Development of the analyzing system for oral function

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 10671919
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 矯正・小児・社会系歯学
• Research Institution: HOKKAIDO UNIVERSITY
• Principal Investigator: YAMAMOTO Takashi Hokkaido Univ., Dental Hp., Lec., 歯学部・付属病院, 講師 (40230560)
• Co-Investigator(Kenkyū-buntansha): IFUKUBE Tohru Hokkaido Univ., Research Inst. For Elec. Sci., Pro., 電子科学研究所, 教授 (70002102) ; UMEDA Kazuhiro Hokkaido Univ., Dental Hp., Inst., 歯学部・付属病院, 助手 (80271691) ; IMAI Tohru Hokkaido Univ., School of Dent., Asso. Pro., 歯学部, 助教授 (40160030) ; NAKAMURA Shinji Hokkaido Univ., School of Dent., Pro., 歯学部, 名誉教授 (80001791)
• Project Period (FY): 1998 – 1999
• Keywords: Skeletal malocclusion / Oral disfunction / Tongue movement / Acoustic characteristic

Research Abstract

We have developed a 3D tongue movement measuring sysytem employing an electromagnetic sensing system that, uses five small and lightweight coils. This system was used to measure and compare tongue movements in normal subjects and in skeletal Class III subjects during articuration of five Japanese vowel (/a/, /I/, /u/, /e/ and /o/) sounds. The subject sat in a relaxed postsure on a chair, and the subject's head was positioned so that the Frankfurt horizontal plane and floor were approximately parallel. Before commencing the experiment, the subject was given sufficient practice at pronouncing vowel sounds with measurement device in place. The vowel sounds were acoustieally analyzed to investigate the acoustic characteristics. The subjects included three normal subjects (3 males) who had no impairments in hearing or articulation and three skeletal Class III subjects (3 females).
The following results were obtained. 1) The distances between two vowels in the skeletal Class III patients: wer e greater in the antero-posterior direction but smaller in the vertical direction compared to those in the normal subjects. 2) The distances between the vowel and rest position in the skeletal Class III patients were greater than those in the normal subjects. 3) The distances between two vowels were smaller in the lateral direction than in the antero-posterior direction and in the vertical direction. 4) The frequency distribution of the first formant frequency and the second frequency of five vowels in the skeletal Class III subjects were narrower than that in the normal subjects. The results of this study suggest that the movement range of the tongne during speech production in skeletal Class III patients is smaller in the vertical direction and larger in the antero-posterior direction compared to that in normal people. The areas of the point of articulation of the five vowels in the skeletal Class III patients were narrower than those in normal people in the vertical and antero-posterior direction.