Mentalis Under The Skin

Description

Anterior chin anatomy is presented with the skin retained as a translucent layer over the lower face, allowing the paired mentalis muscles to be seen deep to the subcutaneous tissue and superficial fascia. Each triangular bundle arises from the anterior mandible in the incisive fossa, inferior to the mandibular incisors and lateral to the midline symphysis, then descends to insert into the dermis of the chin at and just inferior to the pogonion. Medially, the left and right mentalis approach one another across the midline, while laterally they blend with the depressor labii inferioris and, more peripherally, the depressor anguli oris. Clinically, this is the muscle behind the chin “pout” and the peau d’orange texture that appears with mentalis hyperactivity. It also matters in lower incisor and symphyseal surgery: a mentalis-splitting approach for genioplasty or mandibular symphysis access can leave postoperative chin ptosis and lower lip incompetence if reattachment is imprecise. Numbness of the chin after trauma or dental procedures often tracks with injury to the mental nerve near the mental foramen, a landmark that sits lateral to the mentalis field. Facial anatomy and dental students will find this view useful when learning the relationship of the mentalis to the pogonion, the mandibular symphysis, and the overlying skin folds that define the labiomental crease. It also supports plastic surgery and maxillofacial publications discussing botulinum toxin injection planning, chin augmentation, or postoperative soft tissue changes after genioplasty. Anatomical accuracy verified by SciePro's Medical Advisory Board.