成人不同垂直骨面型颧牙槽嵴区骨皮质密度分析

目的 通过三维重建技术对成人颧牙槽嵴区骨皮质密度进行测量分析,比较不同骨面型间颧牙槽嵴区骨皮质密度以及不同位点间骨皮质密度的差异。方法 选取成人患者螺旋 CT 图像60例（男28例,女32例）进行三维重建,根据下颌平面角( FH-MP) 的大小分为低角、均角、高角3组,分别测量上颌左侧颧牙槽嵴区不同层面基准线上方13、15、17 mm处的骨皮质密度,采用 SPSS 17.0软件包进行数据分析。结果 颧牙槽嵴区骨密度在性别之间无统计学差异;在不同垂直骨面型间存在统计学差异（P<0.05),其中,低角组[(1331.65±185.70) HU]的骨密度最高,高角组[(1245.62±207.63) HU]最低;在不同垂直骨面型组的不同位点之间骨密度存在统计学差异（P<0.05),各组骨密度的集中区域是,高角组位于第一磨牙近中颊根层面,均角组位于近、远中颊根之间,低角组位于第一磨牙远中颊根层面。结论 成人不同垂直骨面型间颧牙槽嵴区骨皮质的密度以及位点分布存在显著差异,该研究为成人选择微种植支抗钉的适宜部位,保证正畸治疗中支抗钉的稳定性提供了参考依据。

Analysis of cortical density in zygomatic alveolar ridge of different vertical facial types

PURPOSE: To measure the density of the cortex in the zygomatic alveolar ridge region of adults by 3D reconstruction, and to analyze the differences of cortical bone density between different vertical facial types in the zygomatic alveolar ridge in different vertical facial types. METHODS: Spiral CT scanning data of 48 patients (24 males and 24 females) were chosen for 3D reconstruction and divided into 3 groups(low-angle group, average-angle group and high-angle group) according to the size of the mandibular plane angle (FH-MP), 18 points at which the six planes of the zygomatic alveolar ridge on the left of the upper jaw intersected at 13, 15 and 17 mm above the baseline(the horizontal line of mesial buccal tip of the first maxillary molar) were measured. SPSS 17.0 software package was used for statistical analysis. RESULTS: There was no significant difference between genders, there was significant difference among different vertical bone facial types (P<0.05）, among which the low-angle group [(1331.65±185.70) HU] was the highest and the high-angle group [(1245.62±207.63) HU] was the lowest. There was significant difference in BMD between different sites in different vertical facial types and the sites with the highest BMD in each group were located at 17 mm above on the occlusion plane. Cross-sectional evaluation showed that the high-angle group was located at the level of the proximal and middle buccal root of the first molar, and the mean-angle group was located between the proximal and distal buccal root, and the low-angle group was located at the level of the distal buccal root of the first molar. CONCLUSIONS: There was significant difference in density and distribution of bone cortex in zygomatic alveolar ridge between different vertical facial types in adults, which provides a reference basis for adults to select appropriate site of micro-implant anchorage and to ensure the stability of anchorage in orthodontic treatment.