alveolar bone thickness. Methods Among 168 cases with malocclusion in early permanent dentition stage, 93 patients were male and 75 patients were female. All patients（aged 10 - 14 years） were divided into 9 groups by different facial skeletal types, mandibular anterior alveolar bone thickness in patients′lateral cephalometric films were measured. ANOVA were performed to measurement results with the SPSS 13.0 statistical software. Results Though sagittal facial skeletal types were the same, there were significant differences between different vertical facial types groups. The order was low- angle group, average- angle group and high- angle group according to the size. A high- angle individual often had a thin anterior alveolar bone while a low- angle individual often had the oppositemorphology character. There was no statistical significance between skeletal type Ⅰ, Ⅱ and Ⅲ. But group of skeletal type Ⅲ also had a thin alveolar bone thickness which had no significant difference with high- angle group. Lowangle group Ⅲ had no significant difference with average- angle groupⅠ and Ⅱ in alveolar bone thickness. Conclusion Sagittal facial skeletal types have little influence on anterior alveolar morphology, but the vertical facial skeletal types have strong connection with anterior alveolar bone thickness.
