OBJECTIVE: Early interfering orthodontics were used to treat maxillary hyperplasia by face mask and extra-oral bow technique in teenages.The position changes of maxilla after orthodontic treatment were evaluated.METHODS:The cephlometric variables before and after treatment were measured.Variables after treatment were compared with normal values in children with same ages,and changes of the maxillary position was determind.RESULTS:The position of the maxilla after orthopedics was significantly advanced (P<0.001),but there was still difference from normal values.CONCLUSION:In the peroid of mixed dentition of patients with cleft lip and palate,early orthodontics on maxillary hyperplasia could stimulate maxillary development and growth,remove or improve crossbite,extra-oral bow and face mask were efficient tools for this kind of patients.