不同垂直面型骨性Ⅲ类患者切牙牙槽骨骨量的研究

Alveolar bone in upper and lower incisor’s region of patients with different vertical facial types of skeletal Ⅲ malocclusion

目的通过CBCT数据测量不同垂直面型骨性Ⅲ类错(牙合)畸形患者的切牙根周牙槽骨面积、根尖区牙槽骨厚度和牙槽嵴高度,评估牙槽骨骨量的差异。方法选取110例骨性Ⅲ类错(牙合)畸形患者的CBCT资料,根据下颌平面角(GOGN-SN)和面高比(FHI)将患者分为3组:长面型组(23例),均面型组(51例)和短面型组(36例)。分别测量各组上下切牙根周颊侧和舌侧牙槽骨面积(BA/LA)、根尖颊侧和舌侧牙槽骨厚度(BW/LW)以及颊侧和舌侧牙槽嵴高度(BH/LH),并对测量数据进行统计分析。结果长面型组BA和BW小于均面型组和短面型组(P<0.001),而LW在3组中最大(P<0.001)。BA和BW与GOGN-SN呈负相关,而与FHI呈正相关,LW与GOGN-SN呈正相关,与FHI呈负相关。结论不同垂直面型骨性Ⅲ类患者上下切牙根周牙槽骨骨量有差异,长面型患者的上下切牙颊侧牙槽骨面积和根尖颊侧牙槽骨厚度均较小,而根尖舌侧牙槽骨厚度较大,此差异与下颌平面角和面高比存在显著相关性。

Objective To investigate differences in alveolar bone of patients with different vertical facial types of skeletal Ⅲ malocclusion through measuring alveolar bone area around root, apical alveolar bone thickness and alveolar crest height in incisors’ region basing on CBCT data. Methods One hundred and ten CBCT scans of skeletal Ⅲ malocclusion with different vertical facial types were selected. Patients were categorized into three groups based on vertical facial types(GOGN-SN and FHI):long-face group(23 patients), average-face group(51 patients) and short-face group(36 patients). Buccal and lingual alveolar bone area around root(BA/LA), buccal and lingual alveolar bone thickness(BW/LW) at apical region and buccal and lingual height of alveolar crest(BH/LH) were measured and used for statistical analysis. Results In long-face group, BA and BW were significantly smaller than those in average-face group and short-face group(P<0.001), and LW was largest among three groups(P<0.001). BA and BW were negatively correlated with GOGN-SN, but positively correlated with FHI. LW were positively correlated with GOGN-SN, but negatively correlated with FHI. Conclusion There are differences in the amount of alveolar bone around root in the upper and lower incisors’ region in patients of skeletal Ⅲ malocclusion with different vertical facial types. Long-face patients with skeletal Ⅲ malocclusion have smaller buccal alveolar bone area of root, smaller buccal alveolar bone thickness at apex and bigger lingual alveolar bone thickness at apex in upper and lower incisor’s region. These differences are significantly correlated with the mandibular plane angle and face-height ratio.