Comparison of Orthopanand Computerized Tomographic Examination of Root and Alveolar Bone Resorption in Orthodontic Patients

Purpose: The aim of the study was to determine whether fixed orthodontic appliances cause root and alveolar bone resorption and to compare the precision of orthopantomography and computerized tomography in detection of resorption process. Methods: Eighty-five patients scheduled for orthodontic therapy with fixed appliances were included in prospective self-controlled study. Before and after orthodontic treatment orthopantomography was done for all patients and thirty-five patients were sent to CT scan of upper or lower incisors and canines in order to compare the precision of two radiographic procedures. The root lenght was measured as the distance from cementoenamel junction to the root apex and the alveolar bone height from root apex to the most coronar point of alveolar bone. Results: During orthodontic therapy root length of anterior teeth changed. The decrease of root length was detected on OPT for upper incisors (central right 0.3033 mm, central left 0.6711 mm) and lower left central incisors (0.3176 mm). Saggital CT scan of central incisors showed root resorption of 0.7750 oraly and 0.555 mm buccaly. Orthodontic appliances induced also alveolar bone resorption around anterior teeth. The highest values for alveolar bone resorption on OPT were detected around maxillary right (1.2169 mm) and left lateral incisors (1.2284 mm) and lower central incisors (1.0873 mm). The alveolar bone resorption detected on CT scan of central incisors was less than on OPT (0.11 mm bucally, 0.1550 oraly). Conclusion: Fixed orthodontic appliances cause root and alveolar bone resorption which is more accurately determined by using computerized tomography than orthopantomography.