OrthoCalc: The six degrees of freedom measurement workflow of rotational and displacement changes for maxilla positioning evaluation.

Background: This study is undertaken to establish the accuracy and reliability of OrthoCalc, a 3D application designed for the evaluation of maxillary positioning.

Methods: We registered target virtual planned models, maxillary models from pre-operative and post-operative CT scans, and post-operative intra-oral scans to a common reference system, allowing for digital evaluation. To assess rotational changes, we introduced a novel measurement method based on virtual cuboid models. Displacement errors were calculated based on proposed registration matrices. We also compared OrthoCalc to established commercial medical software as a benchmark.

Results: Statistical significance calculated showed no significant differences between OrthoCalc and commercial software. the biggest error of 0.04 degree in rotation change was found in the yaw. A maximum displacement change of 0.75 mm was found in the X direction.

Conclusions: Our study validates OrthoCalc as a precise and reliable tool for assessing maxillary position changes with six degrees of freedom in orthognathic surgery, endorsing its clinical utility.