THE EDITOR'S CORNER
If I were an x-ray salesman, I would make a real effort to sell orthodontists on the idea of frontal cephalometric analysis as a routine part of orthodontic diagnosis and evaluation. The orthodontist and the patient would benefit from the additional understanding and visualization of complex problems and I would double my sales of 8 X 10 film.
Even in the days when tailors were not permitted to touch the Emperor of Japan, they were permitted to walk around him. We don't walk around patients very much. Most of us are hung up on that profile view.
The fact that asymmetry of the face is the rule rather than the exception has been amply demonstrated long ago in that now famous experiment in which photographs of faces were divided vertically and two faces made up of a half-face and its mirror image. The resulting composites were as different as one face from another. You can duplicate this experiment for yourself on any full face photograph you care to use. If the composite experiment were repeated on skulls, using frontal cephalometric x-rays, the same degree of asymmetry of the underlying skull would be revealed.
Orthodontists in the past have occasionally gotten into difficulties of understanding, measurement, and diagnosis on the basis of relating landmarks that are in different planes of space and in different sagittal compartments. It has been part of the price of viewing a three-dimensional object from a two-dimensional side view. two and two do not make three. So, adding another two-dimensional view with frontal film is less than a perfect visualization but, until we are able to replicate three dimensional diagrams or three-dimensional x-rays, the added information can't hurt. But, what good would it do?
There are obvious benefits from the frontal view in a routine evaluation of the midlines of the face, the skull, and the dentition. We have not disregarded this, but we have tended to center the dentition and not be too concerned with asymmetries of the face which we seem to have relegated to natural variation in facial esthetics.
In the usual procedure for trimming art bases on study models, we have consistently limited our visualization of the orientation of the occlusal plane by trimming the bases parallel to the maxillary occlusal plane. In cephalometrics, we have not done much more with the occlusal plane than measure it occasionally. We have not really related it to function. From that point of view, the frontal view of the occlusal plane is at least as important as the side view. If you don't think it can vary much, place a flat plane between the teeth and observe its parallelism with an interocular plane or with an imaginary Frankfort plane, both of which incidentally may also be tilted in a frontal view. It is a reasonable possibility that a tipped occlusal plane from a frontal view may have a significant effect on function and on comfort and on wear and tear of teeth and joints. As far as occlusal plane is concerned, we are deceiving ourselves with our study models and depriving ourselves of additional useful information by not taking a frontal film.
An additional benefit of frontal x-ray is the visualization of dental arch width related to bony arch width. It has been pointed out more than once that this relationship can affect the correct decision in the choice of rapid or slow palatal expansion. Also, a visualization of the tilt of the mandibular plane is different from a frontal view. It doesn't take much imagination to speculate about the possible unfavorable muscle, nerve, bone, tooth and joint reactions to a mandibular plane tilted in the frontal view.
A frontal x-ray view would provide orthodontists with more information about nasal capacity than most EENT specialists have; and respiration is probably going to become a more important consideration in several fields, including orthodontics.
A study of frontal x-rays is likely to increase the diagnosis of the need for surgical orthodontic procedures, while improving those procedures at the same time. It seems likely that we will come to believe more frequently than we presently do, that a surgical procedure in addition to orthodontics will help to correct an abnormality of growth and add a significant improvement in facial esthetics, dental esthetics, function, stability, oral health, dental comfort and improved longevity of the whole complex system through limitation of unnecessary wear and tear.
Orthodontic treatment is rapidly becoming more sophisticated and frontal x-ray is yet another dimension that will distinguish an orthodontist from a tooth mover. If logic demands a broadening of our vision toward a three-dimensional view, science demands that we discover what the detriments of asymmetry are to the dentition, the joints, to function and health; what the limits are beyond which asymmetry must be treated; and what procedures are required to treat orthodontically and/or surgical-orthodontically in the frontal plane.
