The Application Of Face-mask Protraction Therapy In Early Class Ⅲ Skeletal Ⅲ Malocclusion

Objective: this study was designed to observe and evaluate the clinical effect of face-mask in classⅢ,skeletalⅢ.Mathod: One Chinese female case with Angle classⅢmalocclusion was selected from Dalian Doctor clinic in 2008,who was 10-years-old 9 months. aimed at treating anterior classⅢrelationship . A lateral cephalogram was taken before treatment, immediately posttreatment .Results: A positive result was obtained in this case.Anterior crossbite had been relieved,and OB,OJ became normal. The arch width had been expanded , meanwhile ,canine began to erupt . Left molar relationship was still classⅢrelationship , but better than pretreatment. The right side had changed to classⅠrelationship.SNA was increased from 79°to 85°, SNB increased1°,ANB decreased 5°.Profile has been improved.Conclusion:Face-mask can be used effectively in classⅢmalocclusions in mixed dentition,improving class m facial profile.