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January 1998 • Volume 113 • Number 1


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Facts do not cease to exist just because they are ignored.

—Aldous Huxley

The College of Diplomates of the American Board of Orthodontics held its annual meeting at the Chateau Frontenac in Quebec City, July 13-17, 1997. The theme of the meeting was "Early Treatment."

Through the years, the orthodontic specialty has been divided into two camps. One, largely espoused by the so-called American school, called for placement of appliances in almost all patients in the permanent dentition, or at least with a permanent dentition present on completion of treatment. Efficient multibanded fixed appliances over a short period of time, plus extraoral force, as needed, provided the tooth-moving mechanisms.

The European approach depended heavily on removable appliances and functional appliance guidance, starting patients with abnormal neuromuscular patterns and maxillomandibular malrelationships in the mixed dentition. Elimination of abnormal perioral muscle function and growth guidance were primary objectives.

Advocates of each group showed dramatic anecdotal changes. The past 30 years, however, have produced a melding of both approaches around the world. More efficient functional appliances, as well as great advances in fixed appliance materia technica, are part of the armamentaria of most ortho­dontists. But the gnawing (biting?) question remains: when and what is the best and most efficient way to correct skeletal malocclusions that have neuromuscular compensations? Even the best ortho­dontists in the world have altered their approach during the course of their careers. Charles Tweed, often called the world's greatest orthodontist, produced outstanding results with full-banded appliances in the permanent dentition. But toward the end of his career, he stressed that mixed dentition therapy was vital, and he accepted only mixed dentition cases in his practice. Tweed wrote, "As we learn more about growth and its potentials, more about influences of function on the developing denture, and more about normal mesiodistal position of the denture in its relation to basal jawbones and head structures, we will acquire a better understanding of when and how to intervene in the guidance of growth processes so that Nature may better approximate her growth plan for the individual patient. In other words, knowledge will gradually replace harsh mechanics, and in the not-too-distant future the vast majority of orthodontic treatment will be carried out during the mixed dentition period of growth and development and prior to the difficult age of adolescence." This was in 1963! European orthodontists have eagerly adopted Tweed's concepts and multibanded philosophies, augmenting functional appliances in their practices.

Yet considerable controversy still exists over the best time to institute orthodontic therapy. A host of questions arises after a perusal of the literature and research reports of the past 50 years. Does early treatment produce better results? Can all orthodontic treatment objectives be achieved in one-phase treatment in late mixed dentition or permanent dentition phase? What is the optimum time to take the greatest advantage of growth? Indeed, is there such a thing as growth guidance? Can we stimulate maxillary and mandibular growth? Redirect or restrict jaw growth? Can we change mandibular form? Can we change glenoid fossa morphology and position? Can we use neuromuscular forces to effect significantly favorable changes in the dentofacial morphology? With functional appliances, what is better? Daytime wear? Nighttime wear? All-the-time wear? How much of the induced change is skeletal? How much is dentoalveolar? Does two-phase treatment take longer? What cases should be treated in the mixed dentition? Permanent dentition? Are treatment results more stable with early treatment? Late treatment? Two-phase treatment? What approach is least likely to produce iatrogenic response? With managed care creating a demand to see more patients per unit of time, what is the most efficient approach from a business point of view?

There are three invited editorials in this issue that call attention to the multifaceted nature of early orthodontic treatment, and an opinion piece at the end of the volume that questions first-phase treatment in most patients. David Hamilton, immediate past president of the AAO and an innovative clinician who has great experience in early treatment, attended the CDABO meeting and took an active part in the deliberations. His cogent observations and projections stress the need for a paradigm shift for the new millennium with properly managed early treatment procedures that need not impact on the financial aspects or total treatment time for patients.

Much of the basic and clinical research on growth guidance has been done at the University of Toronto, under the aegis of Donald Woodside. His fine analytical critique of growth guidance in the second editorial, particularly with functional appliances, is the most perceptive résumé of what we know and what we don't and the problems encountered, which make reasoning from the particular case to the general population difficult. The third editorial, on the rationale of early orthodontic treatment, by Michael Arvystas, represents his philosophy and justification of his approach, based on many years of clinical experience. The Bowman article summarizes the views of the "one-phase" school of thought and is purposely placed at the end to leave the reader with a sense of balance of the issues involved.

