Effect of intra-articular Botulinum toxin injections on temporo-mandibular joint pain

Temporo-mandibular joint dysfunction can be painful and disabling. In some cases, it is refractory to classical treatment. Intra-articular Botulinum toxin injections have been shown to have an anti-inflammatory and analgesic effect. The aim of this study was to evaluate the effectiveness of such injections on severe, refractory temporo-mandibular joint pain. This was a retrospective study. Patients were included if they still had joint pain≥5 on a Visual Analogue Scale following completion of all other treatments. A complete treatment protocol (including physiotherapy, tongue splints, intra muscular injections of Botulinum toxin and injections of hyaluronic acid, excluding surgery) having being done before the injection of 30 Botox* units (Botulinum toxin A), the treatment being considered clinically successful if the Visual Analogue Scale decreases by at least 2 points. Seventy-seven patients were included. Sixty-six percent of patients have a significant reduction in pain at 1 month which lasted at least until 3 months. Mouth opening and quality of life also improved. Moreover, no complications were reported. Further randomized, controlled studies are needed to confirm the results, however this study suggests intra-articular injection of Botulinum toxin is a safe and effective treatment for severe, refractory temporo-mandibular joint pain, avoiding surgery.