Temporomandibular disorders (TMDs) cause chronic pain and interfere with quality of life (QoL). Botulinum toxin is one of the treatment modalities popularly used for TMDs. The primary objective of this retrospective study was to evaluate improvement in QoL after botulinum toxin injections in patients with TMD.

Twenty-eight patients diagnosed with TMD were included in this study. In accordance with the Research Diagnostic Criteria for Temporomandibular Disorders, all patients had myofascial pain. They received botulinum toxin A (BTX-A) injections in temporalis and masseter muscles. QoL was measured using a French translated version of the validated Oral Health Impact Profile-14 (OHIP-14) and a second questionnaire, which was an adaptation of the temporomandibular joint replacement QoL questionnaire (TMJ-QoL). Patients answered both questionnaires and a visual analogue scale (VAS) before the injection, at 1 month after the injection and at 3 months after the injection. Relationship between QoL and factors such as bruxism, age, sex and body mass index (BMI) were also evaluated.

All patients reported significant improvements in QoL (OHIP-14 and TMJ-QoL) and VAS Scores at 1 and 3 months after BTX-A injections (P < 0.0001). A significant moderate positive correlation was noted between TMJ-QoL before BTX-A injections and BMI (P = 0.016).

Overall, QoL in patients with TMD improved significantly at 1 and 3 months after BTX-A injections. BTX-A injection in masticatory muscles of patients with TMD can be a useful supportive therapy to control pain and improve QoL.