ABSTRACT

Orthodontic induced apical root resorption is an unavoidable side effect of orthodontic treatments which is seen in more than 90% of the cases. Orthodontic Induced Inflammatory Root Resorption (OIIRR) occurs as a result of individual biologic variations and mechanical stimuli effects.

In this study the extent of root resorption is compared in patients who have received fixed orthodontic treatment (by straight wire system), with two different sizes of slots (0.018 inch and 0.022 inch) and the same wire diameter. For this purpose, panoramic radiographs were used to examine some 720 teeth before and after the treatment. Two different approaches were used to evaluate the root resorption, first based on Malgren classification and the other based on Crown-Root ratio (C/R).

Average duration of treatment for patients treated by 0.018-inch slot brackets was 26 months and for those who were treated by 0.022-inch slot brackets it was 25 months. No significant difference was found in the two groups explored in this study (p-value = 0.684). Slot size has no effect on root resorption and there are some other features including the efficiency of the slots which might be influential.

As no significant difference was found in the two groups explored in this study, it could be argued that slot size has no effect on root resorption and there are some other features including the efficiency level of the slots which might be influential. As previous studies indicate, 0.022-inch slot brackets could have more influence on root resorption. Apex shape has no effect in that regard.