A longitudinal study on malocclusion in relation to signs and symptoms of cranio-mandibular disorders in children and adolescents.

Two-hundred-and-thirty-eight subjects in three different age-groups (7, 11, and 15 years) were followed over a period of 4-5 years in respect of morphological malocclusions, and signs and symptoms of functional disturbances. About half of the 7-year-olds had at least one of the morphological malocclusions registered while the corresponding figure was 38 per cent at the age of 20. Some subjects had received corrective orthodontic treatment. When compared with subjects without such treatment, there were no differences in prevalences of occlusal interferences, nor in signs or symptoms of craniomandibular disorders (CMD). The associations between CMD and different morphological malocclusions were low. Nevertheless, some malocclusions were found to be more important than others. In a long-term perspective cross-bite, both uni- and bilateral, anterior open bite, post-, and prenormal occlusion had some association with the development of CMD.