THE MAIN OBJECTIVE of the study was to determine the extent of external apical root resorption at the end of orthodontic treatment and to identify the possible pre-treatment and treatment factors that would allow to predict the possible incidence of root resorption before the start of treatment.
Patients and methods: Panoramic radiographs of 75 patients that had been treated with full fixed appliances were used to assess apical root resorption in maxillary incisors. The degree of root resorption was measured in millimetres and the scale of Shape was used.
Results: The results showed that the resorption in the maxillary incisors is on the average 1.5 mm, the severe resorption was seen in 2.6% of patients. The worst resorption was seen in teeth with abnormal root shape. There were no differences in the severity of root resorption when comparing males and females as well as children and adults. Increased overjet, overbite and extraction therapy were not associated with greater root resorption. Duration of treatment and length of treatment time with rectangular wires were associated with greater root resorption. Patients wearing composite brackets with a metal slot had more resorption than patients wearing metal brackets.
Conclusion: Pre-treatment risk indicator for root resorption was abnormal root shape. Risk indicators for root resorption that were related to treatment procedures included length of treatment time with rectangular wires, duration of treatment and treatment with composite brackets with a metal slot.