EARLY PREDICTION AND PATTERNS OF MANDIBULAR THIRD MOLAR IMPACTIONS-A RADIOLOGICAL STUDY

Background- Third molar impaction occurs in approximately 9.5 % to 68 % of populations, with these teeth typically emerging between the ages of 17 and 21 years. Objectives- To determine the prediction and pattern of impacted mandibular third molar on digital panoramic radiograph and to compare the linear and angular measurements. Method-Linear measurements like of Mesio-distal width (MDW), lower eruption space to mandibular ramus (LES-R), lower eruption space to Xi (LES-Xi) and angular measurements as alpha angle, gamma anglewere noted on 300 digital OPG. R1 and R2 (Space width ratio) calculated. The measurements of impacted teeth were compared with erupted teeth. We computed the independent sample t test. ROC curve analysis was used and predictive validity with sensitivity and specificity were interpreted utilizing these parameters. Result-LES-R, LES-Xi, R1, R2 and alpha-angle showed significant statistical difference between the impacted and erupted groups. R1, LES, LES Xi, and R2 all have values near 1, indicating that the mandibular third molar will erupt first.Alpha angle followed by gamma angle and mesiodistal width of mandibular molar showing positive predictive value for impaction. The impaction is favored by decrea Conclusion- se in lower eruption space, increase in mesio-distal width of mandibular third molar, space width ratio and angulation of third molar.