Pesquisa da fadiga nos músculos faciais e mastigatórios: revisão de literatura

Immediate effects of red (660 nm) and infrared (808 nm) photobiomodulation therapy on fatigue of the orbicularis oris muscle: a randomized clinical study

PURPOSE

To compare the immediate effects of laser photobiomodulation at wavelengths of 660 nm and 808 nm on fatigue of the orbicularis oris.

METHODS

This is a randomized study with 60 women aged between 19 and 43 years. The participants were divided into four groups. Group RG received photobiomodulation with a laser wavelength of 660 nm at four points of the orbicularis oris; group IRG received photobiomodulation with a laser wavelength of 808 nm at the same points; the control group did not receive light treatment; and the placebo group underwent the same procedures as RG and IRG but with the equipment switched off. The irradiation was performed with a laser of 100 mW of power, 4 J of energy per point and 133.3 J/cm2 of fluency. An electromyography evaluation was performed before and after the irradiation, concomitantly with the exercise of lip protrusion maintained until the sensation of fatigue. Fatigue was evaluated by a median frequency using the electromyographic fatigue index. The amplitude of the signal was evaluated, examining the root mean square, and the values were normalized by the peak. The difference in amplitude between the upper and lower lips was also analyzed. All variables were compared before and after irradiation.

RESULTS

No significant difference was found between the measures taken before and after irradiation.

CONCLUSION

Photobiomodulation with the parameters investigated in this study had no immediate effect on orbicular oris fatigue.

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.

Effect of Phototherapy on Masseter and Anterior Temporal Muscles Before Induction of Fatigue: A Randomized, Sham-Controlled, Blind Clinical Trial

OBJECTIVE

This is a randomized, sham-controlled, blind clinical trial that aimed to evaluate the effect of phototherapy on bite force, mandibular range of motion, sensitivity to palpation, and fatigue in the masseter and anterior temporal muscles of young patients when administered before the induction of fatigue.

MATERIALS AND METHODS

Fifty-two healthy volunteers aged 18-23 years were randomly allocated to a laser group and sham group. Both groups were submitted to a clinical evaluation to record mandibular range of motion, bite force, muscle sensitivity to palpation, and muscle fatigue. The laser group was then submitted to phototherapy (780 nm, 25 J/cm², 50 mW, 20 sec, and 1 J per point) on three points of the masseter and one point of the anterior temporal muscle on each side. The sham group was submitted to the same procedure, but with the device switched off. The volunteers were then instructed to chew two pieces of gum (one on each side) for 6 min, with the pace set by a metronome calibrated to 80 bpm, followed by the reevaluation of all variables. The results were submitted to t-test and Wilcoxon test. A significance level of 5% (p < 0.05) was considered in all analyses.

RESULTS

No statistically significant intergroup or intragroup differences were found for the variables analyzed.

CONCLUSIONS

With the proposed protocol, phototherapy administered before the induction of fatigue did not lead to any changes in bite force and mandibular range of motion, indicating that further studies are needed with different phototherapy dosimetric parameters.

Risk Factors of Orofacial Pain: A Population-Based Study in West Java Province, Indonesia

Background:

The management of orofacial pain in Indonesia has not been well performed, which consequently led to an increase in the orofacial pain occurrences and a decreased quality of life. One of the possible reasons for this particular matter is the lack of evaluation on the risk factors that might induce orofacial pain in some individuals.

Objective:

The objective of the current study was to evaluate the risk factors of orofacial pain on productive age population in West Java province, Indonesia.

Methods:

One thousand and fifty-six participants (522 males; 534 females) were recruited for the study. A questionnaire that consists of demographic questions and questions evaluating several assumed risk factors for orofacial pain was used in a single interview. All data was analyzed by using Chi Square test to test the significance, Odds Ratio (OR), as well as Relative Risk (RR) by using SPSS version 23 (IBM Statistic, USA).

Results:

The result of the current study revealed that bruxism (p<0.01), daytime clenching (p<0.01), and unilateral chewing (p<0.01) were significantly related to the occurrence of orofacial pain. It was also found that participants who performed multitude of heavy liftings at work have an increased risk (RR=1.19: 95% CI: 1.04 – 1.35) of having orofacial pain compared to those who do not.

Conclusion:

Risk factors for the occurrence of orofacial pain on productive age population in Indonesian sample consisted of oral parafunctional habits and non-parafunctional habits, such as heavy lifting. Further study in this particular topic is of importance.