The CDABO program under President John Cheek, General Chair John Kanyusik, and Program Chair Terry Guenther tried to provide answers for some of the more vexing questions. In the CDABO articles, Lionel Sadowsky first discusses the current knowledge of the correlation of growth with treatment timing, based on both basic and clinical research. Larry White outlines some of the most commonly treated problems in his article; he also gives his opinions on early treatment. Asuman Kiyak and associates present the results of their research on psychological aspects and treatment timing. Her excellent study points out that children of mixed dentition age are likely to be more cooperative than during puberty. There is relatively little controversy over interceptive procedures.

Three major, ongoing, NIH-funded, randomized prospective clinical studies of mixed dentition treatment of Class II, Division 1 malocclusion from the University of Florida, University of Pennsylvania, and University of North Carolina are presented by Timothy Wheeler, Joseph Ghafari, and Camille Tulloch, respectively. All used extraoral force and compared this modality with functional appliances. The Pennsylvania study used a Fränkel functional appliance, whereas the other two studies used modified bionators. Time of wear varied some in the different studies. A biteplate was also used with the extraoral headgear appliance in the Florida study. Applied forces with the extraoral appliances, directed against the maxillary first molars, were apparently 8 to 10 oz, which is considered essentially in the tooth-moving range. Conventional lateral film cephalometric measurements were used in these studies. As noted above, the facebow extraoral force was directed against the maxillary first molars, not the maxillary arch as a unit (as Dr. Dugoni shows in his case report in this issue). Rather than comment on the specifics of these studies, I refer the reader to the published articles, as well as to a previous article by Camille Tulloch that appeared in the April 1997 issue of the AJO/DO.

Missing in all these studies is any assessment of changes that might occur in the glenoid fossa morphology and position, pointed out as early as 1940 by Breitner, later by Derichsweiler, and in the studies done at the University of Toronto and elsewhere as quoted by Don Woodside in his editorial in this issue.

If we are going to talk about orthopedic forces, we have to do more than conventional two-dimensional cephalometric assessment of maxillomandibular relationships, mandibular length, and position of apical bases of both jaws with respect to the cranial base. Magnitude of force and direction of force are significant factors for extraoral appliances. Even 8 to 10 oz of headgear force can have some effect beyond a distalizing tooth-moving impetus for the maxillary first molars, as shown by Tulloch. Despite a relatively low level of force against the molars, there appeared to be some restriction of normal downward and forward maxillary movement. But what would heavy orthopedic forces have done? We won't find out from these three studies. What is needed is a true orthopedic force of much greater magnitude directed against the maxilla as a unit.

If we are going to try to determine the greatest potential of functional appliances, full-time wear that does not rely on patient compliance is indicated to reduce one of the hidden variables of all these studies: patient compliance. Assurance that the appliance is indeed worn when the jaws are functioning—during the day for eating, swallowing, speaking, etc.—is of paramount importance. Landmark retrospective studies that can give us much information on bonded protractive mandibular appliances are already in the literature from Pancherz et al. The current popularity of modified Herbst fixed appliances like the Jasper Jumper and Eureka Spring indicate a need to eliminate the patient cooperating variable. But, as Dr. Woodside points out in his editorial, there are many factors, not the least being individual variability of response. Thus, properly designed prospective studies are still needed to really determine the full possibilities of growth guidance during the mixed dentition or at any time growth is still operative.

Many of the questions posed are addressed in the summary by Bishara, Justus, and Graber of the break-out workshop sessions by CDABO members at the Quebec meeting. Some of the consensus response is surprising, in light of the controversy engendered, that is, the overwhelming endorsement of early treatment. Remember, the workshop members are all Board certified orthodontists in active practice. Surely, this represents the best that orthodontics has to offer.

The fine case report by Steven Dugoni points up some of the questions just answered. The old adage, "It is not the tool but how you use it," applies here. It is hard for me as a clinician, with a lifetime of practice and recording of my results in periodicals and books, to remain unbiased. The approach used by Dr. Dugoni is quite similar to what I have used, together with a biteplate, as was done in the Florida prospective study of Drs. Wheeler, King, and Keeling. It would be interesting to see what difference there is, if any, in the use of the biteplate, as compared with the other two prospective headgear patient samples reported in this issue.

