You enjoy teaching 1 day a week in the orthodontic residency program at your local university. At a clinic session that is slower than usual, you find time to chat with another part-time instructor interested in publishing a scientific paper. He says that he and a resident are developing a clinical study to assess peripubertal growth rates using pretreatment and posttreatment, large-field, cone-beam computed tomography (CBCT) scans. You ask how he expects to obtain institutional review board (IRB) approval for this project. You are aware that production of CBCTs for research stands little chance of approval in the United States. He explains that all his patients routinely receive CBCT scans, regardless of the severity of their malocclusion. He has petitioned the IRB with the statement that the investigation will be conducted retrospectively, using his routine CBCTs while treating his patients. “I should have no problem with the IRB,” he says, “because I explain that I need these films to treat my patients and assess their treatment results. I also make that quite clear to their parents!” You begin to ponder the ethical issues involved here. First, is it ethical to produce CBCTs for all patients regardless of the severity of their malocclusion? Do their parents understand that such exposure is not the accepted standard of care in the United States and is under stronger scrutiny in Europe? Is it ethical to sidestep the IRB by using films that are retrospectively introduced for a study? Finally, would every parent consent to CBCT imaging for a child if he or she knew the unanswered questions about this modality?

A renowned philosopher who addressed human experimentation was Hans Jonas (1903-1983). He believed that a subject’s own prerogative to participate in a study was more important than his obligation to advance society’s scientific knowledge. Except in an extreme emergency such as an uncontrolled plague or a state of war, a person has no societal obligation to sacrifice his welfare for the pursuit of knowledge. Jonas also stipulated that the subject must be knowingly committed to the experiment’s objectives before conceding to participate. Without these 2 conditions, subjects were merely “tokens” whose “threatened dignity” would sacrifice the uniqueness and “self determining status of the individual.” Although opponents of this philosophy argue that human research could never be conducted because of the difficulty in identifying subjects with such a commitment to research, other philosophers agree that a subject’s consent to become involved in a nontherapeutic study requires more than simple autonomy. Most importantly, the subject must be fully aware that his involvement is for investigational purposes before he consents to participate.

In prescribing routine CBCT images for orthodontic diagnosis, one must ask whether the informed consent for treatment sufficiently apprises the patients or parents of the uncertain effects of radiation exposure. Are autonomy and veracity (truth-telling) respected? Does every patient need a CBCT? How specific can the consent process be, especially when the dose might be unspecific? Discretion is essential in determining which patients qualify for CBCT scans. And there is evidence of large variations in radiographic exposure in commercial CBCT units. Dose variations between 11 and 674 μSV in dentoalveolar fields of view (<10 cm) and 30 to 1000 μSV in skull films (>10 cm) have been reported to vary by scanning protocol, field of view, and unit manufacturer. Furthermore, a specific CBCT dose index is elusive. The need for CBCT scans of every patient is disputable. Finally, CBCT imaging on less complex malocclusions infrequently causes clinicians to change their treatment plans.

You begin to wonder whether a scrupulous clinician can also be a discerning researcher. Is it appropriate for your faculty friend to use CBCT imaging routinely in his practice with the undisclosed intent to eventually publish? Should editorial boards and reviewers accept papers that inappropriately amass data by routine, retrospective CBCT imaging studies? Most basically, does every patient need a CBCT scan to receive the ultimate level of care? The ethical concepts of beneficence, nonmaleficence, veracity, and autonomy must be maintained as our patients place their health in our hands. Our integrity—and the integrity of their trust—depends on it.