METHODS: A total of 3700 CBCT scans were screened, and 154 scans that met the inclusion and exclusion criteria were randomly selected. The scans were assessed using 3-dimensional multiplanar imaging for the following structures: the location of MF and the MC course, its intrabony location, and its relationship to the apices of the mandibular posterior teeth. The data were analysed statistically using SPSS software.
RESULTS: The MC ran lingually and inferiorly at the posterior region and became more buccal and superior towards the MF. The distal root of the mandibular second molar was found to be the closest root to the MC (2.06 ± 1.83 mm). Moreover, the most common location of the MF was distal to the contact area between the 2 premolars (0.83 ± 1.84 mm) with a significant negative correlation to age (with and increase in age, the MF moves distally). The distance between the root apices and the MC was statistically significantly affected by age (positive correlation) and gender (male patients had a greater distance).
CONCLUSIONS: The common course of the MC is lingual and inferior posteriorly and becomes more buccal and superior towards the MF, which is located mostly between the mandibular first and second premolars. Furthermore, the distal root of the mandibular second molar is the closest to the MC and has a positive relationship with age.
方法:共筛选了3700个CBCT扫描,随机选择符合纳入和排除标准的154次扫描.使用三维多平面成像对以下结构进行扫描评估:MF的位置和MC路线,它的骨内位置,及其与下颌后牙尖的关系。数据采用SPSS软件进行统计分析。
结果:MC在后部区域舌状和向下移动,变得更加颊状且向MF向上。发现下颌第二磨牙的远端根最接近MC(2.06±1.83mm)。此外,MF最常见的位置是2个前磨牙之间的接触区域(0.83±1.84mm)的远端,与年龄(随着年龄的增长,MF向远端移动)。根尖与MC之间的距离受年龄(正相关)和性别(男性患者的距离更大)的统计学影响。
结论:MC的常见过程是舌侧和向后下方,变得更加颊侧和向MF更优越,主要位于下颌第一和第二前磨牙之间。此外,下颌第二磨牙远根最接近MC,与年龄呈正相关。