Changes in function of the masticatory system from 7 to 10 years of age in relation to articulatory speech disorders.

The aim of the present study was to determine changes in function of the masticatory system in children with articulatory speech disorders and in the controls by re-examining a sample of 287 previously studied children from 7 to 10 years of age. Articulatory speech disorders were diagnosed by the same speech therapist during spontaneous speech and test words using the Remes Articulation Test. Mandibular movement capacity, occlusal interferences, slide between retruded and intercuspal positions, and signs and symptoms of the craniomandibular disorders (CMD) were recorded by a dentist. The follow-up results showed that mandibular movement capacity increased in almost all individuals, decreasing only in about 10% of cases. However, among children with speech disorders lateral jaw movements decreased in about 30% of subjects. During growth the prevalence of CMD increased while single signs and symptoms fluctuated. Differences between the groups for expression of CMD, mandibular movement capacity and occlusal recordings mainly levelled off. Higher constancy of subjective symptoms and retrusive interferences in children with speech disorders than in the controls supports our previous findings that, in growing individuals, different orofacial dysfunctions seem to be associated with each other.