Objective:To evaluate the vertical direction developmental difference between skeletal Class Ⅲ malocclusions in different age groups in Chongqing by Delaire cephalometric analysis.Methods:30 children patients(age 9~11) and 44 adult patients(age 19~21) of Class Ⅲ malocclusion with different vertical skeletal facial profile were recruited into the research

which were marked and analyzed by computer aided Delaire cephalometric analysis.Hypothesis testing was analyzied by SAS9.0

and independent-samples t-test were used to analyze the data when homogeneity of variance

while Satterthwaite t-test were used to analyze the data when variance arrhythmias.Results:The Delaire cephalometric values of these samples were obtained

the difference of ∠2

∠4

(Pts-M)/C2

(M-Cp)/C3(%)

Np-F1in high-angle group between adult and children were statistically significant(P<0.05);While the difference of ∠1

(Pts-Cp)/C2 in low-angle group between adult and children were statistically significant(P<0.05).However

there were no significant differences in other indicators.Conclusion:With the individual growth and development

the Class Ⅲskeletal deformities with different vertical skeletal facial profile and different age present definite developmental difference in a three-dimensional orientation of the skull

face

jaw

and the neck.And the difference is deserved to guide the orthodontic treatment planning which for the different Class Ⅲ skeletal deformities.It is also beneficial to the exacter therapeutic regimen which combination of orthodontics and straight jaw

and stability for the long-term effect.