Wei Chen1, Yue-Hua Liu, Qi Xu. 1. Department of Orthodontics, Hangzhou West Dental Hospital. Hangzhou 310013, Zhejiang Province, China. E-mail:88294426@qq.com.
Abstract
PURPOSE: To investigate the effect of maximum anchorage on upper airway in adolescent patients with bimaxillary protrusion and extraction from three-dimensional direction on cone-beam computed tomography(CBCT). METHODS: A retrospective evaluation was carried out on pre- and post-orthodontic treatment records of 50 adolescents with bimaxillary protrusion treated by maximum anchorage extraction. The changes on upper airway pre- and post-treatment were measured. The data were analyzed using SPSS 17.0 software package. RESULTS: It was found that the volume, mean cross-section area, minimum cross-section area of oropharyngeal and hypopharyngeal airway were significantly decreased after treatment (P<0.001). The cross-section morphology of oropharyngeal and hypopharyngeal airway showed more ellipsoid(P<0.001). Pearson's correlation analysis indicated that the lower incisor retraction and hyoid retraction was correlated with mean cross-section area of hypopharyngeal airway (P<0.05). There was significant correlation in the upper and lower incisor retraction and hyoid retraction(P<0.01). CONCLUSIONS: The upper airway dimension should be given serious consideration on the decision when closing the space with maximum anchorage in adolescent patients.
PURPOSE: To investigate the effect of maximum anchorage on upper airway in adolescent patients with bimaxillary protrusion and extraction from three-dimensional direction on cone-beam computed tomography(CBCT). METHODS: A retrospective evaluation was carried out on pre- and post-orthodontic treatment records of 50 adolescents with bimaxillary protrusion treated by maximum anchorage extraction. The changes on upper airway pre- and post-treatment were measured. The data were analyzed using SPSS 17.0 software package. RESULTS: It was found that the volume, mean cross-section area, minimum cross-section area of oropharyngeal and hypopharyngeal airway were significantly decreased after treatment (P<0.001). The cross-section morphology of oropharyngeal and hypopharyngeal airway showed more ellipsoid(P<0.001). Pearson's correlation analysis indicated that the lower incisor retraction and hyoid retraction was correlated with mean cross-section area of hypopharyngeal airway (P<0.05). There was significant correlation in the upper and lower incisor retraction and hyoid retraction(P<0.01). CONCLUSIONS: The upper airway dimension should be given serious consideration on the decision when closing the space with maximum anchorage in adolescent patients.