title: Orthognathic treatment and temporomandibular disorders: a systematic review. Part 1. A new quality-assessment technique and analysis of study characteristics and classifications.
abstract: BACKGROUND
  Orthognathic treatment is undertaken to correct jaw discrepancies and involves a combination of orthodontics and surgery. The effects of orthodontic treatment on temporomandibular disorders (TMD) have been widely debated in the literature, but fewer studies focus on the effects of orthognathic treatment on TMD.
  
  
  METHODS
  A systematic review was conducted to (1) determine the percentage of orthognathic patients with signs or symptoms of TMD, (2) establish the range of signs or symptoms, and (3) examine studies that followed patients longitudinally through treatment to determine the effect of orthognathic intervention on TMD symptoms.
  
  
  RESULTS
  Of 480 identified articles, 53 were eligible for inclusion in this review. Part 1 of this 2-part article describes the methodology of conducting this review, the difficulties encountered (including the quality-assessment issues), and a narrative analysis of study characteristics and classification methods. Part 2 reports the remaining results, evidence tables, and meta-analyses.
  
  
  CONCLUSIONS
  The diversity of diagnostic criteria and classification methods used in the included studies makes interstudy comparisons difficult. There is a definitive need for well-designed studies with standardized diagnostic criteria and classification methods for TMD.
authors.affiliation: Orthodontic Unit, UCL Eastman Dental Institute, London, United Kingdom. s.alriyami@eastman.ucl.ac.uk
authors.forename: Salma
authors.initials: S
authors.lastname: Al-Riyami
authors.forename: David R
authors.initials: DR
authors.lastname: Moles
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Cunningham
mesh_terms: D003131:Combined Modality Therapy; D018865:Dental Research / Q000379:methods / Q000592:standards*; D006801:Humans; D008310:Malocclusion / Q000601:surgery; D019647:Oral Surgical Procedures / Q000706:statistics & numerical data*; D009970:Orthodontics / Q000592:standards*; D011785:Quality Assurance, Health Care; D013705:Temporomandibular Joint Disorders / Q000145:classification / Q000175:diagnosis* / Q000628:therapy