Abstract :
Objective: Purpose of this study to check accuracy and validity of new indicators i.e SAR Angle, HBN Angle and ? Angle in subjects with Skeletal Class I & II malocclusion and also find the corelation of ANB Angle with these new indicators. Materials and Method-Total 80 pretreatment lateral cephalograms of 16-25 years old individuals ( 40 each Class I & Class II) were collected and divided into Skeletal Class I & II on the basis of ANB Angle,Wits Appraisal and Mandibular Plane angle further subdivided into males and females (n=20). Stable landmarks were used to construct these new angles. Results- Mean and Standard Deviations were calculated for both the groups using Student’s t test and Pearson’s co-relation was used to find co-relation of ANB Angle with other angles. Mean values of SAR, HBN and ? angles for Skeletal Class I and Class II groups were 59.2 ±1.34 & 54.12±1.57, 41.37±1.46 & 34.87±1.63, 20.05±2.53 & 8.97±2.84 respectively. ANB angle had significant but negative correlation with SAR angle(r = - 0.431**) & (r = -0.341*) in Skeletal Class I & Class II groups respectively. Conclusion- SAR angle, HBN angle and ?-angle were statistically significant angles to assess antero-posterior
disparities in Skeletal Class I & II groups. ANB angle had negative correlation with SAR angle in
both groups. Clinical Relevance-Instead of relying on any one single parameter,these new indexes can be used along with conventional cephalometric analyses for assessment of anteroposterior jaw discrepancies
Keyword :
Antero-posterior jaw discrepancies, SAR Angle, HBN Angle and ? Angle..