title: Orthodontics is temporomandibular disorder-neutral.
abstract: OBJECTIVE
  To assess if subjects with a clinical diagnosis of temporomandibular disorders (TMDs) have a similar prevalence of orthodontic history as a population of TMD-free individuals and to assess if those subjects who have a history of ideal orthodontics have fewer symptoms than those with a history of nonideal orthodontics.
  
  
  METHODS
  Two groups of age- and sex-matched individuals belonging to either a study ("TMD") or a control group were recruited. Subjects who underwent orthodontic treatment were classified as having a history of ideal or nonideal orthodontics based on the current presence of normal values in five reference occlusal features.
  
  
  RESULTS
  The correlation with a history of orthodontic treatment was not clinically significant for any of the TMD diagnoses (ie, muscle pain, joint pain, disc displacement, arthrosis), with Phi (Φ) coefficient values within the -0.120 to 0.058 range. Within the subset of patients with a history of orthodontics, the correlation of ideal or nonideal orthodontic treatment with TMD diagnoses was, in general, not clinically relevant or was weakly relevant.
  
  
  CONCLUSIONS
  Findings confirmed the substantial absence of clinically significant effects of orthodontics as far as TMD is concerned. The very low correlation values of a negative or positive history of ideal or nonideal orthodontics with the different TMD diagnoses suggest that orthodontic treatment could not have a true role for TMD.
authors.affiliation: a   Associate Professor, Temporomandibular Disorders Clinic, Section of Maxillofacial Surgery, Department of Neuroscience, University of Padova, Padova, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Manfredini
authors.affiliation: b   Professor and Head, Department of Neuroscience, School of Dentistry, University of Padova, Padova, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Stellini
authors.affiliation: c   Researcher, School of Dentistry, Department of Neuroscience, University of Padova, Padova, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gracco
authors.affiliation: d   Researcher, Postgraduate School of Orthodontics, University of Ferrara, Ferrara, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Lombardo
authors.affiliation: e   Head, Temporomandibular Disorders Clinic, Section of Maxillofacial Surgery, Department of Neuroscience, University of Padova, Padova, Italy.
authors.forename: Luca Guarda
authors.initials: LG
authors.lastname: Nardini
authors.affiliation: f   Professor and Head, Postgraduate School of Orthodontics, University of Ferrara, Ferrara, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Siciliani
mesh_terms: D000328:Adult; D003729:Dental Care; D005260:Female; D006801:Humans; D008297:Male; D009970:Orthodontics; D009971:Orthodontics, Corrective; D015995:Prevalence; D013705:Temporomandibular Joint Disorders / Q000150:complications*
keywords: Orthodontics; Temporomandibular disorders