SỰ TĂNG TRƯỞNG CHIỀU RỘNG CUNG RĂNG Ở CÁC GIAI ĐOẠN CỦA TRẺ EM MƯỜNG TỪ 12 ĐẾN 14 TUỔI

Abstract

Objectives: To evaluate dental arch dimensional changes of Muong Vietnamese children. Material and methods: 678 dental casts were taken from 226 children of Muong ethnic group (107 males; 119 females) with parmanent dentition. Thesestudents were selected from secondary schools aged 12, according to the following criteria: Well-aligned upper and lower dental arches,parmanent dentition with 28 teeth, good facial symmetry and no previous orthodontic treatment. Dental arch dimensions were taken by one examiner using an electronic digital sliding caliper. The t-test was used to compare the dental arch dimensions ofthe subject groups.. Results: From 12 to 14 years of age, all maxillary arch widths of males and femalesincreased, the change ranged from 0.22mm to 1.34mm. This  change  was  statistically  significant  (p<0, 05) . The  widths  of the upper posterior arches of males(U66W increased by 0.67 mm, U77W increased by 1.34 mm) increased more than that of females(U66W increased by 0.42 mm, U77W also increased by 0.42 mm). Besides, the upper intercanine withs (U33W) of males (which saw anincrease of 0.42 mm) increased more slowly than that of thefemales (which increased by0.45 mm). The males' upper middle widths (U55W) (which increased by 0.34 mm) was greater than that of thefemales upper middle widths (increased by 0.23mm). At this stage, the widths of the lower arches of both males and females increased, the change ranged from 0.01 mm to 0.77 mm. This change was statistically significant (p<0, 05). the lower intercanine withs (L33W) and the lower inter-second premolar withs of males(increasedby 0.03 and 0.01mm) increased more slowly than that of the females (increased by 0.11 and 0.08 mm). The lower posterior arch widths (L66W, L77W) of malesincreased more than that of females. Conclusions: The trend as well as the growth rate of the dental arches of Muong children between the ages of 12 and 14 has been determined.