Fred F. Schudy, DDS, on the Vertical Dimension

DR. WHITE What kind of appliance did you use in 1942 when you started orthodontic practice?

DR. SCHUDY I was using the Angle edgewise appliance before I went into the U.S. Army and after I returned.

DR. WHITE Did you use gold brackets and bands or stainless steel?

DR. SCHUDY I used gold brackets and gold bands, but I used stainless steel archwires. We also soldered two eyelets on each band.

DR. WHITE Did you band all of the teeth?

DR. SCHUDY I banded all of them. We didn't band upper second molars as consistently as we do nowadays, but we always banded lower second molars.

DR. WHITE What were your force mechanisms?

DR. SCHUDY In addition to the archwires, we used straight-pull headgears, high-pull headgears, and cervical-pull headgears hooked to the archwires, as well as a cervical facebow. We made all of the headgears in the office, and it was a pretty slow process.

DR. WHITE How many patients would you ordinarily have in treatment at any one time?

DR. SCHUDY About 100 patients was a fairly good size practice. In fact, I limited my practice to six new patients per month.

DR. WHITE That number was all you could take care of comfortably?

DR. SCHUDY Charlie Tweed said that anyone who took more than 40 patients a year was a charlatan, and who wants to be a charlatan? He influenced all of us. I was just afraid that I would get in over my head and not be able to do the work correctly, so I was very cautious, too cautious in fact, and I limited my practice to six new patients per month. I remember in May 1956, I was unable to take another new patient until the next year. It's hard to imagine limiting yourself to a predetermined number of patients today.

DR. WHITE Who were some of the orthodontists who influenced you early in your career?

DR. SCHUDY Hayes Nance, from California, came to Houston in 1942 and gave five or six in our study group a short course. He was an outstanding man, a terrific person, and just a wonderful orthodontist. I listened to everything he ever told me. He was the first person I ever heard suggest second-bicuspid extractions. I said to myself, "If Hayes Nance believes it can be done, then I'm certain it works." I guess I'm one of the early ones who started second-bicuspid extractions, and I'm more enthusiastic about it today than I was then.

DR. WHITE Why do you say that it is usually better to extract second bicuspids instead of first bicuspids?

DR. SCHUDY There are several good reasons:

1. It usually produces better interdigitation, because the upper first bicuspid is wider mesiodistally than the second bicuspid, and this positions the first molar farther distally in relation to the lower molar and gives better interdigitation.

2. The upper first bicuspid has two roots that are longer than those of the second bicuspid and divergent, which makes it much more capable of resisting lateral stress.

3. The upper first bicuspid has a longer buccal cusp than that of the second bicuspid, which helps to disocclude the molar teeth in lateral excursions.

4. The upper first bicuspid looks much better because of its length.

5. The lower second bicuspid is wider mesiodistally than the lower first bicuspid and therefore allows the first molar to be positioned farther forward, also helping to produce better interdigitation.

6. When lower cuspids are tipped distally into the extraction space, the apices tend to get into the labial bone. When this happens it is next to impossible to again torque the roots back into the center of the alveolar ridge. As a result, many orthodontists leave them there, and this leaves the cuspids leaning lingually with the root apices too far apart. This causes poor function because the upper cuspid contacts the lower cuspid on the labial surface instead of on the tip of the cusp.

7. As treatment is in progress, when the long buccal cusp of the upper first bicuspid becomes locked mesial to the lower first molar, it acts as a powerful factor in establishing permanent interdigitation.

8. Finally, the denture is more stable when second bicuspids are extracted because the cuspids require less movement and manipulation.

DR. WHITE At the time of Nance, I guess a lot of people were still wedded to the concept of no extractions at all, as Angle had proposed.

DR. SCHUDY Yes, that's true, but by the time I came along most proficient orthodontists felt they had to extract sometimes. Charlie Tweed was one of the first people to recommend the removal of bicuspids.

DR. WHITE Did he influence you much?

DR. SCHUDY I contacted Dr. Tweed as soon as I started practicing in Houston, and I went to Tucson for seven or eight years to his seminars. Yes, he influenced me a great deal.

DR. WHITE You mentioned a study group. Who was in that?

