Comparative analysis of three jaw motion tracking systems: A study on precision and trueness

Purpose:The purpose of this study was to assess the precision and trueness of threejaw motion tracking systems, the KaVo ARCUSdigma system, SDiMatriX system, andModjaw system, in recording mandibular movements based on optical and ultrasonicprinciples.Materials and Methods:Twenty-five healthy subjects were selected for the presentstudy to measure protrosive movement and left and right lateral movements using thethree jaw motion tracking systems. Each subject's mandibular movement was recordedtwice with a 1-week interval. Five parameters-sagittal condylar inclination (SCI)angle, incisal guide angle, Bennett angle, lateral condylar inclination angle, and Fis-cher's angle-were acquired for further analysis. The precision of the jaw motiontracking systems was evaluated by comparing the results of two measurements of thesame parameter. Simultaneously, cone beam computed tomography (CBCT) was uti-lized during the initial data acquisition and was aligned with intercuspal position (ICP)and edge-to-edge occlusion intraoral scan data. Bone landmarks were used to calculatebilateral SCI as a reference for comparison with the SCI values from each jaw motiontracking system. An independent-samplet-test was conducted to compare parameterdifferences, with statistical significance set at ap-value below 0.05.Results:There were no significant differences among the three jaw motion trackingsystems regarding the corrected values of SCI, incisal guide angle, Bennett angle,lateral condylar inclination angle, and Fischer's angle during the 1-week interval(p>0.05). The values of bilateral SCI obtained by CBCT were 48.57 +/- 6.74 (L) and48.35 +/- 5.28 (R), respectively. No significant differences were found between the ref-erence SCI and those parameters measured by the KaVo ARCUSdigma system andthe Modjaw system (p>0.05), while the results obtained from the SDiMatriX systemindicated a significant difference compared to the reference SCI (p<0.05).Conclusions:The three jaw motion tracking systems exhibited favorable results interms of precision. Regarding trueness, both the KaVo ARCUSdigma system and theModjaw system demonstrated a satisfactory levels suitable for applications in digi-tal prosthodontics within clinical settings. However, further refinement is needed toenhance the trueness of the SDiMatriX system.