A Analysis Of Upper Airway And Hyoid Bone In Adolescents Skeletal ClassⅠbased On Cone-beam Computed Tomography Images

Objectives:One aim of the study was to investigate the difference of normal adolescence’s upper airway dimensions and hyoid bone position in two different age-groups,and the gender difference in the two age-groups.The other aim is to investigate the difference of the upper airway dimensions and hyoid bone position in female adolescence with different vertical facial types.Method:According to the inclusion criteria and exclusion criteria,66 adolescent patients in skeletal Class Ⅰwere selected,who aged 10～16 years old and scanned cone-beam computed tomography(CBCT)image in the first visite for dental treatment from July 2014 to March 2016.The samples was including 40 patients(20 male,20 female)in nomal vertical facial types,13 female patients in low vertical facial types and 13 female patients in high vertical facial types.Then imported all the images into materialism’s interactive medical image control system(MIMICS)(v.16.0,materialise)to accomplish the reconstruction of upper airway,measuring and analyzing the upper airway dimensions and the hyoid bone position in the software.40 patients in nomal vertical facial types were divided into two groups based the age,to investigate whether there were an aged and gender difference in adolescence’s upper airway dimensions and hyoid bone position,and using two sample t test for statistical analysis.39 female patients were divided into 3 groups:low angle group(GoGnSN<27.3。),normal angle group(27.3。<GoGnSN<37.7。)and high angle group(GoGn-S N>37.7°)by GoGnSN angle,to investigate whether there were a difference in the upper airway dimensions and hyoid bone position among the 3 groups,and the results were analyzed by Oneway ANOVA.Result:Along with the age growth,the measurement index of upper airway was increasing.There was statistical difference in male upper airway including L3,LAT3,LAT4,V-OL1,VOL4,and male hy-oid bone including H-Y,H-EB,H-PNS,and female upper airway including L1,L(P<0.05).No statistical difference was found in female hyoid bone(P>0.05).Gender-related was found in group aged 14～16 years,the airway including L4,L,LAT3,VOL4,and the hyoid bone including H-Y,H-EB,H-P-NS(P<0.05).Among 3 groups,there was statistical difference in AP,AP2,R2(P<0.05),excepting length,cross-sectionalarea,volumes(P>0.05).the AP2 of normal angle group was lower than low angle group,similarly,the API and AP2 of high angle group were lower than low angle group,while the R2 was the opposite of the API and AP2(A-P1,R2:P<0.01,AP2:P<0.01).There was statistical difference in hyoid bone position in C3-Me,H-X,H-S-Ba among 3 groups(C3-Me,H-X:P<0.05,H-S-Ba:P<0.01),and all the intems of high angle group were lower than low angle group(P<0.01).Conclusion:There was an obvious growthing in male nasopharyngeal and laryngopharyngeal volume,and male hyoid bone was downward develop.The female adolescence aged 14～16 years has a bigger laryngopharynx than male’s,but male hyoid bone in the place of the skull base was more downward than male’s.There was statistical difference in the upper airway dimensions and hyoid bone position in female adolescence with different vertical facial types.