Characteristics of the upper airway growth in class Ⅲ malocclusion patients

doi:10.3969/j.issn.2095-4344.2017.08.011

Abstract：BACKGROUND: Class Ⅱ malocclusion has been found to be associated with the morphology of upper airway, but development of upper airway in patients with class Ⅲ malocclusion, and its correlation with the craniofacial morphology have not yet been reported.OBJECTIVE: To investigate the characteristics of the upper airway growth in patients with class Ⅲ malocclusion according to quantitative cervical vertebral maturation (QCVM), thus providing references for the upper airway construction and studies on the craniofacial development.METHODS: 368 patients with class Ⅲ malocclusion aged 4-39 years old were enrolled and allocated to four groups according to QCVM (QCVM Ⅰ, Ⅱ, Ⅲ and Ⅳ). The lateral cephalometric radiographs were measured, and then the sagittal depth of upper airway was analyzed.RESULTS AND CONCLUSION: All measurements showed no significant differences in QCVM Ⅰ. In QCVM Ⅱ, Ⅱ and Ⅳ, only the distance of epiglottic vallecula and posterior pharyngeal wall showed significant difference. The PNS-R,PNS-AD2, V-LPW of upper airway in male increased from QCVM Ⅰ to QCVM Ⅲ, and SPP-SPPW, U-MPW, TB-TPPW increased from QCVM Ⅱ, and the increase of PNS-UPW made a significance from QCVM Ⅰ to QCVM Ⅱ. In female,the PNS-R, PNS-AD2 of upper airway increased from QCVM Ⅰ to QCVM Ⅲ, and SPP-SPPW, U-MPW, TB-TPPW,V-LPW increased from QCVM Ⅱ, and the increase of PNS-UPW made a significant difference from QCVM Ⅰ to QCVM Ⅱ. While from QCVM Ⅲ to QCVM Ⅳ, the changes made no significance. There was a correlation between the sagittal depth of upper airway and craniofacial structure. Different vertical facial types exposed influence on the sagittal depth of upper airway. To conclude, the upper airway is related to the craniofacial development in class Ⅲ malocclusion patients, paving the way for the future study on the correlation between the upper airway and class Ⅲ malocclusion.