Corelaton of corrected ANB angle with other sagital discrepancy indicators

ABSTRACT

Sagital skeletal discrepancy is being evaluated Cephalometrically by using various parameters; ANB angle and the Wit's value[1.2] being the most commonly used. ANB angle is affected by various environmental factors including SN-GoMe [vertical pattern of patient] and SNA angle [antero -posterior / vertical position of nasion and point A] and Wits value is dependent on the assessment and inclination of occlusal plane, thus are not considered reliable sagital discrepancy assessment indicator. Corrected ANB angle was calculated using the formula ANB = Original ANB angle + 0.5 x [81.5° -SNA angle] + 0.25 x [32°- SN-GoMe angle] which is considered independent of the above mentioned variables. Aim of this study was to assess the reliability of Corrected ANB angle and establishment of its correlation with ANB angle and wits value. Study was conducted using lateral cephalograms of 100 subjects age ranged 18-30 yrs and it was concluded that 1. High correlations exist among the three parameters used to assess the sagital jaw discrepancy i.e. Corrected ANB angle, ANB angle and Wits Appraisal showing that these sagital parameters could be used interchangeably, 2. Coefficient of correlation [r] confirmed ANB angle dependence on SN-GoMe and SNA and wits unpredictability. 3. Coefficient of correlation [r] confirmed that corrected ANB angle is statistically insignificantly related to SN-GoMe and SNA angle, thus is a better assessor of sagital discrepancy assessment indicator