title: Effects of Class II treatment with a banded Herbst appliance on root lengths in the posterior dentition.
abstract: BACKGROUND
  The aim of this study was a retrospective analysis of posterior teeth in 20 adolescents and young adults with Angle Class II Division 1 malocclusion treated with a banded Herbst appliance to check for inhibited root development and apical root resorption.
  
  
  METHODS
  Panoramic radiographs were taken of every patient at the beginning and after the completion of functional orthopedic treatment. The magnification of the area of the posterior teeth was determined individually for every radiograph. Then the vestibular lengths of the molars and premolars were assessed metrically. To assess root-length changes, the difference between the lengths of the teeth before and after treatment was calculated.
  
  
  RESULTS
  After treatment with a banded Herbst appliance, tooth length generally increased in the area of the anchorage. But there was a tendency toward root-length decrease in teeth immediately adjacent to the Herbst fittings in the vestibular roots of both the maxillary first molars (distovestibular, -0.02 ± 2.31 mm; mesiovestibular, -0.06 ± 2.05 mm) and the mandibular first premolars (-0.46 ± 3.53 mm).
  
  
  CONCLUSIONS
  The banded Herbst appliance might deliver unphysiologic forces to immediate anchor teeth, thereby exposing these to a higher risk of root resorption than in other teeth incorporated into the anchorage either directly via bands or indirectly via occlusal or approximal contacts. Looking at uncompromised root morphology in the area of the anchorage, we believe that early treatment with fixed functional appliances can be predicted to yield better outcomes than late treatment because of the higher biologic tolerance expressed by teeth with an apical latency.
authors: Department of Orthodontics, University of Saarland, Homburg, Germany. kinzinger@kfo-homburg.de
authors: Gero S M
authors: GS
authors: Kinzinger
authors: Susanna
authors: S
authors: Savvaidis
authors: Ulrich
authors: U
authors: Gross
authors: Norbert
authors: N
authors: Gülden
authors: Björn
authors: B
authors: Ludwig
authors: Jörg
authors: J
authors: Lisson
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000000981:diagnostic imaging / Q000473:pathology*; D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008334:Mandible / Q000000981:diagnostic imaging; D008437:Maxilla / Q000000981:diagnostic imaging; D008963:Molar / Q000000981:diagnostic imaging / Q000473:pathology*; D009805:Odontogenesis / Q000502:physiology; D009811:Odontometry / Q000379:methods; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation; D016382:Orthodontic Appliance Design; D017289:Orthodontic Appliances, Functional; D011862:Radiography, Panoramic; D012189:Retrospective Studies; D012391:Root Resorption / Q000000981:diagnostic imaging / Q000209:etiology; D013314:Stress, Mechanical; D013997:Time Factors; D019227:Tooth Apex / Q000000981:diagnostic imaging / Q000473:pathology; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000473:pathology*; D055815:Young Adult