To investigate the relationship between the morphology of the oropharyngeal airway and the maxillofacial skeletal morphology by comparing the three-dimensional morphology of the oropharyngeal airway in different sagittal features of the high angle adult.

60 high angle adults aged 18 to 36 years were divided into 3 groups based on their ANB angles, there were 20 adults in each group, the number of males were equal to females. The In vivo Dental 5.1 software for reconstructing the CBCT image of each one was used, the middle sagittal plane and axial plane in coronal, sagittal and axis view was adjusted, then the distances, volumes and minimum cross-sectional areas were measured. The differences among 3 groups and between different gender were compared.

There was statistical difference in W-ETP among 3 groups (P ＜ 0.05). There were statistical difference in H-GP、H-Total、W-PNSP、W-ETP、V-GP、V-Total (P ＜ 0.05) between males and females, and these measurements of males were bigger than of females.

The difference of the size and shape of the oropharyngeal airway of high angle adults among different sagittal skeletal patterns was mainly reflected in the lowest width of glossopharyngeal airway, the oropharyngeal airway of males was bigger and longer than females.

To compare the depth of the curve of Spee in Angle classⅡ malocclusion patients with different vertical skeletal patterns and to investigate the relationship between the depth of the curve of Spee and dentofacial morphology.

101 Angle classⅡ malocclusion patients were selected and randomly divided into 3 groups based on their GoGn-SN angles-high angle, average angle and low angle. Lateral cephalograms and dental models of all patients were evaluated to analyze Spee curve depth difference among different groups, Correlation analysis and a multiple linear regression analysis were performed to determine the relationship between the depth of the curve of Spee and all selected cephalometric variables.

There was statistical difference in depth of the curve of Spee among different groups P＜0.05. The depth of the curve of Spee was least in the high angle group and greatest in the low angle group. GoGn-SN angle had statistically significant negative correlation with the depth of the curve of Spee, r = 0.428, P = 0.000, ODI, S-Go/N-Me、L7-GoGn angle had statistically significant positive correlation with the depth of the curve of Spee, r = 0.381, 0.357, 0.333, P = 0.000, 0.000, 0.001. The multiple linear regression analysis with stepwise method showed GoGn-SN angle had significant contribution to the depth of the curve of Spee.

In Angle classⅡ malocclusion patients, there was statistical difference in depth of the curve of Spee among different vertical skeletal patterns. The depth of the curve of Spee is correlated with dentofacial morphology, GoGn-SN angle had significant contribution to the depth of the curve of Spee, which should be taken into consideration during orthodontic diagnosis and treatment.

To investigate the relationship between the morphology of oropharyngeal airway and craniofacial morphology in high angle patient by cone beam CT images.

CBCT images of 60 high-angle adult patients were randomly selected in the Affiliated Stomatological Hospital of Nanchang University. The line distances, volumes and min cross-sectional areas of each part of oropharyngeal airway were measured by the Invivo Dental 5.1 software. Pearson correlations analysis of all measurements was performed on all the parameters of oropharyngeal airway and maxillofacial structures.

In male group, SNB showed positive correction with UTL, PPV, GPV, OPV, MinS. Thereas the GoGn-SN angle showed negative correction with UTL, ETL, PPV, GPV, OPV, MinS, S-Go/N-Me was positive correlated with UTL. In female group, SNA showed negative correction with PNSW. The SNB angle showed negative correction with GPH、PNSW、UTW, GoGn-SN showed positive correction with GPH.

In high angle adults, the morphology of oropharyngeal airway exist some degrees of correlation with the maxillofacial structures. In male group, the dimension of the oropharyngeal airway tend to increase with the forward of mandible, and tend to decrease or obstruct with the clockwise rotation of mandible. In female group, with the changes of position of maxilla and mandible, oropharyngeal airway showed only partial morhological change.