Biometric Characteristics of TMJ, Masticatory Muscles and Teeth in Dental Malocclusion in an Asymptomatic Population

**Specific Aim:** With biometric technologies, the interrelationship between the TM joints, the masticatory muscles, and the teeth can be accurately measured, providing insight into disc displacements, hyperactive musculature, and abnormal bite force distribution. The Specific Aim was to use JVA, T-Scan, and EMG, to report baseline occlusal parameters in Angle Class I, II and III malocclusion patients. **Method & Materials:** A total of 68 asymptomatic patients were divided by Angle’s Class into 3 groups, and subjected to JVA, TScan/BioEMG recordings of Maximum Intercuspation (MIP), excursive movements and the full range of TMJ motion. Recorded TM joint vibrations, bite force imbalances, Occlusion Time (OT) and Disclusion Time (DT), and muscle hyperactivity observed per Class, were analyzed with the Chi-square, Student t-test and ANOVA. **Results:** Subjects with normal JVA had significantly lower Total Integrals, larger mouth opening, and lower peak amplitudes compared to the non-normal subjects as indicated by JVA. More Class II subjects had non-normal Occlusion Time (OT) (p = 0.015). Class III subjects demonstrated the worst force distribution, as no Class III subjects approached the Standard Deviation Center of Force (COF) position (inside the grey outer COF target). And 45.5% of the Class III subjects’ COF was outside the COF target (p < 0.001). Class I subjects demonstrated the best force distribution, with many Class I COFs positioned inside the normative target. **Conclusion:** Despite being asymptomatic, most of the subjects exhibited abnormal TM joints, unbalanced bite force, and/or muscle hyperactivity, suggesting that presenting without symptoms does not indicate that good occlusal, muscular, or TM joint health exists. A treating clinician should understand that any pre-existing masticatory system abnormality may impact an occlusal treatment outcome.