Investigations on prevalence and treatment of fingernail biting.

Numerous investigations indicate that there is a parallel between emotional stress and hyperactivity of the masticatory muscles connected with mandibular parafunctions. Elimination of mandibular parafunctions is difficult and almost impossible, therefore, this paper proposed a treatment whereby nonharmful motor habits are substituted for the parafunction. Questionnaire investigations were carried out in 2905 subjects, with an attempt at treatment in the youngest group of 222 pupils. It was found that good results were obtained through adult supervision and cooperation.