To: Editor, The Angle Orthodontist Response to: Recovery of multiple impacted maxillary teeth in a hyperdivergent Class I patient using temporary skeletal anchorage devices and augmented corticotomy. Kyung A. Kim; Hyeon-Shik Hwang; Kyu-Rhim Chung; Seong-Hun Kim; Gerald Nelson. Angle Orthod. 2018;88:107–121.

Thank you for your interest in our case report.

The initial cone-beam computed tomography image demonstrated that the crown of tooth 11 faced the palatal surface and the severely dilacerated root was just below the floor of the nose and in the cortical bone of the anterior nasal spine. But teeth 12 and 13 demonstrated incomplete transposition. Considering the success rate for impacted teeth, we evaluated that the risk of traction failure for tooth 11 was very high. In addition, due to the multiple impacted teeth, the traction path was entangled three-dimensionally. The first surgical exposure for teeth 12 and 13 was done and, after the traction of teeth 12 and 13, we secured the traction path for tooth 11. Once the obstacle was removed, we could easily evaluate the success or failure of traction 11. So we decided to perform two-stage surgical exposure.

In answer to your second question, the risk of traction failure for tooth 11 was very high. Therefore, we needed to evaluate the feasibility of traction tooth 11 without any side effect on adjacent teeth. For vertical traction force of the impacted maxillary central incisor without reactive force of the adjacent teeth, we used I type C-tube miniplate in the mandibular symphysis area with intermaxillary elastics.¹

In answer to the third question, the impacted teeth had erupted out of the thin and mobile oral mucosa, with gingival scarring and compromised alveolar housing. During the traction of the incisors, the unexpected torque discrepancies between the central and lateral incisors occurred. To resolve the torque discrepancy and to increase bony support, root labial movement of the lateral incisor with sufficient anterior alveolar thickness was needed. So we performed bone augmentation of maxillary right anterior region during the orthodontic treatment instead of at completion of the treatment. We also wanted to use the regional acceleratory phenomenon after the corticotomy and bone augmentation procedure.^2,3

We appreciate your valuable comments on this case report. There is no exact answer for correction of impacted teeth. We hope this kind of different approach showed some alternatives for complicated cases of impaction. Thank you so much.