Mandibular involvement by oral squamous cell carcinoma.

Detecting mandibular bone involvement by oral carcinoma prior to definitive therapy poses a difficult problem for the head and neck surgeon. A retrospective study of 104 patients who underwent segmental mandibular resection for oral squamous cell carcinoma was undertaken to detect the incidence of mandibular bone involvement. Specimens from 23 patients (22%) demonstrated tumor invasion on decalcified histologic examination. Histologic evidence of bone involvement was correlated with the site of lesion, stage of the disease, the grade of tumor, the clinical impression of bone involvement, and the presence or absence of neck disease. Bone invasion on histologic examination was also compared with preoperative bone scans and radiographs. The data obtained demonstrates significant mandibular involvement with alveolar tumors and lesions clinically adjacent to the mandible. There was also a high incidence of histologic bone involvement in patients who had radiologic or bone scan evidence of tumor erosion. We support segmental mandibulectomy on the basis of providing adequate tumor margins for patients fulfilling these criteria.