Angle Orthod. 2020 Jan;90(1):39-46. doi: 10.2319/021019-92.1. Epub 2019 Aug 12.
To examine changes in the airway and cephalometric measurements associated with orthodontic treatment of adults with and without premolar extractions. The study investigated whether extractions had a direct or indirect effect on the airway and examined selected skeletal and dental features.
This retrospective study used pre- (T1) and posttreatment (T2) cone-beam computed tomography scans of 83 adult patients matched for age and sex. A total of 15 airway and 10 skeletal and dental measures were analyzed by means of repeated-measures analysis of variance.
There were no results showing that extractions affected airway dimensions that could not be accounted for as reflections of measurement error. There was no evidence that extractions affected the airway indirectly through skeletal and dental changes. There were strong and consistent findings that patients with small airways showed larger ones after treatment and that patients with large airways showed smaller ones later. These effects were independent of whether or not extractions were part of treatment. The measurement phenomena of regression toward the mean and of differential unfolding of natural changes over time could have accounted for the results observed.
There was no evidence that extractions in nongrowing patients have negative consequences on the size of various airway measures in the nasopharynx, retropalatal, or retroglossal regions.
研究有无拔牙的成年人正畸治疗后气道和头影测量的变化。本研究探讨拔牙是否对气道有直接或间接影响，并检查了一些骨骼和牙齿特征。
本回顾性研究使用了 83 名年龄和性别匹配的成年患者的治疗前（T1）和治疗后（T2）锥形束 CT 扫描。通过重复测量方差分析对 15 项气道和 10 项骨骼及牙齿测量指标进行了分析。
没有结果表明拔牙会影响气道尺寸，而这些影响无法用测量误差来解释。也没有证据表明拔牙会通过骨骼和牙齿的变化对气道产生间接影响。有强有力的一致性发现，气道较小的患者在治疗后气道会变得更大，而气道较大的患者在治疗后气道会变得更小。这些影响与拔牙是否为治疗的一部分无关。回归均值和自然变化随时间差异展开的测量现象可能解释了观察到的结果。
在未生长的患者中，拔牙对鼻咽、腭后或舌后气道各测量指标的大小没有负面影响。
