||Quantitative evaluation of masseter muscle stiffness in patients with temporomandibular disorders by shear wave elastography
Takashima, Makiko高嶋, 真樹子
学位の種類: 博士（歯学）. 報告番号: 甲第4144号. 学位記番号: 新大院博（歯）甲第342号. 学位授与年月日: 平成28年3月23日
We aimed to quantify masseter muscle stiffness in patients with masticatory myofascial pain. Masseter muscle stiffness was measured by acoustic radiation force impulse (ARFI) imaging, which expresses stiffness as shear wave velocity (Vs). Muscle stiffness was 1.96 m/s (4.28 kPa) in 11 patients in Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) group Ia, 2.03 m/s (4.53 kPa) in 11 patients in RDC/TMD group Ib and 1.37 m/s (2.10 kPa) in 13 control subjects. Vs was significantly greater in groups Ia and Ib than in control (Steel–Dwass test, p <0.05). Characteristic pain intensity (CPI) became clear as an independent factor impacting Vs (partial regression coefficient = 0.625; multiple regression analysis, p < 0.05). Masseter muscles stiffness correlated with CPI (Spearman’s rank order test, p < 0.05) and was about two-fold greater in groups Ia and Ib than in healthy subjects.