title: Long- and short-term effects of headgear traction with and without the maxillary second molars.
abstract: BACKGROUND
  A quantitative assessment of maxillary first molar distalization with and without the maxillary second molar (M2) was carried out.
  
  
  METHODS
  Fifty-six cervical headgear patients undergoing fixed appliance orthodontic treatment were divided into 2 groups: before (G - M2) and after (G + M2) eruption of the maxillary second molars (ages, 11.87 ± 1.20, and 13.05 ± 1.55 years, respectively). The tightness of the dental contact point (TDCP) and the space between the second premolar and the maxillary first molar were measured at 6 levels of headgear force (0-15 N) at 3 intervals 6 months apart (T0, T1, T2).
  
  
  RESULTS
  Relationships were found between space and TDCP, time, and presence or absence of the maxillary second molar at T1 and T2 (P <0.001). The TDCP decreased and space increased with increase in initial headgear force. An increase in initial force beyond 6 to 9 N did not significantly increase the initial maxillary first molar distalization. The G - M2 TDCP and space measurements were similar to those of G + M2 at T2 with the eruption of the maxillary second molar. From T0 to T1, maxillary first molar distalization was greater in G - M2. In comparison with our previous headgear-alone study, initial distalization with a fully bonded appliance was reduced by 4-fold.
  
  
  CONCLUSIONS
  Headgear therapy is more effective before the eruption of the maxillary second molar. Once it erupts, the distalization pace of the maxillary first molar is reduced, but it can nevertheless be pursued at a slower pace when the maxillary second molar is present.
authors.affiliation: Chair, Department of Orthodontics, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. Electronic address: nshpack@post.tau.ac.il.
authors.forename: Nir
authors.initials: N
authors.lastname: Shpack
authors.affiliation: Chair, Department of Oral Biology, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Tamar
authors.initials: T
authors.lastname: Brosh
authors.affiliation: Private practice, Tel Aviv, Israel.
authors.forename: Yoav
authors.initials: Y
authors.lastname: Mazor
authors.affiliation: Instructor, Department of Orthodontics, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Yoav
authors.initials: Y
authors.lastname: Shapinko
authors.affiliation: Lecturer, Department of Orthodontics, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Davidovitch
authors.affiliation: Lecturer, Department of Orthodontics, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Rachel
authors.initials: R
authors.lastname: Sarig
authors.affiliation: Senior researcher, Department of Oral Technology, Center of Dento-Maxillo-Facial Medicine, Faculty of Medicine, University of Bonn, Bonn, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Reimann
authors.affiliation: Endowed professor, Center of Dento-Maxillo-Facial Medicine, Faculty of Medicine, University of Bonn, Bonn, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bourauel
authors.affiliation: Chair, Department of Orthodontics, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Vardimon
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000473:pathology; D002508:Cephalometry / Q000379:methods; D002648:Child; D003724:Dental Arch / Q000473:pathology; D005115:Extraoral Traction Appliances; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy; D008437:Maxilla / Q000473:pathology; D008963:Molar / Q000473:pathology*; D009811:Odontometry / Q000379:methods; D013314:Stress, Mechanical; D014078:Tooth Eruption; D014087:Tooth Movement Techniques / Q000295:instrumentation*