Anterior Tracting Correction in Treatment of Permanent Teeth Crowded Bone Malocclusion in III Dimension

Objective To investigate the effectiveness of maxillary protraction treatment in skeletal Class Ⅲ malocclusion with crowding.Methods 11 patients,4 males,7 females with skeletal Class Ⅲ malocclusion with crowding in early permanent deatition were included.the mean age was 10.8.These patients were consecutively treated with rapid maxillary expasion about one months and maxillary protraction facemask about 12 months.Lateral cephalometric radiographs were used to quantify the skeletal and dental changes before treatment and after treatment.T-test was assessed to compare significant difference between the two groups.Results With 12 month treatment,overjet was overcorrected.SNA、SNB、SN/MP、U1-FHP、U6-FHP and crowding degree were significantly larger in after treatment group.SNB、L1/NB1、L1/MP、U1/L1 were significantly smaller in after treatment group.Conclusion Maxillary protraction is very effective method to correct skeletal Class Ⅲ malocclusion with crowding in early permanent dentition.