Study Of The Outer Nasal Surface Area Measurement Method

Objective:To investigate the measuring method of surface area on external nose;to establish normal value databank of surface area on external nose about adult normal;to research the relation of the surface area of every sector of external nose and the relation between the surface area of every sector and correlated distances in adult normal.Method:1.A study on the reliability of measuring system and landmarks. To measure 10 distances of basic external nose with sliding caliper,to measure the same from the 3D reconstruction image with software,then the mean error of measurements were determined;to measure the distances from nasion to other landmarks from the 3D reconstruction image with software tow times,to compare the variance of software measuring and the reliability of landmarks.2.To divide the external area into five with landmarks and measure every sector areas from 3D reconstruction image with correlated software;to measure the left and right areas of every sector.3.To establish linear regression equation for other sector areas from the root and back areas;to establish regression equation for every sector areas from correlated distances.Results:1.The mean error of 10 distances of basic external nose was lower than 0.5mm with handiwork and software,the mean error of the distances from nasion to other landmarks in two times software measuring was lower than 0.5mm,and there was no significant differences in statistics. These results suggest that the selected landmarks are identified easily and the error of repeated measurement can be neglected. 2.To establish normal value databank of each sector surface area on normal adult nose,there was significant differences in statistics between male and female;to establish symmetry index normal value databank of each sector surface area on normal adult nose, there was no significant differences in statistics between male and female.3.To obtain linear regression equation for other sector areas from the root and back areas;to obtain regression equation for every sector areas from correlated distances.Conclusion: It was accurate to measure surface area of external nose apllying SCT 3D reconstruction image and correlated software;normal value databank of surface area on external nose and regression equation were underlaying dada for foundation study and clinical application.