低位上颌窦缺牙患者上颌窦底牙槽骨的测量分析

Measurement of the height and width of residual alveolar crests in low-set maxillary sinus patients with missing upper molar

目的:应用螺旋CT图像结合Simplant软件对低位上颌窦缺牙患者缺牙区上颌窦底不同部位牙槽骨宽度及高度进行测量,探讨患者性别、年龄、缺牙时间及拔牙原因等对牙槽骨宽度与高度的影响。方法:选择43例上颌后牙缺失、全景片示缺牙区牙槽嵴顶距上颌窦底距离为4～6mm的患者CT图像为对象,利用Simplant软件进行重建,测量缺牙区上颌窦底不同部位处牙槽骨的宽度及高度,采用SPSS16.0软件包对数据进行t检验、方差分析和秩和检验。结果:①缺牙区牙槽嵴顶至上颌窦底距离为4.03～6.00mm,平均为(5.26±0.58)mm;②在上颌窦底上方不同水平,除上颌第二磨牙在3.75mm水平处,窦底内侧壁宽度与外侧壁宽度均存在显著差异(P<0.01);③随年龄增长及缺牙时间延长,缺牙区剩余牙槽骨高度及上颌窦底宽度显著减小(P<0.01),而对于距窦底1.25mm以上的上颌窦底侧壁宽度则无显著影响(P>0.05);④因牙周炎拔除患牙者,其剩余牙槽骨高度明显小于因冠折或无法修复的残根(冠)而拔除者(P<0.01)。结论:患者年龄、缺牙时间及拔牙原因对剩余牙槽骨量具有重要影响,而对于上颌窦底上方不同水平上颌窦底侧壁宽度则影响较小。上颌磨牙区上颌窦底内侧壁宽度总体大于外侧壁宽度,植入种植体可考虑该解剖特点,并根据患者年龄、缺牙时间及拔牙原因,适当改变种植体植入位置和方向,使一部分低位上颌窦缺牙患者能够避免行复杂的上颌窦提升术。

PURPOSE：Using spiral computed tomography and Simplant software to measure the width and height of residual alveolar crest of agomphious upper molar region at different levels around bottom of low-set maxillary sinus.To evaluate the impact of sex,age,agomphious duration,and cause of tooth extraction on the width and height of residual alveolar crest.METHODS：Forty-three patients with missing uppers molar and residual alveolar bone height being 4 to 6mm showed by panoramic radiographs were scanned by spiral computed tomography.3D model of the alveolar crest and maxillary sinus were reconstructed using the images from CT scan and Simplant software.The height and width of the residual alveolar crest of agomphious upper molar region at different levels around bottom of maxillary sinus were measured.The data was analyzed with SPSS16.0 software package for Student＇s t test,analysis of variance（ANOVA） and Kruskal-Wallis H test.RESULTS：①The mean distance between the top of residual alveolar crest and the floor of sinus was（5.26±0.58）mm.②The difference between the width of internal bone wall and that of external bone wall at different levels above the bottom of maxillary sinus was significant（P0.01）,except for agomphious upper second molar at 3.75mm.③The height of residual crest and width of sinus floor decreased remarkably with age and agomphious duration（P0.01）while the width of sinus lateral walls didn＇t change so much with them（P0.05）.④Height of residual crest of the tooth extracted due to periodontitis was obviously lower than that of the tooth extracted due to residual root（crown） or crown fracture（P0.01）.CONCLUSIONS：The height and width of residual crest change significantly with age,agomphious duration and causes of tooth extraction.However,the width of lateral walls above sinus floor do not change so much with those factors.The internal wall of maxillary sinus floor is wider than the external wall at agomphious molar.This anatomic feature may be taken into consideration during implantation.The site and direction of implant can be adjusted equally according to the age,agomphious duration and causes of tooth extraction,so that maxillary sinus augmentation can be avoided in part of patients with low-set maxillary sinus.