An evidence-based review of botulinum toxin (Botox) applications in non-cosmetic head and neck conditions

Abstract

Botulinum toxin (Botox) is an exotoxin produced from Clostridium botulinum. It works by blocking the release of acetylcholine from the cholinergic nerve end plates leading to inactivity of the muscles or glands innervated. Botox is best known for its beneficial role in facial aesthetics but recent literature has highlighted its usage in multiple non-cosmetic medical and surgical conditions. This article reviews the current evidence pertaining to Botox use in the head and neck. A literature review was conducted using The Cochrane Controlled Trials Register, Medline and EMBASE databases limited to English Language articles published from 1980 to 2012. The findings suggest that there is level 1 evidence supporting the efficacy of Botox in the treatment of spasmodic dysphonia, essential voice tremor, headache, cervical dystonia, masticatory myalgia, sialorrhoea, temporomandibular joint disorders, bruxism, blepharospasm, hemifacial spasm and rhinitis. For chronic neck pain there is level 1 evidence to show that Botox is ineffective. Level 2 evidence exists for vocal tics, trigeminal neuralgia, dysphagia and post-laryngectomy oesophageal speech. For stuttering, ‘first bite syndrome’, facial nerve paresis, Frey's syndrome, oromandibular dystonia and palatal/stapedial myoclonus the evidence is level 4. Thus, the literature highlights a therapeutic role for Botox in a wide range of non-cosmetic conditions pertaining to the head and neck (mainly level 1 evidence). With ongoing research, the spectrum of clinical applications and number of people receiving Botox will no doubt increase. Botox appears to justify its title as ‘the poison that heals’.

Effective applications of botulinum toxin in dentistry and in head and neck surgery

“…The application of the botulinum toxin to the Masseter muscle can also address some other rare syndromes and symptoms such as myalgia bite, "the symptom of first bite pain" and oromandibular dystonia. 18 The possible failure of this method was experienced in our department only due to under-dose. Due to the size of the Masseter muscle, the application of the botulinum toxin is usually up to five times higher than into facial muscles in aesthetic indications.…”

Bruxism as a neurological problem (literature review)

“…Она нашла свое безальтернативное приме-нение в лечении фокальных дистоний, спастичности, но доказательная база ботулинотерапии в лечении бруксизма пока невелика [4]. Имеющиеся обзоры [27][28][29] анализируют немногочисленные контролиру-емые исследования, соответствующие критериям…”

“…В обзоре R. Persaud и соавт. [28] приведены данные высокой степени доказательности относительно эф-фективности ботулинотерапии при бруксизме, однако значительное число публикаций не поддерживают эту точку зрения. По нашему мнению, отрицательные результаты могут быть связаны с тем, что в большин-стве исследований по эффективности лечения брук-сизма БНП были инъецированы только жевательные мышцы, в некоторых -жевательные и височные, и практически нет исследований, где инъекции про-водились в латеральные крыловидные мышцы (ЛКМ) [4].…”

Surgical management of movement disorders

“…The mainstay of focal dystonia is local intramuscular injection with botulinum toxin, which causes local paralysis of the injected muscle fibres. [10] This can allow the patient with focal types of dystonia, such as musician's cramp or cervical torticollis, to have normalised movements of their hands or neck, depending on the pathology and the selected injection sites. Botulinum toxin is effective for 5 -6 months, and usually requires repeated injections to control the disability.…”