Adjunctive Acupuncture for Persistent Myofascial Temporomandibular Disorder Pain

Temporomandibular disorders (TMDs) can cause persistent pain in the jaw muscles and limitations in jaw function. Occlusal splints are commonly used to manage these symptoms, but some patients continue to experience pain despite long-term splint use. The purpose of this exploratory study was to describe short-term changes after adding acupuncture to ongoing occlusal splint therapy in adults with persistent myofascial TMD pain. The study included 30 adults who had experienced pain in the masseter and/or temporalis muscles for more than 12 months and had used a maxillary full-arch stabilization splint for at least five consecutive years while remaining symptomatic. All participants continued their occlusal splint therapy and received four 30-minute acupuncture sessions, administered once per week. Assessments were performed before the first acupuncture session and after the fourth session. The assessed outcomes were pain intensity, the amount of pressure required to produce pain in the jaw muscles, maximum mouth opening, and the electrical activity of the masseter and temporalis muscles. All participants received the same intervention, and there was no control or comparison group. The study was therefore designed to characterize short-term changes within participants rather than to determine whether acupuncture was superior to another treatment or whether it directly caused the observed changes.

Inclusion Criteria: * Age 18 years or older. * Ability to understand the study procedures and provide written informed consent. * Diagnosis of myalgia according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Axis I. * Persistent or recurrent pain in the masseter and/or temporalis muscles for more than 12 months, including pain during the 30 days before enrollment, with muscular pain confirmed by clinical examination. * Use of a maxillary full-arch stabilization splint for at least five consecutive years before enrollment. * Persistence of temporomandibular disorder-related muscular pain despite ongoing occlusal splint use. Exclusion Criteria: * History of significant trauma to the temporomandibular joint. * Poorly controlled systemic metabolic disease. * Active cancer. * Pregnancy. * Significant neurological disorder. * Use of medications affecting neuromuscular function during the 30 days before enrollment. * Needle phobia. * Inability to comply with the intervention and assessment schedule.