In a study published in the Journal of Oralfacial Pain, 2010 (J Orofac Pain 2010, 24(1):106-12), authors J Fernandez-Carnero and colleagues from the Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine at the Universidad Rey Juan Carlos, Spain, found in a randomized controlled trial that a single dry needling of a masseter trigger point caused an increase in pressure pain threshold (PPT) and in jaw opening in comparison to sham needling.
Twelve females aged 20-41 years with myofascial pain involving the masseter muscle were enrolled in the study. Subjects randomly received either dry needling or sham needling at two clinical sessions spaced days apart. Each subject was evaluated five minutes before and after each interventionby an examiner that was blinded to the actual procedure. The two variables of interest were the PPT of the masseter and jaw opening.
Statistical analysis revealed that those who received the actual dry needling were significantly better than those subjects who received the sham needling. There were significant increases in the pressure pain threshold and jaw opening. Subjects receiving the dry needling also showed greater improvement than the sham subjects with respect to other variables as well.
excerpt from: http://dental.healthimaginghub.com/portals/dental-implants-news-article/2531-dry-needling-of-masseter-trigger-points-improves-tmd.html