There had been some arguments and differences of opinion on the T4 criteria for the T classification in lower gingival carcinomas. Japan Society for Oral Tumors held a workshop for this problem at the 11th general meeting in 1993, and it was concluded after several years' investigation that the level of mandibular canal ( LMC ) criteria was the most appropriate criteria. In the meantime, clinical records of lower gingival carcinomas were registered from the 24 national facilities that agreed to collaborate. The details of these cases were statistically analyzed on the basis of 1187 cases registered as lower gingival carcinomas. Multivariate analyses such as mathematical quantification method II and logistic regression analysis were applied to the materials including method of therapy and treatment outcome, and relative risk of local recurrence of carcinomas was estimated. In the surgical treatment of lower gingival carcinomas it is critical whether marginal resection is enough or further surgery including segmental resection is appropriate. A guideline for mandiblectomy in primary site surgery, which recommended combining LMC criteria and bone invasion pattern, was proposed. In brief, marginal mandiblectomy or less surgery is a treatment choice for T1 tumor and segmental mandiblectomy or further surgery is recommended for T4 tumor. Marginal mandiblectomy is adequate for T2, T3 tumors with no bone invasion or pressure type bone invasion, on the other hand, segmental mandiblectomy is recommended for T2, T3 tumors with moth-eaten type bone invasion.

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Chemoradiation, targeted intraarterial infusion of Carboplatin (CBDCA) plus irradiation, was performed in patients with oral squamous cell carcinoma (Oral SCC) . Forty-three patients with Oral SCC were analyzed in terms of the expression of side effects. Dose of CBDCA was determined by Calvert's formula (AUC 4.5) . Total dose of radiation was 30 Gy, which consisted of 2 Gy/day 5 times per week, or 1.5 Gy twice a day 5 times per week. The patients were 33 males and 10 females, ranging between 30 and 86 years of age. The total dose of CBDCA ranged from 260mg to 740mg. Allopurinol gargle or poraprezinc-sodium alginate suspension was applied to prevent radiation and/or chemotherapy induced stomatitis, and Ancer 20 injection was administered by subcutaneous injection. Most patients had erythrocytopenia, leukocytopenia, thrombocytopenia, dermatitis and stomatitis. Especially, stomatitis was recognized in all patients. According to WHO criteria, 6 cases had grade 3 stomatitis, and only one case had stopped X-ray irradiation because of severe stomatitis.

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Objective: To clarify the correlation between the morphological CT pattern and histopathologic features in adenoid cystic carcinoma (ACC) of the head and neck region.
Study Design: CT images of 15 patients with ACC in the head and neck region were evaluated concerning the morphological tumor-growth pattern. The growth pattern of ACC on the CT was classified into a well-defined massive (M) type and a diffuse invasive (I) type. Positive tumor cells at the surgical margin, a neural invasion, and a vascular invasion were assessed with a hematoxylin-eosin stained preparation of the surgical specimen. The histopathologic subtype was classified into the tubular, the cribriform, and the solid type. The relationship between the CT pattern and the histopathologic features was analyzed.
Results: The M type was predominant in the cribriform type, but in contrast, the I type was predominant in the solid type. However, the tubular type was dominant in both the M type and the I type, and thus, there was no definite association between the CT pattern and histopathologic subtype. There was no definite association between the CT pattern and the outcome.
Conclusion: There was no definite association between the morphological tumor-growth CT pattern and histopathologic features in ACC of the head and neck region. Both the M type and the I type based on the CT frequently showed infiltrations into the surrounding parenchymal tissue beyond the field that was predicted as the tumor extent based on the CT.

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Reconstruction of segmentally resected mandible using nonvascularized autogenous iliac bone secured with A-O reconstruction plate was performed in 26 patients. Primary reconstruction was performed in 12 patients, and secondary reconstruction in 14 patients. Grafted bone was bicortical, containing the outer and inner plates of the iliac crest, in 22 patients and was monocortical, containing the inner plate, in 4 patients. The sizes of the grafted bones ranged from 3.2cm to 13.0cm in length and from 1.0cm to 2.5cm in height. The follow-up period ranged from 1 year 8 months to 18 years 10 months. Resorption of bone height in the grafted region was calculated using panoramic radiographs based on the size of the reconstruction plate. The average resorption rate was 13.0% of the original height in the bicortical grafts and 26.2% in the monocortical grafts. Reconstruction plates were removed at about 1 year postgraf ting in most patients. Resorption of the grafted bone occurred during the 1-year fixation period. Prolonged fixation did not, however, affect the resorption rate, except in the patient who received the longest graft (13.0cm) in this series. For the bicortical grafts, resorption rate showed no significant difference between primary and secondary reconstruction. The postsurgical complications were nonunion in 2 patients, fracture in 2 patients and infection in 3 patients including total removal in 1 patient. Bicortical grafts shorter than 9 cm are recommended, irrespective of the timing of reconstruction.

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