title: Association among pain, masticatory performance, and proinflammatory cytokines in crevicular fluid during orthodontic treatment.
abstract: BACKGROUND
  Orthodontic patients usually complain about masticatory limitations associated with the activation of fixed appliances. The aim of this investigation was to evaluate whether orthodontic pain reflects differences in the objective evaluation of mastication and in the levels of proinflammatory cytokines in the crevicular fluid of patients undergoing orthodontic treatment.
  
  
  METHODS
  Twenty patients with malocclusions requiring orthodontic treatment were included in this prospective study. Their pain experience, masticatory performance, and levels of interleukin 1-beta and prostaglandin E2 in crevicular fluid were evaluated at 3 times: before bracket placement, 24 hours after archwire placement, and 30 days after the initial appointment. All variables were compared with those of a control group of 25 subjects with normal occlusion.
  
  
  RESULTS
  The masticatory performance of the patients was significantly reduced at 24 hours after bracket placement, the period in which they reported higher values of pain and had higher levels of interleukin 1-beta. The levels of prostaglandin E2 did not change in the periods evaluated, and there were no correlations between the levels of cytokines and the functional limitations observed. The only significant correlation was between pain and decreased masticatory performance.
  
  
  CONCLUSIONS
  The masticatory performance of orthodontic patients is significantly reduced only during the period of greatest pain. However, these alterations did not correlate with any measurement of interleukin 1-beta or prostaglandin E2 in the crevicular fluid, suggesting that these solitary measurements are inadequate to predict the temporary pain and masticatory limitations experienced by patients undergoing orthodontic treatment.
authors.affiliation: Adjunct professor, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil. Electronic address: gustavo.gameiro@ufrgs.br.
authors.forename: Gustavo Hauber
authors.initials: GH
authors.lastname: Gameiro
authors.affiliation: Undergraduate student, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Christian
authors.initials: C
authors.lastname: Schultz
authors.affiliation: Postgraduate student, Department of Surgery and Orthopedics, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Marcos Porto
authors.initials: MP
authors.lastname: Trein
authors.affiliation: Adjunct professor, Department of Surgery and Orthopedics, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Karina Santos
authors.initials: KS
authors.lastname: Mundstock
authors.affiliation: Associate professor, Department of Periodontology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Weidlich
authors.affiliation: Postgraduate student, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Jéferson Ferraz
authors.initials: JF
authors.lastname: Goularte
mesh_terms: D000293:Adolescent; D015232:Dinoprostone / Q000032:analysis*; D005260:Female; D005500:Follow-Up Studies; D005883:Gingival Crevicular Fluid / Q000276:immunology*; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis*; D053583:Interleukin-1beta / Q000032:analysis*; D008137:Longitudinal Studies; D008297:Male; D008310:Malocclusion / Q000145:classification / Q000628:therapy; D008409:Mastication / Q000502:physiology*; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D010146:Pain / Q000276:immunology / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods; D010316:Particle Size; D011446:Prospective Studies; D012828:Silicones / Q000737:chemistry; D013997:Time Factors; D055815:Young Adult
chemical_list: D018836:Inflammation Mediators; D053583:Interleukin-1beta; D012828:Silicones; D015232:Dinoprostone