HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Hidaka, O. Articles by Takada, K. Search for Related Content PubMed PubMed Citation Articles by Hidaka, O. Articles by Takada, K.

Mental Stress-induced Physiological Changes in the Human Masseter Muscle

Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan;

View larger version (12K): [in a new window]   Figure 1. Diagram of the experimental protocol. MST, mental stress task; MVCs, muscle voluntary contractions; HRV, heart rate variability.

View larger version (11K): [in a new window]   Figure 2. Effects of mental stress on HRV spectral parameters. Lo/Hi, an indicator of the sympathetic nervous system activity; Hi/TPW, an indicator of the parasympathetic nervous system activity; MST, mental stress task. Data are expressed as means ± SEM (standard error of the mean) (n = 12). ** p < 0.01 (Scheffé).

View larger version (12K): [in a new window]   Figure 3. Effects of mental stress on IEMGs of the masseter and temporalis muscles. IEMG, integrated electromyographic activity; MST, mental stress task. Ordinates: values normalized to the maximum of measurements from the 6 analyzed periods (Rest1, Rest2, and MST1-4). Data are expressed as means ± SEM (standard error of the mean) (n = 12) * p < 0.001 (Scheffé).

View larger version (9K): [in a new window]   Figure 4. Effects of mental stress on hemodynamics of the masseter muscle. OxyHb, oxygenated hemoglobin; DeoxyHb, deoxygenated hemoglobin; TotalHb, total haemoglobin (OxyHb + DeoxyHb); StO2, tissue blood oxygen saturation (OxyHb/TotalHb x 100); MST, mental stress task. Ordinates: values normalized to the maximum of measurements from the 6 analyzed periods (Rest1, Rest2, and MST1-4). Data are expressed as means ± SEM (standard error of the mean) (n = 12). p < 0.1, ** p < 0.01, *** p < 0.001 (Scheffé).