Effect Of Maxillary Protraction And Rapid Maxillary Expansion On The Craniofacial Structure And Upperairway Of Skeletal ? Adolescents In Urumqi

Objectives: To observe the changes of craniofacial and upper airway morphology and hyoid position of skelatal type ? adolesents in Urumqi after maxillary protraction combined with rapid arch expansion,and to provide some reference for the treatment of skletal ? patients.Method: Twenty-seven Uygur patients with maxillary dysplasia skeletal type ? were selected,including 13 males and 14 females.The X-ray lateral cephalometric films was taken before and after maxillary protraction and rapid maxillary expansion.The means and standard deviations of the changes in various measurements were obtained with SPSS software.The changes of craniolfacial structure and upper airway morphology and hyoid position before and after treatment were compared by paired t test.Results: There were significant changes in craniolfacial structure and upper airway shape and hyoid position after treatment.There were significant differences in craniofacial parameters such as SNA,SNB,ANB,NA-PA,MP-SN U1-SN,L1-MP and PPSN(P<0.05),The sagittal diameter of upper airway nasopharynx PNS-R increased,and the sagittal diameter of palatopharynx such as UPW-PNS,SPP-SPPW,MC1-MC2,UMPW,among which UPW-PNS and SPP-SPPW increased,and there were no significant difference between MC1-MC2 and U-MPW;the soft palate index SPL and SPT decreased,and the difference was statistically significant;upper airway oropharynx index PAS and V-LPW decreased with statistical significance;the hyoid index AH-FH,AH-SN,AH-Or and AH-MP incresed with statistical significance while the other indexes had no statistical significance.Conclusion: Maxillary protraction combined with rapid maxillary expansion can promote maxillary development,improve lateral appearance and increase mandibular plane angle.Maxillary protraction combined with rapid expansion can increase sagittaldiameter of nasopharynx and palatopharynx of upper airway and decrease sagittal diameter of oropharynx.After treatment,hyoid bone shifted backward and downward,which reduced the sagittal diameter of oropharynx.