华南地区成人上颌中切牙与牙槽骨相对位置关系CBCT分析

CBCT analysis of the relative position between maxillary central incisors and alveolar bone in Southern Chinese adults

摘要

目的 探究华南地区成人上颌中切牙在牙槽骨中的位置及其骨壁厚度特征，为上颌中切牙即刻种植术前设计提供临床参考。方法 获得医院伦理委员会审批及患者知情同意，采集2018年1月至2021年12月，南方医科大学口腔医院就诊的990例华南地区成人健康上颌中切牙患者的口腔锥形束CT（cone beam computer tomography，CBCT）影像，按性别和年龄分组。从CBCT影像中，确定适宜矢状面和标志点，分析牙根在牙槽骨位置关系，测量釉牙骨质界（cementoenamel junction，CEJ）下4 mm、根中处和根尖处的唇侧及腭侧骨壁厚度，同时测量牙长轴与牙槽骨长轴夹角。比较不同性别组唇腭侧骨壁厚度，比较不同性别组及年龄组（20 ~ 39岁；40 ~ 59岁；60~79岁）牙齿长轴与牙槽骨长轴夹角关系。结果 华南地区成人上颌中切牙矢状面牙根在牙槽骨的唇腭侧位置关系存在显著差异，其中根尖在牙槽骨唇侧1/3处占比为95.8%（948/990），根尖在牙槽骨中1/3处的占比为4.1%（41/990），根尖在牙槽骨腭侧1/3处占比为0.1%（1/990）；腭侧CEJ下4 mm、根中、根尖处骨壁厚度为（1.82 ± 0.56）mm、（3.20 ± 1.10）mm、（7.70 ± 2.00）mm，均大于唇侧的（1.21 ± 0.32）mm、（0.89 ± 0.35）mm、（1.86 ± 0.82）mm，差异有统计学意义（P<0.05）；男性骨壁厚度普遍大于女性（P<0.05）；男性牙与牙槽骨长轴夹角为14.77° ± 5.66°，女性为12.80° ± 5.70°，差异有统计学意义（P<0.05）；40~59岁组和60~79岁组牙与牙槽骨长轴夹角均大于20~39岁组，差异有统计学意义（P<0.05）。结论 95.8%的华南地区成人上颌中切牙的牙根偏向唇侧骨壁，根尖处腭侧骨厚度大于唇侧；所测位点中，根中处唇侧骨壁厚度最小。华南地区成人中男性上中切牙与牙槽骨长轴夹角大于女性，且夹角随年龄增长而增大。上颌中切牙即刻种植术前需关注根周骨壁厚度和牙根与牙槽骨长轴夹角大小，合理选择种植方案。

Abstract

Objective Exploring the position and bone wall thickness characteristics of the maxillary central incisors in Southern Chinese adults to provide a clinical reference for the design of immediate maxillary central incisor implantation surgery. Methods The hospital ethics committee approved the study, and the patients provided informed consent. CBCT images of 990 adult patients (aged 20-79 years) from the Stomatology Hospital (January 2018 to December 2021) were categorized based on the dental arch form and age-sex groups. Sagittal CBCT images of the maxillary central incisors were used to measure the labial and palatal bone thickness wall at 4 mm the CEJ to apical, the middle of the root, and the angle between the tooth long axis and the long axis of the alveolar process, to compare the thickness of the labial and palatal bone walls in samples of male and female patients, and to explore the relationship between the angle between the tooth long axis and the alveolar process long axis in samples of male and female patients in different age groups (20-39 years; 40-59 years; 60-79 years). Results Significant differences were found in the labiopalatine side of the alveolar bone of the maxillary incisor root position. A total of 95.8% (948/990) of the maxillary incisors were positioned more buccally, 4.1% (41/990) were positioned more midway, and 0.1% (1/990) were positioned more palatally. The thicknesses of the bone wall at the CEJ of 4 mm below the palatal side, the middle of the root, and at the apex were greater (1.82 ± 0.56 mm, 3.20 ± 1.10 mm, and 7.70 ± 2.00 mm, respectively) than those at the labial side (1.21 ± 0.32 mm, 0.89 ± 0.35 mm, and 1.86 ± 0.82 mm, respectively), with statistical significance (P<0.05). Male bone wall thickness was generally greater than female bone wall thickness (P<0.05). The angle between the long axis of male teeth and the alveolar bone was 14.77° ± 5.66°, while that of female teeth was 12.80° ± 5.70°, with a statistically significant difference (P<0.05). The angle between the long axis of teeth and the alveolar bone in the 40-59-year-old group and the 60-79-year-old group was greater than that in the 20-39-year-old group, and the difference was statistically significant (P<0.05). Conclusion A total of 95.8% of adults in South China have maxillary central incisors with root deviation toward the labial bone cortex. The thickness of the labial bone wall is much thinner than that of the labial bone wall, which is the middle of the thickness of the root. In Southern Chinese adults, the angle between the upper central incisor and the long axis of the alveolar bone in males is greater than that in females, and the degree of the angle increases with age. It is recommended to pay attention to the thickness of the bone wall around the root and the angle between the teeth before immediate implantation surgery to choose a reasonable implantation plan.

关键词

锥形束CT / 上颌中切牙 / 上切牙根位置 / 即刻种植 / 唇侧骨壁 / 腭侧骨壁 / 牙体长轴 / 牙槽骨长轴

Key words

cone-beam computed tomography / maxillary central incisor / upper incisors position / immediate implant / labial bone wall / palatal bone wall / the long axis of tooth / the long axis of alveolar bone

Author summay

丁子凌，主治医师，在读硕士研究生，Email：[e-mail]