Temporomandibular Joint Acoustic Emissions in Children With Juvenile Idiopathic Arthritis Differ From Those in Healthy Children.

PURPOSE

Articulation of the temporomandibular joint (TMJ) generates sounds with specific characteristics known as joint acoustic emissions (AEs). The purpose of this project was to determine if AEs as described by the joint health score (JHS) in children with juvenile idiopathic arthritis (JIA) differ from AEs in healthy children.

METHODS

The investigators implemented a cross-sectional study with age- and sex-matched controls to compare AEs from 4 groups: (1) healthy subjects without TMJ sounds, (2) healthy subjects with TMJ sounds, (3) subjects with JIA without TMJ sounds, and (4) subjects with TMJ sounds. Predictor variables were JIA status (ie JIA/healthy) and joint sounds (present/absent). The outcome variable was AEs. Subjects wore a specialized headset and performed specific jaw movements that generated AEs. AEs were recorded and analyzed using an aggregated decision tree classification model that calculates a JHS for each group. JHSs were compared using a receiver operating characteristic curve and classification accuracies. The study team used a 2-tailed unpaired t-test to determine if score distributions were different. Significance was P < .05.

RESULTS

A total of 51 subjects (102 TMJs; 37 females) with an average age of 13.1 years (range, 7 to 18) participated. Children with JIA and TMJ sounds had AEs with large repetitive clicks. Children with JIA without sounds had smaller repetitive clicks. Healthy children had grinding sounds with lower amplitude. The receiver operating characteristic curve had a classification accuracy of 71.6%. This accuracy compares against the gold standard clinical assessment for placing these patients into their groups (JIA vs healthy). JHSs of children with TMJ sounds and children with JIA and TMJ sounds were statistically significant (P < .0001).

CONCLUSION

In our sample, the AE of TMJs in healthy children may be different than that in children with JIA. Assessment of an AE is a promising and noninvasive technique to determine involvement of TMJs in children with JIA.