A Single-Blinded Prospective Study on Using Botulinum Toxin Type A for Reducing Alar Mobility.

Abstract

With widespread utilization of instant social media, people desire a minimally invasive treatment to improve alar dynamic aesthetic, but few practical procedures on reducing alar mobility have been conducted. This study aimed to verify the effects of botulinum toxin on reducing nasal alar mobility and provide a supplemental treatment of rhinoplasty. This single-blind prospective study included a cohort of 20 participants with the desire to improve their alar dynamic aesthetic. The experimental group was injected with 3U botulinum toxin type A at dilator naris anterior, dilator naris vestibularis, levator labii superioris alaeque nasi, and dilator naris, and the control group received the equivalent of saline. Standardized facial movement (from rest to maximum smile without revealing teeth) was recorded with a 3-dimensional imaging system. The changes between rest and maximum smile statuses represented alar mobility and were generated by MOBILITY=WIDTHsmile-WIDTHrestWIDTHrest×100%. Alar mobility and root mean square analysis were employed for postoperative evaluations. In the experimental group, alar flaring mobility decreased from 10.05% ± 6.40% to 4.91% ± 3.48%(P < 0.05), and alar base mobility decreased from 16.83% ± 5.69% to 12.50% ± 4.89% (P < 0.05), whereas no significant changes in alar mobility were found in the control group. In root mean square analysis, changes in the experimental group were significantly higher than in the control group (P < 0.05). Botulinum toxin type A can effectively restrain alar mobility without any significant adverse events and improve alar dynamic esthetic, which can serve as a minimally invasive method or supplemental treatment for rhinoplasty.