A survey of craniomandibular disorders in 500 19-year-olds.

This study examines the development of signs and symptoms of craniomandibular disorders (CMD), and some effects of orthodontic treatment from the age of 12-19 years of age. The data is drawn from a special sample of adolescents recruited at 11 years of age by random stratified sampling to contain a high prevalence of malocclusions of particular orthodontic interest. The sample does not reflect malocclusion in a normal population. The prevalence of frequent headache and TMJ disorders shows a major increase from 12 to 15 years of age. From 15 to 19 years of age, there is some increase in the prevalence of TMJ disorders in girls, but altogether the prevalence of signs and symptoms of CMD is much more stable. When the data from subjects who received orthodontic treatment were compared with data from subjects who had not received orthodontic treatment, only small differences were found.