The purpose of this study is to evaluate the effects of facemask therapy in patients with Class III malocclusion with two types of bonded expanders covering different numbers of anchored teeth and to compare the anchorage value of two types of bonded expander. Eighteen subjects with Class III malocclusion in early mixed dentition were included in this study, and subjects were divided into two groups based on the number of teeth covered by bonded expander: group 1 (splinting four teeth on each side, 9 subjects) and group 2 (splinting three teeth on each side, 9 subjects). Lateral cephalograms were obtained and assessed before (T1) and after (T2) the treatment. The facemask therapy showed skeletal effects including anterior movement of maxilla and backward rotation of mandible in both groups, with no significant differences between groups. Mesial movement of maxillary molars which indicates anchorage loss of the bonded expander was found in both groups, but significantly larger mesial movement was found in group 2 than in group 1. In conclusion, the value of anchorage was different according to the number of teeth covered by bonded expander as an intraoral anchorage of facemask, but there were no significant differences in skeletal effects.