Abstract: Objective To evaluate the effect of maxillary bite plate combined with screw expander appliance correcting anterior crossbite. Methods 20 cases of anterior crossbite caused by maxillary anterior arch hypoplasia in deciduous or mixed dentition were treated with maxillary bite plate with screw expander appliance. Computerized cephalometric analysis was carried out. Wilcoxon igned-rank test was performed. Results Anterior crossbite was corrected in all patients after 5 months’ treatment. SNA, SNPr, U1-NA, U1-PNS, the arch length and the Wits value were increased significantly (P <0.05). Conclusion Maxillary bite plate with screw expander appliance could correct anterior crossbite, promote maxillary base bone and increase dental arch effectively.

Key words: maxillary bite plate with screw expander appliance, arch expansion, arch length, anterior crossbite