DR. SCHUDY It was composed of the original group that Hayes Nance came to teach here in Houston, and it wasn't a formal organization, just a small group of Texas orthodontists. There was C.T. Roland from San Antonio, Eddie Arnold, Albert Westfall, Paul Gilliam, and myself from Houston. A little while later Bob Gaylord, from Dallas, joined us, and that was the beginning of the Texas Tweed Study Group. It grew and grew and now includes members from other states.

DR. WHITE As a result of Tweed's influence, were you less reluctant to take out teeth in the treatment of patients?

DR. SCHUDY Yes, but I never did go all the way with Dr. Tweed. He felt the Tweed Triangle was his greatest contribution to orthodontics, but I didn't think so. It tended to produce teeth that were too far back in the face.

DR. WHITE Was the cephalometer in use then?

DR. SCHUDY Yes, but only in schools. Dr. Herbert Margolis adapted the cephalometric radiograph to the private orthodontic office in 1950. This was one of the greatest events in orthodontics, second only to Dr. Broadbent's development of the device. Dr. Margolis never accepted any financial aid for the development of the cephalometer, which is quite unique in today's world.

DR. WHITE When did orthodontists come to an agreement about points of reference on the cephalometric x-ray that were useful and universal?

DR. SCHUDY I'm not sure we have yet come to complete agreement, but Broadbent, Brody, and Downs selected most of the points we use today. Many orthodontists have added other anatomical entities to the total list that is used today.

DR. WHITE When did you start using cephalometrics?

DR. SCHUDY Well, I got my first cephalometer in 1953. Dr. Milton Yellen was practicing in Houston at the time. He had done graduate work at the University of Washington in Seattle, and I asked him to come to my office and show me how to find some anatomical points of reference. He very graciously gave me a one-hour course in cephalometrics, and that was the extent of mytraining.

DR. WHITE I suppose that was an exciting time.

DR. SCHUDY Indeed it was. To get in on the ground floor of a movement that was destined to turn the orthodontic world upside down was indeed a great privilege.

DR. WHITE What were you concentrating on when you first started using the cephalometer?

DR. SCHUDY I was interested in relating the position of the teeth to the face. I was already aware that one had to be careful about moving incisors back too far. I was very cautious about it, but it was only after I saw before-and-after head x-rays that I realized how hard it was to accomplish. I remember a couple of cases in particular. I thought I had done a good job on them, but after I looked at the head x-rays I wasn't a bit happy because the incisors had moved too far lingually and the lips followed the incisors. I was more careful from then on.

DR. WHITE When you corrected Class II malocclusions, were you limited to Class II elastics or a headgear of some kind?

DR. SCHUDY That's right, and the headgear was primary a cervical-pull facebow, which I used until I learned better.

DR. WHITE When did you become aware that a cervical force might not be doing everything you wanted to correct a Class II?

DR. SCHUDY As soon as I started intensively studying head x-rays, I began to notice that cervical headgears moved upper molars occlusally. About 1956 I had a very traumatic treatment experience. I had treated a 12-year-old young lady with a severe vertical dysplasia. She had a steep mandibular plane angle, a large ANB angle, and an unattractive smile because of a display of gum tissue. I used straight-pull headgear to hooks on the archwire, and Class II elastics. All your readers will know what happened. The mandibular plane became steeper, the smile displayed more gum, and the Class II condition was only partially corrected. This caused me such mental anguish that I resolved to find some answers if it was the last thing I ever did.

DR. WHITE How did you discover the importance of the vertical dimension?

DR. SCHUDY I took a large number of patients and began to catalogue them. I took a large number of high-angle cases and a large number of low-angle cases, and I compared them. I saw that the low-angle patients had certain characteristics and that high-angle patients had other characteristics. It finally dawned on me that they grew differently, and I realized they had to be treated differently. Cephalometric studies showed me Class II elastics and cervical facebows extruded molars, particularly in high-angle patients. I then began to change my treatment technique. Once you have a valid concept, then supporting mechanics will develop. That's why Tom Creekmore, my associate at that time, and I developed the high-pull headgear. We wanted to prevent the downward development of the maxillary molars. The more we pull with long Class II elastics, the more the chin goes backward, because the lower molars move occlusally. This, in turn, causes the mandible to move downward and backward, making it more difficult to correct the Class II condition.

