Use of botulinum toxin in masseteric muscle hypertrophy

Objective: Unilateral and bilateral masseteric muscle hypertrophy is an idiopathic enlargement of the masticatory muscles without age and sex prevalence. Today it is often found and diagnosed in patients with temporomandibular disorders like bruxism and other stress-related teeth clenching and grinding. This case report aims to evaluate the effect of botulinum toxin therapy in patients with bilateral masseter hypertrophy. Method: A 30-year-old female patient, with a tender bilateral masseteric enlargement due to a severe form of bruxism, was treated with a stabilization Michigan splint for three months. After initial therapy, she was injected with 60 units of botulinum toxin (Dysport 500) diluted in 3ml sterile, preservative-free saline solution (0.9% sodium chloride injection solution) in each masseteric muscle. Results: Four weeks after treatment the patient reported a significant reduction in pain symptoms and muscle strength. She also noticed slimming of the lower third of the face and a rounded mandibular angle. Clinical palpation post-treatment revealed a reduction in muscle strength and we had a high patient satisfaction level. Conclusion: Neuromodulators have been successfully used to control painful symptoms and aesthetic de-bulking of the masseter muscle. Further research is required to ensure the safe and effective use of neuromodulators in this common disorder. Keywords: bruxism, masseteric hypertrophy, botulinum toxin