Short-term quantitative ultrasonographic assessment of masseter muscle changes following botulinum toxin injection in patients with bruxism: A prospective pilot study.

OBJECTIVES: To evaluate short-term clinical and ultrasonographic changes in the masseter muscle following botulinum toxin type A (BoNT-A) injection in participants clinically assessed as having bruxism. METHODS: Seventeen participants received standardized bilateral BoNT-A injections. Masseter muscle thickness was measured by ultrasonography at baseline, 14 days, and 90 days. Pain intensity (VAS), histogram parameters, and fractal dimension were also assessed. Bilateral measurements were averaged for statistical analysis. RESULTS: VAS scores and masseter muscle thickness decreased significantly at days 14 and 90 compared with baseline, with no significant difference between follow-up visits. Histogram and fractal dimension analyses showed no significant changes over time. CONCLUSION: BoNT-A significantly reduced pain and masseter muscle thickness, whereas ultrasonographic texture parameters remained unchanged during the 90-day follow-up.Clinical trials number: NCT07545200.