Materials and methods: The prospective randomized controlled animal study was conducted between November 2023 and January 2024. Thirty-two male Sprague-Dawley rats (mean weight: 300±30 g; range, 270 to 330 g; mean age: 8±1 weeks) with experimentally induced facial nerve injury were divided into five subgroups: control, paralyzed, methylprednisolone (2 mg/kg/day, intramuscular), ozone (1.1 mg/kg/day, intraperitoneal), and combination (ozone+methylprednisolone). Treatments were administered for 14 days. Functional, histologic, and immunohistochemical examinations were made.

Results: Posttreatment comparison of treatment groups showed that whisker movements (p=0.001) and total clinic scores (p=0.023) were significantly higher in the combination group compared to the ozone group. In histologic analysis, vascular congestion was significantly lower in the methylprednisolone group than in the ozone group (p=0.012). On the other hand, apoptosis levels, indicating cell death in the facial nerve, were significantly lower in the combination group compared to the methylprednisolone (p=0.016) and ozone (p=0.036) groups.

Conclusion: The combination of methylprednisolone and ozone lead to the most favorable functional and cellular outcomes. Further studies are required to confirm the benefits of ozone therapy for human facial paralysis, understand the molecular mechanisms behind its effectiveness, and determine the optimal doses for combined treatment. Keywords : Corticosteroid, facial paralysis, methylprednisolone, ozone, rat