CBCT imaging analysis of three-rooted mandibular molars in children
Objective:To investigate the occurrence rate and distribution pattern of three-rooted mandibular molars in children using CBCT.Methods:CBCT images of 206 children aged 4-11 years were retrospectively analyzed.The root numbers of the bilateral man-dibular first and second deciduous molars,and the permanent mandibular first molars were recorded.A chi-square test was used to de-tect the gender and side difference.Spearman correlation test was used to analyze the relation between the bilateral homologous teeth and the mandibular first and second deciduous molars on each side.Results:The occurrence rate of three-rooted mandibular first and second deciduous molars and mandibular permanent first molars was 10.9％(19/175),25.1％(46/183)and 28.4％(57/201)for individuals,respectively(x2=18.543,P＜0.01),and 8.7％(32/366),19.0％(73/384)and 23.6％(95/402)for teeth(x2=30.692,P＜0.01),re-spectively.Gender difference was not detected for each tooth type(all P＞0.05),while side differences were detected in mandibular sec-ond deciduous molars and the frequency of three-rooted molar on the right and left side was 23.7％and 14.2％(P＜0.05),respectively.The concurrence rate of bilateral three-rooted mandibular deciduous first and second molars and mandibular permanent first molars was 57.9％(11/19),47.8％(22/46)and 66.7％(38/57),respectively,and the rho was 0.710,0.597 and 0.745,respectively(all P＜0.01);between the three-rooted deciduous first and second molars on the left side,rho=0.188(P＜0.05)and on the right side,rho=0.304(P＜0.01).Conclusion:The occurrence rate of three-rooted mandibular molars in children increases in the following sequence:first deciduous molars＜second deciduous molars＜first permanent molars.They frequently occur bilaterally and exhibit a moderate to high degree of correlation.However,the correlation was very weak between the mandibular deciduous first and second molars.
NETL
NSTL
万方数据
