Objectives: To correlate temporomandibular joint (TMJ) morphology and position among cone beam computed tomography (CBCT) images, Joint Vibration Analysis (JVA), and Jaw Tracker (JT) to offer a radiation-free, dynamic method for screening and monitoring the TMJ in orthodontic patients.
Methods: Overall, 236 orthodontic patients without symptoms of mandibular joint disorders and who had undergone CBCT were selected for JVA and JT tests. The TMJ position and morphology were measured using three-dimensional analysis software. JT measurement involved six opening-closing cycles, and JVA measurement was performed using a metronome to guide the mouth opening-closing movements of patients. The correlations among these three measuring devices were evaluated.
Results: Abnormalities in condyle surface morphology affected the mandibular range of motion. The cut-off value results show that when various measurement groups are within a certain range, there may be abnormalities in morphology, with the area under curve (AUC) being 0.81 (p<0.001). A 300 Hz/<300 Hz ratio ≥ 0.085 suggested abnormal morphology (p<0.05). Correlations were observed between the maximum opening velocity, maximum vertical opening position, and joint spaces in the JT measurement. Correlations were also observed between the >300 Hz/<300 Hz ratio, median frequency, total integral, integral<300 Hz, and peak frequency with joint spaces in JVA measurements.
Conclusions: JT and JVA may serve as rapid, non-invasive, and radiation-free dynamic diagnostic tools for monitoring and screening TMJ abnormalities before and during orthodontic treatments.

Keywords: TMJ, CBCT, Joint Vibration Analysis, Jaw Tracker