Precise positioning of an intraoral distractor using augmented reality in patients with hemifacial microsomia

Through three-dimensional real time imaging, augmented reality (AR) can provide an overlay of the anatomical structure, or visual cues for specific landmarks. In this study, an AR Toolkit was used for distraction osteogenesis with hemifacial microsomia to define the mandibular osteotomy line and assist with intraoral distractor placement.

20 patients with hemifacial microsomia were studied and were randomly assigned to experimental and control groups. Pre-operative computed tomography was used in both groups, whereas AR was used in the experimental group. Afterwards, pre- and post-operative computed tomographic scans of both groups were superimposed, and several measurements were made and analysed.

Both the conventional method and AR technique achieved proper positioning of the osteotomy planes, although the AR was more accurate. The difference in average vertical distance from the coronoid and condyle process to the pre- and post-operative cutting planes was significant (p < 0.01) between the two groups, whereas no significant difference (p > 0.05) was observed in the average angle between the two planes. The difference in deviations between the intersection points of the overlaid mandible across two cutting planes was also significant (p < 0.01).

This study reports on an efficient approach for guiding intraoperative distraction osteogenesis. Augmented reality tools such as the AR Toolkit may be helpful for precise positioning of intraoral distractors in patients with hemifacial microsomia in craniofacial surgery.