Evaluation of the accuracy of beta angle in determining of antero-posterior relationship of jaws

Aim: Some cphalometric angles change during growth and in accordance with facial height and other 'facial landmarks which make it less reliable for orthodontic diagnosis. The purpose of this study was to find out relationship between Beta Angle and the anterior-posterior position of jaws. Materials and Method: Sixty lateral cephalograms of ۱۶ boys and ۴۴ girls with class I, H or HI malocclusions were evaluated in our study. we traced all of the cephalograms to measure Beta angle and compare these values between different types of malocclusions. Data were annalized by means of T-student statistical test. Results: Beta angle was ۲۸.۵° - ۳۷.۵° for class ۱, less than ۲۸.۵° for class II and more than ۳۷.۵° for class III. There was no correlation between t۳ angle and facial height. Conclusion: Beta angle is independent from facial height. Beta Angle has an acceptable specificity and sensitivity for determining the anterior posterior position of Jaws (IJO ۲۰۰۶; ۱: ۱۸۴-۷). 

کلیدواژه ها:

Cephalometry ، Beta angle ، Facial height