ABSTRACT
Objective:To compare the differences of cranial base morphology between high-angle and low-angle malocclusion patients with geometric morphometrics.Methods:Pretreatment lateral cephalograps of 80 skeletal Class I patients(40 hypodivergent,40 hyperdivergent)were selected.All cephalographs were scanned,and 13 homologous landmarks of cranial base were identified and digitized.Average geometries of cranial bas e were created by means of Procrustes analysis.Thin-plate spline analysis was applied to cranial base configurations to determine local morphology differences between the two vertical facial types.Results:1.high-angle patients had the cranial base characteristics as follow:(1)Horizontal and vertical expansion occured in the sphenoida region,(2)The anterial and posterior cranial bases circled S point opposite direction revolving,which caused cranial base angle to reduce significantly.2.The low-angle the cranial base characteristics was just opposite with high-angle′s.Conclusion:The shape of cranial base was different between high-angle and low-angle malocclusion patients.