Abstract

The purpose of the study was to investigate the characteristics of the pronunciation of Korean vowels in patients with class Ⅲ malocclusion. 11 adult male patients with class Ⅲ malocclusion(mean ages 22.3 years) and four adult males with normal occlusion(mean ages 26.5 years) were selected for the analysis of eight Korean monophthongs /ㅣ, ㅔ, ㅐ, ㅏ, ㅓ, ㅗ, ㅡ, ㅜ/. The values and relationships of F1, F2 and F3 were derived from the stable section of target vowel in each sentence, and the analysis using formant plots and vowel triangles' distance and area was conducted to find the features of two groups' vowel distributions. Consequently, it was identified that the pronunciation of males patients with class Ⅲ malocclusion showed high values of F1 in the low vowels, high values of F2 in the back vowels, and remarkably low position of /ㅏ/. The vowel triangle suggested that the triangle areas of male patients with class Ⅲ malocclusion were shown wider vertically and narrower horizontally than those of males with normal occlusion. These characteristics could reflect the structural features of class Ⅲ malocclusion such as the prognathic mandible, low tongue position, and advancement of back position of the tongue.