Abstract: Objective To measure and compare differences in sagittal condylar inclination (SCI) and sagittal frontal table inclination (SFTI) under different setting values and operating paths through in vitro experiments. Evaluate the accuracy and reproducibility of parameter results obtained by optical sensing mandibular movement tracing system. Methods Based on the actual intraoral scan data and dentition coordinate data files from recruited subjects, personalized measurement models and fixtures were designed and 3D-printed, then installed on the fully adjustable articulator. Bilateral SCI and SFTI were set with gradient changes from 10° to 60°, resulting in a total of 12 groups. The articulator module was used to complete the tracing of the mandibular movement and get the measurement parameters, followed by statistical analysis. Results Except for the 40° and 60° SCI groups and the 10° SFTI group, statistical differences were observed between the measured values and the set values, with standard deviation ranging from 0.300° to 2.994°. There was no statistical difference in SCI values obtained at different acquirement timings of hinge axis during operation. Conclusion The accuracy and reproducibility of parameters obtained by optical sensing mandibular movement tracing system can meet the needs of clinical applications, but there are still certain differences between the measured values and the setting values. Ensuring the stability of the test device, multiple tests on the same object, whether repeated hinge axis positioning is performed or not, has no significant impact on the results.

Key words: Mandibular movement tracing, Reproducibility, Articulator parameter setting