So you've taken a course on Invisalign and
now you think you can straighten
teeth. Maybe so. But watch out.
These high-tech plastic aligners may
not work as well as old-fashioned
braces...in which case there could
be a lawyer in your future.
That's the word from Daniel
Kuncio, D.D.S., a New York
orthodontist, and his colleagues at
the Montefiore Medical Center in the
Bronx. The team compared the teeth
of 11 patients treated with
Invisalign to 11 treated with
conventional braces three years
after the two groups had finished
their treatments. They found that
the Invisalign patients' teeth had
relapsed significantly more than the
patients using traditional braces.
"The take-home message is that
you have to be very careful with
this product," says Dr. Kuncio,
study was published in the
September issue of Angle
Orthodontics. "It's easy to get
into trouble." Kuncio should know.
He was called as an expert witness
in the malpractice trial of a
general dentist accused of botching
an orthodontic treatment with
Invisalign. He warns that many such
lawsuits could crop up soon as more
and more general dentists begin
"The take-home message: be very
careful with this product"
Introduced in 1999, the system
caught on fast, partly because it
requires less expertise and less
training than conventional braces,
opening the world of orthodontics a
bit to general dentists. Dentists
simply make impressions of their
patients' teeth, then send them to
Invisalign's creator, Align
Technology of Santa Clara, Calif.
Technicians at the company use
computer modeling to create a set of
clear plastic aligners, each
designed to move teeth a little bit
farther in the desired direction.
Invisalign is popular among
patients because the transparent,
removable aligners are much less
noticeable and more comfortable than
conventional braces, says Robert L.
Boyd, D.D.S., M.Ed. chair of
orthodontics at the University of
the Pacific in San Francisco.
Hundreds of thousands of patients
have received Invisalign treatment,
and because of its appeal, the
technique is expanding the market
for elective orthodontic treatment,
But how effective is it? While no
one disputes that the aligners can
move teeth, experts debate which
kinds of problems it can fix and
which kinds should be treated using
conventional techniques. Dr. Boyd, a
paid board member and shareholder in
Align, has published several studies
describing the advantages of Align
over traditional orthodontics. For
example, he points to unpublished
research showing that Invisalign
patients experience less root
resorption than conventional
And Dr. Boyd argues that general
dentists can and should be using
Invisalign -- in fact, his school is
teaching the procedure to general
dentistry students. He has also
published research suggesting
orthodontists can use it for fairly
But independent researchers have
found Invisalign wanting. A
review of Invisalign studies
published in the April 2007
Journal of the Canadian Dental
"Achieving similar results to those
of more conventional fixed
appliances may be difficult."
The only two clinical trials
comparing Invisalign to traditional
braces reached similar conclusions.
First came a Sept. 2005
study in the
American Journal of Orthodontics &
The investigators compared 48
patients immediately after treatment
with Invisalign to 48 patients
immediately after treatment with
braces, using American Board of
Orthodontics (ABO) Phase III
examination criteria. Twenty-seven
percent fewer Invisalign patients
had passing scores.
Now comes Dr. Kuncio's work using
the ABO system to score the teeth
after three years. "What I saw in my
research was that Invisalign
relapsed more," he says.
Dr. Boyd dismisses these results.
"There is a bit of negativity out
there," he says. "Whenever you get
into something new, there is at
least a third of the old guard who
will hate it just because it's new."
He calls Dr. Kuncio's study
"biased," arguing that the
investigators just didn't like
Invisalign. And he says the study
was "poorly done" because the
orthodontist treating the two groups
of patients, Clarence E. Shelton,
Jr., was much more experienced with
braces than with Invisalign.
Dr. Kuncio responds that he and
his colleagues do like Invisalign.
"I use it everyday," he says. He
also acknowledged that it would have
been more ideal to compare patients
treated by an orthodontist equally
well-practiced in both techniques.
But he points out that the two
groups had equivalent ABO scores
immediately post treatment.
He argues that Align should
market Invisalign to orthodontists
rather than general dentists because
general dentists don't know what to
do if they get into trouble.
Orthodontists, by contrast, can fall
back on conventional techniques. For
those general dentists who do want
to try Invisalign, he recommends
extreme caution. "Start slow with
simple cases," he says.
And in the end, that's where the
two experts agreed. "Don't start
with anything but the simplest
cases," echoes Dr. Boyd. He also
advises treating only patients over
14 and only those patients who are
truly motivated. "Cooperation is the
number one issue," he says.
Copyright © 2010 DrBicuspid.com
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