular intrasulcular incision between 3.3 and 3.7; 2) exposure of bone, debridement just below the apexes of teeth 3.4 and 3.5; 3) denticles extraction; 4) revision of the surgical site, detection of the intact IAN and rinsing; 5) cavity filling with fibrin sponge and flap suture. RESULTS. Histological examination confirmed the working diagnosis: fibrous connective tissue sac surrounding the denticles. The dental tissues forming these denticles consist of a central core similar to pulp tissue, surrounded by primary dentin and covered with partially demineralized enamel and primary cement. In spite of the denticles close adherence to IAN, the patient was asymptomatic with no evidence of nerve injury one month after surgery. Moreover, the subsequent radiographic controls showed the complete recovery of the bone at one year after surgery. CONCLUSIONS. Odontomas are not really rare hamartomas in the general practice of oral and maxillofacial surgeons. The most common location is the anterior region of the maxilla (67%), as compared with the mandible (33%), but the peculiarity of this case was the location of a multiple odontoma in the posterior mandible. Usually, odontomas may cause disturbances in the eruption of teeth such as impaction, delayed eruption or retention of primary teeth; in those cases or in the event of any dentition anomaly or jaw deformation in children or adolescents, it is very important to investigate the presence of possible odontomas with radiographic examinations. In the above case, no delayed eruption was found. The radiographs alone enabled us to identify the firm adherence of the odontoma to the alveolar nerve and to prevent possible nerve compression consequences. The lesion was surgically excised in a conservative way, using an intraoral approach with total anesthesia, to ensure that the nerve is preserved.