多层螺旋CT三维重建技术在辅助微螺钉种植支抗植入中的选择应用

背景：提高正畸支抗系统微螺钉种植体稳定性的关键在于种植前对局部骨质、骨量进行精确评估,但常规二维影像学检查,如根尖片、曲面断层摄影片、侧位头影测量片等均存在不同程度的局限性。 目的：分析总结多层螺旋CT多种图像重建技术在辅助微螺钉种植支抗植入中的不同特点及优势,以便精确指导微螺钉的种植,提高其稳定性。 方法：种植前以多层螺旋CT对猪颅骨进行定位扫描及多种图像重建,通过多种图像联合应用初步观测种植区骨质骨量及解剖情况,然后利用计算机在影像上精确设计三维种植角度,根据影像信息制作隧道式手术模板指导种植32枚微螺钉支抗,种植后多层螺旋CT再次扫描重建,将种植前后多层螺旋CT设计及测量角度与术后解剖组织块实物测量角度作对比分析。 结果与结论：32枚微螺钉种植情况满意,无伤及邻近牙根及周围重要组织结构的情况。种植前设计与种植后多层螺旋CT测量角度比较,以及种植后多层螺旋CT测量与实物测量角度比较,在轴位面及侧断面上其差异均无显著性意义(P > 0.05),且一致性极好。说明多层螺旋CT能够提供精确而丰富的影像信息,恰当选择合理应用能充分实现微螺钉种植影像学检查目的,从而为提高种植的成功率提供可靠保障。

Selection and application of multi-slice CT 3D reconstruction techniques in assisting mini-implant ahchorage implant surgery

BACKGROUND:The key method to improve the stability of miniscrew orthodontic anchorage system is accurate preoperative bone mass evaluation in the implant region. Routine 2D image examinations such as periapical radiography and panoramic tomography and lateral cephalometric radiography have limitations. OBJECTIVE:To analyze the traits and advantages of various multi-slice CT (MSCT) reconstruction images in assisting miniscrew anchorage surgery to improve the stability of miniscrew. METHODS:Preplant MSCT scanning and various images reconstruction were made and helped to exam the peri-implant bone mass and density and the anatomical relation to important structures comprehensively. According the implant anchorage angles in MSCT images accurately designed by computer, the tunnel-type surgical template was made to assist 32 miniscrews implant surgery. Then the skulls of two pigs were rescanned by MSCT. After dissected the pig alveolar process, the MSCT preoperative designed angles, the MSCT postoperative measured angles and the measured angles of anatomic bone samples were analyzed statistically. RESULTS AND CONCLUSION:The 32 miniscrews were implanted successfully. They did not damage dental roots or surrounding important structures. Compared MSCT preoperative designed angles with MSCT postoperative measured angles and anatomic bone samples measured angles, there were no significant differences in axial sections or cross-sections (P > 0.05), and the r concordance correlations were very good. Results show that MSCT can provide accurate and abundant image information. Exact selection and application can help to fully attain the objects of imaging examination on miniscrew anchorage surgery, thus improving the success rate of miniscrews.