Measuring the beta angle of different skeletal patterns in 262 cases from Urumqi city with Photoshop 8.0 software / 中国组织工程研究

ABSTRACT

BACKGROUND:Beta angle,as a new index for the assessment of sagittal jaw relationship,has been widely used by clinical doctors.However,hand-made measurement but not academic software is still adopted in some hospital.OBJECTIVE:To study the beta angle of different skeletal patterns in Urumqi city for the clinical use of the method to assess the sagittal jaw relationship,and verify the possibility of Photoshop software to measurement of beta angle.DESIGN,TIME AND SETTING:An observational experiment and measurement design was performed at Department of Orthodontics,the First Affiliated Hospital of Xinjiang Medical University from July 2006 to May 2009.PARTICIPANTS:A total of 262 malocclusion cases including 94 males and 168 females were lived in Urumqi City.They were divided into three groups based on type of facies ossea,including type Ⅰ group (n=119),type Ⅱ group (n=74),and type Ⅲ group (n=69).METHODS:Lateral position of skull was photographed using X-ray,and beta angle was measured using Photoshop 8.0 software.Sex and type of facies ossea were compared using one-way analysis of variance and t test.MAIN OUTCOME MEASURE:Beta angle of male and female;beta angle of the types Ⅰ,Ⅱ,and Ⅲ.RESULT:There was no significant difference in beta angle between males and females (P>0.05).Beta angle of type Ⅰ was (34.15±3.88)°,that of type Ⅱ was (26.42±2.65)°,and that of type Ⅲ was 42.41°±1.88°.There was significant difference in beta angle among three types of facies ossea (P<0.01).CONCLUSION:Beta angle is an index for the assessment of sagittal jaw relationship.The reference range of the beta angle is 30°-38°.Photoshop 8.0 software is a novel tool to measure cephalometry.