Parental control of nocturnal thumbsucking.

This study evaluates two procedures for the elimination of nocturnal thumbsucking in a 10-yr-old boy. The subject's mother recorded the occurrence of thumbsucking four times each night. Reliability checks were done twice a week by another family member. A plastic splint, usually employed to protect a damaged thumb, was placed on the subject's thumb at bedtime. The results showed that when the splint was used, the incidence of thumbsucking decreased from 100% of the checks made during baseline to 0% during intervention. Several naturally occurring and one planned reversal demonstrated the effectiveness of the splint in controlling thumbsucking.