成人安氏Ⅱ^2错[牙合]颧牙槽嵴区骨量的CBCT评价

A CBCT Study on the Alveolar Bone Thickness of Infrazygomatic Crest(IZ crest)in Adults of Angle'sⅡ^2 Malocclusion

目的:研究成人安氏Ⅱ^2颧牙槽嵴区牙根间距、牙根间对应颊侧骨量及骨密度,为此区支抗钉植入位点的选择提供参考,以提高支抗钉植入的安全性及成功率。方法:收集符合实验要求的成人安氏Ⅱ^2患者30例,拍摄CBCT影像后,以DICOM格式输入Dolphin软件进行重建并测量,选取距上颌第一磨牙近中/远中牙根颊侧釉牙骨质界(Cemento-enamel junction,CEJ)根方4、5、6、7mm四个不同截面为参考平面,分别测量:①上颌第二前磨牙与第一磨牙近中颊根、第一磨牙远中颊根与第二磨牙近中颊根的牙根间距;②颊侧骨皮质到对应牙根间中点的牙槽骨厚度;③上颌第二前磨牙与第一磨牙近中颊根、第一磨牙远中颊根与第二磨牙近中颊根间骨皮质及骨松质密度,将结果进行统计学分析。结果:①上颌第二前磨牙与第一磨牙近中颊根根间距在四个不同截面上均大于第一磨牙远中颊根与第二磨牙近中颊根之间的距离,差异有统计学意义(P<0.05);②上颌第一磨牙远中颊根与第二磨牙近中颊根间颊侧骨量在四个截面上均大于第二前磨牙与第一磨牙近中颊根间,差异有统计学意义(P<0.05);③上颌第二前磨牙与第一磨牙牙根间距在4mm和7mm及5mm和7mm截面高度有统计学意义(P<0.05);④距CEJ4mm及5mm高度截面水平上颌第一磨牙远中颊根与第二磨牙近中颊根间骨松质密度大于第二前磨牙与第一磨牙近中颊根间骨松质密度(P<0.05),其余截面两者间骨松质密度及四个截面上两者间骨皮质密度均无统计学差异(P>0.05)。结论:对于成人安氏Ⅱ^2病例,颧牙槽嵴区支抗钉植入位置选择第一磨牙与第二磨牙之间颊侧可以获得较多骨组织支持,但尽量避免直接植入牙根之间以防止牙根损伤。如果需要在第二前磨牙与第一磨牙之间植入种植支抗时,靠近根尖方向安全性较高。

Objective To investigate the root space between adjacent teeth and the corresponding buccal bone thickness of the infrazygomatic crest(IZ crest)area in adult Angle'sⅡ^2 malocclusion,for providing a reference to select implantation sites and improving the safety and success rate of implantation.Methods Thirty requested adult Angle'sⅡ^2 cases were selected.Dolphin software were used for 3D reconstruction after CBCT scan.Four different horizontal planes,4-7mm respectively from the CEJ at the mesial/distal-buccal of the maxillary first molar,were selected as the reference planes.The bone cancellous density,cortical density,interradicular distances between the second premolar and the first molar,the first molar and second molar were measured and analyzed statistically,as well as the corresponding buccal alveolar bone thickness.Results①The interradicular space of the second premolar and the first molar was significantly larger than the space of the first molar and second molar in all four different planes(P<0.05).②The buccal alveolar bone thickness between the first molar and second molar were much thicker than the second premolar and the first molar in all four different planes(P<0.05).③There are statistical differences of the interradicular space between 4mm and 7mm planes together with 5mm and 7mm at the site of the second premolar and the first molar(P<0.05).④In the 4mm and 5mm planes,the bone cancellous density between the second premolar and the first molar were higher than those between the first molar and second molar.Conclusion For adult Angle'sⅡ^2 cases,selecting the buccal side between the first molar and the second molar can get more bone tissue support for safety mini-implant.Do not implant between roots of teeth directly or they may get hurts.If there is a need to implant between the second premolar and the first molar,the higher the safer.