Botulinum toxins in dentistry--the new paradigm for masticatory muscle hypertonicity.

A variety of factors, such as stress, hormones, diet, drugs, trauma, and certain neuromuscular diseases, can lead to an increase in sympathetic muscle tone, which results in masticatory muscle hypertonicity and parafunction. Dentists have traditionally attempted to treat and prevent this transient disease with methods that are expensive, risky, irreversible, and not evidence-based. There is a need for a conservative reversible noninvasive treatment that is quick, easy, relatively inexpensive, long acting, and effective. Botulinum toxin, a natural protein, is one of the most potent biological substances known. Masticatory muscle relaxation can be reliably achieved by injecting measured doses of botulinum toxin into specific sites in the major muscles of mastication. A reduction in dystonia and pain with optimization of function is easily achievable with a site- and dose-specific injection protocol. The use of botulinum toxin offers the dentist an extremely effective tool to add to the armamentarium for treating conditions that derive from masticatory and other pericranial muscular conditions, and offers the general dentist who is not an expert in gnathology and occlusion a safe, effective treatment for controlling the symptoms of masticatory muscle hypertonicity.