Longitudinal study of functional conditions in the masticatory system in Flemish children.

A 5-yr longitudinal study on occlusal and functional parameters has been made in 75 children aged 8-11. They were selected at random from an original group of 510 studied 5 yr earlier. The following parameters were measured: frequency of frontal open bite lateral and frontal crossbite, the attrition on molars and on front teeth, the contacts on lateral excursion, pain on condyle palpation, TMJ clicking, deviations in the opening and lateral movement, and the maximal interincisal distance. There was an increase in the percentage of deep bite and crossbite. Attrition on molars was seen in 41% and on front teeth in 13% of the children. No real pattern could be observed as a function of age. The mean maximal opening range was 43.7 mm, varying between 23 and 52 mm. Restricted opening was found in one girl. In 60% a deviation in the opening has been found. In 26% TMJ sounds were observed and 28% had pain on condyle palpation. In most of the children the symptoms were very mild to moderate. No significant correlation could be found between dysfunctional signs and occlusal parameters. The present results did not provide any conclusive answer to the tremendous increase in dysfunctional signs over this 5-yr period. The treatment need is, however, low and should not be overestimated.