Comparison Of The Cephalometric Of Growth Modification And Ungrowth Modification In Treatment Of Skeletal Class â…¡ Malocclusion

[Objective] To evaluate the mechanism of functional appliance , this research adopt Pancherz cephalometric analysis, to implement a quantitative analysis to the changes on dental and skeletal of class II division I malocclusion patients during growthing after function treatment and extraction treatment.[Methods] This research selected 50 cases of skeletal class II division I malocclusion patients , according to Hagg carpal slice analyze, all cases in the phase of FG-G, no Orthodontics treatment history. Adopt randomization principle, to design three groups: the control group: no treatment; Group A: treatment of functional appliance; Group B: extraction treatment with edgewise appliance; to exclude the influence of the naturally growth factor, the changes of each group' cephalometric value were compared by Paired T-test, the changes of cephalometric value between groups were compared by T-test,[Results] (1)Compared with the control group, group A and B both show obviously reduce on overbite and overjet.. Compared with the situation before treatment, the overbite of group A reduces 3.27 mm averagely (P <0.01), the overjet reduces 4.85mm (P<0.001); the overbite of group B reduces 3.1mm (p <0.01), the overjet reduces 5.61mm (p<0.001). The reduction of overbite and overjet between group A and B has no significance difference. The reduction of overbite and overjet between group A and B to the control group has obviously difference . (2) The length of mandible of Group A increases 3.95mm averagely (P<0.001) after treatment, show significance difference compare with group B and the control group. The length of mandible between group B and the control group has no significative difference on statistics;(3)the vertical height of me/NL of group A increases 3.1mm averagely (P<0.01), the vertical height of ar/Go increased 2.38mm (P <0.01). The increase of the vertical height of me/NL and the vertical height of ar/Go of group B has no statistics meaning. (4) upper incisor of group B was retruded most obviously after treatment, move 5.11mm on average (P <0.01).[ Conclusion ] functional appliances apply to Class II malocclusion can stimulate the modification of the mandibular condyle and fossa, promote the development of the mandible., improve incisor overjet relations and the first molar' II class relations and skeletal II class relations, modifacation of skeletal plays the most important role. Edgewise treatment only can obtain space by extraction treatment, to improve the relations of tooth and the face form by the etrude of the upper incisors and move of the lower molar, shown as the compensatory change of the tooth mainly.