Mentolabial Sulcus, Lateral View

Description

Viewed in lateral profile, the mentolabial (labiomental) sulcus is defined by the junction of the inferior labial soft tissues and the anterior chin, where skin and subcutaneous fat drape over the orbicularis oris superiorly and the mentalis muscle inferiorly. Just deep to the fold, fibers of depressor labii inferioris and depressor anguli oris blend into the perioral musculature, while the mentalis anchors onto the mandibular symphysis and elevates the chin pad. The bony contour of the mental protuberance lies inferior and slightly posterior to the vermilion border of the lower lip, establishing the characteristic step between lip and chin in a female face. A lateral rendering of this region matters because small changes in mentalis tone or chin pad volume can exaggerate or efface the labiomental fold, altering lower facial balance more than many learners expect. Overresection of the mentalis during intraoral genioplasty, or inadequate reattachment after chin implant placement, can lead to mentalis ptosis with deepening of the mentolabial sulcus and lip incompetence. Injection planning also hinges on this anatomy, since filler placed too superficial at the fold can create a shelf, while neuromodulator spread into depressor labii inferioris risks an asymmetric lower lip. Facial anatomy teaching benefits from this clean side-on view when explaining the relationship between perioral muscles and mandibular landmarks in dentistry, orthodontics, and head and neck gross anatomy courses. It also supports plastic surgery and dermatology publications discussing labiomental fold correction, chin augmentation, and complications such as witch’s chin deformity. A reliable profile reference. Anatomical accuracy verified by SciePro's Medical Advisory Board.