title: A systematic algorithm for the management of lower lip asymmetry.
abstract: OBJECTIVE
  An asymmetric smile, caused by loss of function of the lip depressors, can be functionally and cosmetically debilitating. Although some surgeons report excellent results with muscle transfer to the lower lip, many facial reanimation surgeons find that dynamic techniques do not consistently address the lower lip. Our objectives were to retrospectively review our outcomes after treatment of the asymmetric lower lip, and to propose a progressive, stepwise algorithm for the management of lower lip asymmetry in facial paralysis.
  
  
  METHODS
  Retrospective chart review was performed on all patients treated in a multidisciplinary facial nerve center with lower lip asymmetry over an eighteen month period. Treatment ranged from a temporary trial of lidocaine, to chemodenervation with botulinum toxin, to pedicled digastric muscle transfer, and/or resection of the nonparetic depressor labii inferioris (DLI).
  
  
  RESULTS
  Fifty-seven patients were treated with chemodenervation with botulinum toxin, four with anterior belly of the digastric transfer, and 3 with DLI resection. All patients with DLI resection had undergone chemodenervation to the contralateral lower lip with botulinum toxin and were pleased with the appearance of their smile.
  
  
  CONCLUSIONS
  We have found that lower lip asymmetry is optimally managed by adherence to a standardized protocol that offers patients insight into the likely outcome of chemodenervation or surgery and progresses systematically from the reversible to the irreversible. We present our algorithm for the management of the asymmetric lower lip, which reflects this graduated approach and has resulted in high patient satisfaction.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA. robin_lindsay@meei.harvard.edu
authors.forename: Robin W
authors.initials: RW
authors.lastname: Lindsay
authors.forename: Colin
authors.initials: C
authors.lastname: Edwards
authors.forename: Chris
authors.initials: C
authors.lastname: Smitson
authors.forename: Mack L
authors.initials: ML
authors.lastname: Cheney
authors.forename: Tessa A
authors.initials: TA
authors.lastname: Hadlock
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001905:Botulinum Toxins / Q000627:therapeutic use; D005146:Facial Asymmetry / Q000503:physiopathology / Q000628:therapy*; D005158:Facial Paralysis / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008047:Lip Diseases / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000637:transplantation; D009465:Neuromuscular Agents / Q000627:therapeutic use; D020127:Recovery of Function; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D009465:Neuromuscular Agents; D001905:Botulinum Toxins