We appreciate Dr Ang’s interest in our article and are happy to have an opportunity to respond.
Of course, we are concerned about bone remodeling around the mandibular incisor. But, at the present time, there are no long-term follow-up studies after extreme retraction of the mandibular incisors. Perhaps our patient has a similar condition to that reported in the example of Wehrbein et al. They found low density and decreased thickness of alveolar bone around the mandibular incisors; however as far as I can determine, their CT image showed decreased thickness and low density of alveolar bone around the premolars. Therefore, I think bone remodeling in the mandible was in process at 3 months posttreatment.
In addition, the report of Sarikaya et al certainly gave us a shock. We have never seen such severe bone resorption, although we have moved mandibular incisors significantly in some cases. I’m afraid that the patient had some systemic problems during her orthodontic treatment.
I recalled our patient last month. After 3 years of retention, neither attachment loss nor abnormal physiologic mobility was found in her mandibular incisors, and they seemed clinically normal. Moreover, significant root resorption was not found in her 2-dimensional radiographic evaluation. However, I will take 3-dimensional computed tomography scans to make a detailed observation soon. Thank you for your advice.
In the past decade, temporary anchorage devices have evolved as a mainstream orthodontic technique, and their use makes it possible to achieve tooth movement that is impossible with traditional orthodontic mechanics. Your opinion makes us aware of the importance of long-term observation, especially in patients treated with temporary anchorage devices.