Revisional Chin ptosis
The mentalis muscle elevates the central portion of the lower lip. It originates from the chin just below the teeth and inserts on the chin pad. It is often divided and inadequately repaired or detached and not reattached to the bone during intraoral approaches to chin implant placement or sliding genioplasty. When this occurs, the lower lip assumes a low position with increased lower tooth show. There is often ptosis, (drooping) of the chin pad. Because the superior origin of the mentalis muscle defines the inferior limit of the intraoral gingival buccal sulcus, mentalis damage is usually associated with deepening of the sulcus.