We appreciate Drs Xiaoxia Feng and Zhihe Zhao’s interest and comments on our case report (Mirabella D, Giunta G, Lombardo L. Substitution of impacted canines by maxillary first premolars: a valid alternative to traditional orthodontic treatment. Am J Orthod Dentofacial Orthop 2013;143:125-33) in the January 2013 issue.
Drs Feng and Zhao commented positively about the clinical outcome that was achieved but raised some questions regarding the severity of the impaction and the accuracy of the panoramic radiograph used as the diagnostic tool in our patient. Their point is that a panoramic radiograph is not a valid diagnostic tool to accurately determine the position of an impacted canine. They also questioned whether the right canine was really high and horizontally impacted because “in Figure 4, it appeared to be labial and oblique”; this suggested that the tooth might be obliquely impacted.
We all agree that a cone-beam computed tomography image is currently the recommended diagnostic tool to evaluate the position of an impacted canine, and we suggest its routinely use when impacted canines are suspected. However, we still believe that the right canine was located very high with respect the occlusal plane and horizontally oriented. In Figure 4, it can be noted that the crown of the right canine is partially above the palatal plane and horizontally oriented.
In the treatment plan, extracting the impacted canines that would be replaced by the first premolars was selected not only because of the severity of the position of the impacted canines, but also to eliminate the potential adverse effects associated with an orthodontic-surgical approach. Our case report was intended to be somewhat provocative, because a good-looking smile and a well-functioning occlusion (at least in the middle term) were obtained with an unusual extraction pattern.
The second question of Drs Feng and Zhao regards the clinical management of the maxillary first premolars. When preadjusted appliances are used, it is advisable to use the corresponding bracket for each tooth to maintain the correct values of in and out and torque. Accordingly, we used a −7° Tq/0 tip preadjusted maxillary premolar bracket (Victory series; 3M Unitek, Monrovia, Calif); as mentioned in the article, some slight negative torque was added in the finishing stage. The maxillary premolar crowns were long, and canine guidance was easy to achieve. Reduction of the maxillary premolar palatal cusps was not performed because a careful evaluation of the static and dynamic occlusion did not show a need for equilibration.