CBCT observation of root morphology and incidence of the second root in maxillary second permanent molars

WU Zhou; YIN Jian; DING Fang

doi:10.19749/j.cn.cjgd.1672-2973.2024.02.005

Abstract：Objective To observe the root morphology and root canal number of maxillary second molars by CBCT image interpretation,and to explore the incidence of MB2 and its ageing changes in maxillary second molars.Methods The CBCT of patients who visited Beijing Anzhen Hospital from September 2021 to June 2022 were collected,divided into two groups according to age at the age of 60 years,.The root number,root morphology,root canal number and root canal morphology of maxillary second molar were observed,and the proximal buccal root canal was classified according to Vertucci root canal classification.the distance between near buccal root MB and palatine root P,near buccal root second canal MB2 and palatal root P was measured.The angle between the MB-P and MB-MB2 lines is α,and the distance l from the root canal mouth to the first root canal bifurcation.The chi-square test and t-test were used to statistically analyze the two sets of data.Results Among the 137 maxillary second permanent molars(70 in young and middle-aged group and 67 in elderly group),93(67.88％)had ordinary three-root morphology,and the remaining 44(32.12％)had other root morphologies.41 teeth had MB2(29.93％)(20 in young and middle-aged group(28.57％)and 21 in elderly group(31.34％)).There was no significant difference in the incidence of MB2 between the two groups(P＞0.05),and there was no significant difference in the incidence of MB2 between different tooth positions and genders(P＞0.05).In the teeth with MB2,type Ⅱ(2-1 type)root canal was the most common in the two groups.There was no significant difference in the MB-P distance,MB2-P distance,MB-MB2 distance,and the angle α between the two groups(P＞0.05).The length l averages 2.6 mm.Conclusion The incidence of MB2 in elderly patients is no different from that in young and middle-aged patients.MB2 should be carefully sought in the treatment to improve the success rate of root canal treatment.