A pilot study on an infrared jaw-tracking method for mandibular motion based on modified bite-fork registration: Accuracy and feasibility.

Objectives: This study developed a novel method for repeated tracking without requiring secondary cone-beam computed tomography (CBCT) exposure or additional registration operations.

Methods: An infrared jaw-tracking method based on the registration of a modified bite-fork was developed. The accuracy of the method was evaluated by comparing head-simulator linear distance measurements obtained using the jaw-tracking and CBCT imaging methods and calculating the root mean square (RMS) errors associated with linear distance deviations. Feasibility was evaluated by analysing the opening-closing motion of the incisor in 15 participants, tracked by 15 dentists, and collecting ratings from both of them.

Results: Linear distance measurements showed no significant differences between the jaw-tracking and CBCT imaging methods at each position (all P > 0.05). The overall RMS errors of the jaw-tracking method were within 0.35 mm. Mean length of the opening curvilinear path (50.80 ± 6.86 mm) was not significantly different from the reported value (P = 0.684), and the intraclass correlation coefficient for the opening curvilinear path length was 0.947 (P < 0.001). A 'figure-eight' pattern of the opening-closing trajectory was observed. The mean rating score for each item was ≥4.0.

Conclusions: This jaw-tracking method based on modified bite-fork registration enables repeated tracking without requiring secondary CBCT radiation exposure or additional registration operations.

Clinical Significance: The infrared jaw-tracking method offers a promising approach for short-term repeated evaluation of mandibular motion due to its low radiation exposure and minimal chair-site costs.