title: Ptosis of the chin and lip incompetence: consequences of lost mentalis muscle support.
abstract: Ptosis of the chin and lip incompetence are worrisome complications of surgery in the mandibular symphyseal region. This article relates the normal anatomy and physiology of the muscles in this region to these complications. It suggests a sequence of surgical planning that can prevent them and also offers ways of dealing with the problems should they occur.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Washington, Seattle.
authors.forename: B C
authors.initials: BC
authors.lastname: Rubens
authors.forename: R A
authors.initials: RA
authors.lastname: West
mesh_terms: D000328:Adult; D002680:Chin; D005152:Facial Muscles / Q000473:pathology; D005260:Female; D006801:Humans; D008047:Lip Diseases / Q000209:etiology* / Q000473:pathology; D008875:Middle Aged; D009135:Muscular Diseases / Q000209:etiology* / Q000473:pathology; D011183:Postoperative Complications; D011391:Prolapse