title: The effect of extracapsular injuries on growth and development of the mandible condyle: an experimental study in growing dogs.
abstract: OBJECTIVE
  To investigate the effects of condylar extracapsular injuries on the development of the mandibular condyle and try to find a way to treat condylar hyperplasia by electively using such injuries to restrict the overdeveloped mandibular condyle.
  
  
  METHODS
  Sixty 6-month-old beagle puppies were divided randomly into five groups: blank control; unilateral fracture to the condylar neck; unilateral fracture to the condylar neck treated with rigid internal fixation; unilateral periosteum injury; unilateral decortication of the condylar neck. Computed tomography,99 mTc single-photon emission computed tomography, and tetracycline-calcein double-labeling were performed after surgery. The puppies were sacrificed 12 and 24 weeks after surgery. Morphologic analyses and examination of growth activity were done.
  
  
  RESULTS
  Unilateral fracture of the condylar neck without fixation caused local morphologic changes during the early postoperative period, but compensatory growth of the condyle altered such changes after healing. The other types of injury failed to inhibit the growth of the condyle and the mandible, whereas functional deviation of the chin was found after unilateral fracture of the condylar neck with or without fixation.
  
  
  CONCLUSIONS
  The four types of extracapsular injury described here failed to inhibit the growth of the mandibular condyle and could not be selected as alternatives to treat condylar hyperplasia.
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Orthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, PR China.
authors.forename: Siying
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, PR China.
authors.forename: Mingchao
authors.initials: M
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, PR China.
authors.forename: Yanpu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, PR China.
authors.forename: Guiyu
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Radiology, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, PR China.
authors.forename: Jinwu
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Orthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, PR China. Electronic address: doc_dingyin@163.com.
authors.forename: Yin
authors.initials: Y
authors.lastname: Ding
mesh_terms: D000818:Animals; D004285:Dogs; D005593:Fracture Fixation, Internal / Q000379:methods; D017102:Fracture Healing / Q000502:physiology*; D008335:Mandibular Condyle / Q000000981:diagnostic imaging / Q000254:growth & development* / Q000293:injuries*; D008337:Mandibular Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D011857:Radiographic Image Interpretation, Computer-Assisted; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed