A utilização da toxina botulínica tipo A no controle do bruxismo: revisão de literatura

Abstract

Bruxism is a repetitive muscle activity of the jaw, defined by squeezing or grinding the teeth and/or by immobilization or projection of the jaw. The symptoms of this condition include tooth wear and fracture, fractures in restaurations, tooth sensitivity, facial asymmetry, toothed tongue, trituration sounds, endodontic problems and failures in prosthetics rehabilitations. Various therapies were established with the purpose of trying to minimize the muscular hyperactivity related to bruxism. The use of the botulinum toxins is one of them. The botulinum toxin typeA is a substance produced by the bacteria Clostridium botulinum. It acts relaxing the musculature through temporarily blocking the acetylcholine liberation in the synaptic cleft. The goal of this study is to review the literature regarding the use of the botulinum toxin type-A in the bruxism control, highlighting the application methods, efficiency, adverse effects and its advantages and disadvantages. In this perspective, a review was performed in the databases PubMed, BVS and SCOPUS, using the English keywords “botulinum toxins”, “bruxism” and “treatment” and the synonyms “sleep bruxism” and “therapeutics”. Only clinical studies were included. The research resulted in 192 found articles. We excluded 181 studies after reading the titles, abstract and critical analyses. Furthermore, an article was selected through a manual search, resulting in a total of 12 included articles in this review. The botulinum toxin therapy showed good results in the reduction of the muscular contraction strength and hyperactivity and secondary pain of bruxism when it was used in an isolated form and in association with occlusal plates. Moreover, good results were seen in refractory bruxism cases unresponsive with the conventional control methods. However, the toxin activity in the bruxism genesis related to the reduction of the number and time of the events were not a consensus between the reviewed studies. In addition, the variability of the injection protocols and the possibility of adverse effects can complicate the use in the clinic ambience. Consequently, the botulinum toxin A seems to be efficient to the reduction of the muscular hyperactivity and contraction strength and pain associated with bruxism. However, better defined protocols regarding its indication and application are necessary.