Identifying the optimal mandibular midsagittal plane for systematic asymmetry correction: application in virtual...

The plane-matching method is a bone-reference virtual surgery protocol determining bone position by matching the local midsagittal plane (MSP) with the global MSP. Using an optimized mandibular MSP may ensure the optimal surgery planning, but is limited by its complex optimization process. A simpler yet clinically viable alternative would enhance its utility. The aim of this retrospective cross-sectional study was to identify the optimal pretreatment skeletal Class III patients were included. A total of 727 landmarks were digitized on the distal segment of the mandible. The root mean square (RMS) distances between the original and mirrored landmarks across six candidate mandibular MSPs (one optimized and five cephalometric) were compared in symmetric and asymmetric groups. The results revealed no significant interaction between facial asymmetry and the MSPs (P = 0.39). The asymmetric group had a significantly larger RMS distance than the symmetric group (2.5 ± 1.7 mm vs 1.7 ± 1.5 mm; P < 0.001). Among the cephalometric MSPs, Go.Go.Me_Me.midGo, MF.MF.PM_Me.bisectMF, and B.Me.midGo had the lowest RMS distances and were statistically equivalent (P = 1.0). In conclusion, these three cephalometric MSPs are viable alternatives to the optimized MSP. With proper selection guidelines, the plane-matching method utilizing these cephalometric MSPs may enhance the diagnostic benefits of bone-referenced virtual surgery planning.