Radiographic Assessment for Predicting the Mandibular Third Molar Eruption after Orthodontic Treatment in First Premolar Extraction Group and Non-Extraction Group: A-retrospective Study

Abstract

Introduction: The third molars are the most congenitally missing teeth. If present, they might follow ectopic eruption path and become impacted. Because it is the last tooth erupt in the arch, and usually there is no space in the arch. Effects of orthodontic treatment may also affect the position of third molar after treatment and may changes the eruption pattern of third molar. Materials and Methods: 30 patient’s pre-treatment and post-treatment lateral cephalogram and orthopantomogram (OPG) were taken out of which 15 patients were treated with first pre-molar extraction, and 15 patients were treated with non-extraction approach. Cephalomatric and OPG tracing were done at T1 (pre-treatment) and T2 (post-treatment). Distance from Xi-point to distal surface of second molar, distance from anterior border of ramus to the distal surface of second molar, angulation of third molar in relation with second molar and mesio-distal width of third molar were checked. Descriptive analysis was perform for both the groups and paired t-test and un-paired t-test were performed for first pre-molar extraction and nonextraction group with two different methods such as panoramic radio graph (OPG) and lateral cephalograms at significant level P < 0.05. Results: In extraction group, there were more possibility of the eruption, more mesial movement and more angulation changes noted compare to non-extraction group. Conclusion: Panoramic radiographs were more accurate when compared to lateral cephalogram while checking minor changes.