That is why I quit using Class II elastics so much and started to use short Class II elastics. The short Class II elastics stretch from a hook distal to the lower cuspid, to a hook mesial to the upper cuspid, and then back to the upper molars. Both strands of the elastics run together so that there is tension even when the teeth are in occlusion. They are anterior to the lower molars, and will not extrude them regardless of how long they are worn.

At that time, all orthodontists everywhere were treating all types of patients the same way. There was no differential treatment. They treated hyperdivergent patients the same way as hypodivergent patients. That was the state of the art in 1960. In 1958, the American Association of Orthodontists sponsored a workshop to study cephalometrics, with a view to determining how the head x-ray could be used in diagnosis and treatment. To this meeting were invited researchers, professors, and prominent clinicians from the USA, Canada, and possibly from Europe. A year later the proceedings of the meeting were published, and I couldn't wait to get my hands on the publication. To my surprise and disappointment, there was not one word spoken from the floor concerning the vertical dimension.

DR. WHITE Did you find the short Class II elastics to be effective?

DR. SCHUDY Yes, very effective, and I used them as long as I practiced. They have recovered or prevented many open bites over many years.

DR. WHITE How did you prove to the orthodontic profession that the vertical dimension was important?

DR. SCHUDY In order to produce an illustration that would be convincing, I used an edentulous individual to show that as we increased molar height, the chin moved downward and backward. The horizontal movement of the chin is about equal to the vertical. This showed that the vertical development of the molars also greatly affected the horizontal position of the chin. The article entitled "The Rotation of the Mandible Resulting from Growth", written in 1962 and published in 1964, was proclaimed a classic in 1991. The reviewer stated that it is just as valid today as when it was written 30 years ago.

DR. WHITE Was this data readily accepted when you first presented it?

DR. SCHUDY No, it was not accepted at all. I first presented it in Chicago at the Tweed Foundation Meeting in 1960. Dr. Downs and Dr. Margolis and others discussed the paper from the floor. Dr. Tweed was invited to discuss the presentation, but he declined. Nobody mentioned the content of the presentation. They pointed out errors in nomenclature, sentence construction, and grammatical errors. They found fault with my illustrations. All of these comments were justified. I thought I had suddenly developed halitosis as my good friends avoided me. They never asked me a question. Nobody wanted to discuss it. Dr. Ron Roth was a student at the time and was present at the meeting. He later told me that if that was the way orthodontists treated one another, he wasn't sure he wanted to be an orthodontist. I felt very lonely for the next four or five years, but I never lost faith that it would one day be accepted.

DR. WHITE But it finally was, wasn't it?

DR. SCHUDY Yes, I'm happy to say that it is now well accepted all over the world.

DR. WHITE Didn't you publish an audiovisual film for the AAO Library entitled "Discover the Vertical Dimension"?

DR. SCHUDY Yes, I did, and it is fairly fundamental and a good place for students to start learning.

DR. WHITE What kind of brackets did you use in your practice?

DR. SCHUDY For a good part of my professional career, I used the .018" Steiner bracket. It's a single bracket with two flexible rotating wings.

DR. WHITE Did you always use the .018" bracket?

DR. SCHUDY At first we had only the .022" bracket. At the Santa Barbara meeting of the Angle Society in 1947, I heard Cecil Steiner say, "I think we need a smaller bracket and we need to fill it with wire." I kept this in the back of my mind.

DR. WHITE Didn't you eventually develop an .016" bracket?

DR. SCHUDY Yes, I did. I kept turning over in my mind what Steiner had said about smaller brackets, and in 1970 I changed to an even smaller bracket, the .016".

DR. WHITE What made you think about trying a smaller bracket?

DR. SCHUDY Well, I found myself dreading to place a big wire the first time because of the discomfort it caused patients. I didn't like the tears I saw in the patients' eyes.

DR. WHITE What size archwire did you typically finish cases with?

