Botulinium toxin applications in the lower face and neck: A comprehensive review.

[BACKGROUND] Botulinum toxin has been widely and mainly used for the treatment of conditions affecting the upper and middle face; however, recent efforts have expanded the indications of botulinum toxin injection to the lower face and neck areas for cosmetic and medical purposes.

[AIMS] We have reviewed the latest updates on using botulinum toxin in the lower face and neck focusing on cosmetic purposes and have discussed the existing concerns as well as the adverse sequelae of these newer indications.

[PATIENTS/METHODS] A comprehensive literature search was performed using the following keywords [[botulinum] AND [[Toxin] OR [Neurotoxin]]] AND [[Lower AND Face] AND/OR [Neck]] within the main databases including Web of Science, PubMed, Embase and gray literature on and before February 2023. The data were screened using titles and abstracts and those relevant to the topic were included in the paper.

[RESULTS] Botulinum toxin injection has considerable cosmetic and therapeutic effect on facial contouring, masseteric hypertrophy, lower face and neck scars, gummy smile, drooping lip corner and even skin rejuvenation.

[CONCLUSION] BNT injection has been widely used for the treatment of different medical and cosmetic purposes. Low rates of side effects, which were self-limited in most cases, have been reported in the literature, making BNT a safe therapeutic medication in most cases. However, regulatory status needs to be updated and more accurately revised in many countries and more comprehensive research is required to address the existing gaps in this area including the site, dosage, and method of injection in each case.