ABSTRACT
OBJECTIVE: The purpose of this study was to evaluate morphologic differences in the mandibular arch between Egyptian and Korean subjects. METHODS: The Egyptian sample consisted of 94 mandibular casts (35 Class I, 32 Class II and 27 Class III). The Korean sample consisted of 462 mandibular casts (114 Class I, 119 Class II, and 135 Class III). The most facial portion of 13 proximal contact areas was digitized from photocopied images of the mandibular dental arches. Clinical bracket points were calculated for each tooth. The subjects were grouped according to arch form to compare the frequency distribution of the 3 arch forms between the ethnic groups in each Angle classification. RESULTS: Egyptians had significantly narrower intermolar and intercanine widths (p < 0.001), and shallower intermolar and intercanine depths (p < 0.001) than Koreans. There was an even frequency distribution of the 3 arch forms within the Egyptian group (p = 0.46). However, in the Korean group, the most frequent arch form was the square arch form (46.7%), while the frequency of the tapered arch form was significantly lower (18.8%). CONCLUSIONS: These results might provide helpful information in evaluating morphologic differences between ethnic groups in selection of preformed superelastic archwires.