目的：研究正畸正颌联合治疗的骨性Ⅲ类错牙合患者上、下颌前牙牙槽骨厚度的特征。方法：选取2011年11月至2015年1月于北京大学口腔医院进行正畸正颌联合治疗的54名成人骨性Ⅲ类错牙合患者，摄取治疗前头颅侧位片，利用单样本t检验方法与北京大学正常牙合样本库的相应数值进行比较，获取其牙槽厚度的特征,对样本病例的矢状向及垂直向骨性测量值与上、下颌前牙牙槽骨厚度采用Pearson相关性分析。根据颌骨矢状向和垂直向关系将患者分成4 组，（1）A 组：ANB 角<－4°，SN-MP角≤ 37.7°，11例；（2）B 组：ANB 角≥－4°，SNMP角≤ 37.7°，16例；（3）C 组：ANB 角<－4°，SNMP角>37.7°，14例；（4）D 组：ANB 角≥－4°，SN- MP角> 37.7°，13例。通过头影测量的方法，对4组前牙牙槽骨厚度进行单因素方差分析，多重比较采用SNK方法。结果：骨性安氏Ⅲ类患者上、下前牙区牙槽厚度均较正常牙合小（P<0.05），相关性分析显示，垂直向骨型均与上、下前牙牙槽骨厚度有一定相关性（P<0.05），而矢状向骨型与下前牙牙槽骨厚度有一定相关性（P<0.05）。按不同骨型分组的4组病例在前牙牙槽骨厚度特征方面，下前牙舌侧及总牙槽骨厚度均显示C、D组患者小于B组（LP,LW,P<0.05）；对于上前牙牙槽骨总厚度，C组较B组明显小［UW (upper alveolar bone thickness）分别为7.86、9.05 mm］。结论：骨性安氏Ⅲ类错牙合上、下前牙区牙槽厚度均较正常牙合小；不同骨面型上、下前牙牙槽骨厚度的特征有所不同，在对其进行前牙去代偿时尚需谨慎。

Objective：To investigate the compensation of the anterior alveolar bone thickness in skeletal class Ⅲ patients treated with orthodontic-surgical treatment. Methods: The samples consisted of 54 ske-letal class Ⅲ patients treated with orthodontic-surgical treatment. Lateral cephalograms were taken before treatment. Descriptive statistics were calculated for corresponding variables, and the differences between the samples and the norms from Peking University normal occlusion sample library were assessed by independentsample t test. Correlation analyses were performed to find associations between skeletal characteristics and anterior alveolar bone thickness. According to skeletal anteroposterior discrepancy/vertical type (ANB, criteria=-4°; SN-MP, criteria=37.7°), the samples were allocated into group A (severe anteroposterior discrepancy/hypodivergent vertical type, n=11), group B (moderate anteroposterior discrepancy/hypodivergent vertical type, n=16), group C (severe anteroposterior discrepancy/hyperdivergent vertical type, n=14), and group D (moderate anteroposterior discrepancy/hyperdivergent vertical type, n=13),and one-way ANOVA with SNK multiple comparison test were performed. Results: The anterior alveolar bone thickness of the skeletal class Ⅲ patients were thinner compared with norm values (P<0.05). Correlational analyses showed that，both the upper and lower anterior alveolar bone thickness was correlated with the skeletal vertical discrepancy (P<0.05), but the anteroposterior type was only correlated with the lower anterior alveolar bone thickness (P<0.05). For the 4 groups according to skeletal anteroposterior discrepancy/vertical type, hypodivergent vertical type had thinner lower ligual and total bone thickness (LP, LW, P<0.05). while for upper alveolar bone thickness (UW), group C and group B exhibited the thinnest and thickest (the values of UW were 7.86 mm and 9.05 mm). Conclusion:The upper and lower anterior alveolar bone thickness of skeletal class Ⅲ patients are thinner compared with normal occlusion. Different skeletal anteroposterior discrepancy/vertical type results in differences in the anterior alveolar bone thickness, so decompensation should be treated differently and carefully.