Three-Dimensional Evaluation of the Upper Airway Morphological Changes in Growing Patients with Skeletal Class III Malocclusion Treated by Protraction Headgear and Rapid Palatal Expansion: A Comparative ResearchReport as inadecuate




Three-Dimensional Evaluation of the Upper Airway Morphological Changes in Growing Patients with Skeletal Class III Malocclusion Treated by Protraction Headgear and Rapid Palatal Expansion: A Comparative Research - Download this document for free, or read online. Document in PDF available to download.

Objective

The aim of this study was to evaluate the morphological changes of upper airway after protraction headgear and rapid maxillary expansion PE treatment in growing patients with Class III malocclusion and maxillary skeletal deficiency compared with untreated Class III patients by cone-beam computed tomography CBCT.

Methods

Thirty growing patients who have completed PE therapy were included in PE group. The control group n = 30 was selected from the growing untreated patients with the same diagnosis. The CBCT scans of the pre-treatment T1 and post-treatment T2 of PE group and the control group were collected. Reconstruction and registration of the 3D models of T1 and T2 were completed. By comparing the data obtained from T1, T2 and control group, the morphological changes of the upper airway during the PE treatment were evaluated.

Results

Comparing with the data from T1 group, the subspinale A of maxilla and the upper incisor UI of the T2 group were moved in the anterior direction. The gnathion Gn of mandible was moved in the posterior-inferior direction. The displacement of the hyoid bone as well as the length and width of dental arch showed significant difference. The volume and mean cross-sectional area of nasopharynx, velopharynx and glossopharynx region showed significant difference. The largest anteroposterior-the largest lateral AP-LR ratios of the velopharynx and glossopharynx were increased, but the AP-LR ratio of the hypopharynx was decreased. In addition, the length and width of the maxillary dental arch, the displacement of the hyoid bone, the volume of nasopharynx and velopharynx, and the AP-LR ratio of the hypopharynx and velopharynx showed significant difference between the data from control and T2 group.

Conclusion

The PE treatment of Class Ⅲ malocclusion with maxillary skeletal hypoplasia leads to a significant increase in the volume of nasopharynx and velopharynx.



Author: Xueling Chen , Dongxu Liu , Ju Liu, Zizhong Wu, Yongtao Xie, Liang Li, Hong Liu, Tiantian Guo, Chen Chen, Shijie Zhang

Source: http://plos.srce.hr/



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