Temporomandibular Disorder Patients Benefit From Intramuscular Botulinum Toxin Type a Injections.

[PURPOSE] The aim of this study was to analyze the clinical outcome of the use of botulinum toxin type A (BTX) intramuscular injections to the head and neck, particularly the masticatory muscles of patients with temporomandibular disorder (TMD).

[METHODS] The medical records of all patients who had received intramuscular BTX injections between 2005 and 2018 at Päijät- Häme Central Hospital, Lahti, Finland were analyzed retrospectively. Gender, age, previous medical history, number of injections, injection areas, and therapeutic results were collected and analyzed. The outcome was divided into three categories based on the patients' subjective reports: not beneficial, beneficial, and highly beneficial.

[RESULTS] A total of 68 patients had received intramuscular BTX injections in our unit for TMD symptoms. Clinical effectiveness could be analyzed from 63 patients. Overall, 87% of them reported fävorable outcomes. 8 (13%) reported BTX injections as not beneficial, 15 (24%) as beneficial, and 40 patients (63%) as highly beneficial.Most patients had already received conventional treatment with an occlusal splint (93%) combined with pain medication (60%) in the primary care units before they were referred to our hospital.There were 59 (83%) female patients, and they responded better to BTX therapy than the male patients: 91% versus 57% (P value = 0.04). Average age at the first BTX injection visit was 44.6 years (range 17.8-77.2). Most commonly (65%), BTX was divided bilaterally to the masseter and temporalis muscles.

[CONCLUSIONS] BTX injections had good therapeutic outcomes for our TMD patients. However, most patients require multiple injection visits.