Is there Correlation between the Root Apex Anatomy with External Root Resorption

The aim of this study was to correlate the root apex anatomies with external root resorption in patients orthodontically treated through panoramic radiography and cone beam computed tomography (CBCT) methods. Two hundred and forty dental roots were evaluated by tomographic and radiograph images from thirty patients submitted to orthodontic treatment. Orthodontic treatment with fixed appliances was developed based on the technique of straight arc (Straightwire) with Roth prescription. Dental roots anatomy were classified based on shape as: Score 0 – normal root; Score 2 – short root; Score 2 – blunt; Score 3 – bent; and Score 4 – pipette shape. Measurements of external root resorption (ERR) were performed before and after orthodontic treatment by means of CBCT and panoramic radiograph. All patients and 72% of the 173 roots presented with ERR. The frequency of root type, the normal root (score 0) was 88.75% in panoramic radiography and only 18.75% for CBCT. The frequency of ERR was high in maxillary central incisors (73%), maxillary lateral incisors (73%), mandibular central incisors (72%), mandibular lateral incisors (70%). Statistical analysis showed no correlation between the methods, type root and tooth type (p < 0.05). The CBCT had better results for identifying apical roots resorption than panoramic radiograph, but the correlation between the type of root and ERR was not confirmed.