Effects of maxillary protraction combined with screw expansion on maxillofacial structure and upper airway of children with classⅢmalocclusion in mixed dentition
CHE Xiaonan
Abstract：Objective To investigate the effects of maxillary protraction combined with screw expansion on maxillofacial structure and upper airway of children with class Ⅲ malocclusion in mixed dentition.Methods Forty children with classⅢmalocclusion in mixed dentition who were treated in our hospital were enrolled in the study,who were divided into observation group and control group,with 20 patients in each group.The patients in observation group were treated by maxillary protraction combined with screw expansion,however,the patients in control group were treated by maxillary protraction only. The changes of maxillofacial structure and upper airway were observed and compared between two groups. Results After treatment,the 17 patients with malocclusion in observation group was completely cured,in contrast to that,the 8 patients with malocclusion in control group was completely cured. There were significant differences in the levels of SNA,ANB,L1-MP, FH-MP,Ptm-A,SN-PP,ANS-Me,Wits in both groups before treatment and after treatment(P<0.05),moreover,the levels of ANB,FH-MP,SN-PP,ANS-Me,Wits in observation group were significantly higher than those in control group (P<0.05), however,the levels of U1-SN,L1-MP in observation group were significantly lower than those in control group (P<0.05). After treatment,PNS-R levels in both groups were significantly increased,as compared with those before treatment (P <0.05).The SPL levels in both groups were significantly decreased after treatment,as comapred with those before treatment, however,there were no significant differences between two groups (P>0.05).After treatment,the NP volume,NP area,NP sag.,NP cor value in both groups were significantly increased,as compared with those before treatment,moreover, the NP volume,NP area,NP sag and NP cor value in observation group were significantly higher than those in control group (P<0.05).Conclusion The therapeutic effects of maxillary protraction combined with screw expansion in treatment of class Ⅲmalocclusion in mixed dentition are satisfactory,which can maintain the stablity of upper and lower jaws and teeth,decrease the relapse rate of malocclusion, moreover,which can expand upper airway gap and decrease lower airway gap to increase the upper airway volume and improve respiratory function.
Keywords：maxillary protractionscrew expansionmixed dentitionmaxillofacial structureupper airway
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 3217-3220 )