Masseter Myofascial Pain Relief Following an Intra-muscular Injection With Botulinum Toxin Type A.

Investigating the effect of a single intramuscular injection with botulinum toxin (BTX) compared to NaCl in patients with jaw muscle myalgia. This investigation is designed as an double blind multicenter pilot study for hypothesis generation on 48 patients with chronic jaw muscle myalgia at four specialist dental clinics. The subjects visit the clinic on 3 predefined occasions, one telephone call and one scheduled evaluation by mail. The objective is primarily to evaluate the change in number of days with pain at two months following one session of BTX injections of the masseter and temporalis muscles in subjects with jaw muscle myalgia pain. The outcome of this study will serve as a basis for a later randomized controlled trial