Abstract: PURPOSE: To evaluate the effect of anterior crossbite patients with bad tongue habit treated by tongue crib combined with chincup by cephalometric analysis. METHODS: A total of 25 patients (8 males, 17 females, age range 7～13 years, average age 8.6 years) of anterior crossbite with bad tongue habit or incorrect tongue position were selected. All cases used tongue crib combined with chincup therapy. Lateral cephalometric films taken at the beginning and the end of treatment were analyzed by Winceph 9.0 cephalometric software. All 19 measurement items were assessed by SPSS 17.0 software package. Following the consistency test, Mann-Whitney U test and Wilcoxon singed-rank test were carried out to compare the differences between pre- and post-treatment. RESULTS: All 25 cases obtained satisfactory results, the saggital relative position of maxilla and mandible was improved, anterior crossbite was corrected, occlusion was perfect and bad tongue habit and position were improved. Compared with pre-treatment, SNA, ANB, convexity were U1-SN, U1-NA, overjet and upper lip to E line increased significantly (P<0.05). SN-PP, SN-OP, L1-MP, L1-NB decreased significantly after treatment (P<0.05). The measurement items related to gender were analyzed separately. ANS-PNS and Cd-Gn increased in both male and female (P<0.05). CONCLUSIONS: Tongue crib can effectively correct bad tongue position, promote maxillary forward growth, and prevent the mandible from going ahead combined with chincup. It is an ideal interceptive orthodontic scheme for anterior crossbite with bad tongue habit.

Key words: Anterior crossbite, Bad tongue habit, Tongue crib, Interceptive orthodontics, Cephalometric analysis