Peripheral Osteoma on the Medial Surface of the Mandibular Ramus: A Case Report.

Peripheral osteomas are uncommon benign osteogenic lesions that arise from the periosteum, with the lingual mandibular surface being a recognized site. However, solitary pedunculated lesions at the posterior medial ramus-body junction are rare. This case report describes a 34-year-old man who presented with mild, intermittent dull pain in the right posterior mandible, exacerbated by mastication for three months, without swelling or paresthesia. Clinical examination revealed tenderness near the ramus-body junction. Cone-beam computed tomography (CBCT) demonstrated a well-circumscribed, pedunculated radiopaque mass (1.5 cm) with a homogeneous bone-like density attached via a narrow stalk to the medial surface of the right mandibular ramus-body junction, with an intact surrounding cortex and no periosteal reaction. Surgical excision via an extraoral submandibular approach allowed optimal visualization and safe en bloc removal. Histopathological examination confirmed the presence of mature lamellar bone with Haversian systems and a thin fibrous periosteal covering, lacking cellular atypia or cartilaginous elements, which is diagnostic of compact-type peripheral osteoma. Postoperative recovery was uneventful, with complete pain resolution and no recurrence at six-month follow-up. This case highlights the value of CBCT in preoperative planning and the efficacy of conservative surgical excision of symptomatic peripheral osteomas in anatomically challenging posterior mandibular locations.