Upper Airway Changes after Orthodontic Extraction Treatment in Adults: A Preliminary Study using Cone Beam Computed Tomography

• Published in: PloS one 2015-11, Vol.10 (11), p.e0143233-e0143233
• Main Authors: Zhang, Jingjing, Chen, Gui, Li, Weiran, Xu, Tianmin, Gao, Xuemei
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Adults; Airway Remodeling - physiology; Bicuspid - diagnostic imaging; Bicuspid - pathology; Bicuspid - surgery; Body mass; Body mass index; Case-Control Studies; CAT scans; Computed tomography; Cone-Beam Computed Tomography; Cross-sections; Dental occlusion; Dimensional analysis; Dolphins; Female; Females; Headgear; Humans; Hyoid Bone - anatomy & histology; Hyoid Bone - diagnostic imaging; Incisor - diagnostic imaging; Incisor - surgery; Incisors; Male; Males; Malocclusion, Angle Class II - diagnostic imaging; Malocclusion, Angle Class II - pathology; Malocclusion, Angle Class II - surgery; Marine mammals; Maxilla - diagnostic imaging; Maxilla - surgery; Molar - diagnostic imaging; Molar - surgery; Morphology; Oropharynx - anatomy & histology; Oropharynx - diagnostic imaging; Orthodontics; Patients; Position measurement; Respiratory tract; Retrospective Studies; Sleep; Studies; Systematic review; Teeth; Tomography; Tooth Extraction
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0143233

Whether the orthodontic treatment with premolar extraction and maximum anchorage in adults will lead to a narrowed upper airway remains under debated. The study aims to investigate the airway changes after orthodontic extraction treatment in adult patients with Class II and hyperdivergent skeletal malocclusion. This retrospective study enrolled 18 adults with Class II and hyperdivergent skeletal malocclusion (5 males and 13 females, 24.1 ± 3.8 years of age, BMI 20.33 ± 1.77 kg/m2). And 18 untreated controls were matched 1:1 with the treated patients for age, sex, BMI, and skeletal pattern. CBCT images before and after treatment were obtained. DOLPHIN 11.7 software was used to reconstruct and measure the airway size, hyoid position, and craniofacial structures. Changes in the airway and craniofacial parameters from pre to post treatment were assessed by Wilcoxon signed rank test. Mann-Whitney U test was used in comparisons of the airway parameters between the treated patients and the untreated controls. Significant level was set at 0.05. The upper and lower incisors retracted 7.87 mm and 6.10 mm based on the measurement of U1-VRL and L1-VRL (P < 0.01), while the positions of the upper and lower molars (U6-VRL, and L6-VRL) remained stable. Volume, height, and cross-sectional area of the airway were not significantly changed after treatment, while the sagittal dimensions of SPP-SPPW, U-MPW, PAS, and V-LPW were significantly decreased (P < 0.05), and the morphology of the cross sections passing through SPP-SPPW, U-MPW, PAS, and V-LPW became anteroposteriorly compressed (P