The relation between W angle and other methods used to assess the sagittal jaw relationship

Abstract

Background: This study aimed to evaluate the mean value for the W angle in Iraqi adults with a Class I, II, and III skeletal relations and to verify the existence of sexual dimorphism, also to study the correlation between this angle with the other methods (ANB, Wits appraisal, BETA angle, YEN angle) used for evaluation of the antero-posterior (AP) jaw relationship. Materials and methods: One hundred and fifty-two cephalometric radiographs of patients between the age of 18 and 25 years were selected. They were again subdivided into Classes I, II, and III groups on the basis of Beta angle, Wits appraisal, and ANB angle, traced using AUTO CAD 2007. The W angle was measured between the perpendicular from point M on S–G line and the M–G line. The mean and the standard deviation for the W angle were calculated. Independent sample t- test, the one-way analysis of variance, LSD and Pearson correlation were obtained. Results: The results showed that a patient with a W angle between 51 and 56 degrees can be considered to have a Class I skeletal pattern. With an angle less than 51 degrees, patients are considered to have a skeletal Class II relationship and with an angle greater than 56 degrees, patients have a skeletal Class III and there is significant difference in the mean value of W angle among the three skeletal patterns with a no gender difference. The W angle had a negative significant relation with ANB in all three classes and with WITS appraisal in class III group, while it had a positive significant relation with BETA and YEN angles in all the three skeletal relations.