Myectomy and botulinum toxin for paralysis of the marginal mandibular branch of the facial nerve: a series of 76 cases.

Abstract

Paralysis of the marginal mandibular branch of the facial nerve is frequently seen in patients with oromandibular reconstructions or facial palsy. However, deformities caused by overpulling of the depressor muscles of the contralateral lower lip without being antagonized by the diseased counterpart is often quite conspicuous. Depressor myectomy of the contralateral lower lip therefore provides a method for correcting the dynamic deformity. Seventy-six patients with paralysis of the marginal mandibular branch of the facial nerve were treated with either surgical depressor myectomy of the lower lip (25 patients), depressor myectomy with subsequent botulinum toxin injection (eight patients), or only chemical depressor myectomy with botulinum toxin injections (43 patients). Good to fair results were always achieved, with near balance of the lower lip during mouth opening and in facial expressions. Surgical myectomy may still result in recurrence in eight patients (24 percent), which will necessitate further treatment with botulinum toxin injections. Using myectomy for paralysis of the marginal mandibular branch of the facial nerve can be an effective treatment for this significant deformity. Chemical myectomy with botulinum toxin injection is a safe and convenient mode of treatment; however, the disadvantage is that it needs repeated injections and costs more.