Usefulness of Botulinum Toxin Injection in Rehabilitation of Facial Paralysis: Improving Mouth Angle Asymmetry

Hong, Chang Kee; Byun, Jae Yong; Yeo, Seung Geun; Park, Mun Suh; Cha, Chang Il

Abstract

BACKGROUND AND OBJECTIVES: A number of surgical procedures exist to improve facial symmetry for patients with facial paralysis. Whereas static symmetry is often improved, dynamic asymmetry frequently persists because of the imbalance of complex coordinated movements of facial expression. The paralyzed face is often distorted by the excessive pull of the normal contralateral face during emotional expression. We report the use of botulinum toxin in patients with facial paralysis to improve lower facial asymmetry by limiting the excessive pull of contralateral face.
SUBJECTS AND METHOD
Ten adult patients with unilateral facial paralysis were included in this study. Patients had injections at contralateral facial muscle which were zygomaticus major, levator labii superioris and depressor angularis orii. The effectiveness of the botulinum toxin injections on facial symmerty and patient appreciation of this were assessed by measuring the level difference of both mouth angles and difference in the distance from the midline to both mouth angles before and 1 month after injection. Also patients were asked to fill up the questionnaire about the magnitude of effect and any related side effects of injection at 1 month follow up.
RESULTS
Botox injection decreased the level difference of both mouth angle and difference of distance from midline to both mouth angles in patients with unilateral facial paralysis at full-denture smiling. Five of ten patients were reported as moderate to marked improvement in expressive facial asymmetry after botulinum toxin injection into normal lower face.
CONCLUSION
Botulinum toxin injection is a useful ancillary technique for improving dynamic facial asymmetry of the paralyzed face.