Assessment of Correlation Between Changes of Shear Wave Elastography and Surface Electromyogram of the Masseter

Diagnoses and follow up of muscles diseases lack imaging. Severity assessment of masticatory dysfunction and follow up of treatment effectiveness is currently based only on clinical features. Supersonic ShearWave Imaging® is a new, non-invasive, non-irradiating and dynamic imaging technique that uses ultrasound and allows shear wave elastic modulus in a muscle in order to study its viscoelastic properties. In this study, the investigators study the correlation between changes of shear wave elastography modulus and surface electromyogram features of the masseters between rest and maximal voluntary contraction.