Fig. 2. (A) Burst number, (B) mean burst length (s) and (C) duty time (%) for 1 day in week 9 (filled bars) and week 14 (open bars). Muscle activities exceeding 5%, 20%, 50% and 90% of the peak-EMG for all tested muscles are shown. Values are means ± S.D. Diga, digastric; Msan, superficial masseter; Mppo, posterior deep masseter; Ptm, medial pterygoid; Tem, temporalis. Asterisks indicate significant differences (P<0.05). Asterisks in A and C exceeding 50% and 90% indicate that the superficial masseter and medial pterygoid significantly differed from the digastric, deep masseter and temporalis.