A review on bigonial width reduction by botulinum toxin injections in masseter.

It is of interest to study the efficacy of botulinum toxin injection in masseter reducing bigonial width of the face. Online databases such as PubMed, Cochrane Library, Google Scholar, Science Direct database and ResearchGate were searched from initiation until October 2022 using keywords such as "masseter muscle injections", "botulinum toxin," "bigonial width reduction," "masseter muscle hypertrophy," and "lower face contouring" All available retrospective as well as prospective studies, were included with specific weightage to the efficiency of Botulinum Toxin (BT) injection in masseter muscle and the technique, unfavorable events, and the extent of its effects. A total of 20 publications were acknowledged. All prospective studies were included. Relevant data on patient selection, injection methods, efficiency, dose, rate of recurrence, and significant side effects of BT injections in masseters were collected. All excluding one were prospective studies. Bilateral injections were used in all the studies. Follow up period was 3-48 months. This systematic review focuses on the effectiveness of Botulinum toxin injection in lowering the bigonial width by decreasing the volume of the masseter. Repeat treatment at regular intervals is advisable to maintain desired results. The procedure was carried out in an office environment and was completed within 15 mins. There are no permanent adverse events related to the procedure. Further studies involving randomized control trials with larger sample sizes are warranted to optimize the dose and frequency of BT injection.