DR. SCHUDY I always filled the bracket. When I used the .022", I finished with an .0215" x .025" wire, and I always filled the bracket when I used .018" brackets. You can't torque teeth proficiently without filling the bracket. This is particularly true with narrow brackets like the ones I used. But regardless of the bracket you use, you just can't get good labiolingual position unless you fill the bracket with wire.

DR. WHITE Did you feel the smaller brackets allowed you to use smaller, more resilient and gentle wires?

DR. SCHUDY Yes, definitely. The smaller wires delivered less force to the teeth, and the force was more biologically compatible.

DR. WHITE Could you tell our readers about your system of .016" brackets?

DR. SCHUDY I called the system the "Biometric System" because we used .016" brackets on the anterior teeth and .022" brackets on the posterior teeth. The idea was that you could fill all the brackets by twisting an .016" x .022" wire distal to the cuspids and fully control the torque on the anterior and posterior teeth.

DR. WHITE What was the purpose of the .022 " brackets on the posterior teeth?

DR. SCHUDY It enabled you to fill the bracket in one portion of the system and not another portion. It enables you to level the arches with rectangular wires. I would say that a great percentage of all orthodontists everywhere level with a round wire, and that is grossly incorrect. Round wires move the roots of the lower incisors lingually. Of course, you can recover if you're discerning, sufficiently skilled, and conscientious. You can do it, but it is difficult. Once you throw the roots of the lower incisors lingually against the lingual plate of the mandible, you have a hard time getting them back to where they once were. Consequently, most orthodontists usually just leave them there.

You don't want to fill the posterior brackets when you're leveling. Those teeth need to move horizontally and vertically. You must have some play around the wire in the posterior regions while you're leveling so the posterior teeth can slide anteroposteriorly along the wire and then move vertically. A wire that completely fills the posterior bracket prevents these leveling movements from occurring. A round archwire allows the posterior teeth to move anteroposteriorly, but then you throw the incisor apices lingually. By using a rectangular wire to level you can control the lower incisors, and by having play in the posterior areas you can get the flexibility you need and don't have to take the archwire out as often. You can level by taking your archwire out only one or two times. Changing archwires is hard on the patient and the orthodontist and is completely unnecessary with this system of brackets.

DR. WHITE Why do you think most people continue to level with round arches?

DR. SCHUDY With ordinary, same-size brackets all around the mouth, it is difficult to level with rectangular wires. Round wire is easier to work with. I think controlling the lower incisors and leveling is very important, but obviously a lot of people don't think so.

DR. WHITE Has the Biometric appliance been well received?

DR. SCHUDY No, not really. You can get it only with a special order from American Orthodontics now. One of the big problems we had with it was getting accurate-size .016" x .022" wires. The supply companies either can't or won't make accurate wires, and that was frustrating with this technique. We found ourselves trying to place .023" wire in an .022 " bracket, and that is pretty hard to do.

DR. WHITE Do you feel the Biometric concept is as important as your discovery of the vertical dimension?

DR. SCHUDY No, definitely not. But I predict that one of these days some charismatic spellbinder will come along and convince everybody that they should use .016" brackets in the front. I don't know how long it will take, but you can count on it.

DR. WHITE Have we seen much progress in appliance design over the past 30 years?

DR. SCHUDY Orthodontics hasn't made much technical progress over the last 30 years except for the nickel titanium wires. These products have saved us. Had these wires not been developed, I think the .016" bracket would have been better accepted. It would have had to be in order for us to use a smaller, more resilient wire.

DR. WHITE Hasn't your son, George, capitalized on these concepts and developed a new bracket that allows the use of smaller wires?

DR. SCHUDY Yes, he calls it the "Dual Environment Bracket". Actually, we've used the .016" bracket for 22 years. This bracket that George developed was designed to give more intrabracket space and to provide more resiliency in the initial phase of treatment. The gradual engagement or "piggyback" slotted bracket gives the clinician the ability to use a larger slot (.030" in single brackets and .035" in twins) in the initial or gross alignment phase. Maximum flexibility and low force levels are needed in this phase. For further alignment in the initial phase and precision in the rectangular wire phase, the bracket has an .016" slot in the bottom corner of the larger slot. Currently, .022 " and .018 " are the main options. He feels (and I do, too) that while .022" is larger, it doesn't provide enough intrabracket space for the initial phase, and that the .018" is not small enough to give good control with smaller .014" x .018" and .015" x .020" wires.

