We read the case report describing traction of impacted canines in a skeletal Class III malocclusion in the June 2017 issue (Ferreira JT, Romano FL, Sasso Stuani MB, Assed Carneiro FC, Nakane Matsumoto MA. Traction of impacted canines in a skeletal Class III malocclusion: a challenging orthodontic treatment. Am J Orthod Dentofacial Orthop 2017;151:1159-68). We appreciate the authors’ efforts in sharing this difficult case with us. However, we have some questions about diagnosis and therapy progress.

First, the total treatment time is unclear. The table of cephalometric evaluations showed that the treatment time was from January 1995 to July 1996, and retention records were gathered in 2004, after 8 years. From the table, we estimated that the total treatment time was 19 months. The abstract mentioned that the girl was 7 years old when she first visited, but a series of 3 radiographs (Fig 4 in the article) shows movement of the maxillary canines before traction, and the middle image was taken when the girl was 10 years old. The posttreatment records show a patient who had already finished her growth. Therefore, the treatment time must have been much longer.

Second, in the diagnosis section, both the intraoral assessment and the panoramic radiography failed to show the buccal or lingual direction of the maxillary permanent canines. And progress photographs to show the appliances and their designs were lacking. In the conclusions, the authors pointed out the importance of the precise location of dental traction, but in the article we found no way to know the exact location of the impacted canines. We also wanted to know the way of dental traction without the help of cone-beam computed tomography.

Third, the radiograph in Figure 4, C , shows a difficult and complicated case, but in the very next image, Figure 5, A , it was much easier. Although the authors mentioned a Hilgers pendulum, a transpalatal arch, and 0.014-in to 0.020-in stainless steel archwires with first-order bends and stop loops to the molar tube to solve the problem, we are still curious about why the growth direction of canines changed. Could you please describe this process in detail?

We appreciate the beautiful case and want to know about it in detail.