The evaluation of the relationship between changes in masseter muscle thickness and tooth clenching habits of bruxism patients treated with botulinum toxin A

Background: Bruxism is defined as recurrent masticatory muscle activity. Although there is not an agreed treatment method for bruxism, the application of botulinum toxin A (BT-A) has become a reliable lately. This study aimed to evaluate the correlation between the changes in masseter muscle thickness and clenching habits in bruxism patients treated with BT-A. Methods: Twenty-five patients, 23 females and 2 males, diagnosed with possible sleep bruxism were included in the study. The Fonseca Anamnestic Index was applied to the patients to determine their clenching habits and depression levels both before the treatment, and 6 months after it. The masseter muscle thickness was measured using ultrasonography before the treatment and 3 months and 6 months after the treatment. All the patients were injected with a total of 50 U of BT-A, 25 U to each masseter. Results: A statistically significant decrease in masseter muscle thickness was observed in the ultrasonography 3 and 6 months after the BT-A treatment. There was a statistically significant decrease in the Fonseca scores, in which the teeth clenching habits of the patients were evaluated 6 months after the treatment. Although there was a decrease in the depression levels of the patients 6 months after the treatment, this difference was not statistically significant. Conclusion: When the results of this study were evaluated, it was seen that the BT-A injections are an effective, safe, and side effect-free method in the treatment of bruxism and masseter hypertrophy.