title: The correlation between surface electromyography and bite force of mastication muscles in Asian young adults.
abstract: BACKGROUND
  Mastication function is related to mandible movement, muscle strength, and bite force. No standard device for measuring bite force has been developed. A linear relationship between electromyographic activity and bite force has been reported by several investigators, but data on the reliability of this relationship remain limited in Asian young adults.
  
  
  OBJECTIVE
  The purpose of this study was to develop a clinically applicable, reliable, quantitative, and noninvasive system to measure the kinetic mastication function and observe the correlation between surface electromyography (sEMG) and bite force.
  
  
  METHODS
  The study group consisted of 41 young healthy adults (24 men and 17 women). Surface electromyography was used to evaluate bilateral temporalis and masseter muscle activities, and an occlusal bite force system was used concurrently to measure the bite force during maximal voluntary biting. Bilateral symmetry was compared, and the correlation between EMG and bite force was calculated.
  
  
  RESULTS
  The sEMG signals were 107.7±55.0 μV and 106.0±56.0 μV (P=0.699) on right and left temporalis muscles and 183.7±86.2 μV and 194.8±94.3 μV (P=0.121) on right and left masseter muscles, respectively. The bite force was 5.0±3.2 kg on the right side and 5.7±4.0 kg on the left side (P=0.974). A positive correlation between sEMG and bite force was observed. The correlation coefficient between the temporalis muscle and bite force was 0.512, and that between the masseter muscle and bite force was 0.360.
  
  
  CONCLUSIONS
  No significant difference between the bilateral electromyographic activities of the temporalis and masseter muscles and bilateral bite force was observed in young healthy adults in Taiwan. A positive correlation between sEMG signals and bite force was noted. By combining sEMG and bite force, we developed a clinically applicable, quantitative, reliable, and noninvasive system for evaluating mastication function by using characteristics of biofeedback.
authors.affiliation: From the *Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC; †Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan, ROC; and ‡Graduate Institute of Medical Mechatronics, Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Cheng-I
authors.initials: CI
authors.lastname: Yen
authors.forename: Shih-Hsuan
authors.initials: SH
authors.lastname: Mao
authors.forename: Chih-Hao
authors.initials: CH
authors.lastname: Chen
authors.forename: Chien-Tzung
authors.initials: CT
authors.lastname: Chen
authors.forename: Ming-Yih
authors.initials: MY
authors.lastname: Lee
mesh_terms: D000328:Adult; D044466:Asian People; D001732:Bite Force; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000502:physiology; D008409:Mastication / Q000502:physiology*; D013703:Temporal Muscle / Q000502:physiology; D055815:Young Adult