传统与改良Hyrax扩弓器对牙弓、牙槽骨、基骨影响的CBCT对比研究

目的应用CBCT比较传统Hyrax扩弓器与改良Hyrax扩弓器对牙弓、牙槽骨及基骨的影响。方法将30例上颌牙弓狭窄的患者随机分为2组,传统Hyrax扩弓器组15例患者,8男7女,平均年龄(14.1±2.5)岁,改良Hyrax扩弓器组15例患者,9男6女,平均年龄(13.9±2.6)岁。收集2组患者扩弓前及扩弓3个月后的CBCT扫描数据,重建三维影像并测量牙弓、牙槽骨及基骨的相应指标,应用配对样本的t检验分析2组扩弓后测量指标的变化,应用独立样本的t检验分析2组测量指标之间的差异。结果 2组都存在基骨的改变及牙弓宽度的增加,2组之间的比较显示传统Hyrax组的第一、二前磨牙牙弓宽度大于改良Hyrax组,第一磨牙颊侧及腭侧牙槽骨厚度的变化2组并无统计学的差异,而第一前磨牙颊侧及腭侧牙槽骨的厚度变化2组有统计学差异,此外,2组之间绝对牙倾斜度比较也并无统计学差异。结论两种快速扩弓方法对于纠正上颌牙弓狭窄都有较为明显的效果,传统Hyrax扩弓器对第一前磨牙牙弓宽度及颊腭侧牙槽骨厚度的影响更大。

Comparative study of the effects of conventional and hybrid Hyrax appliances on arch width,dentoalveolar and basal bone

Objective To compare the effects of conventional and hybrid Hyrax appliances on arch widths, dentoalveolar and basal bone. Methods 30 patients requiring maxillary expansion were randomly divided into two groups. A conventional hyrax appliance was applied in one group, consisting of 15 patients (8 boys, 7 girls;mean age (14.1±2.5) years), and a hybrid hyrax appliance was used in the other group of 15 patients (9 boys, 6 girls;mean age (13.9±2.6) years). Cone?beam computed tomography records were taken before and 3 months after expansion, and dental arch width, dentoalveolar, and basal bone variables were measured on the rebuild 3?D images. The paired?samples test was used to evaluate treatment changes for both groups. The independent?samples test and the t test were used to compare the variables between the two groups. Results Significant basal bone changes and increases in dental arch width were observed in both groups. However, the widths between the first and second premolars were significantly greater in conventional Hy?rax appliance than those in hybrid Hyrax appliance. There were no significantly differences in buccal and palatal alveolar bone thickness changes of the first molar between the two groups, whereas changes of the first premolars significantly differed between the two groups. No significant intergroup difference was found in the absolute dental tipping. Conclusions The two rapid expansions are both effective methods for a narrow maxilla treatment. However, the conventional hyrax appliance can result in greater expansion in the premolar dent?al arch width and the buccal and palatal alveolar bone thickness.