Comparison of Complicated and Simple Guiding Templates in Mandibular Reconstruction Using Vascularized Iliac Crest Flap

OBJECTIVE: This study aims to compare the degree of accuracy achieved in mandibular reconstruction between complicated guiding templates (CGT) and simple guiding templates (SGT), to evaluate the necessity to spend more time to design complicated templates prior to surgery. METHODS: The preoperative virtual surgery plan (VSP) was used to simulate the osteotomy and accurate mandibular reconstruction strategy. Then the guiding templates were designed and printed to transfer the VSP into the real operation. Between July 2013 and November 2014, we used the SGT in 13 L-type mandibular defect reconstructions utilising vascularized iliac crest bone (VICB). From March 2015 to March 2018, we used CGT in 14 L-type mandibular defects, also reconstructing with VICB. The indicators of mandibular symmetry, midline deviation, alveolar height loss, bone conjunction gap, and operation time were analyzed and compared between the two groups. RESULTS: The overall bone graft success rate was 100% (27/27) between all patients. The SGT and CGT groups showed similar symmetry (1.01 ± 0.03 vs. 1.03 ± 0.04, P = 0.11) and mandibular midline displacement (1.0 ± 0.7 mm vs. 1.2 ± 0.8 mm, P=0.29). The CGT group showed less alveolar height deficiency than the SGT group (3.0 ± 2.4 mm vs. 7.8 ± 6.8 mm, P=0.01) and lesser bony conjunction gap between the graft and the mandible (1.6 ± 0.7 mm vs. 2.4 ± 1.2 mm, P = 0.02). The average operation time was significantly lower in the CGT group than in the SGT group (340.5 ± 74 min vs. 391.9 ± 41.7 min, P = 0.02). CONCLUSION: In the simple mandibular reconstruction, the time-consuming CGT did not significantly improve the symmetry and midline displacement compared to SGT, but it demonstrated less reduction (increased preservation) in alveolar height and decreased the size of the bone conjunction gap. And in addition, CGT also reduced the average operation time and simplified intraoperative procedures compared with SGT.