经嵴顶上颌窦底提升术后不植骨同期种植的影像研究

Radiography study on osteotome sinus floor elevation with placed implant simultaneously with no graft augmentation

目的:应用锥形束计算机断层(cone beam computed tomography,CBCT)及三维测量研究经嵴顶上颌窦底提升术不植骨同期植入种植体后窦内骨高度和骨体积的变化,分析影响窦内骨增量的相关因素。方法:选择2014年1月至2019年12月在北京大学口腔医院第二门诊部就诊的38例牙列缺损患者影像学资料进行回顾性分析,38例患者经牙槽嵴顶上颌窦底提升后不植骨同期植入44枚种植体。比较分析术前和术后9~68个月拍摄的CBCT,测量种植体颊侧、腭侧、近中和远中位点的窦内新增骨高度,通过Mimics软件建模配准,布尔(Boolean)运算计算出上颌窦内新增的骨体积,并且分析影响窦内新增骨高度和新增骨体积的相关因素,根尖片追踪监测边缘骨吸收情况。结果:术前上颌窦底平均剩余牙槽骨高度(residual bone height,RBH)为(3.41±1.23)mm,种植体突入长度(protruded length,PL)为(3.41±1.28)mm,种植体周围各位点窦内新增骨高度远中为(2.44±1.23)mm、近中为(2.88±1.20)mm、颊侧为(2.83±1.22)mm和腭侧为(2.96±1.16)mm,术后窦内平均新增骨高度为(2.78±1.13)mm,窦内新增骨体积为(122.15±73.27)mm3。多因素分析显示调整性别、年龄、吸烟等因素后,窦内平均新增骨高度与PL和成骨时间呈正相关,与术前RBH呈负相关,而窦内新增骨体积与PL和成骨时间呈正相关。观察期内种植体成功率100%,平均边缘骨吸收为0(0~1.41)mm。结论:经嵴顶上颌窦底提升术不植骨同期植入种植体可增加种植体周围窦内骨高度,不植骨亦可以获得窦内一定体积的新骨形成,RBH、PL及成骨时间均是影响窦内成骨量的重要因素。

Objective:To investigate the change of endo-sinus bone height and bone volume in osteotome sinus floor elevation(OSFE)without bone graft but placing implants simultaneously by using cone beam computed tomography(CBCT)and three dimensional analysis,and to find the impacting factors on endo-sinus bone augmentation.Methods:OSFE was performed in 38 edentulous patients with missing teeth at posterior maxillary region,and 44 implants were placed and referred for OSFE using no graft materials.CBCT was performed pre-surgery and 9-68 months post-surgery when the patients encountered another implant surgery.The gained bone height at mesial,distal,buccal and palatal sites around the implant in sinus were measured,volumetric measurements of the endo-sinus gained bone volume(ESGBV)in the elevated region were calculated by Mimics software.Univariate analysis and multiple linear regression were performed to investigate the impacting factors on the gained bone height and ESGBV.Marginal bone loss was recorded according to the periapical radiography after implant restoration.Results:The mean residual bone height(RBH)pre-surgery was(3.41±1.23)mm,the mean protruded length(PL)into sinus of implant post-surgery was(3.41±1.28)mm,the mean endo-sinus gained bone height was(2.44±1.23)mm at distal sites,(2.88±1.20)mm at mesial sites,(2.83±1.22)mm at buccal sites and(2.96±1.16)mm at palatal sites,the mean endo-sinus gained bone height at distal sites was significantly lower than the other three sites(P<0.05).The average endo-sinus gained bone height was(2.78±1.13)mm.The mean ESGBV was(122.15±73.27)mm3.Univariate analysis showed the more RBH,the less bone height gained in sinus,which existed at buccal,lingual,mesial and distal sites(P<0.001),and the more RBH,the smaller ESGBV gained(P=0.012).The ESGBV was significantly higher in the subjects whose bone generation period was more than 24 months than those whose bone generation period less than 24 months(P=0.034).The more PL,the more bone height and ESGBV gained(P=0.008).Multivariate analysis showed after adjusting factors of gender,age,smoking,width of sinus floor,thickness of sinus membrane pre-surgery,diameter and length of the implant,PL and bone generation period was positively correlated with mean endo-sinus gained bone height and ESGBV,while RBH negatively correlated with mean endo-sinus gained bone height.During the follow-up,the mean marginal bone loss was 0(0-1.41)mm and all the implants loaded successfully.Conclusion:OSFE without bone graft but with placed implant simultaneously can increase endo-sinus gained bone height and ESGBV.RBH,PL and bone generation period are the significant factors impacting endo-sinus bone augmentation.