Korean J Orthod.  2007 Oct;37(5):364-375.

Comparison of arch forms between Korean and Japanese in Class I, II, and III malocclusion

  • 1Department of Orthodontics, Graduate School of Clinical Dental Science, The Catholic University of Korea. kook190036@yahoo.com
  • 2Department of Orthodontics, Tokyo Dental College.
  • 3Department of Orthodontics, The Institute of Oral Health & Science, Samsung Medical Center, Sungkyunkwan University School of Medicine.


The purpose of this study was to compare arch dimensions and frequency distribution of arch forms between Korean and Japanese Class I, II, and III malocclusion groups.
The sample consisted of 368 Korean cases (114 Class I, 119 Class II, and 135 Class III malocclusion) and 160 Japanese cases (60 Class I, 50 Class II, and 50 Class III malocclusion). The most facial portion of 13 proximal contact areas was digitized from photocopied images of the mandibular dental arches. Clinical bracket slot points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. Measurements are statistically analyzed in each malocclusion group. The dental arches were classified into square, ovoid, and tapered forms to determine and compare the frequency distributions between the two ethnic groups.
The findings of this study showed that Japanese females in Class I and II groups had a statistically significant narrower mandibular dental arch width compared with the Japanese males, Korean males and Korean females. But in the Class III group, there was no significant difference in the mandibular dental arch size according to the two ethnic groups and genders.
The majority of Koreans and Japanese in all the malocclusion groups exhibited square and ovoid arch forms. The most frequent arch forms found in Koreans was square but ovoid for Japanese.


Dental arch form; Malocclusion; Classification of dental arch form
Full Text Links
  • KJOD
export Copy
  • Twitter
  • Facebook
Similar articles
Copyright © 2021 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr