Mandibular reconstruction with the vascularized fibula flap: comparison of virtual planning surgery and conventional surgery

Abstract

This study evaluated the accuracy of mandibular reconstruction and assessed clinical outcomes in both virtual planning and conventional surgery patients. ProPlan CMF surgical planning software was used preoperatively in the virtual planning group. In the virtual planning group, fibula flaps were harvested and osteotomized, and the mandibles were resected and reconstructed assisted by the prefabricated cutting guides and templates. The main outcome measures included the operative time, postoperative computed tomography (CT) scans, facial appearance, and occlusal function. The ischemia time and total operation time were shorter in the virtual planning group than in the conventional surgery group. High precision with the use of the cutting guides and templates was found for both the fibula and mandible, and a good fit was noted among the pre-bent plate, mandible, and fibula segments in the virtual planning group. Postoperative CT scans also showed excellent mandibular contours of the fibula flaps in accordance with virtual plans in the virtual planning group. This study demonstrated that virtual surgical planning was able to achieve more accurate mandibular reconstruction than conventional surgery. The use of prefabricated cutting guides and plates makes fibula flap moulding and placement easier, minimizes the operating time, and improves clinical outcomes.

Mandibular defects due to tumour ablation, infection, trauma, or congenital defects have both functional and aesthetic consequences, and accurate reconstruction of the mandible is challenging. The features of a successful mandibular reconstruction include a healed wound, restoration of functional dentition and mastication, facilitation of speech, swallowing, and breathing, and restoration of the mandibular contours. Microvascular bone grafts and postoperative dental rehabilitation are the most commonly used and preferred methods to achieve these goals. The vascularized free fibula graft was introduced to maxillofacial reconstruction by Hidalgo in 1989, and has since become a workhorse technique for the restoration of various mandibular defects. However, this traditional technique is not ideal for shaping the straight fibula bone, as it lacks precision in achieving the correct mandibular contours and positioning of the bone to allow for proper bone contact, condylar position, and symmetry of the lower third of the face.

Recent advances in computer-aided design and manufacturing (CAD/CAM) software have allowed surgeons to attempt more accurate mandibular resections and reconstructions. This precise medical technique allows the surgeon to perform a mandibular resection, fibula osteotomy, and inset of the fibula flap during virtual surgery preoperatively on a computer; precise templates and cutting guides for the procedure can also be generated preoperatively. As a result, intraoperative accuracy and speed have improved greatly, and the rate of flap failure after mandibular reconstruction using fibula free flaps has decreased. In this study, a detailed description of virtual surgical planning for accurate mandibular reconstruction with vascularized fibula flaps is presented. The postoperative outcomes of virtual planning surgery were compared with those of conventional surgery.

Patients and methods

From February 2013 to February 2015, 21 patients underwent mandibular reconstruction with vascularized fibula grafts using the virtual surgical planning software ProPlan CMF (Materialise, Leuven, Belgium). Conventional surgery based on the surgeon’s experience was performed in another 35 patients. This study was approved by the necessary ethics committee.

The patients included 34 males and 22 females with a median age of 52 years (range 20–77 years). The primary diseases were osteoradionecrosis (17 patients), ameloblastoma (13 patients), lower gingival carcinoma (12 patients), oral floor carcinoma (six patients), intra-osseous carcinoma of the mandible (three patients), mandibular sarcoma (three patients), and mandibular osteofibroma (two patients). The defects were divided into four classes according to the Jewer classification of mandibular defects : L ( n = 24), H ( n = 9), C ( n = 6), and LC ( n = 17). The patients in the virtual surgical planning group and conventional surgery group were operated on by one surgical team. The clinical data are shown in Table 1 .

Table 1
Clinical details of the two groups of patients.
Virtual planning surgery group Conventional surgery group
Number of patients 21 35
Sex, M/F 13/8 21/14
Age, years, mean ± SD 50.3 ± 4.2 53.6 ± 5.9
Diseases
Osteoradionecrosis 7 10
Benign tumour 8 7
Malignant tumour 6 (1 a ) 18 (4 a )
Defect type
L 9 15
H 4 5
C 2 4
LC 6 11
Length of fibula flap, cm, mean ± SD 10.3 ± 2.1 11.7 ± 3.5
Number of fibula segments, mean ± SD 2.3 ± 0.6 2.7 ± 0.9
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Dec 15, 2017 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Mandibular reconstruction with the vascularized fibula flap: comparison of virtual planning surgery and conventional surgery
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