Mentalis Muscle, Lateral View

Description

Arising from the anterior surface of the mandible just inferior to the incisive fossa, the mentalis forms a paired muscular cone whose fibers descend and insert into the skin of the chin over the mental protuberance near the pogonion. From a left lateral perspective, its belly sits inferior to the orbicularis oris and anterior to the depressor labii inferioris, with the labiomandibular sulcus marking their surface boundary. The muscle’s contraction pulls the soft tissue of the mentum superiorly and anteriorly, creating chin dimpling and elevating the lower lip. Small but unmistakable. Facial surgeons and injectors care about this view because the mentalis is the main driver of “peau d’orange” chin and a common target for botulinum toxin when hyperactivity produces a pebbled mentum or contributes to lower-lip incompetence. Close proximity to the mental foramen matters, since the mental nerve and vessels emerge below the premolars and cross the region during genioplasty, mentalis-splitting approaches to the mandibular symphysis, and lower-lip laceration repair. Misidentifying its relationship to depressor labii inferioris can leave a postoperative “witch’s chin” deformity from inadequate reapproximation. Use this illustration in head and neck anatomy teaching to anchor the perioral mimetic muscles in lateral profile, and in oral and maxillofacial surgery, plastic surgery, or dermatology materials covering chin augmentation, genioplasty, and neuromodulator injection patterns. It also fits well in patient-facing education on chin dimpling and lower-lip posture, where the spatial relationship between mentalis and orbicularis oris needs to be clear. Anatomical accuracy verified by SciePro's Medical Advisory Board.