Clinical Anatomy for Botulinum Toxin Injection

A wrinkle, or rhytide, is categorized into dynamic and static conditions. Static wrinkles can be further divided into either fine lines or furrows/deep furrows. Dynamic wrinkles can be seen at the glabellar region when frowning or around the periorbital regions when smiling. Glabellar furrows and nasolabial folds are representative cases of deep furrows. The process of the wrinkle formation begins from dynamic wrinkles, and then the dynamic wrinkles become fixed as fine lines. With age, fine lines transform into deep furrows accompanied by the gradual loss of the underlying soft tissues.