顎関節症患者の咀嚼筋痛に対するボツリヌス毒素の効果：無作為化、二重盲検、プラセボ対照パイロット試験

Effect of Botulinum Toxin on Masticatory Muscle Pain in Patients with Temporomandibular Disorders: A Randomized, Double-Blind, Placebo-Controlled Pilot Study.

抄録

本研究は、咀嚼筋痛（MMP）と頭痛を伴う顎関節症（TMD）患者におけるA型ボツリヌス毒素（BoNT/A）の有効性を評価することを目的とした。この無作為二重盲検プラセボ対照パイロット試験は、両疾患を同時に評価した初めての臨床試験である。筋原性顎関節症患者21人を無作為に2群に割り付けた。実験群と対照群には、咬筋、側頭筋、脾頭筋、胸鎖乳突筋、僧帽筋を含む計16の筋部位の触診後に圧痛を示す部位に、BoNT/Aまたは生理食塩水のいずれかを注射した。各診察時に、口腔顔面痛の強さ（OVAS）、頭痛（HVAS）、圧痛点の数（TP）、最大開口度（MMO）、頭痛頻度（HF）に基づく臨床効果を、両群とも注射前、注射後4、8、12週の4時点で評価した。解析にはフリードマン検定とマン・ホイットニー検定を用いた。実験群では、MMOを除き、OVAS、TP、HVAS、HFの減少に経時的な有意差が認められたが、対照群ではいずれの変数にも有意差は認められなかった。さらに、TPの低下は、すべての時点、特に4週後と12週後において、注射前と比較して実験群と対照群で有意差が認められた。結論として、BoNT/Aによる治療は、生理食塩水のプラセボと比較して、顎関節症および頭痛による咀嚼筋痛に比較的有効であった。

This study aimed to evaluate the efficacy of botulinum toxin type A (BoNT/A) in patients with temporomandibular disorders (TMDs) associated with masticatory muscle pain (MMP) and headaches. This randomized, double-blind, placebo-controlled pilot study is the first clinical trial to evaluate both disorders simultaneously. Twenty-one patients with myogenous TMD were randomly assigned to two groups. The experimental and control groups received injections of either BoNT/A or saline into the sites showing tenderness after palpation of a total of 16 muscle areas, including each masseter, a temporalis, splenius capitis, sternocleidomastoid, and trapezius muscle. During each visit, the clinical effects, based on the intensity of orofacial pain (OVAS), headache (HVAS), number of tender points (TPs), maximum mouth opening (MMO), and headache frequency (HF), were evaluated at four time points, namely, pre-injection and 4, 8, and 12 weeks after the injection, in both groups. Friedman and Mann-Whitney tests were used for the analyses. In the experimental group, the reductions in OVAS, TP, HVAS, and HF showed significant differences over time, excluding MMO, whereas there was no significant difference in any of the variables in the control group. In addition, the decline in TPs was significantly different between the experimental and control groups at all time points, especially after 4 and 12 weeks, compared to that during pre-injection. In conclusion, treatment with BoNT/A was relatively effective for masticatory muscle pain caused by TMDs and headache compared to the saline placebo.