One hundred two patients (115 lesions) with oral leukoplakia were studied and followed up for an average period of 6 years 2 months. Of all cases, 38 showed an abnormal epithelium with no dysplasia and the 77 others showed some degree of epithelial dysplasia. The grade of epithelial dysplasia was thought to be related to the following changes in the WHO criteria (1978).
·loss of polarity of the basal cells.
·the presence of more than one layer of cells having a basaloid appearance.
·dro P-shaped rate processes.
·irregular epithelial stratification.
·nuclear hyperchromatism.
Epithelial dysplasia or high mean scores based on the new scoring system for dysplastic changes were found in the following types of patients: Site: tongue (lateral borders, inferior surface), floor of the mouth. Age: fourth and fifth decades of life. Clinical type: leukoplakia erosiva. Habits: drinkers or drinkers and smokers. Three patients subsequently developed squamous carcinomas in an average time of 5 years 9 months, and these patients originally had moderate to severe epithelial dysplasia.
The cumulative frequency of oral carcinoma in cases of oral leukoplakia was 0 % by 1 and 3 years, 1.2 % by 5 years, and 6.6 % by 10 years. This study suggests that certain of the characteristics of oral leukoplakia described above are associated with greater risks of malignant transformation, and thereby warrant consideration for more aggressive management.
