Delayed surgical management is not effective for severe Bell's palsy after two months of onset.

Aims: To assess the effectiveness of delayed surgery and follow-up observation in managing severe Bell's palsy after two months of onset.

Methods: Forty-one Bell's palsy patients with severe facial paralysis were treated after two months of onset. Eighteen patients in group I underwent decompression operations between two and three months after onset, and eight patients in group II underwent surgery after three months of onset; 15 patients in group III were managed with follow-up observation. All patients were followed up at the end of 3rd, 6th and 12th months, and surgical outcomes were compared with follow-up observations using House-Brackmann score and Facial Clinimetric Evaluation (FaCE) scale.

Results: Between groups I and III, the difference in the proportion of the patients with fair or poor recoveries was statistically significant (p < 0.05) at the three-month follow-up visit. There was no significant difference in the distribution of complete, fair or poor recoveries at the 12-month follow-up visits among the three groups (p < 0.05). The total FaCE score and five individual domains were significantly improved at the end of the follow-up period in groups I and III (p < 0.05). However, in group I, the lacrimal control scores were significantly decreased at the end of the follow-up period compared to scores before surgery (p < 0.05). After surgery, four patients had sensorineural hearing loss, three patients had tinnitus and no patients had vertigo.

Conclusion: Patients with severe Bell's palsy after two months of onset would not benefit from delayed decompression surgery.