Investigation of the relationship between static and dynamic balance performance and temporomandibular dysfunction symptoms in healthy adults

This study was planned to investigate the relationship between temporomandibular dysfunction (TMD) symptoms and balance performance in healthy adults. The study included 90 volunteer university students aged 18-30 who met the inclusion criteria and completed the evaluations. TMD symptoms of the participants were evaluated by Temporomandibular Dysfunction Diagnostic Criteria (TMD/DDK) Clinical Examination Form, presence of TMD was evaluated by Fonseca Anamnestic Questionnaire (FAA), pain felt in the TMJ region was assessed by Numeric Pain Scale (NAS), head forward posture was evaluated by goniometer, pressure pain threshold of masseter muscle was assessed by algometer, static and dynamic balance performance was evaluated by The CoreBalance System. The Neurotrac Myoplus Pro 4 superficial EMG device recorded masseter muscle activations during balance performance. No significant correlation was found between FAA scores, TMJ pain at rest and during mastication, range of motion and balance scores (p>0.05). Negative and moderately significant relationships were found between the pressure pain threshold of the right and left masseter muscle and balance performance (p<0.05). A significant correlation was found between head forward posture and only eyes open static balance scores (r=0.237, p=0.025). The mean %MVC (maximal voluntary contraction) values of the right masseter muscle were 33.69, 29.34 and 26.28, respectively, and the mean %MVC values of the left masseter muscle were 34.35, 29.45 and 24.93, respectively. Spontaneous activation of the masseter muscle was observed in almost all participants during balance performance, and no significant difference was found between right and left masseter muscle activations (p>0.05). In conclusion, this study showed no direct relationship between balance performance and TMD; the low-pressure pain threshold of the masseter muscle and increased head forward posture were associated with decreased balance performance, and spontaneous activation of the masseter muscle occurred during balance performance.