The management of oromandibular motor disorders and facial spasms with injections of botulinum toxin

The fact that a toxin produced by the anaerobic bacterium Clostridium botulinum is able to block motor nerve conduction was discovered and converted to therapeutic use more than 3 decades ago. This block lasts 8 to 16 weeks with botulinum toxin type A. This article discusses the various disorders (Table 1) in the orofacial region for which botulinum toxin has been used. The disorders listed in Table 1 seem to be helped in varying degrees by botulinum toxin injections, and any clinician who has used this medication would testify to its powerful and dramatic effect in some cases. In general, this treatment is only palliative, however, except perhaps in some headache disorders, in which chronic headache pain may diminish substantially and for a much longer time than the 8- to 16-week effect seen in muscle spasm. The nature of this evidence is not discussed in this article; whether the putative long-lasting effects of botulinum toxin on headaches are serendipity or real is being determined by ongoing controlled blinded clinical trials. With regard to the masticatory muscle spastic disorders described in this article, most of the data reviewed were open-label clinical trials or case reports. Caveats Although most of the problems discussed in this article are clear-cut motor disorders; two excessive secretion problems, sialorrhea and hyperlacrimation, are included because they also occur in the orofacial region. Most of the reports described in this article relate to botulinum toxin type A,