Dados do Trabalho

Título

Botulinum neurotoxin type A for tinnitus management in patients with temporomandibular disorders: a double-blind randomized controlled trial

Resumo

Introduction: Tinnitus is a common otological symptom eventually leading to the development of serious physical and emotional disorders. Although uncertainties remains about pathophysiological mechanisms, the high prevalence of such complaint and the relationship to temporomandibular disorders make this and important topic on clinical medicine. Treatment is challenging and currently there are no approved drugs. Objective: To evaluate efficacy and safety of BoNT-A injection in the masticatory muscles to treat tinnitus intensity compared to 2% lidocaine and 0.9% saline solution in patients with TMD and tinnitus. Methods: A double-blind, placebo-controlled, randomized controlled trial (RCT) involved 96 patients who were diagnosed with TMD and tinnitus. The Fonseca Anamnestic Index (FAI) was assessed to characterize the severity of TMD symptoms in patients. The protocol included evaluation using the Visual Analog Scale (VAS), Tinnitus Handicap Inventory (THI), and Survey of Pain Attitudes—brief version (SOPA-brief). Patients in all the 3 groups received injections in bilateral masseters and temporalis muscles, according to the American Pain Society criteria. Insulin needles and a 1-mL syringe (Ultra Fine Syringe 1 mL 6 ´ 0.25; UNIQMED ) were used for injection. Group A received 100 IU of onabotulinumtoxin A (Botox®) diluted in 2 mL of 0.9% saline solution; group B received 2 mL of 2% lidocaine (without vasoconstrictor); and group C received 2 mL of 0.9% saline solution. The dose was equally divided and administered in the right and left sides. Results: Myofascial pain was found in 92 patients (92.7% of TMD patients). Myofascial pain with limited opening was found in 71 patients (71.7%), disc displacement with reduction in 51 patients (51.5%), and osteoarthritis or osteoarthrosis in only 17 patients (17.2%). Evaluation using THI after 30 days of the treatment showed a significant improvement in tinnitus symptoms in the treated group [ F (2.94) = 6.498; p < 0.001]. The post hoc least significant difference test showed that the average THI score measured on the 30th day of the treatment in BONT-A group differed from that of the lidocaine group (27.9 ± 4.6 vs 22.5 ± 4.3; p < 0.001) and the saline solution group (27.9 ± 4.6 vs 23.4 ± 3.8; p < 0.001). Conclusion: This study demonstrated that BoNT-A is effective in treating tinnitus in TMD patients. However, further studies are necessary to understand better the longterm effects of BoNT-A on tinnitus.