We appreciate the interest of Drs Sivakumar and Sivakumar regarding our article. Their comments are welcome and pertinent. We are glad to clarify these points for the readers of the AJO-DO .
Severe root resorption can be catastrophic to orthodontic treatment. Unfortunately, the current state of knowledge does not allow orthodontists to identify which patients are vulnerable. In a recent systematic review, Weltman et al stated that “only 11 trials were considered appropriate for inclusion in this review, and their protocols were too variable to proceed with a quantitative synthesis. This reflects the state of the published scientific research on this topic.” Moreover, no studies provide consistent evidence on the longevity of teeth with severe root resorption. The frustration expressed by Drs Sivakumar and Sivakumar is understandable and certainly represents the feelings of orthodontists worldwide. However, the current literature furnishes valuable information that might make the difference between success and failure of orthodontic treatment in patients with severe root resorption. As reported in our study and stressed by Drs Sivakumar and Sivakumar as well as by Weltman et al, radiography should be performed 6 months into the treatment. In patients with severe resorption, there is evidence that a 2- to 6-month pause in treatment (with a passive archwire) decreases further root resporption. One important aspect of our study that left us apprehensive was that, even among the patients who experienced pauses in the mechanical treatment (6%), there was severe resorption at the end of treatment. This suggests the influence of genetic factors and further increases the responsibility of orthodontists with regard to this issue. If severe resorption is identified, the treatment plan should be reassessed with the patient. Alternative options might include prosthetic solutions to close spaces, releasing teeth from active archwires if possible, stripping instead of extracting, and early fixation of resorbed teeth.
Finally, an important clarification: at no time does our study refer to the edgewise technique or associate it with increased severe root resorption. As stressed by doctors, this could not be addressed by the study design. The expressive results might perhaps be explained by the sample size, which was larger than those described in the literature we researched. In this context, the evidence indicates no differences in the amount of root resorption when comparing the straight wire and standard edgewise techniques.