Botulinum toxin injection of both sides of the face to treat post-paralytic facial synkinesis.

Objective: An attempt has been made to produce a new 'balance' in facial dynamics between a paralysed and a non-paralysed face with reduction of synkinesis, by concomitant injection of botulinum toxin A (BTX-A) on both sides in patients with long-lasting facial sequelae.

Study Design: Prospective clinical study.

Setting: University hospital.

Subjects And Methods: Forty-two consecutive patients who recovered partially from facial nerve paralysis were enrolled for this study. The amount injected per site of the paralysed side with synkinesis varied from 1.5 to 2.5 U, and the total dose used per patient was 10-26 U (mean 17.12±5.3 U). That of the non-paralysed side with muscular hypertrophy varied from 2.5 to 5 U, and the total dose used per patient was 35-72 U (mean 52.6±9.7 U). All patients had been evaluated by the Sunnybrook (SB) facial nerve grading systems and developed dynamic facial asymmetry ratio.

Results: After administration of injection of BTX-A on both sides of the face, relief of facial synkinesis and enhancement of facial symmetry were observed in all patients. Before the injection, the patients showed an SB score of 38.8±10.68. After the injection, changes of synkinesis and symmetry score were 7.9±1.81 and 8.4±3.25, respectively, resulting in a 58.4±12.46 score at the last evaluation. Before the administration, the mean±standard deviation (SD) value of dynamic facial asymmetry was 0.83±0.06 and it was increased significantly to 0.90±0.05 1 month after administration.

Conclusion: After BTX-A injection on both sides for synkinesis and contralateral hypertrophy, the patients showed significant suppression of the synkinesis and improvement of facial symmetry with resulting elevated quality of life, social interaction, personal appearance and food intake.