ABSTRACT
BACKGROUND:Two-dimensional radiographs and plaster models are used to evaluate the changes in the maxillary bone and airway after rapid maxillary expansion,but the shortcomings like distortion,one-sidedness,and overlapping appear.Cone-beam CT can effectively solve the above problems and achieve the three-dimensional reconstruction and measurement of the maxillary bone and airway.OBJECTIVE:To investigate the morphological changes of nasomaxillary complex and upper airway in adolescent patients with malocclusion after rapid maxillary expansion by cone-beam CT and Dolphin software.METHODS:Thirty adolescent patients with malocclusion were enrolled to receive rapid maxillary expansion.All patients underwent cone-beam CT examination before and after treatment,and Dolphin software was used for image processing,three-dimensional reconstruction,fixed point and measurement,to evaluate the morphological changes of the nasomaxillary complex and upper airway.RESULTS AND CONCLUSION:After treatment,the nasal cavity and maxillary width was increased by (2.13±1.80) and (4.12±2.15) mm,respectively (P ＜ 0.05);the coronal diameter and area of the airway on the hard plate was increased by (3.30±2056) mm and (75.37±53.92) mm2,respectively (P ＜ 0.05),and all above indexes showed significant difference compared with baseline.While the sagittal diameter of the airway on the hard plate showed no significant changes.After treatment,the upper airway showed a significant increase in the area and volume at the nasopharynx,which was increase by (33.57±57.10) mm2 and (1 009.59±1 350.91) mm3,respectively (P ＜ 0.05).The upper airway showed no significant changes in the area and volume at the velopharynx and glossopharynx,as well as the height at each part.To conclude,in the growing patients with malocclusion after rapid maxillary expansion,the nasomaxillary complex and area and volume of upper airway at the nasopharynx showed a significant increase,but the airway at the velopharynx and glossopharynx reveal no significant changes.