Written Statement of
Lawrence A. Tabak, D.D.S., Ph.D.
Director, National Institute of Dental and Craniofacial Research
National Institutes of Health
April 6, 2006
Mr. Chairman and Members of the Committee:
I am pleased to present the President’s budget request for the
National Institute of Dental and Craniofacial Research (NIDCR) for
Fiscal Year (FY) 2007. The FY 2007 budget includes $386,095,000, a
decrease of $3,241,000 from the FY 2006 level of $389,336,000,
comparable for transfers proposed in the President’s Request.
STRENGTHENING THE EVIDENCE BASE IN DENTAL CARE
Health care decisions should be guided by the preponderance of
clinical research data, or evidence, whenever possible. This approach
is known as "evidence-based medicine", a concept that has evolved into
a driving force in healthcare.
Recognizing the concept’s value, dentistry also has embraced an
evidence-based approach. Yet, having sufficient clinical data from
which to build that base can be challenging. For some oral health
problems, evidence-based approaches are possible; for many others,
knowledge gaps must be filled before an evidence-based approach can
take root. As the nation’s leading supporter of oral, dental, and
craniofacial research, the NIDCR is uniquely positioned to fill those
gaps while continuing its efforts in the laboratory to develop new and
even more effective ways to prevent, diagnose, and treat dental
diseases. I would like to highlight over the next few minutes how the
NIDCR is sowing the clinical seeds of progress to advance
evidence-based dentistry in America and, above all, improve the
nation’s oral health.
PRACTICE-BASED RESEARCH NETWORKS
Healthcare providers sometimes comment that too often they are not
included as participants in research, noting that their clinical
experience and insight are significant assets to understand and address
patients’ most pressing health concerns. I believe that there is much
to be gained from engaging clinical practitioners in research. That is
why the NIDCR recently established three regional practice-based
research networks (PBRNs) to investigate everyday issues in oral
healthcare.
Each PBRN involves 100 or more oral health practitioners who will
propose and conduct studies of common dental procedures across a range
of patient and clinical conditions. For example, some of the early
investigations will gather data on methods dentists use to restore
teeth with deep decay, and to assess caries risk. Each network will
conduct 15 to 20 clinical studies over the next seven years. The PBRNs
also will collect information to generate data on disease, treatment
trends, and the prevalence of less common oral conditions.
While the PBRNs aim high, their success will be rooted in their
focus on real-world clinical issues and their ability to generate
information that will be of immediate value to practitioners and
patients alike. The studies will involve topics and procedures that
clinicians themselves identify as relevant and in need of systematic
research to help guide clinical decisions. I believe the PBRNs have
the potential to generate a body of high quality clinical research data
in a relatively short period of time. Most importantly, their research
will substantially enhance the base of evidence clinicians can use to
inform treatment decisions, translate newer information into daily
practice, and directly affect and improve routine dental care.
GREATER EMPHASIS ON LARGE CLINICAL STUDIES
The nation’s progress against heart disease, cancer, and infectious
diseases has been accelerated by large clinical studies yielding
results that can be generalized and can clarify the interplay of many
variables. In dentistry, clinical research traditionally has involved
smaller studies with fewer participants. The NIDCR is changing this
trend by supporting larger clinical studies whose outcomes have the
potential to fundamentally change dental practice and improve public
health. I would like to tell you about some examples.
PERIODONTAL DISEASE AND PRETERM BIRTH
In the United States, about one in eight babies is born prematurely
. Preterm babies can be so small and underdeveloped that they must
remain hospitalized for months and, if they survive, spend years
battling chronic health problems. This heartbreaking situation has
spurred scientists to identify risk factors associated with premature
births. Risk factors such as smoking, hypertension, and diabetes allow
doctors to identify women who are more likely to deliver prematurely
and to tailor their prenatal care. However, identification of risk
factors is a work in progress. One in four of preterm births (more
than 125,000 per year) occurs without any known explanation.
Scientists have assembled an intriguing body of preliminary evidence to
suggest that women who have severe gum, or periodontal, disease during
pregnancy are at increased risk of preterm delivery. This raises the
question: Does treatment for periodontal disease during pregnancy help
women reach full term and give birth to healthy babies?
