title: Orthodontic risk factors for temporomandibular disorders (TMD). I: Premolar extractions.
abstract: Concern about claims that premolar extractions may put patients at risk for temporomandibular disorders (TMD) led to this study. We report first findings from a longitudinal study of orthodontic patients begun in 1983. By using the methods of Helkimo, we collected TMD data before initiation of orthodontic treatment, between 0 and 12 months after debanding, and 12 to 24 months after debanding. Analyses related Helkimo scores with premolar extractions in 65 patients for whom orthodontic treatment had been completed. Twenty-six patients were treated without premolar extractions, 25 had four premolars extracted, and 14 had two upper premolars extracted. Tests for significance of differences between mean Helkimo scores were conducted for the nonextraction group compared with the extraction groups, and between pretreatment and posttreatment Helkimo scores for each group. Results included: (1) no significant intergroup differences between mean pretreatment or posttreatment scores, and (2) small but statistically significant (p less than 0.05) differences (in the direction of improvement) between mean pretreatment and posttreatment scores for both the nonextraction group and for the four premolar extraction group.
authors.affiliation: Department of Orthodontics, University of Iowa, Iowa City.
authors.forename: C R
authors.initials: CR
authors.lastname: Kremenak
authors.forename: D D
authors.initials: DD
authors.lastname: Kinser
authors.forename: H A
authors.initials: HA
authors.lastname: Harman
authors.forename: C C
authors.initials: CC
authors.lastname: Menard
authors.forename: J R
authors.initials: JR
authors.lastname: Jakobsen
mesh_terms: D000328:Adult; D001641:Bicuspid / Q000601:surgery*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008311:Malocclusion, Angle Class I / Q000628:therapy; D008312:Malocclusion, Angle Class II / Q000628:therapy; D011446:Prospective Studies; D012307:Risk Factors; D012690:Serial Extraction / Q000009:adverse effects*; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis / Q000209:etiology*; D013997:Time Factors; D014087:Tooth Movement Techniques