Abstract: Objective:To make a double malor distalization pendulum appliance, and apply it in the treatment of children with Angel class Ⅱ malocclusion accompanied by odontogenic crowded anterior teeth .Methods:Fifteen subjects (6 males, 9 females) with Angel classⅡmalocclusion accompanied by odontogenic crowded anterior teeth are selected and asked to wear a double thrust molar pendulum appliance for half a year.Then lateral cephalometric radiograph and models are measured and analyzed before and after the treatment. Measuring project mainly includes:distance of malordistalization, degree of molar intrusion, buccal lingual offset of molar, near far slope of molar, U1-SN value and the cover of front teeth.The measured data are processed by using t test statistical method and SPSS17.0 software statistical processing.Results:Clinical observation shows that double malor distalization pendulum appliance has great effects on the treatment of children with Angel classⅡmalocclusion accompanied by odontogenic crowded anterior teeth.Statistics shows that the difference between distance of malor distalization, degree of molar intrusion, buccal lingual offset of molar, near far slope of molar meaured before and after the treatment is statistically significant (P< 0.05), while that between U1-SN value and the cover of front teeth before and after the treatment is of no statistical significance (P>0.05); Difference between male and female before and after the treatment is also of no statistical significance (P> 0.05). This is consistent with the clinical observation.Conclusion:When this double malor distalization pendulum appliance is applied in the treatment of children with Angel classⅡmalocclusion accompanied by odontogenic crowded anterior teeth the distance ofmolar distalization changes significantly and face height is under better control. Moreover, it protects the front teeth anchorage and prevents the rotation and buccal lingual inclination of the molar. The curative effect is distinct and has nothing to do with gender.

Key words: malor distalization, pendulum appliance, Angel class Ⅱ malocclusion, curative effect