title: Effect of chin-cup treatment on the temporomandibular joint: a systematic review.
abstract: OBJECTIVE
  To systematically search the literature and assess the available evidence for the influence of chin-cup therapy on the temporomandibular joint regarding morphological adaptations and appearance of temporomandibular disorders (TMD).
  
  
  METHODS
  Electronic database searches of published and unpublished literature were performed. The following electronic databases with no language and publication date restrictions were searched: MEDLINE (via Ovid and PubMed), EMBASE (via Ovid), the Cochrane Oral Health Group's Trials Register, and CENTRAL. Unpublished literature was searched on ClinicalTrials.gov, the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. The reference lists of all eligible studies were checked for additional studies. Two review authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion or the involvement of an arbiter.
  
  
  RESULTS
  From the 209 articles identified, 55 papers were considered eligible for inclusion in the review. Following the full text reading stage, 12 studies qualified for the final review analysis. No randomized clinical trial was identified. Eight of the included studies were of prospective and four of retrospective design. All studies were assessed for their quality and graded eventually from low to medium level of evidence. Based on the reported evidence, chin-cup therapy affects the condylar growth pattern, even though two studies reported no significance changes in disc position and arthrosis configuration. Concerning the incidence of TMD, it can be concluded from the available evidence that chin-cup therapy constitutes no risk factor for TMD.
  
  
  CONCLUSIONS
  Based on the available evidence, chin-cup therapy for Class III orthodontic anomaly seems to induce craniofacial adaptations. Nevertheless, there are insufficient or low-quality data in the orthodontic literature to allow the formulation of clear statements regarding the influence of chin-cup treatment on the temporomandibular joint.
authors.affiliation: *Clinic of Orthodontics and Paediatric Dentistry, University of Zurich, Switzerland.
authors.forename: Monika A
authors.initials: MA
authors.lastname: Zurfluh
authors.affiliation: **Department of Orthodontics and Dentofacial Orthopedics, Faculty of Medicine, University of Bern, Bern, Switzerland.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Kloukos
authors.affiliation: *Clinic of Orthodontics and Paediatric Dentistry, University of Zurich, Switzerland.
authors.forename: Raphael
authors.initials: R
authors.lastname: Patcas
authors.affiliation: *Clinic of Orthodontics and Paediatric Dentistry, University of Zurich, Switzerland, theodore.eliades@zzm.uzh.ch.
authors.forename: Theodore
authors.initials: T
authors.lastname: Eliades
mesh_terms: D005115:Extraoral Traction Appliances; D006801:Humans; D008313:Malocclusion, Angle Class III / Q000628:therapy; D008335:Mandibular Condyle / Q000254:growth & development; D011446:Prospective Studies; D012189:Retrospective Studies; D013704:Temporomandibular Joint / Q000033:anatomy & histology*; D019224:Temporomandibular Joint Disc / Q000033:anatomy & histology; D013705:Temporomandibular Joint Disorders / Q000209:etiology