A series of clinical studies on squamous cell carcinoma of the lower alveolus and gingiva were performed in order to establish the method of accurate diagnosis and therapy. In this article, the results of clinical observations on primary lesion of thirty four cases which were treated surgically were discussed.
On the age range of the patients, sex distinction and the part of the primary lesion, the same results as described elsewhere were obtained. In the TNN1 classification, it was considered that definition of T4 case was not always clear, concerning with mandibular destruction. In this paper, we assumed the case, which invaded in the mandible including mandibular canal, as T4. However, much more discussions have to be made for the classification of T4 case.
In the relevance between T and N, the rate of clinically N positive case in each grade of T (T1-4) was 0, 60, 50, and 67 percent respectively. The grade of T was not always compatible with regional lymph node metastatic rate. Inspective type of the primary lesion was classified into two groups i. e. elevated type and ulcerated type. The former was subclassified as nodular type and cauliflower like type. The latter was subclassified as flat ulcer type,
crater type and cavein type. It was suggested that roentogenographic degree of mandibular resorption by carcinoma was not always compatible with the rate of regional lymph node metastasis. In the relevance between roentogenographic type of mandibular invasion by carcinoma and rate of regional lymph node metastasis, it was suggested that N positive percentage was more frequent in motheaten type than in erosive type.
