Chinese Journal of Tissue Engineering Research ›› 2011, Vol. 15 ›› Issue (22): 4073-4079.doi: 10.3969/j.issn.1673-8225.2011.22.020

Previous Articles     Next Articles

Mathematics model evaluation of soft tissue changes after Twin-block treatment

Yan Bao-yong1, Zuo Yan-ping1, Liu Ya-fei1, Cui Li-juan2   

  1. 1Department of Orthodontics, First Affiliated Hospital of Hebei Medical University, Shijiazhuang  050031, Hebei Province, China
    2Basci Medical College, Hebei Medical University, Shijiazhuang  050011, Hebei Province, China
  • Received:2010-10-16 Revised:2010-11-22 Online:2011-05-28 Published:2011-05-28
  • Contact: Zuo Yan-ping, Doctor, Professor, Chief physician, Department of Orthodontics, First Affiliated Hospital of Hebei Medical University, Shijiazhuang 050031, Hebei Province, China zyp6381@sina.com
  • About author:Yan Bao-yong☆, Doctor, Chief physician, Department of Orthodontics, First Affiliated Hospital of Hebei Medical University, Shijiazhuang 050031, Hebei Province, China yafei_lyf@sina.com

PDF

383

Abstract:

BACKGROUND: Because the subjects of functional appliance are young people in the growing period, children’s growth and development need to be considered to study whether the functional appliance is valid.
OBJECTIVE: To build a mathematical model to analyze the correlation between craniofacial soft and hard tissues after the correction of Class Ⅱ malocclusion with twin-block treatment.
METHODS: Thirty-one Class Ⅱ Division 1 malocclusion subjects with hand-wrist radiographs in FG-G stage were selected. Among the 31 cases, 14 abandoned treatment. The remaining 17 subjects received Twin-block treatment. All the subjects were taken cephalometric radiographs before and after twin-block treatment as well as before and after natural growth of hard and soft tissue to observe the variation rule of soft and hard tissue cephalometric values so as to build the corresponding mathematical models.
RESULTS AND CONCLUSION: Based on the mathematical models, the soft tissue indicators (Ls-EP, Pn-HP, NB-Pg'-Ls) and hard tissue indicators (ANB) showed the curve relationships. The formula were: NB-Pg′-Ls=-0.119 1(ANB)2 +3.002 9 (ANB)+ 6.148 5; Pn-HP=0.021 4(ANB)2 –1.026 7(ANB)+ 0.347 4; Ls-EP =0.132 4(ANB)2–0.536 4(ANB)+1.553 7. The results of this study provided evidence that ANB angle was to the decisive factor to improve soft tissue profile of Class II malocclusion patients after twin-block treatment.

CLC Number: