• mandibular invasion
• oral cavity cancer

Malignant tumors of the oral cavity, 95% of which are squamous cell carcinoma (OSCCs), account for approximately 30% of all head and neck cancers . Although oral OSCC represents 1-2% of all human malignancies , it is the sixth most common cancer worldwide, with more than 500,000 new cases diagnosed each year. The most common sites for OSCCs are the tongue and gingiva .
Carcinoma of the mandibular gingiva, in particular, is associated with bone invasiveness in many patients . Gingival SCC may eventually directly invade the mandible, a feature probably associated with a worse prognosis. According to the American Joint Committee on Cancer Classification, mandibular invasion is the most advanced primary stage (T4) and overall stage (IV) for these tumors. The 5-year survival of patients with stage IV oral lesions has been demonstrated to be 39%, as compared with 53, 68 and 70% for stages III, II and I, respectively .
The management of tumors invading the mandible has been controversial. with our study we aim to investigate the mechanisms of mandibular invasion and the prognostic and therapeutic invasion.