The volition concerning tooth cleaning influences the effect on tooth brushing for children. This study was conducted to evaluate the relationship between the willingness and the effect of the tooth brushing, and as well as the effectiveness of the progressive method on the physically handicapped children. The progressive method with social reinforcements for the group instruction was once used in the Boy Scout League and is now employed for the education of handicapped children. The subjects were 50 physically handicapped children from 5 to 20 year of age: 37 with cerebral palsy (11 of the athetose type and 26 of the spastic type) and 13 with various other diseases. They were divided into the independent group of 26 patients acting on selfreliance and the dependent group of the 24 patients with nursing assistance. In the progressive method the official announcemence and the giving of medalls were taken as the social reinforcement and the reward. Before beginning the 3 months session, the plaque index (PIa)was checked and 10 cases with a good oral hygien condition were announced and after 3 months the plaque index (PIb) and the gingival index (GI) were checked.
The following results were obtained:
1) In the independent group, the average PI decreased remarkably from 0.79to 0.64 (p<0.01). The result proves that social reinforcement is a valiable method for the instruction of the tooth-brushing for the physically handicapped.
2) For both the dependent and the independent group, there were no remarkable differences concerning the GI.
3) There was no relationship between the types of cerebral palsy and the alteration of the average of PI.
4) PIb corelates with IQ and SQ (p<0.05). This suggests that the deterioration of adaptionability to social life trends to show a poor PI.