Leonardo Ciocca^*; Achille Tarsitano; Riccardo Mattoli; Cristiana Breccia; Pietro Felice; Lorenzo Breschi

Department of Biomedical and Neuromotor Science, University of Bologna, Bologna, Italy

Background: Restoring the correct anatomy and occlusion of the mandible after cancer ablative surgery is a challenge, but modern CAD-CAM techniques enable customized new bone plates to position the fibula-free flap (FFF) as related to the occlusion and prosthetic gingival/crown ratio.

Aim/Hypothesis: The present prospective clinical study aimed to describe the workflow of prosthetically guided mandibular reconstruction, and the results are verified in a case series.

Material and Methods: Fourteen consecutive patients (mean age 36.1; range: 16–61 years) affected by benign and low-grade malignant diseases involving the mandible were selected. All patients underwent surgical resection and mandibular reconstruction with the microvascular FFF using a double-level customized titanium bone plate. The FFF positioned at the level of the alveolar bone allowed for restoration of the correct gingival/crown ratio. Six months after surgery, the oral implants were positioned with static/dynamic navigation, and the prosthetic rehabilitation was completed 6 months later. The positions of the FFF segments were isolated by overlapping their planned digital design with the postoperative computed tomography data. Rotation angles, translation vectors, and total error were investigated to determine the exact deviation for the planned position of the FFF. Occlusal and aesthetic results of the prosthetic rehabilitation were also evaluated.

Results: Analyzing the average mean distance as an absolute value, the surface deviation between the preoperative fibular cranial segment (FCS_plan) and the postoperative FCS_post-op was 1.04 mm, while the average signed distance was −0.28 mm. Patients underwent implant surgery and were rehabilitated with a partial fixed prosthesis. One patient developed a major complication during follow-up (bony flap necrosis). All implant positions and the relative prosthetic rehabilitation respected the initial planning. The aesthetic profile of the lower third of the face was preserved.

Conclusion and Clinical implications: The height discrepancy between the FFF and the native mandible was challenging in the present clinical study, as we proposed a new prosthetically guided protocol to reconstruct the mandible. The double-level bone plate allowed for restoration of the correct prosthetic gingival/crown ratio, the aesthetic face profile, and native occlusion. The digital projection provided a high level of accuracy during reconstructive surgery of the mandible with the FFF.

Disclosure of Interest: None Declared.

Keywords: bone graft, CAD/CAM, clinical studies/trials

莱昂纳多·乔卡^* ; 阿喀琉斯·塔西塔诺；里卡尔多·马托利；克里斯蒂安娜布雷西亚；彼得罗费利斯；洛伦佐·布雷斯基

意大利博洛尼亚博洛尼亚大学生物医学和神经运动科学系

背景：在癌症消融手术后恢复下颌骨的正确解剖结构和咬合是一项挑战，但现代 CAD-CAM 技术使定制的新骨板能够定位与咬合和假牙龈/牙冠相关的无腓骨瓣 (FFF)比率。

目的/假设：本前瞻性临床研究旨在描述假体引导下颌骨重建的工作流程，结果在一系列病例中得到验证。

材料与方法：连续选择了 14 名患有涉及下颌骨的良性和低度恶性疾病的患者（平均年龄 36.1；范围：16-61 岁）。所有患者均使用双层定制钛骨板进行微血管 FFF 手术切除和下颌重建。位于牙槽骨水平的 FFF 允许恢复正确的牙龈/牙冠比。术后6个月，采用静态/动态导航定位口腔种植体，6个月后完成修复。FFF 节段的位置通过将其计划的数字设计与术后计算机断层扫描数据重叠来隔离。旋转角度、平移向量、和总误差进行了调查，以确定 FFF 计划位置的确切偏差。还评估了修复修复的咬合和美学效果。

结果：分析的平均平均距离为绝对值，术前腓骨颅段（FCS之间的表面偏差_计划）和术后FCS_的术后为1.04毫米，而平均带符号距离为-0.28毫米。患者接受了种植手术，并用部分固定假体进行了康复。一名患者在随访期间出现严重并发症（骨瓣坏死）。所有种植体位置和相关的修复修复都遵循最初的计划。面部下三分之一的美学轮廓得以保留。

结论和临床意义：在目前的临床研究中，FFF 和天然下颌骨之间的高度差异具有挑战性，因为我们提出了一种新的修复引导方案来重建下颌骨。双层骨板可以恢复正确的修复牙龈/牙冠比、美观的面部轮廓和自然咬合。在使用 FFF 进行下颌骨重建手术期间，数字投影提供了高度的准确性。

利益披露：无声明。

关键词：骨移植，CAD/CAM，临床研究/试验