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

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

• Lee CH
• Mo SS
• Kang YG
• Nojima K
• Kim YH
• Kook YA

Abstract

OBJECTIVE
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.
METHODS
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.
RESULTS
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.
CONCLUSIONS
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.

Keyword

Dental arch form; Malocclusion; Classification of dental arch form

MeSH Terms

Asian Continental Ancestry Group*
Dental Arch
Ethnic Groups
Female
Humans
Male
Malocclusion*
Tooth