TY - JOUR
T1 - Mechanomyographic activity in the human lateral pterygoid muscle during mandibular movement
AU - Kawakami, Shigehisa
AU - Kodama, Naoki
AU - Maeda, Naoto
AU - Sakamoto, Shunichi
AU - Oki, Kazuhiro
AU - Yanagi, Yoshinobu
AU - Asaumi, Jun Ichi
AU - Maeda, Teruta
AU - Minagi, Shogo
PY - 2012/1/15
Y1 - 2012/1/15
N2 - The activity of the lateral pterygoid muscle has been regarded to be related to the pathological condition of the temporomandibular joint (TMJ) in the craniomandibular disorders. Because the lateral pterygoid muscle is a deep muscle, a needle electrode is necessary for EMG recordings. The purpose of this study was to establish a non-invasive method for the evaluation of muscle activity of the lateral pterygoid muscle using mechanomyogram (MMG). In three male subjects, surface electromyogram (EMG) in the left masseter muscle, left anterior and posterior belly of the temporal muscle, left anterior belly of the digastric muscle and needle EMG of the inferior head of the lateral pterygoid were recorded during mandibular movement tasks simultaneously with the MMG derived from a condenser microphone in the external ear canal. There were significant positive correlations between the needle EMG signal of the lateral pterygoid muscle and the MMG signal for the tasks of static jaw opened position of 30mm of interincisal distance (p=0.000, R 2=0.725), static jaw opened position of 40mm of interincisal distance (p=0.000, R 2=0.753), 5mm protruded mandibular position (p=0.000, R 2=0.653), the most protruded mandibular position (p=0.000, R 2=0803). On the contrary, for the task of maximal clenching, there was no significant correlation between the EMG signal of the lateral pterygoid muscle and the MMG signal. These results suggest that the activity of the lateral pterygoid muscle could be evaluated by the MMG signals recorded in the external ear canal, unless jaw closing major muscles show active contraction.
AB - The activity of the lateral pterygoid muscle has been regarded to be related to the pathological condition of the temporomandibular joint (TMJ) in the craniomandibular disorders. Because the lateral pterygoid muscle is a deep muscle, a needle electrode is necessary for EMG recordings. The purpose of this study was to establish a non-invasive method for the evaluation of muscle activity of the lateral pterygoid muscle using mechanomyogram (MMG). In three male subjects, surface electromyogram (EMG) in the left masseter muscle, left anterior and posterior belly of the temporal muscle, left anterior belly of the digastric muscle and needle EMG of the inferior head of the lateral pterygoid were recorded during mandibular movement tasks simultaneously with the MMG derived from a condenser microphone in the external ear canal. There were significant positive correlations between the needle EMG signal of the lateral pterygoid muscle and the MMG signal for the tasks of static jaw opened position of 30mm of interincisal distance (p=0.000, R 2=0.725), static jaw opened position of 40mm of interincisal distance (p=0.000, R 2=0.753), 5mm protruded mandibular position (p=0.000, R 2=0.653), the most protruded mandibular position (p=0.000, R 2=0803). On the contrary, for the task of maximal clenching, there was no significant correlation between the EMG signal of the lateral pterygoid muscle and the MMG signal. These results suggest that the activity of the lateral pterygoid muscle could be evaluated by the MMG signals recorded in the external ear canal, unless jaw closing major muscles show active contraction.
KW - Electromyogram
KW - Jaw movement
KW - Lateral pterygoid muscle
KW - Mechanomyogram
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U2 - 10.1016/j.jneumeth.2011.09.026
DO - 10.1016/j.jneumeth.2011.09.026
M3 - Article
C2 - 21985760
AN - SCOPUS:81555205732
VL - 203
SP - 157
EP - 162
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
SN - 0165-0270
IS - 1
ER -