背景:基于三维锥形束CT模型设计的手术导板已有报道,但由于锥形束CT不能重建精细的牙龈等软组织,只能设计单纯牙齿固位的导板,稳定性相对较差.目的:采用三维自动配准方法将锥形束CT模型和三维数字化牙颌模型进行匹配,建立高精度三维整合牙颌模型,以此模型为基础设计与制作个体化微种植体手术导板.方法:选择6例错颌畸形患者进行头颅锥形束CT扫描、牙列石膏模型光学扫描,分别获取三维模型,采用三维自动配准方法将两模型重叠,获得三维整合牙颌模型.在三维整合模型上精确定位并虚拟植入微种植体,以此为基础设计并采用快速成型技术制作高精度个体化树脂手术导板,利用游标卡尺检测导板的轨道内径.于患者口内试戴树脂手术导板,嘱患者咬合,检查其就位及固位情况.结果与结论:模型配准精度高,所有树脂手术导板口内试戴吻合,患者咬紧后固位增强,患者佩戴舒适,无压迫或其他不适感;树脂手术导板轨道内径为(1.79±0.23) mm,不同操作者间的测量误差无统计学意义(P > 0.05).结果表明,基于高精度三维整合模型设计的手术导板精度高,能够为进一步研究手术导板的临床应用提供基础.%BACKGROUND: Surgical guides designed based on a three-dimensional cone-beam CT (CBCT) model have been reported. However, CBCT cannot remodel fine soft tissue such as gums, and it can only be used to design a simple dental retainer with relatively poor stability. OBJECTIVE: To establish a high-precision three-dimensional (3D) integrated maxillodental model by matching CBCT model with 3D digital maxillodental model using 3D automatic registration method, based on which, we designed and manufactured individualized miniscrew surgical guides. METHODS: CBCT maxillodental models and laser-scanned dentition models obtained from six malocclusion cases were matched and overlapped using the 3D automatic registration method to fabricate the 3D integrated maxillodental model. Then, we accurately positioned and virtually implanted a micro-implant into the 3D integrated maxillodental model. Subsequently we prepared a high-precision individualized resin surgical guide by rapid prototyping technology. The inner diameter of the guide track was detected by a vernier caliper. Patients tried on the resin surgical guide, and then occlusion condition, guide seating and retention were detected. RESULTS AND CONCLUSION: Due to the high-precision registration of the model, all the resin surgical guide plates were suitable. The plate retention was enhanced after tooth clinching, and all the patients felt comfort when wearing the surgical guide plate, with no compression or other discomforts. The inner diameter of the guide track was (1.79±0.23) mm, and the measurement error was not statistically significant (P >0.05). These findings demonstrate that the high-precision surgical guide plate based on the high-precision 3D integrated model can provide the foundation for further investigations on the clinical application of surgical guides.
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