Three-dimensional oropharyngeal airway changes in adolescent patients treated with extractions: a preliminary study

Objectives: To evaluate three-dimensional oropharyngeal airway changes after the extraction treatment in adolescents. Methods: : Forty class I adolescents were selected, treated with extraction of four first premolars with non-maximum anchorage. The upper airway was reconstructed and segmented with Dolphin 11.8. The changes of oropharyngeal airway volume and cross-sectional area were measured. The measurements were analyzed with SPSS 26.0. Results: : Compared with pre-treatment, the palatopharyngeal volume, glossopharyngeal volume, total oropharyngeal volume and minimum cross-sectional area increased significantly (P < 0.05), and the minimum cross-sectional area of oropharynx was mostly located in the glossopharyngeal region. The cross-sectional area and the maximum anterior and posterior diameter of the uvula tip decreased significantly. Univariate correlation analysis showed that there was significant difference after the retraction of upper and lower central incisors (P < 0.05). The results of multivariate regression analysis showed that the retraction (OR=1.821,95% CI: -1.554~-0.060, P=0.042) of the mandibular central incisor was an independent risk factor for the decrease of the cross-sectional area of the uvula tip after tooth extraction. Conclusions: : With non-maximum anchorage, the effect of extractions on the oropharyngeal airway of skeletal class Ⅰ adolescents is generally small, but it will change the shape and is related to the retraction of anterior teeth.