Abstract: Giant complex odontoma of the mandible is a relatively rare odontogenic tumor. This article reported the clinical diagnosis and treatment process of a 42-year-old male patient with a giant complex odontoma in the left mandible accompanied by infection, along with a discussion based on relevant literature. Complex odontomas typically were asymptomatic and grew slowly, but giant odontomas (diameter >3 cm) may cause tooth displacement, mandibular swelling, or even infection. The uniqueness of this case lies in the odontoma penetrating the oral mucosa, leading to localized infection, which increased the complexity of clinical management. Surgical excision was the primary treatment for giant odontomas, and cautions must be taken to avoid intraoperative damage to the inferior alveolar nerve and blood vessels, as well as postoperative mandibular fractures. The eruption mechanism of complex odontomas may be related to bone resorption or the pushing force of impacted teeth, though the exact mechanism requires further investigation. This case highlights that early diagnosis and precise surgical intervention for giant mandibular complex odontomas can effectively prevent infection and pathological fractures, thereby improving prognosis.

Key words: Odontogenic tumor, Complex odontoma, Mandible, Surgical removal