Comparison of Yen angle in Angle?s Class 2 Division 1 and Division 2 Malocclusion in South Indian Population-A Retrospective Cephalometric Study
Aim: To compare the Yen angle in class 2 division 1 and class 2 division 2 in the South Indian population and to evaluate whether the position of maxillary incisor in skeletal class II patients influence the location of point M and also whether it influences the Yen angle. Methodology: 40 lateral cephalograms were obtained for the study. The samples were screened from the records of the patient who visited the Orthodontic Department of Saveetha Dental College and Hospitals. Forty pre-treatment Cephalometric radiographs were selected based on ANB, Wits appraisal, and beta angle confirming skeletal Class II. The same cephalograms were again classified into Angle’s class II division 1 and division 2 based on the position of the maxillary incisors and canines. The Yen angle is traced. Results: Statistical analysis (independent t-test) results were significantly different (P>0.001). Conclusion: There was a statistically significant difference for the values for yen angle within the two groups. The inclination of the incisor influences the position of point M and thus it influences the yen angle. Also the autorotation of the mandible to compensate for the retroclined maxillary incisors in Angle’s class II division 2 malocclusion causes anterior displacement of the G point which also influences the Yen angle. According to the results in our study, the M point is highly correlated with the inclination and position of the maxillary incisor questioning the reliability of Yen angle.