Abstract: PURPOSE: To investigate the effect of extraction on condylar process position and upper airway in 12-14 years old females with skeletal ClassⅡhigh angle. METHODS: Twenty seven 12-14 years old females with skeletal ClassⅡhigh angle (experimental group) and 30 physical examinees without malocclusion (control group) in Stomatology Hospital Affiliated to Southwest Medical University from January 2016 and June 2017 were enrolled. All patients received cone-beam CT (CBCT) examinations. Mimics 20.0 was used to process the data. The changes of the condylar process position and upper airway were recorded. The data were analyzed using SPSS 20.0 software package. RESULTS: Before treatment, patients in the experimental group had higher Sa as well as lower Sp than those of the control group (P<0.05), but with no difference in Su between 2 groups before treatment (P>0.05). After treatment, Sa was decreased in the experimental group (P<0.05), but no change was observed in Sp and Su(P>0.05). After treatment, the joint space indexes were increased in the experimental group (P<0.05). Before treatment, the V total, V tongue, V mouth, and SMIN in the experimental group were significantly lower than those of the control group (P<0.05). Before treatment, V nose, V palate, V larynx, APTE, APHP and APSP in the experimental group showed no difference with those of the control group (P>0.05). V nose, V larynx, APHP and APTE showed no difference before and after treatment within the experimental group (P>0.05). After treatment, the V total, V tongue, V palate, V mouth, SMIN and APSP in the experimental group were significantly increased (P<0.05). CONCLUSIONS: Extraction treatment can widen the airway, suggesting that there may be a certain correlation between the changes of condyle position and upper airway volume.

Key words: Skeletal ClassⅡ high angle, Extraction rectification, Condyle, Upper airway