A Comparative Study on Chewing Movement in Normal Occlusion and Skeletal Class III Malocclusion

정상교합자와 골격성 III급 부정교합자의 저작운동형태의 비교

  • SUNG, Kee-Hyuk (Department of Orthodontics, School of Dentistry, Kyungpook National University) ;
  • SUNG, Jae-Hyun (Department of Orthodontics, School of Dentistry, Kyungpook National University)
  • 성기혁 (경북대학교 치과대학 교정학교실) ;
  • 성재현 (경북대학교 치과대학 교정학교실)
  • Published : 1997.10.01

Abstract

A comparative study was made on the chewing movements of normal occlusion and skeletal class m malocclusion. Thirty normal occlusion subjects and twenty skeletal class III malocclusion patients were given chewing gums for the study : using BioPAK system, the chewing movement on the frontal plane was recorded and analyzed. With a typical chewing path chosen representing each subject, chewing width, opening distance, opening and closing angles, maximum opening and closing velocities were observed. Seven characteristic patterns were classified based on the types of chewing paths. The followings are the results : 1. Compared with the normal occlusion group, the skeletal class III malocclusion group showed more varied and vertical chewing patterns. 2. In comparision of chewing widths, skeletal class m malocclusion group showed narrower path than the normal occlusion group(p<0.01). 3. In opening distance, skeletal class III malocclusion group appeared shorter than the normal occlusion group without statistical significance(p>0.05). 4. In opening and closing angles, skeletal class III malocclusion group showed more acute angles than the normal occlusion group(p<0.01). 5. In maximum opening and closing velocities, skeletal class III malocclusion group was slower than the normal occlusion group but with no statistical significance(P>0.05). 6. In the classification of chewing movement pattern, the normal occlusion group had Type II as the highest rate at 73.4% ; in skeletal class III malocclusion group, the highest rate was Type III at 35.0%, followed by Type II at 30.0% 7. In the classification of chewing movement pattern, Type IV(chopping type)of skeletal class III malocclusion group showed a higher rate with 25.0% over 3.3% of normal occlusion group.