An evaluation of YEN and W angle in the assessment of anteroposterior jaw relationship

Abstract

Cephalometry marked a beginning of a new era in the orthodontic diagnosis and treatment planning. [1] Many measurements were incorporated by various researchers to get an accurate method to assess skeletal base discrepancy. [2] Till date, various measurements have been developed such as A-B plane angle, ANB angle, AXB angle, AXD angle, PABA angle, FABA angle, APDI angle, AB/TH angle, Beta angle, and linear measurements such as Wits appraisal, AB/PP distance, AB/SN distance, AD/SN distance, AB/FH distance, and AB/TH distance. [3] All these methods have their own merits and demerits.Although the ANB angle is very popular and useful, there is often a difference between the interpretation of this angle and the actual discrepancy between the apical bases. Studies have shown that the position of nasion is not fixed during growth, and any displacement of nasion directly affects the ANB angle. [4] A second widely used measurement, the Wits appraisal, was introduced by Jacobson to overcome problems related to the ANB angle. However, the Wits appraisal has its own shortcomings. First, accurate identification of the occlusal plane is not always easy or accurately reproducible, especially in mixed dentition patients or patients with open bite or missing teeth. [5] Second, any change in the angulation of the functional occlusal plane, caused by either normal development of the dentition or orthodontic intervention, can profoundly influence the Wits appraisal. [6]