Relationship between craniomandibular dysfunction and pattern of speech sound production in a series of first-graders.

This report investigates associations between prevalence of functional disturbances of the masticatory system and speech disorders. The subjects were 157 children referred for speech therapy to the hospital and a control group all 130 first-graders at two elementary schools, mean age 7 years 6 months. During clinical examinations, signs and symptoms of TMJ dysfunction were recorded by the same dentist. Articulatory speech disorders were diagnosed by the same phoniatrician using the Remes Articulatory Test (Remes, 1975) for the Finnish language. The results showed that in the hospital referral group the mean value for maximal opening was smaller while laterotrusion movements and maximal protrusion of the mandible were larger than in the control group. The study group also more often had CM disorders and occlusal interferences than children of the first grade sample. In the present data, a higher frequency of subjective symptoms and several clinical signs of CMD were related to certain articulatory speech disorders. Risk of having too anteriorly-produced sounds, mainly 's'-sounds, decreased with advancing age in 6-8-year-old children. In conclusion, expression of both craniomandibular disorder and disorders in speech sound production seem to a considerable extent to reflect immaturity of fine motor control of the orofacial muscles in 6-8-year-old children.