Mandibular movement capacity in 19-year-olds with and without articulatory speech disorders.

Associations between articulatory speech disorders and mandibular movement capacity, as well as between malocclusions and jaw movements, were examined in two groups of adolescents, i.e. 52 individuals with and 45 without misarticulations of speech. The mean age of the whole sample was 19.2 years. Articulatory speech disorders and functioning of the speech articulators were diagnosed by a phoniatrician. Mandibular movement capacity, malocclusions, occlusal interferences, and signs of temporomandibular dysfunction were recorded by an orthodontist. Multiple regression analyses showed that subjects with articulatory speech disorders were likely to have smaller opening capacity than subjects with a correct speech articulation. Excessive overjet, lateral cross bite, and a tendency to anterior open bite were associated with large movements of the jaw. These results suggest that in young adulthood mandibular movement capacity seems to vary depending on occlusion and is related to misarticulations of speech.