成人骨性Ⅰ类患者拔牙强支抗矫治前后上气道形态变化的CBCT研究

目的 使用Dolphin软件利用口腔锥形束CT(cone beam computed tomography, CBCT)观察不同垂直骨面型骨性Ⅰ类双颌前突患者拔除4颗第一前磨牙强支抗矫治后对患者上气道形态的影响。方法 以2016年1月—2021年12月我院正畸科收治的56例成人双颌前突骨性Ⅰ类患者为研究对象,所有患者均拔除4颗第一前磨牙,强支抗内收上下前牙。根据SN-MP角将患者分为高角组、均角组、低角组。利用Dolphin软件对收集的治疗前后CBCT数据进行三维的气道重建,并测量腭咽、舌咽及喉咽气道体积及口咽部最小横截面积。结果 对56例成年患者的测量结果显示低角组和高角组的上气道口咽部最小横截面积明显小于均角组。而高角组和低角组之间差异无统计学意义。腭咽、舌咽、喉咽的气道体积三组间差异无统计学意义。进一步对于治疗前后不同组间上气道进行三维分析,结果显示三组治疗前后腭咽、舌咽、喉咽的气道体积差异无统计学意义。低角组和均角组治疗后上气道口咽部最小横截面积明显减小,但高角组治疗前后口咽最小横截面差异无统计学意义。结论 基于CBCT证据,对于成年患者拔除4颗第一前磨牙,强支抗内收前牙的正畸治疗,高角患者应注意垂直方向的控制防止上气道进一步减少,均角和低角患者在制定治疗方案时应结合患者面型和上气道形态进行个性化考量。

CBCT study on morphological changes of upper airway after orthodontic extraction treatment with strong anchorage in adult skeletal Class Ⅰ patients

Objective To observe the effect of orthodontic extraction treatment of first premolar with strong anchorage on morphological changes of upper airway in adult patients with skeletal Class Ⅰ bimaxillary protrusion with different vertical skeletal patterns by Dolphin software and CBCT. Methods Fifty-six adult patients with bimaxillary protrusion treated from January 2016 to December 2021 were selected. All subjects extracted 4 first premolars and retracted the anterior teeth with strong anchorage. The patients were divided into high angle group, average angle group and low angle group according to SN-MP. The collected CBCT scans before and after treatment were reconstructed by using Dolphin software for measuring the airway volumes of velopharynx, glossopharynx, laryngopharynx and the minimum cross-sectional of oropharynx. Results Measurements of 56 adult patients showed that the minimum cross-sectional area of oropharynx in low angle group and high angle group was significantly smaller than that in average angle group. There was no significant difference in airway volume of velopharynx, glossopharynx and laryngopharynx among three groups. Furthermore, three-dimensional analysis of the upper airway showed that there was no significant difference in the airway volume before and after treatment in each group. The minimum cross-sectional area of oropharynx in low angle group and average angle group decreased significantly after treatment, but there was no significant difference in high angle group before and after treatment. Conclusion Based on CBCT evidence, for high angle adult patients with bimaxillary protrusion who will receive orthodontic extraction treatment, the orthodontist should pay attention to the control of vertical direction to prevent further reduction of the upper airway. For patients with low and average angle, when making the treatment plan, we should consider the patient′s face profile and morphology of upper airway.