Alterations in jaw clenching force control in people with myogenic temporomandibular disorders

Abstract

Isometric bite force control, via measures of force accuracy, force steadiness and force proprioception, was assessed in patients with myogenic temporomandibular disorders (TMDs) compared to healthy controls. Twelve people with myogenic TMDs and twelve age-and gender-matched asymptomatic controls performed maximal voluntary contractions (MVC) of unilateral jaw clenching followed by submaximal isometric contractions, with and without visual feedback of force, at 10, 30 50% and 70% MVC. Force performance was assessed with indices of accuracy (mean distance, MD) and precision (standard deviation, SD) and reported as a percentage of the MVC. A mixed-effect model was used to evaluate differences in MVC, MD and SD. The MVC was lower in the patient group when clenching either ipsilateral or contralateral to the side of greatest pain (p<0.05). No difference in MD was observed between groups. The SD depended on the interaction between group and painful side (p = 0.04) with patients displaying higher SD when executing the task with the most painful side when compared to the ipsilateral or contralateral sides of the control group. The reduced maximal bite force and force steadiness observed in people with myogenic pain may interfere with masticatory function and should be considered when planning therapeutic interventions for TMDs. Joachim Erlenwein is a Medical Doctor working in the Pain

Effects of Therapeutic and Aerobic Exercise Programs on Pain, Neuromuscular Activation, and Bite Force in Patients with Temporomandibular Disorders

“…The results are in line with those observed by other authors, who found that the decrease in masticatory muscle pain intensity led to an increase in BF [46]. Another set of studies evaluating the BF of patients with TMD in comparison with healthy subjects found that the masticatory MVC was reduced in the group of participants with TMD [8,47]. Cho and Lee [7] obtained similar results, since they found that the presence of pain led to a decrease in BF, although it is necessary to emphasize that in these studies, pain was experimentally induced.…”

Occlusal tactile acuity in temporomandibular disorder pain patients: A case‐control study

“…To the best of our knowledge, there are no data on whether patients with painful TMD bite with higher forces than non‐TMD subjects. On the other hand, force control at low level is not impaired in myogenous patients 42 . Fifth, TMD‐pain lasted for less than 6 months, and in only one half of them, the pain had an impact on their daily life.…”

Signal acquisition and analysis of ambulatory electromyographic recordings for the assessment of sleep bruxism: A scoping review

“…This is unfortunate for sleep bruxism studies, in which individuals with pain in the masticatory system are often investigated. It has been shown that the force, measured in N, which is exerted during maximal contraction on force transducers, is decreased in individuals with pain in the masticatory system, compared to pain‐free controls 142,143 . In addition, Manfredini et al found that in individuals with myofascial pain the level of EMG activity of masticatory muscles was significantly lower compared to pain‐free controls, during maximum clenching on cotton rolls 144 .…”