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1. EARLY TREATMENT SYMPOSIUM
Answers in search of questioners
Lysle E. Johnston, Jr, DDS, MS, PhD, FDS RCS (E)
Ann Arbor, Mich
B
ecause the litera-
ture contains
most, if not all, of
what will be said by “the
usual suspects” rounded
up for this early treat-
ment symposium, the
considerable attendance
is both surprising and a
reason for reflection. The
symposium was not a
part of a regular meeting,
so each attendee is here
because of a personal in-
terest in the topic. But
what is the nature of this interest? The advertisements
for the symposium suggest that the “experts” will
supply answers. Speaking personally, there really is not
much that I can say that I have not said better, and more
carefully, in print. Unfortunately, the refereed ortho-
dontic literature is not always seen as a practical source
of clinical information. Much of the literature, includ-
ing most of what I have written, is just answers in
search of questioners. Accordingly, I would like to
suggest a line of questions, the answers to which might
justify the considerable expense of a meeting such as
this.
Given a need for treatment (itself a topic that could
occupy the experts for a day or 2 but that probably
would be discussed before an empty hall), the next
logical question is when? Early or late? Clearly, the
timing of many of the treatments to be discussed at this
meeting probably would generate little controversy.
Indeed, I would argue that the main controversy—and
perhaps the reason for the full lecture hall—surrounds
the treatment of Class II malocclusion. To be more
precise, the controversy surrounds not the occasional
early intervention for a specific reason but, rather, the
routine treatment of Class II malocclusions with some
sort of 2-stage, functional and fixed appliance combi-
nation, commonly with expansion and without extrac-
tion.
Will you treat early? If the answer is no, the
alternative late treatment, commonly begun at the end
of the mixed dentition stage and featuring E-space
conservation and some sort of maxillary distalization,
would seem to be in order. This approach has been
referred to by William Proffit as the gold standard
against which other approaches must be judged. In
other words, if you wish to treat in some other way, you
must seek evidence that it is superior to a single phase
of late mixed-dentition treatment.
If your investigation convinces you that early treat-
ment is better, then you will need to ask yet another
series of simple questions to determine what form this
early treatment will take. Which jaw will your early
treatment target? Treatments aimed at the midface are
out of fashion, perhaps because they generally require
cooperation and commonly are said to target the wrong
jaw. Moreover, lurking in the fringes of organized
dentistry is a vocal minority claiming that backward-
pushing mechanics cause temporomandibular dysfunc-
tion. Unfortunately, if you examine these various as-
sertions and assumptions, you will find a general lack
of supporting data. Indeed, there is a growing body of
evidence that the end results of treatments aimed at the
midface are indistinguishable from those that are de-
signed to “grow” mandibles.
If, on the other hand, you are drawn to the conclu-
sion that treatments should be aimed at the mandible,
you must answer a simple question: Why?
It will be difficult to muster convincing support for
the argument that you must treat the mandible because
a Class II malocclusion is a disease of an underdevel-
oped mandible: young children, both Class I and II,
tend to have relatively small mandibles. The young also
are short and ungainly. Time and the normal pattern of
growth and development presumably will ameliorate
all of these deficiencies. In other words, will Class II
patients still have small mandibles at maturity? If you
conclude that the mandible really is the material cause
of the Class II malocclusion, then it would be appro-
priate to ask whether any treatments effectively target
Robert W. Browne Professor of Dentistry and Chair, Department of Orthodon-
tics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann
Arbor.
Presented at the International Symposium on Early Orthodontic Treatment,
February 8-10, 2002; Phoenix, Ariz.
Am J Orthod Dentofacial Orthop 2002;121:552-3
Copyright © 2002 by the American Association of Orthodontists.
0889-5406/2002/$35.00 ϩ 0 8/1/124163
doi:10.1067/mod.2002.124163
552

2. it. Specifically, are you going to employ 1 or more of
the so-called functional appliances? To answer yes, you
must first ask why. What do you hope to accomplish
and is there any proof that what you hope for is
possible?
Our Association, in calling for early screening
(which, of course, leads to early treatment), has pub-
lished a laundry list of potential benefits. However,
public service announcements often are more akin to
wishful thinking than to a meaningful guideline for a
rational practice. Perhaps the most common biological
reason for using functional appliances is to augment
mandibular growth. It is argued that, much like the
United States Army, these treatments let Class II
patients be all that they can be. Unfortunately, long-
term studies indicate that the only lasting effect is in the
midface, not in the mandible. This surprising result has
led some influential clinicians to argue for earlier
treatments, and others, for later. Both tactics apparently
are designed to preserve the extra growth that is said to
occur in the functional stage of 2-phase treatments. But
what if there is no extra growth? What if functional
appliances serve only to produce a “Sunday bite” that is
slowly made permanent by the excess mandibular
growth commonly seen even in Class II patients? In this
case, functional appliances might be seen to work but
not to confer any special benefits to offset the extra time
and cost of multiphase treatments. Therefore, func-
tional appliances would not constitute a substitute for
surgery, as often is claimed. Supporters might argue
that even if functional appliances cannot “grow man-
dibles” (to put it bluntly), they might minimize the need
for premolar extraction.
How can this be achieved? Growth is a powerful,
seemingly magical word, but it is difficult to see how
growth can create space for a crowded, protrusive
dentition. Bone does not grow interstitially, and the
teeth tend to come forward on their bases. The mandi-
ble has no sutures, so there is no surface at which arch
perimeter can be created. Distalization is not only poor
English, but it is also exceptionally difficult to achieve.
Therefore, the only option is arch development, a
treatment that when called “expansion” was discredited
as unstable and unreliable.
In the upper jaw, extra perimeter can be created, at
least in theory, by rapid maxillary expansion. However,
the effectiveness of this form of development remains
to be seen. Dentoalveolar and basal expansion ulti-
mately have to answer to the envelope of motion of the
lips, cheeks, and tongue. Accordingly, the clinician
interested in nonextraction treatment will seek evidence
of long-term, clinically significant increases in arch
perimeter. Failing that, the potential benefits of early
growth-modification Class II treatments shrink to the
potential of a favorable psychologic impact and the
prevention of incisor fracture.
Clearly, some patients suffer psychologically be-
cause of their protrusive incisors; they would benefit
emotionally from treatment. Moreover, there is at least
some evidence that early incisor retraction might re-
duce the risk of fracture. But are these occasional
benefits enough to support what amounts to an ortho-
dontic growth industry? If the answer is yes, then early
treatment might well be an appreciable benefit for the
Class II patient; however, if the answer is no, then we
must make a decision. The basic tenets of evidence-
based dentistry state that decisions for individual pa-
tients must be based on the best available evidence.
Accordingly, some specific Class II patients probably
would benefit from early intervention. In contrast, if
there is no generalized biological rationale, a decision
to treat most Class II patients early might still make
sense when it is a condition of referral from the family
dentist.
What about the biological questions? I would argue
that they could and should form the basis of yet another
early treatment symposium, this time aimed at referring
dentists whose notions about the benefits of early
treatment have done so much to shape and constrain
contemporary orthodontic practice.
American Journal of Orthodontics and Dentofacial Orthopedics
Volume 121, Number 6
Johnston 553