[Effect of skeletal Class III malocclusion on speech articulation].

The purpose of this study was to investigate the effects of skeletal class III malocclusion on speech articulation. The subject was twenty skeletal class III malocclusion adults. Their articulations were evaluated by phoneticians and the disordered speech sounds were analysed by computerized speech lab. It was manifested that most of the adults had misarticulations, the most common speech sound errors were consonants (zh, ch, sh, z) and the types of errors were distortion and substitution. Compared with the normal consonants acoustic analysis of the disordered ones showed that, the lower boundary frequency got down, spectrum distribution in frequency became widen, as well as the lower frequency components were enhanced. The results suggested that skeletal class III malocclusion may cause deficiency in speech production. The improvement of speech articulation should be considered when the severe skeletal discrepancy was corrected by surgical-orthodontic treatment.