The use of a custom-made mouthguard stabilizes the electromyographic activity of the masticatory muscles among Karate-Dō athletes.
OBJECTIVE
To analyze and compare the electromyographic activity of the temporal (anterior portion) and masseter muscles among Karate-Dō athletes before and after training, with and without the use of a mouthguard.


METHODS
Twenty athletes (14 males and 6 females) with a mean age of 23.7 ± 7.5 years participated. They had surface electromyography recordings taken of their bilateral temporal and masseter muscles before and after training under the following conditions: no mouthguard, with a ready-made mouthguard, and with a custom-made mouthguard. Activity was examined at mandibular rest, while clenching, and at maximum voluntary contraction. The data were normalized using the mean maximum voluntary contraction.


RESULTS
The right (p = 0.005) and left (p = 0.015) temporal muscles showed significantly lower electromyographic activity with a custom-made mouthguard compared with no mouthguard after training while clenching. The electromyographic activity of the temporal and masseter muscles did not show significant differences when tested at mandibular rest and while clenching before or after training with a custom-made mouthguard (p > 0.05).


CONCLUSIONS
The use of a custom-made mouthguard preserved participants' electromyographic profiles before and after training; thus, they allow for stable muscle activity during the training of Karate-Dō athletes.
Midwest State University (Universidade Estadual do Centro-Oeste; Unicentro), Irati, PR, Brazil.
Gilsane
G
Raquel
Coordinator of the Graduate Course in Sports Dentistry, Universidade Positivo, Curitiba, PR, Brazil.
Eli Luis
EL
Namba
School of Dentistry, Federal University of Paraná, Curitiba, PR, Brazil.
Daniel
D
Bonotto
Graduate Program in Dentistry, School of Health and Biosciences, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil.
Edvaldo Antônio
EA
Ribeiro Rosa
Graduate Program in Dentistry, School of Health and Biosciences, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil.
Paula Cristina
PC
Trevilatto
School of Dentistry, Federal University of Paraná, Curitiba, PR, Brazil.
Maria Ângela
MÂ
Naval Machado
School of Health and Biosciences, Pontifícia Universidade Católica do Paraná, Department of Anatomy, Federal University of Paraná, Curitiba, PR, Brazil.
Michelle Santos
MS
Vianna-Lara
Graduate Program in Dentistry, School of Health and Biosciences, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil. Electronic address: l.azevedo@pucpr.br.
Luciana Reis
LR
Azevedo-Alanis
D000293:Adolescent; D000328:Adult; D056352:Athletes; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D016139:Martial Arts / Q000502:physiology*; D008406:Masseter Muscle / Q000502:physiology; D008410:Masticatory Muscles / Q000502:physiology*; D009064:Mouth Protectors; D009119:Muscle Contraction / Q000502:physiology*; D013703:Temporal Muscle / Q000502:physiology; D055815:Young Adult
Facial injuries; Injury prevention; Martial arts