TƯƠNG QUAN GIỮA CHỈ SỐ BOLTON VÀ TÌNH TRẠNG SAI LỆCH KHỚP CẮN, HÌNH DẠNG CUNG RĂNG Ở NGƯỜI TRƯỞNG THÀNH DÂN TỘC MƯỜNG TỪ 18-30 TUỔI

Abstract

Objective: Determine the Bolton index of adult Muong people aged 18–30 in selected communes of Ninh Binh Province, Vietnam, in 2025. Subject and methods: A cross-sectional descriptive study was conducted on 247 Muong ethnic individuals aged 18–30 years, including 116 males and 131 females, using an intraoral scanner to examine the dental arches and measure the dimensions of permanent teeth in the maxillary and mandibular arches. Results: The total mesiodistal width of the six anterior mandibular teeth was 36,46 ± 1,81 mm while that of the six anterior maxillary teeth was 47,23 ± 2,12 mm; the twelve mandibular teeth was 88,42 ± 3,24 mm and 96,29 ± 3,41 mm for the twelve maxillary teeth. The anterior ratio (AR) according to Angle’s malocclusion Class I, II, and III was 78,29 ± 1,68%; 78,10 ± 1,67% and 78,63 ± 1,79% respectively. The overall ratio (OR) for Class I, II, and III malocclusions was 91,70 ± 1,89%; 91,30 ± 1,76% and 92,24 ± 1,90% respectively. With regard to arch form, the AR for oval, square, and tapered arch types was 78,52 ± 1,75%; 78,53 ± 1,69% and 78,15 ± 1,64% respectively; and the corresponding OR values were 91,89 ± 2,01%; 92,11 ± 1,96% and 91,44 ± 1,94% respectively. Conclusions: There was no significant difference in Bolton's anterior ratio (AR) and overall ratio (OR) between male and female adult Muong individuals. A statistically significant difference was found in the OR among Angle’s malocclusion groups, with Class III subjects exhibiting a higher OR compared to Class I and II. However, no significant difference in AR was observed among the malocclusion types. Additionally, Bolton's ratios showed no significant differences across different arch forms or between Muong and Kinh ethnic groups.