Follow-up studies in oral leukoplakia.

Of the precancerous conditions of the mouth, leukoplakia is the most common, and it was considered likely that the long-term follow-up of patients would yield valuable information for the control and treatment of the condition.A study of the histories of 324 patients, in whom leukoplakia had been diagnosed sometime during the previous 23 years, showed that there was a relationship between smoking and the frequency of leukoplakia. Alcohol, mechanical irritants and electric potential difference in the mouth were also important etiological factors, particularly in combination. Many of the cases with mild symptoms improved when the etiological agent was removed.The cases were classified into groups according to whether there were signs of keratinized mucosa, verrucous proliferations or ulcerated white lesions. The more severe cases more frequently developed carcinomas and were treated by surgery.