We appreciate Dr Cao’s interest in our article (Wei YJ, Lin YC, Kuang SH, Yang SF, Lee SY, Lai YL. Esthetic periodontal surgery for impacted dilacerated maxillary central incisors. Am J Orthod Dentofacial Orthop 2012;142:546-51). Dr Cao questioned the longevity of a maxillary central incisor in patient 1 after root-end resection. We believe that it is essential to make an effort to save a maxillary anterior tooth for a growing child to achieve esthetics, phonation, and function. More importantly, tooth extrusion instead of tooth extraction facilitates bone growth in the premaxilla; this shall benefit the patient if further dental treatment in this region is needed. Although the root of the dilacerated maxillary central incisor in patient 1 was short postoperatively, the surrounding periodontal tissue of this tooth was healthy. Up to now, the tooth has been in good function, as shown in regular periodontal recalls. Similar case reports with 6-8 year follow-ups have also demonstrated adequate prognoses of teeth after apicoectomy and surgical eruption.

In addition, Dr Cao was concerned about the prognosis of a tooth with a short root if a second stage of orthodontic tooth movement will be performed. In patient 1, a stable occlusion was achieved after orthodontic eruption of the impacted maxillary central incisor. The dental midline shift in the mandible will be followed until all permanent teeth have erupted and skeletal growth is finished. Although limited information is available regarding orthodontic treatment in patients with short roots, the use of lower forces, resting periods, and decreased treatment times are the common preventive suggestions. We shall also consider implementing proper mechanics, eliminating occlusal trauma, and possibly using temporary anchorage devices to provide maximum anchorage, if this patient needs a second stage of orthodontic treatment. The issue addressed by Dr Cao is interesting and merits further clinical studies to make a stronger clinical recommendation.

For patient 2, Dr Cao pointed out that the early intervention and tooth movement of the dilacerated central incisor might influence the root formation of the lateral incisors. Our radiographic follow-ups showed that the roots of these teeth had continuous development at the early stage of orthodontic treatment. The root shortening of the lateral incisors did occur at the late stage of orthodontic treatment and considered due to the external apical root resorption after tooth movement. We believe that the best time for treating an impacted dilacerated tooth is in the early stages. Other articles have also suggested that the longer the dilacerated tooth is retained, the poorer the prognosis for eruption, axial root growth, and orthodontic traction. Early intervention will minimize the complexity of treatment, reduce the sequelae during orthodontic tooth movement, and solve the child’s emotional problems caused by the failure of maxillary anterior tooth eruption.