DR. WHITE Has it had wide acceptance?

DR. SCHUDY There has been limited acceptance to date. People prefer to keep on doing what they learned in school. What we need are schools that have the foresight, judgment, and courage to teach these valid concepts so that students who graduate don't spend the next 30 to 35 years looking for the "best appliance", and usually retiring before they find it. In its present form, though, the bracket has a weakness that needs to be corrected. The manufacturer cut the larger slot into a conventionally profiled material. This resulted in a weakness, and at times, the force of occlusion will narrow the slot. Those who have used the bracket appreciate its advantages, and we hope the manufacturer will choose to retool and produce the bracket correctly.

DR. WHITE Aside from the early control with small, resilient wires, what do you see as the main advantage of the small brackets?

DR. SCHUDY Early control is important, but there are other features just as important. When we use two bracket sizes in the same mouth, and the anterior brackets are .016", we can level very rapidly with an .015" x .020" wire and have complete control of the incisor inclination. Another feature is the ability to torque the upper incisors very rapidly. Small wires are also much more acceptable to the patient. We thought for years and years that our treatment caused only a minimum of discomfort to our patients. George has taught me that I was causing more discomfort than I thought. He has discovered some things about patient comfort and has taught me a lot. He hurts his patients less and does as good a job or better than I did.

DR. WHITE How does he do this?

DR. SCHUDY He does this with a regimen of gradual activations of everything from power chains to elastics. In the critical initial phase, he starts with a completely dead-soft wire while the patient adjusts to the appliance. He then combines this wire with his first active wire. Finally, he removes the dead-soft wire (without removing the active wire) and continues as usual. His studies show that this technique, in combination with a smaller rectangular wire, reduces discomfort markedly and takes no longer than techniques commonly used.

DR. WHITE So the small brackets allowed you to torque the anterior teeth more gently and earlier in treatment?

DR. SCHUDY You can't torque teeth correctly without filling the bracket with wire. Torquing and intrusion of upper incisors, if needed, should be completed one year before brackets are removed.

DR. WHITE Why do you feel the upper incisors need such intrusion?

DR. SCHUDY The most important thing in orthodontics is the control of the upper anterior teeth. They dictate the smile, lip posture, and ultimately the interdigitation of the posterior teeth. If you can't properly torque, intrude, and position the upper anteriors, you can't control these features.

DR. WHITE If your treatment plan calls for treatment of the maxillary arch and the upper incisors first, how do you handle the lower incisors with a retrusive mandible in a growing vs. a non-growing individual?

DR. SCHUDY I have recommended, in nonextraction treatment, that the upper arch be treated ahead of the lower arch. This applies to both growing and non-growing individuals, but particularly to non-growing patients. We will assume that the patient will not need surgery.

The first six months of treatment must be spent distalizing the crowns of the maxillary molars. Ideally, the apices should also be distalized. During this time the vertical positions of the molars must be carefully controlled. They may need a high-pull facebow at this time. Also, the vertical positions of the incisors must be carefully controlled, and they may need a high-pull headgear attached to the anterior portion of the archwire. I must say parenthetically that I am familiar with the principles of "Common Sense Mechanics" advocated by Dr. Tom Mulligan, and they are completely valid. However, when we use a utility type of archwire and introduce a couple at the site of the first molars, we may move the apices of these teeth forward.

After this first phase of treatment the case must be re-evaluated, and at this point torque must have been partially or completely accomplished. Now the decision must be made, or have been made, as to whether the lower incisor is in an acceptable position or whether it needs to be moved forward or backward. There may be a need to remove proximal enamel. Unless there is spacing of teeth, there is little chance of moving the incisors lingually. I say this advisedly, because these teeth could be moved lingually if the cuspids were expanded enough.

Now the lower arch must be bonded progressively as room is made for the teeth. The principles of "Common Sense Mechanics" can now be used to advantage. Class III elastics may be necessary to help upright molars and prevent the incisors from moving forward. The incisor apices must not be moved lingually during the leveling process. This can be accomplished only with rectangular wires in most cases.

