A critical evaluation of epithelial dysplasia in oral mucosal lesions using the Smith-Pindborg method of standardization.

Standardization is one of the greatest problems in assessing epithelial dysplasia, as is establishing the relative importance of different clinical and dysplastic features. In this study, 214 cases characterized histologically by varying degrees of epithelial dysplasia, were analyzed for various clinical features: and representative sections were assessed histologically and graded according to the Smith-Pindborg standardized scoring system. Data were analyzed by computer. Seven cases with scores of less than 10 were excluded as not dysplastic. There were 85 cases (41%) with scores of 11-25 which were regarded as mild dysplasia; 60 (29%) with scores of 26-45 were regarded as moderate dysplasia; and 62 (30%) with scores of more than 45 which were reported as severe dysplasia. Peak frequency was in the 6th decade and the severe dysplasias were most frequent in the 8th decade. The M:F was 2:1. Tongue (58 cases), lower lip (36), floor of mouth (32) and cheeks (26) were sites most commonly involved. Of 107 cases, 93 were described as homogeneous leukoplakia, 11 as speckled leukoplakia and 3 as erythroplakia. The distribution of mild, moderate and severe dysplasias did not differ significantly by age, sex or race. Half of all cases involving floor of mouth and oropharynx were severely dysplastic, whereas most lesions occurring in cheek and alveolar mucosa/gingiva were mildly dysplastic; but differences were not significantly different. Severe grades of each dysplastic feature, as might be expected, occurred in lesions classified finally as 'severe dysplasia'.(ABSTRACT TRUNCATED AT 250 WORDS)