三维重建仿真模型及计算机辅助设计个性化假体在下颌骨缺损修复中的应用

目的探讨三维重建仿真模型及计算机辅助设计个性化假体在修复下颌骨缺损中应用的可行性,并分析其临床疗效。方法 2002年7月-2009年11月,收治9例下颌骨缺损患者。男4例,女5例;年龄19～55岁。均为下颌骨病变截除术后遗留大面积下颌骨缺损;其中颌骨良性病变8例,下颌牙龈癌1例。缺损部位:缺损跨越中线2例,包括髁状突缺损4例,局限于一侧且未累及颞下颌关节缺损3例。缺损范围为9.0 cm×2.5 cm～17.0 cm×2.5 cm。术前行螺旋CT扫描后三维重建数字化颌骨模型,通过快速成型技术制备个性化假体。一期手术植入假体修复颌骨缺损,6个月后行二期手术种植义齿。结果一期手术中个性化假体就位顺利,耗时10～23 min;延伸板与骨面贴合良好。术后切口Ⅰ期愈合,面部外形满意,咬关系良好,张口时下颌偏斜纠正。二期手术时见种植体牢固无松动,基台穿龈后与对颌牙位置关系良好,达到术前设计理想位置。患者一期术后均获随访,随访时间1～9年。末次随访时复查X线片以及头颅后前位、颅基位、全口曲面断层X线片显示,个性化假体固定良好无松脱,外形对称。结论三维重建仿真模型及计算机辅助设计个性化假体应用于下颌骨缺损修复中能提高手术精度,节省手术时间。

Reconstruction of mandibular bone defects using three-dimensional skull model and individualized titanium prosthetics from computer assisted design

Objective To evaluate the feasibility and effectiveness of reconstruction of mandibular bone defects using three-dimensional skull model and individualized titanium prosthetics from computer assisted design.Methods Between July 2002 and November 2009,9 patients with mandibular defects accepted restorative operation using individualized bone prosthetics.Among 9 cases,4 were male and 5 were female,aged 19-55 years.The causes of mandibulectomy were benign lesions in 8 patients and carcinoma of gingival in 1 patient.Mandibular defects exceeded midline in 2 cases,involved condylar in 4 cases,and was limited in one side without involvement of temporo-mandibular joint in 3 cases.The range of bone defects was 9.0 cm × 2.5 cm-17.0 cm × 2.5 cm.The preoperative spiral CT scan was performed and three-diamensional skull model was obtained.Titanium prosthetics of mandibular defects were designed and fabricated through multi-step procedure of reverse engineering and rapid prototyping.Titanium prosthetics were used for one-stage repair of mandibular bone defects,then two-stage implant denture was performed after 6 months.Results The individualized titanium prosthetics were inserted smoothly with one-stage operative time of 10-23 minutes.All the cases achieved incision healing by first intention and the oblique mandibular movement was corrected.They all got satisfactory face,had satisfactory contour and good occlusion.In two-stage operation,no loosening of the implants was observed and the abutments were in good position with corresponding teeth which were designed ideally before operation.All cases got satisfactory results after 1-9 years of follow-up.At last follow-up,X-ray examinations showed no loosening of implants with symmetry contour.Conclusion Computer assisted design and three-dimensional skull model techniques could accomplish the design and manufacture of individualized prosthetic for the repair of mandibular bone defects.