When the lower arch is leveled, when the rotations are completed, and when the archform is appropriately accomplished, we are now ready for short Class II elastics. The reason for short Class II elastics is to prevent an increase in anterior dental height.

The above recommendations apply primarily to non-growing individuals. But they also apply to growing patients, the difference being that the tooth movements may not be so critical as with the non-growing patient, since growth can compensate.

DR. WHITE Do you feel undertorquing of upper incisors is common?

DR. SCHUDY Very few orthodontists really torque the anterior teeth enough. It is pretty rare to see overtorqued incisors.

DR. WHITE Do you believe early torque control helps in retention?

DR. SCHUDY I think it is awfully important. I remember asking Dr. Don Niewold how long teeth should be in properly torqued positions before we remove the appliances, and he told me a full year. I think you should be finished with your upper arch at least eight months before you remove the braces. Just let them sit there and get happy in that position. When you make the retainers, they're not inclined to change rapidly. It's hard to finish your torque and intrusion quickly enough to give you that much time for the incisors to stabilize when you use large-slotted brackets.

DR. WHITE I recall from one of your articles that you felt it was better to open deep bites by extrusion of the molars, rather than intrusion of the lower incisors. Why is that, and is it stable?

DR. SCHUDY All deep-bite patients, such as Class II, division 2 patients, need more distance between chin and nose. They need anterior vertical development to improve esthetics and provide overbite stability to the finished case. If we erupt the posterior teeth instead of intruding the incisors, we can give the patient this much-needed anterior vertical height. If we intrude lower incisors in a growing patient, we can expect the relapse of the overbite. If the distance from ANS to menton increases as much as the depth of the overbite, then we are assured of permanent overbite correction. Yes, this is quite stable in growing patients.

DR. WHITE What do you think of the straightwire system?

DR. SCHUDY I realize that this system is used by a large number of orthodontists. Many of these orthodontists are outstanding and proficient and they make it work in spite of its shortcomings. It does not place teeth in their proper position automatically as it allegedly is supposed to do. It provides an easy way for the general dentist to try to do orthodontics, believing that it automatically produces good results. I personally have never been impressed with the straightwire system. Placing a lot of torque in the upper incisor brackets, and then never using it by never filling the brackets, is an admission that it is not right for some patients.

DR. WHITE There are many cephalometric analyses in use today. Which one is the best in your opinion?

DR. SCHUDY There are some aspects of the Steiner analysis that are the most basic and most dependable of the analyses with which I'm familiar. Steiner's analysis reflects changes in tooth position and changes in facial contours of the lower face quite accurately. The APo line has only limited value. It does not reflect changes in tooth position and changes in facial contours with any degree of accuracy. Chapter 8 of my recently published book shows illustrations to confirm these comments.

DR. WHITE You've also published quite a bit on the occlusal plane. What significance does the occlusal plane have for orthodontics?

DR. SCHUDY When you talk about the occlusal plane, you're talking about how you move the teeth vertically. The occlusal plane is not going to tip unless you do something to the teeth vertically. The occlusal plane is a measure of how we adjust the teeth vertically--both the lower and the upper. So many orthodontists elongate the upper anterior teeth. Maybe it is just the teeth alone, and maybe it is the entire maxilla, including the palatal bones. Sometimes the lip may grow down with it and still make a pretty nice smile. It's not real undesirable if the lip and the maxilla will adjust too, but sometimes that doesn't happen--only the teeth move down and the lip stays up, and you have a gummy smile. So the occlusal plane is really a reflection of how you move the teeth vertically.

DR. WHITE A lot of orthodontists have said that when you change the occlusal plane in treatment it will rebound in retention. Is that true?

DR. SCHUDY No, this is a misleading statement. It will only rebound if there is post-treatment growth and if the condyles grow more than the molars grow vertically. Everybody knows there is some rebound of the occlusal plane after treatment. But most people think of a rebound like a tooth that rerotates. That can't happen with non-growing patients. In the growing patients, nothing is going back to where it once was. You won't be confused about the occlusal plane changes if you relate the upper and lower teeth to their osseous bases. If those bases grow, they can sometimes rescue an undesirable change in the occlusal plane. But if the face is finished growing, you shouldn't count on nature's rescue.

