Uncommon foreign body reaction caused by botulinum toxin.

Botulinum toxin is composed of 7 botulinum toxin antigenic subtypes. It is produced by Clostridium botulinum bacterial fermentation. Several botulinum toxin subtypes are under investigation for clinical use, but only botulinum toxin type A (BTX-A) is currently approved for cosmetic use because of its clinical safety profile and efficacy. The use of BTX-A in cosmetic facial procedures is a reliable way to enhance aesthetics in the face and is becoming commonplace in oral and maxillofacial surgery. This article reports an uncommon complication after Botox injection in the upper lip, for cosmetic reasons, originating a mass in the anterior region of the maxilla, which leads to failure in orthodontic treatment. Knowledge of the site anatomy, pharmacology, and dose of BTX-A before its use in cosmetic surgery should be strengthened.