Back to the Future II
The past three issues of JCO have contained a series of articles about the DigiGraph Work Station. Although it will not be the last word on this type of sophisticated imaging, it is certainly the first chapter of what I predict will become an ongoing interaction between orthodontists and imaging technology.
This will not occur simply because the technology affords us more accurate visualized treatment forecasts; as we know, predictions become increasingly variable as treatment lengthens. And as chaos theory reminds us, most biological systems are erratic, unpredictable, and fragile--subject to minuscule changes in the environment or the individual. But the DigiGraph and instruments like it will refocus our attention on the complete face, instead of the simplified, abstract drawings we now make of the head in frontal and lateral views.
It will be a little like the movie Back to the Future in that we will revert somewhat to early-20th-century diagnostic techniques, which relied upon the clinical examination, models, and photographs. That isn't as regressive as it might seem at first; after all, Proverbs says to "forget not thine ancient signposts". There is much evidence that overreliance on cephalometrics caused us to neglect some important signposts in orthodontics.
A few months ago in one of my satellite offices, the x-ray machine broke and I was unable to take the customary cephalometric radiograph. I was terribly agitated about the loss of such a valuable diagnostic aid, but as I began the diagnosis without a tracing, I noticed that I was paying far more attention to the facial photographs. They took on a whole new meaning as I studied the maxillary-to-mandibular relationship without lines and angles to prejudice me. Facial asymmetries seemed to leap out of the frontal photographs.
There are many people who, when considered strictly from an abstract tracing, might be thought too protrusive, but in real life are distinctly handsome. I'm certain many orthodontists would want to extract teeth and retract the incisors and lips of Brigitte Bardot if they relied primarily on a cephalometric tracing. But who would really want to change that unique pout?
The Tweed Triangle and the Steiner Analysis permitted us, for the first time, to design treatment positions for teeth and then objectively compare the treatment with the treatment plan. But in addition to giving us improved positional information, cephalometrics insidiously established new standards by which our treatment was judged OK or not OK. If teeth were angled in a particular way, the treatment was accorded success regardless of how the face looked. If preconceived angles were not achieved, the treatment was described as a failure no matter how good the face looked or how well the teeth interdigitated. I don't think there is much doubt that the imposition of arbitrary and rigid cephalometric standards gave impetus to the widespread removal of bicuspids.
On the positive side, when Ricketts, Holdaway, Schudy, Williams, and others began to challenge the justification for these standards, more intensive cephalometric studies indicated a wide range of acceptable positions for anterior teeth. Today, because of those studies, fewer teeth are being extracted for orthodontic purposes.
To my way of thinking, the DigiGraph and similar apparatuses offer the best of both worlds--an accurate way of measuring tooth positions without losing sight of the entire, life-size face. And with the ability to simulate treatment results, we gain significant communication advantages. Listening to the chief complaint in the patient's own words will become even more significant, and I imagine orthodontists will often discover that they and their patients aren't talking about the same treatment goals. Better to discover such discrepancies at the start than later on, when resolution may be impossible.
I don't dispute the value of the cephalometer in orthodontics; I certainly don't intend to put mine in mothballs. It has permitted us to quantify and classify malocclusions more accurately than would have been possible without it. It has helped us measure changes that occur because of orthodontic treatment or the lack of treatment. There is no doubt that orthodontists and their patients have benefited from the widespread use of this instrument.
Nevertheless, the accuracy and dependability of the cephalometer have mesmerized the profession to the point where we rely on cephalometric norms, rather than on what we actually see and hear from the patient. Any device that increases understanding between patient and orthodontist would have to be considered an asset.