DR. WHITE Does a flattened occlusal plane stay flattened?

DR. SCHUDY A leveled and flattened occlusal curve rarely remains as flat as we treat it. But the reason for completely leveling the lower arch is because we cannot, in most cases, get good interdigitation unless the lower arch is completely leveled. If the case is well treated and well retained, nature will restore the amount of occlusal curve that is needed for that individual; and it will do so in harmony with the functional jaw movements.

DR. WHITE In your study of cephalometric growth patterns, were you able to find that the lower jaw always grows along the y-axis?

DR. SCHUDY No, it doesn't at all. It almost never grows along the y-axis. It's not supposed to. People get the idea that it's supposed to grow down the y-axis, but that's not right. If the face were as deep as it is tall, then that would be true. But the face is taller than it is deep. The vertical growth of the face is at least two to three times as much as the growth of its depth. If it grows twice as much as in height, then the y-axis must open down and back. It's perfectly normal.

DR. WHITE So a lot of changes in the y-axis that we attribute to mechanics could, in fact, be due to just normal growth?

DR. SCHUDY Yes, that's right. In the book that I just published, I show a diagram that explains how opening the y-axis can be favorable and how it can be unfavorable. You shouldn't expect the lower jaw to follow the y-axis, because the face grows more in height than in depth.

DR. WHITE This whole concept interests me because patients will treat out nicely, and in the retention period with no active appliances influencing the jaw, the teeth and jaw suddenly begin to move into undesirable positions.

DR. SCHUDY Yes, there are many reasons for this. If the jaws do not grow in harmony with one another, this can happen. That is why you need to retain until growth is completed, so as to limit these post-treatment distortions.

DR. WHITE Did you ever feel that cephalometric prediction tracings were of much value?

DR. SCHUDY I have no objection to prediction if one desires to use it. Growth prediction is based on averages. We can't predict anything but normal growth, and we seldom treat normal patients. Normal growth doesn't need predicting. It's the abnormal growth that needs a forecast, and we can't predict that at all.

It is better to go ahead and let patients grow naturally, and then adjust your treatment to fit that growth. As an example, if the lower jaw is getting steeper, that tells you you're getting too much vertical development and you'd better lay off the Class II elastics and put a high-pull facebow to the maxillary molars.

DR. WHITE Do you believe that these midtreatment adjustments are necessary to control the few biological processes we can influence?

DR. SCHUDY Yes, by all means. We can only influence a few things, like tooth position and alveolar growth, but the mandible and maxilla, in most instances, will continue to grow in spite of our efforts. The alveolar processes will grow as we encourage or discourage them.

DR. WHITE Perhaps this is why the occlusal plane takes on such significance?

DR. SCHUDY We can't influence the maxilla or mandible very much, but we can affect the alveolar processes, and thus the vertical dimension. Sometimes I think we spend too much time concentrating on too many things we can't change appreciably.

DR. WHITE What are you doing now that you aren't actively treating patients?

DR. SCHUDY In addition to doing yard work and church work and delivering meals to shut-ins, I'm doing research. I have a growth study of 95 patients that I collected 25 years ago. Their growth spans are from four to 10 years. I have a home computer and a digitizer. I first do the measurements on Sigma-Scan software. When I'm finished with the measurements (distances and angles), I will import the raw data to Lotus software, where all the calculations will be done. I'm hoping that I can come up with cause and effect. If not, I will settle for whatever I can learn.

DR. WHITE If you had one final word of advice for our readers, what would it be?

DR. SCHUDY The main thing is to care for your patients. Most orthodontists have the intelligence to eventually learn how to correct malocclusions and understand orthodontic principles, but unless they really care for their patients, they don't enjoy their work sufficiently. They don't have the incentive to work hard and learn the necessary principles and concepts to become proficient. I've known a lot of smart people who should have become excellent orthodontists, but did not; and it was simply because they did not care enough for their patients and people in general. When you reach the final years of life it is not too important how much money you've made, but it is very important what you have done for others.