Investigation of impacts of impacted third molars on second molars by CBCT and panoramic radiography

Objective: The aim of this study is to evaluate the correlation between these two methods by comparatively examining the caries, external root resorption and periodontal bone destruction caused by impacted third molars on adjacent teeth by comparing panoramic and CBCT images. Materials and Methods: In this study, all of the OPG and CBCT images of 388 impacted third molars belonging to 205 patients were evaluated. While impacted third molars were differentiated according to Pell & Gregory and Archer and Kruger classification criteria, distal caries, marginal bone loss and external root resorption in the second molar were examined by panoramic and CBCT. Results: 388 impacted teeth were evaluated in 205 patients, and the rate of distal caries was 27.5% in panoramic radiographs and 31% in CBCT (p<0.05). External root resorption formation in second molars observed in CBCT was not observed in 18.8% of panoramic radiographs (p<0.05). Marginal bone loss was observed 9.8% more in CBCT than in panoramic x-ray (p<0.05). All three pathologies were observed at the highest rate in Class 2 position, while distal caries was observed at the highest rate in position B. In the examinations performed for the lower and upper jaws, the rate of all three pathologies was found to be higher in the CBCT evaluation than in the panoramic radiography. Result: CBCT; Although it is disadvantageous in terms of radiation dose and cost, it has been found to be more effective than panoramic x-ray in the detection of distal caries, marginal bone loss and external root resorption pathologies. It is thought that this situation can be considered as a criterion in terms of profit-loss analysis when the examination is requested, thus preventing pathologies from being overlooked. Keywords: impacted molar tooth, distal caries, external root resorption, marginal bone loss, CBCT, panoramic radiography