Cortical Dysfunction in Patients with Temporomandibular Disorders

Effects of mental and physical orofacial training on pressure pain sensitivity and tongue strength: A single-blind randomized controlled trial

OBJECTIVES

The main objective of this study was to analyze differences on pain pressure thresholds, tongue strength and perceived effort between various orofacial motor exercise training dosages of mental representation training through motor imagery (MI) and action observation (AO), first in isolation and then in combination with real exercise performance.

METHODS

A single-blind randomized controlled trial was designed. 48 asymptomatic individuals were randomized into two groups: Intensive training group (IG) and Moderate training group (MG). Both groups performed a first session of MI and AO of orofacial exercises training and a second session of actual orofacial exercises combined with mental representation training, but with different dosage in terms of series and repetitions. Pain pressure thresholds (PPTs) in the masseter and temporal muscles and tongue muscle strength were the main variables.

RESULTS

Regarding the PPT, ANOVA revealed significant between-group differences, where MG showed a significantly higher PPT than IG at post-day2, with a medium effect size. Both groups showed with-in group differences between pre and post intervention measures in the first session, but only the IG showed differences in the second. Regarding tongue muscle strength, ANOVA revealed significant within-group differences only in MG between the pre-day and post-day first intervention.

CONCLUSION

The results of the present study suggest that movement representation training performed in isolation may have a positive effect on PPTs and tongue muscle strength. In addition, the combination with the actual execution of the exercises could be considered effective, but it is necessary to take into account the training dosage to avoid fatigue responses.

Difference in Response to a Motor Imagery Task: A Comparison between Individuals with and without Painful Temporomandibular Disorders

The aim of the study was to investigate the difference in response to a motor imagery task between individuals with and without painful temporomandibular disorders (TMDs). The participants were 24 adults with and without TMD (TMD and control group, resp.). A set of photographic images of the profile view of a person's head and neck and a hand and a foot were presented in a random order. The set consisted of six different orientations with rotations of each image at 0, 60, 120, 180, 240, and 300 degrees and included left and right representations. The participants were required to view the image and make a decision as to whether it was a left or a right side presented, that is, mental rotation (MR) task. Data were collected on 48 tasks (including left and right) at each orientation for each body part. Reaction times (RTs) for correct answers and accuracy in making the left or right judgements were recorded. The RT was slower in the TMD group than in the control group. The RT for the profile image was slower than those for the hand and foot images. For images that were 180 degrees, the RT was slower and the accuracy was lower than those for five of the other image orientations. The judgements made about the 180-degree rotated image were more inaccurate compared to images of all other orientations among all types of stimuli.