Ethical issues have been a popular topic in recent orthodontic meetings. Here again I have a bias based on my presentations on this subject to CDABO, AAO, SAO, MSO, and SWSO constituents. This issue has arisen because of questions by some of our practition­ers. Is it possible to render optimal service to each patient—always our first priority—when we see large numbers of patients each day in a managed care environment? Dr. Jerrold's article on this subject will give us all some needed guidance in a world of telephone book, TV, radio, newspaper, and flyer advertising of orthodontic services. Is early treatment likely to be affected by this development?

Of course, we have to look to the future, too, concerning materials for orthodontic and orthopedic appliances. Developments in this field make us more efficient, tissue changes more biologic, extending our services to more patients. Bob Kusy presents some of the current research and makes future projections on materia technica.

Because Dr. Kiyak's incisive presentation at the meeting was so well received and pertinent to patient management in the mixed dentition stage, we accepted another article on the same subject by Yang and Kiyak on orthodontic treatment timing for this special early treatment issue. The findings of this survey of orthodontists suggest that early orthodontic intervention is the norm, but practice characteristics affect treatment timing, i.e., when to treat TMJ problems. More experienced orthodontists are likely to treat them earlier.

In addition, because it is so difficult to find prospective studies, we include an article by Lund and Sandler "The effects of Twin Blocks: A prospective controlled study" submitted at the time we were assembling the January 1998 issue. The results clearly demonstrate that functional appliances can enhance mandibular growth, but the treatment effects are combined skeletal and dental changes, with retroclination of maxillary incisors and proclination of mandibular incisors a significant part of the end result. Does this mean future need for fixed mechanotherapy in the permanent dentition? Surely this is true for a percentage of the cases. No claim should be made that early treatment procedures are a panacea for all orthodontic ills.

Finally, pertinent to the early treatment theme in our Notes from the Clinic section, S. Jay Bowman adopts the role of skeptic, emphasizing some of the issues still unresolved and pointing out areas of conflicting claims. He notes, "It isn't unprofessional to question a person's science. It isn't uncollegial to demand proof. It isn't impolite to recognize glaring conflicts of interest." Adding balance for clinicians, he cites Anthony Gianelly, ". . . at least 90% of all growing patients can be treated successfully in only one phase by starting treatment in the late mixed dentition stage of development, with only the second primary molars or 'Es' are present. Few if any benefits are unique and dependent on earlier intervention."

Thus, this special issue does not solve all the problems or answer all the questions about early orthodontic treatment. The use of the hand-wrist X-ray film, as used in some of these studies, is notably inaccurate to select optimal growth timing. We need a better way. In addition, as the treatment pendulum swings to both treatment timing extremes, quite spectacular changes are demonstrated in some patients treated in the deciduous dentition with specific problems, as shown by Turley and Hamilton and others. The same is true for permanent dentition cases. However, this volume is the best compilation thus far of prospective, reasonably scientific studies of early Class II, Division 1 treatment.

Perhaps a major contribution of these projects is that we know more definitely what can, indubitably, be done with specific appliances. Can we reason from the particular to the general? I think not. We have not yet learned the ultimate potential of stimulating mandibular growth, because the mechanisms used were not capable of showing this. Regardless, the emphasis now is on diagnosis to determine what is the best time and best method for the particular patient. Blindly following our orthodontic pied pipers exposes us to the thorns of the primrose path. Lysle Johnston, the ultimate iconoclast, says, "A willingness to believe in nonsense is, in effect, a tax on ignorance." But, Virginia, there is a Santa Claus and, yes, Virginia, we can guide the growth of your jaws—we don't have to wait until all your teeth are in!

—Tom Graber

   Articles with References to this Article  TOP 

This article is referenced by these articles:

Treatment timing for Twin-block therapy
American Journal of Orthodontics and Dentofacial Orthopedics
August 2000 • Volume 118 • Number 2
Tiziano Baccetti, DDS, PhDa, Lorenzo Franchi, DDS, PhDa, Linda Ratner Toth, DDS, MSb, James A. McNamara, Jr , DDS, PhDc
ABSTRACT
FULL TEXT