Matching locating holes in multiple plates to record bone position for accurate reconstruction after segmental mandibulectomy

Abstract

Segmental defect areas in the mandible can change immediately following osteotomy due to muscular traction, impacting on accurate reconstruction. The purpose of this article is to introduce a new technique based on virtual surgery planning to record the position of the bony parts prior to mandibulectomy, for use in precise mandibular reconstruction after segmental osteotomy. The position information for the bony parts is transferred to a plate with complementary surface contact and locating holes with specific directions and angles. This technique was performed for six patients with segmental defects and the results were compared to those of six previous patients in whom the technique was not utilized. The design of the location holes shortened the average operation time from 406 minutes to 349 minutes (P = 0.033) and decreased the average, maximum, and minimum graft deviation from 1.21 mm to 0.88 mm (P = 0.015), 1.28 mm to 0.99 mm (P = 0.027), and -1.15 mm to -0.77 mm (P = 0.077), respectively. The design of the locating holes in multiple plates shortened the time taken for the bony repositioning step and hence significantly shortened the total operation time. More importantly, it also increased the reconstructive accuracy.

Keywords: bone defect; bony reposition; mandible reconstruction; mandibulectomy; osteotomy; reconstructive efficiency and accuracy; segmental mandibulectomy; virtual surgery planning.