title: [Histological and ultrastructural variations after radiofrequency for soft palate in porcines].
abstract: OBJECTIVE
  To investigate the histological and ultrastructural variations after radiofrequency volumetric reduction of the soft palate in an animal model.
  
  
  METHODS
  Thirteen porcines were used to evaluate the tissue response to radiofrequency for various time periods. They were divided into two groups. Group 1 was exposed to radiofrequency in the midline of the soft palate with a constant energy of 2.4 KJ. Group 2 served as a control group. The animals in group 1 were sacrificed after 1 hour, 24 hours, 48 hours, 72 hours, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks and 9 weeks, respectively, and after 72 hours, 2 weeks and 4 weeks for the animals in group 2. Then the soft palates from both groups were examined for histological and ultrastructural variations.
  
  
  RESULTS
  Interstitial edema, hemorrhage and infiltration with inflammatory cells were observed in the early acute stage after radiofrequency, and then the neovascularization of the forming scar was observed. In the end, the injured tissue was replaced by collagenous fibers. Intact vessels and nerves were observed around the lesions.
  
  
  CONCLUSIONS
  After radiofrequency, lesion tissue is replaced by collagenous fibers, and it is focused on the lesion site. These findings may help provide a basis for technological suggestion in regard to clinical treatment.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Stomatology, Ninth People's Hospital, Shanghai Second Medical University, Shanghai 200011, China.
authors.forename: Yuan-jin
authors.initials: YJ
authors.lastname: Xu
authors.forename: Zhi-yuan
authors.initials: ZY
authors.lastname: Zhang
authors.forename: Xiao-feng
authors.initials: XF
authors.lastname: Lu
authors.forename: Guo-fang
authors.initials: GF
authors.lastname: Shen
authors.forename: You-sheng
authors.initials: YS
authors.lastname: Tang
mesh_terms: D000818:Animals; D010160:Palate, Soft / Q000473:pathology* / Q000528:radiation effects / Q000648:ultrastructure; D013552:Swine