颧牙槽嵴区域骨密质厚度的锥形束CT测量分析

目的通过锥形束CT（CBCT）测量成年人与青少年的颧牙槽嵴区域骨密质厚度，评价两者的差异，为临床中微种植支抗钉在颧牙槽嵴的应用提供参考。方法采集30例患者口腔颌面部CBCT扫描数据，其中成年人、青少年各15例。分别测量颧牙槽嵴区域颊侧不同层面基准线（上颌第一磨牙近中颊尖顶所在水平线）上方13、15、17mm处骨密质厚度，并对测量数据进行统计源分析。结果成年人颧牙槽嵴区域骨密质厚度为（1．91±0．54）～（2．62±0．74）mm。在3个测量高度上，上颌第一、二磨牙间骨密质最厚，第一磨牙近颊根上方骨密质最薄。青少年颧牙槽嵴区域骨密质厚度为（1．30±0．51）～（3．08±1．01）mm。在不同测量高度上，上颌第二前磨牙与第一磨牙间骨密质最厚，最薄处则位于第二磨牙近颊根上方或第一磨牙远颊根上方。结论就骨密质厚度而言，成年人颧牙槽嵴区域微种植支抗钉的最佳植入点位于上颌第一、二磨牙间，青少年颧牙槽嵴区域微种植支抗钉的最佳植入点位于上颌第二前磨牙与第一磨牙间。成年人与青少年颧牙槽嵴区域各位点骨密质厚度均可为微种植支抗钉的稳定性提供了保障。

Cone beam computed tomography analysis on the cortical bone thickness of infrazygomatic crest

Objective This study aims to measure the cortical bone thickness of adults and adolescents at different sites of infrazygomatic crest and to compare the specific differences between the two groups by cone beam computed tomography（CBCT）. Methods The oral and maxillofacial CBCT data of 30 patients, including 15 adults and 15 adolescents, were collected. Multiple measurements were performed at different slices ofinfrazygomatic crest at 13, 15, and 17 mm apical from the reference line（the horizontal line where the mesio-buccal cusp of the upper first molar lies）. The data were analyzed statistically. Results The cortical bone thickness of the infrazygomatic crest in adults ranged from （1.91±0.54） mm to （2.62±0.74） mm. The cortical bone was thickest at the interradicular space of the maxillary first and second molars and thinnest at the mesial-buccal root of the maxillary first molar. The cortical bone thickness of the infrazygomatic crest in adolescents ranged from （1.30±0.51） mm to （3.08±1.01） mm. The cortical bone was thickest at the interradicular space of the maxillary second premolar and first molar and thinnest at the distal-buccal root of the maxillary first molar or the mesial-buccal root of the maxillary second molar. Conclusion The cortical bone thickness of all the measured sites of the infrazygomatic crest in both adults and adolescents guaranteed the stability of micro-implant anchorage. The best micro-implant anchorage placement sites of the infrazygomatic crest for adults and adolescents lie in the interradicular space of the maxillary first and second molars and the interradicular space of the maxillary second premolar and first molar, respectively.