Study of changes of hard tissues following application of combined rapid maxillary expansion (RME) and maxillary protraction therapy in skeletal class III patients of different ages

Objective To study the effects of ages on combined RME and maxillary protraction therapy. Methods 75 patients with skeletal class Ⅲ malocclusion aged from 3 to 15 were selected,and divided into 3 groups. These cases were treated consecutively with RME and maxillary protraction. Lateral cephalometric radiographs were used to quantify the hard tissue changes before treatment (T1) and after treatment(T2). SPSS11.0 statistical software was used to compare the changes. Results The subjects in three groups all had significant hard tissue changes. And the obvious skeletal and dental differences were observed in the different three age groups. Conclusion It is obvious that age affects the results of RME and maxillary protraction therapy.