Long-term efficacy of onabotulinum toxin in treating persistent myofascial pain and masticatory muscles hypertone in an adolescent with bruxism. A 7-year follow-up case report.

Background: Temporomandibular disorders (TMDs) represent a common chronic complaint, which includes myofascial pain (MP). Although several therapeutical options have been proposed to control bruxism-related muscle hyperactivity, there is not enough evidence to define a standard approach. The present article describes the case of a 14-year old male patient with a history of painful mandibular close lock.

Case Report: The patient was diagnosed with persistent myofascial pain in the left masseter, bilateral disc displacement with reduction, and retrodiscitis and capsulitis in the left temporomandibular joint. Awake and sleep bruxism were also present. Since first line treatments failed in managing the disorders, injections of onabotulinum toxin (BoNT-A ) were performed. After one month the pain decreased significantly and the jaw movements were restored. The patient was recommended to avoid hard and/or rubbery food, wide movements of the jaws and teeth clenching and to wear orthodontic appliance during the night since the joint damage was moderate. We report the 7-year follow-up demonstrating the long-term efficacy of a single injection of onabotulinum toxin in masseters and temporalis muscles in order to treat masticatory pain and dysfunctions.

Conclusion: The authors suggest that BoNT-A could be an optimum treatment for persistent MP and bruxism in young adolescents when first-line therapies fail.