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.