El-Timamy et al are commended for their June 2016 article introducing a new concept of bracket positioning using cone-beam computed tomography imaging (CBCT) and computer-aided manufacturing (El-Timamy AM, El-Sharaby FA, Eid FH, Mostafa YA. Three-dimensional imaging for indirect-direct bonding. Am J Orthod Dentofacial Orthop 2016;149:928-31).
Indirect bonding, stereolithographic trays, and CBCT technologies are undeniably valuable in orthodontic practice. The new concept introduced by the authors appears to be almost the orthodontic counterpart of the computer-guided implant placement. This is of course original.
CBCT is appealing, and when combined with other technologies, the clinician’s work becomes more sophisticated. However, CBCT comes with ionizing radiation exposure to the patient. The current guidelines advise that CBCT must yield a diagnostic benefit to the patient and be justified on an individual basis.
To expose orthodontic patients to CBCT for the benefit of computer-aided manufacturing would increase the collective effective dose for patients and ultimately cause harm to some. This is especially true when treating young patients who are particularly sensitive to radiation. In addition, orthodontic treatment is highly effective presently using 2-dimensional images, and there is no evidence that 3-dimensional imaging approaches are needed to plan the average orthodontic case. Furthermore, indirect bonding is quite possible without the need for ionizing radiation to execute this technique.
The ALARA principle—keeping radiation as low as reasonably achievable—prevails. With the proposed technique, a CBCT scan could indeed minimize the time, armamentarium, and expenses needed for the preparation of models, trays, and positioning devices for conventional indirect bonding techniques. However, it would not be correctly justified.