Over the years, a question that I have routinely been asked is some version of “Do you believe in 1 phase of treatment or 2?” I have always been able to provide an answer, but recently I was looking at some old textbooks, and I realized that my thoughts on the matter had changed quite bit over time.

My very first knowledge of orthodontics was provided in my second year of dental school by a textbook entitled Orthodontics—Principles and Practice , by T. M. Graber. When I paged through my heavily worn and highlighted copy the other day, I ran across several chapters that really were the essence of “early treatment”—something performed when the patient was still quite young—and was later followed by “comprehensive treatment.” In the early 1970s, early treatment was referred to as “preventive” or “interceptive” orthodontics. In essence, the practitioner could consider situations, strategies, and appliances that prevented anything abnormal from occurring, intercepting a malocclusion as it developed or correcting an abnormality that had already developed. In terms of preventive and interceptive orthodontics, many topics were presented, including space maintainers, growth guidance, habit therapy, frenectomies, expansion devices, equilibration, crossbite treatment, diastema closure, tongue thrust appliances, lip plumpers, oral shields, chincap and face-bow headgears, and serial extractions. I have vivid memories of my fascination with all the opportunities and appliances that orthodontists had at their disposal to help patients, and it was clear that the treatments described in the textbook actually worked.

Subsequently, during my orthodontic training, I noted that the emphasis was almost entirely on treatment with fixed orthodontic appliances, which was best initiated after the eruption of the second molars; almost nothing was presented on early treatment. Although that was the style of the time, there was another factor to be considered: an ethical issue. Might a practitioner use various forms of early treatment as a means of increasing overall fees and securing the patient for later treatment? To some, it appeared that the need for early treatment was more a practice management decision, a means of lassoing a patient for later financial gain. Rightly or wrongly, practitioners who did lots of early treatments were viewed as a bit suspect in terms of ethical focus.

This was a dilemma for many practitioners: should they perform early treatment (followed by comprehensive orthodontics) and risk being considered unethical, or should they simply tell potential patients to “come see me when you are 12 years old”? In essence, the question was, should there be 1 phase of treatment or 2? Both had advantages and disadvantages.

Subsequently, functional appliances came on the scene in the United States; they seemed to offer an answer for many difficult problems, and they were touted as able to affect and effect the growth of the jaws. Before that time, many in this country considered that functional appliances were less expensive to construct, required fewer adjustments, and permitted the practitioner to see more patients, but they were also considered inferior to fixed appliances in terms of tooth movement. In an attempt to maximize the good qualities of each approach, a blend was developed that was performed in 2 phases: early treatment with a functional appliance and a later phase with fixed appliances. Of course, the reigning question about functional appliances was “do they work?” This again speaks to the ethical question about whether their use was based on effectiveness or was a practice management decision. Again, the question was, should there be 1 phase of treatment or 2? Both had advantages and disadvantages.

Personally, I was very engaged in the use of functional appliances. At one time, I even treated a 4-year-old Class II patient and a 6-year old Class III patient with Fränkel appliances. There was a rationale, of course, and the patients were great, but the results were underwhelming, and thus no case reports were generated; other patients were more encouraging, but my enthusiasm waned over time. On the research front, there was easily a decade of effort that sought to address the questions about the effectiveness of the appliances. Unfortunately, the many studies produced conflicting conclusions and 2 camps of very passionate believers and nonbelievers.

Now, I am a fan of paradoxes, and this situation reminded me of one that I first heard about many years ago. It is called “Buridan’s Ass,” and it relates to free will. In it, a mule that is both hungry and thirsty is placed at equal distances from a pile of hay and a bucket of water. The paradox assumes that the mule will be drawn to whichever is closer, and because of the equal distances, the mule will stand in place motionless and eventually die of both hunger and thirst, since it cannot decide to choose one direction or the other. Historically, the paradox of Buridan’s Ass has been applied to the hesitation of the United States Congress as it tried to decide between equally plausible routes—through Panama or through Nicaragua—for the Atlantic-Pacific Canal. In a contemporary sense, the decision of which presidential candidate to support might end with the paralyzed choice of voting for no one, because of a rational assessment of equally good and bad alternatives.

Now you might ask at this point what does this paradox have to do with 1- and 2-phase treatments, and can we overcome the quandary of making a choice between the options? The answer is fairly simple: you must suspend judgment as to the best course of action until more is known. In our specialty, when more and better research is conducted, then we will know more. And that is what occurred in the case of 1- vs 2-phase treatments of Class II malocclusions.

Around the turn of the century, several randomized clinical trials were conducted on this question, and the results were clear. In Class II patients, 2-phase treatments took longer, were less efficient, and did not produce a result that was judged superior to 1-phase treatments. Under the conditions of these trials, and given the results, it is clear that any well-informed practitioner should be able to choose between 1- and 2-phase treatments. But is that the death knell of 2-phase treatments? No.

Strategies of treatment must always reflect not what camp you belong to; rather, they must be dictated by the nature of the patient’s problems. For example, there is now clear and compelling evidence that early treatment (ie, the first of 2 phases) should be performed when a patient has protruding maxillary incisors. Such treatment is justified because reducing the protrusion actually protects the incisors from trauma, and also improves self-esteem and social adjustment. This is simple to explain to patients and parents, it is simple to do, and it is justified by the available evidence.

Actually, the number of phases of treatment doesn’t really matter very much because there could be 1, 2, 3, 4, or even more—depending on the patient’s problems. For example, some patients self-select an additional phase of treatment when they do not wear their retainers, and some cleft lip and palate patients might need 5 or more phases of treatment because of the complexity of their problems.

What really matters is that the practitioner evaluates the patient’s condition and then applies the best evidence to the situation in deciding whether and how the treatment should be rendered. Treatments need to be designed to fit the patient’s problem, rather than patient’s problem fitting the treatment. Adopting a prefabricated approach is seldom the best option because each patient is custom-made.

So, to the original question “Do you believe in 1 or 2 phases of treatment?” the answer is yes. To the related question “Do you teach early and late treatment?” the answer is also yes. And to the question “How do you decide what treatment is appropriate?” I say that I consult all the levels of evidence that are available; “experts” who hold a position based solely on their bias and passion are considered last; I certainly would not ask an ass to decide.

Should two courses be judged equal, then the will cannot break the deadlock; all it can do is to suspend judgment until the circumstances change, and the right course of action is clear.