The use of botulinum toxin A in upper lip augmentation.

[BACKGROUND] Full lips are beauty standards. Botulinum toxin A (BTA) paralyzes the orbicularis oris muscle to achieve the eversion of the lip, and thus makes the lip look plump.

[AIMS] This study presents three cases of BTA injection to the lip and evaluates the possible changes in the labial morphology and the lip surface area.

[METHODS] Three patients received a total of 4U BTA injection at the vermilion border of the upper lip. Vectra® H1 3D imaging system was used to capture 3D photographs of the lips before injection and two weeks after injection. Eight linear distances and the upper lip surface area were measured. Anthropometric measurements before and after injection were compared.

[RESULTS] Patients displayed a larger upper vermillion height (P = .038) and a smaller cutaneous upper lip height (P = .024). There was a trend for a larger upper lip surface area, but not statistically significant (P = .109). Symptoms of slight perioral muscular palsy and mouth incompetence lasted about one month in three patients.

[CONCLUSION] BTA helps to enlarge the upper lip and shorten the philtrum. The BTA injection can be an option for lip enhancement with caution.