PURPOSE: The study goal was to investigate the adequacy of marginal resection of the mandibular bone in cases of squamous cell carcinomas of the lower alveolus and gingiva where the radiologically detected bone defect does not extend beyond the mandibular canal. PATIENTS AND METHODS: Sixty-two patients who have had a mandibulectomy performed with or without preoperative radiotherapy and chemotherapy were the study subjects. This retrospective study investigated the correlation between the preoperative radiographic appearance and histopathologic findings of the excised tissue. The results of the treatments were evaluated. RESULTS: In the cases with erosive bone defects, the extent of the bone involvement did not exceed the extent of the radiographically detected bone defects. However, in 7 (36.8%) of the cases with moth-eaten type bone defects, the extent of bone involvement exceeded the bone defects detected by radiography. Further, 10 of the 16 cases with no apparent bone defect showed apparent bone involvement by the tumors histologically. There were no differences in the 5-year cumulative survival rate between the marginal resection and segmental groups. CONCLUSIONS: Marginal resection was effective in controlling mandibular alveolus and gingival cancers when radiologically detected erosive bone defects did not extend beyond the mandibular canal. Marginal resection was inadequate when moth-eaten defects were radiologically detected, except when the bone defects were confined to the alveolar bone.
PURPOSE: The study goal was to investigate the adequacy of marginal resection of the mandibular bone in cases of squamous cell carcinomas of the lower alveolus and gingiva where the radiologically detected bone defect does not extend beyond the mandibular canal. PATIENTS AND METHODS: Sixty-two patients who have had a mandibulectomy performed with or without preoperative radiotherapy and chemotherapy were the study subjects. This retrospective study investigated the correlation between the preoperative radiographic appearance and histopathologic findings of the excised tissue. The results of the treatments were evaluated. RESULTS: In the cases with erosive bone defects, the extent of the bone involvement did not exceed the extent of the radiographically detected bone defects. However, in 7 (36.8%) of the cases with moth-eaten type bone defects, the extent of bone involvement exceeded the bone defects detected by radiography. Further, 10 of the 16 cases with no apparent bone defect showed apparent bone involvement by the tumors histologically. There were no differences in the 5-year cumulative survival rate between the marginal resection and segmental groups. CONCLUSIONS: Marginal resection was effective in controlling mandibular alveolus and gingival cancers when radiologically detected erosive bone defects did not extend beyond the mandibular canal. Marginal resection was inadequate when moth-eaten defects were radiologically detected, except when the bone defects were confined to the alveolar bone.