The hypertrophied temporalis and masseter muscles give a muscular shaped and bulky contour to the face. Botulinum neurotoxin injection methods are commonly used for facial contouring; however, adverse effects have been reported owing to a lack of delicate anatomical information. The anatomical considerations when injecting botulinum neurotoxin into the temporalis and masseter muscles were reviewed in the present study. Current knowledge on the localization of the botulinum neurotoxin injection point with more recent anatomical dissection and modified Sihler staining procedures was assessed. The authors found that, for the muscles, the injection point can be more precisely demarcated. Optimal injection sites are presented for the temporalis and masseter muscles, and the injection technique is suggested. The authors propose the optimal injection sites in relation to external anatomical landmarks for the frequently injected muscles of the face to facilitate the efficiency of botulinum neurotoxin injections. In addition, these guidelines would aid in more precise practice without the adverse effects of botulinum neurotoxin. read more

Plastic and reconstructive surgery

Novel Anatomical Proposal for Botulinum Neurotoxin Injection Targeting Lateral Canthal Rhytids.

Jul, 2022

Botulinum neurotoxin injections near the lateral canthal rhytids are commonly used in cosmetic settings; however, there is a lack of thorough anatomical knowledge, and an effective way to treat them with accumulating knowledge is needed. The anatomical characteristics concerning the injection of botulinum neurotoxin into the orbicularis oculi muscle were evaluated in this review. Current knowledge on the identification of botulinum neurotoxin injection points from recent anatomical research was assessed. The lateral canthal lines are involved with the orbicularis oculi muscle and nearby anatomical structures, and the injection points can be more precisely defined. The best possible injection sites were provided, and the injection procedure was described. This review proposes evidence for injection sites associated with the surface anatomy of the orbicularis oculi muscles to enhance the effectiveness of easing lateral canthal rhytids. read more

Toxins