Objective:To evaluate the soft and hard tissue changes of class II division 1 patients treated by Dynamax appliance. Methods:15 class II division 1 cases, whose hand-wrist radiographs were in FG-G stage, were treated by Dynamax appliance. After scanning the cephalometric tracing and transcripting into the special software of Winceph 7.0, the Cephalometrics analysis was preformed on pre-treatment and post-treatment. Results:After being treated by Dynamax appliance, the SNB, Co-GN,L1-NB,Cm-Sn-Ls was increased significantly,the ANB,Wits,U1-NA,overjet,overbite,Ns-Sn-Pos decreased significantly. Conclusion:Dynamax can effectively induce forward movement of mandible, improved esthetics on soft tissue profile and make face become normal.

Objective:To study the changes of upper airway dimension and morphology in Class Ⅱ mandibular retrusion children af-ter functional treatment by Twin-block appliance.Methods:The Cone-Beam CT(CBCT)data of upper airway of the subjects were measured with Dolphin 11.5 software before and after fuctional treatment by Twin-block appliance.The comparison of upper airway di-mension and morphology between pre-treatment and post-treatment was performed by paired t-text.Results:After functional treatment the volume of total upper airway,velopharyngeal airway,glossopharyngeal airway,laryngopharyngeal airway,oropharyngeal airway,the sectional area of the inferior of the soft palate(SP),tip of the epiglotti(TE),the sagittal diameter of SP,the lateral diameter of SP and TE increased(P <0.05)in the children;the airway's shape of SP was attended to be rounder and TE to be more flat.Conclusion:Functional treatment is effective in the treatment of skeletal Class Ⅱ mandibular retrusion of children by increase of the upper airway and improvement of respiration.

Objective: To study the difference of airway volume among the adolescent subjects with various vertical skeletal patterns. Methods: CBCT records of 88 adolescents with normal sagittal facial pattern were collected and divided into 3 groups according to their FH-MP angle. The subjects of the 3 groups were matched in age and sex. Airway volume and cross-sectional areas were compared among the 3 groups with Dolphin software. Correlation analyses of the airway dimensions with the maxillofacial variables was carried out. Results: There were statistical differences among the 3 groups in volumes of velopharynx,glossopharynx and oropharynx, minimal cross-section area of oropharynx and cross-section area on EP plane,and all the measurements decreased from low angle to normal angle to high angle groups(P ＜ 0. 05). Cross-section areas of HP plane and SP plane in low angle group were significantly larger than that of the normal angle and high angle groups(P ＜ 0. 05). The oropharyngeal airway dimensions showed negative correlation with FMA,and positive correlation with Co-Po,Ar-Gn (except cross-section area of HP). Conclusion: The pharyngeal airway volumes among different vertical skeletal patterns in adolescents are different.