The
NIDCR is supporting the first large, controlled Phase III clinical
trials to answer this important public health question. Two studies
involve over 2,600 women of various racial, ethnic, and economic
backgrounds. The first, called the Obstetrics and Periodontal Therapy
(OPT) trial, will soon report its findings, providing for the first
time the clinical data needed to offer sound scientific advice on this
issue. The results of the second study, called the Maternal Oral
Therapy to Reduce Obstetric Risk (MOTOR) trial, should be forthcoming
next year.
BETTER PAIN TREATMENTS FOR JAW CONDITION
Temporomandibular joint and muscle disorder (TMJMD) is an umbrella
term for conditions affecting the area in and around the
temporomandibular joint, or TMJ. The TMJs connect the jaw to the
skull. Common symptoms of TMJMD include persistent pain in the jaw
muscles, restricted jaw movement, and jaw locking.
Although TMJ disorders vary in their duration and severity, for some
people the pain becomes severe and permanent. NIDCR recently launched
a large, seven-year clinical study to accelerate research on better
pain-control treatments for TMJMDs. The study, called Orofacial Pain:
Prospective Evaluation and Risk Assessment (OPPERA) will collect data
on 3,200 healthy volunteers for three to five years to see how many
develop TMJMD, opening a largely unexplored window from which to
observe the early stages of the disorder. With this unique vantage
point, they can gather data on key genetic, physiologic, and
psychological variables involved in TMJMD pain, ultimately weaving the
information into more effective treatments.
Only a decade ago,
a large study tracking the development of TMJMD over time would have
been scientifically problematic, because little was known about the
basic mechanisms of human pain. However, because progress in the basic
sciences has fed the knowledge pipeline, pain researchers have now
better defined the molecular circuitry involved in pain transmission,
thereby providing the conceptual framework for this important clinical
study.
MOLECULAR MEDICINE AND ORAL CANCER
In the fight against cancer, future weapons of choice likely will
fall within the therapeutic category of molecular medicine. The
concept builds on world-wide efforts to design cancer treatments
targeting the precise molecules that drive the tumor process, leaving
normal cells unscathed. As envisioned, molecular medicine will
increase the benefits of treatment and limit greatly the unwanted side
effects that now afflict cancer patients. For the vision to become
reality, scientists first must learn to correctly identify distinctive
features of the genetic and/or protein profiles of developing tumors.
Much progress has been made in the laboratory, but the promise of
molecular diagnostics remains largely unready for translation to
patient care.
An NIDCR-supported project that has successfully taken that critical
step is a partnership between scientists, dental educators, and a
community clinic in British Columbia. The partners have integrated
molecular techniques with existing screening tools by combining certain
molecular discoveries with clinical use of toluidine blue, a chemical
dye used to determine whether or not to biopsy an abnormal growth. The
technique hinges on laboratory work that showed an association in early
oral lesions between toluidine blue retention and the presence of cells
with distinct, cancer-predisposing chromosomal abnormalities. The
program already has identified several people requiring treatment for
oral cancer and pre-cancerous lesions.
DRY MOUTH AND RADIATION THERAPY
Persistent dry mouth often occurs in head and neck cancer patients
because radiation from the therapy damages the salivary glands. This
irreversible, chronic dryness makes normal chewing and swallowing
difficult, and leads to a range of painful oral diseases. Recently,
NIDCR scientists teamed with researchers at the National Cancer
Institute to develop an important new lead in protecting the salivary
glands during radiation therapy to the head and neck. Their work
involves a synthetic chemical called Tempol, which possesses a unique
ability to protect cells against radiation. In mice, administration of
Tempol 10 minutes prior to radiation therapy to the head and neck
provided significant protection to the salivary glands. Critically,
Tempol did not protect tumors from radiation, and thus did not diminish
the beneficial effects of the radiation therapy. Future clinical
trials in people are likely.
REDUCING DISPARITIES IN THE NATION’S ORAL HEALTH
Although the Nation’s oral health has improved greatly over the past
several decades, this progress has not been equally shared by millions
of low income and underserved Americans. To help reverse this trend,
the NIDCR supports five Centers for Research to Reduce Oral Health
Disparities. The centers are designed to explore, understand, and
improve the oral health of those who reside in underserved
communities. The researchers seek creative but practical approaches
that are inexpensive, can be easily applied, and are exportable to
other underserved communities.
This year, the Disparities
Centers reported several noteworthy findings. For example, after a
two-year clinical study, San Francisco researchers found that infants
and small children who receive at least one fluoride varnish treatment
per year can cut their dental caries rate in half. Fluoride varnish is
a concentrated fluoride in a resin or synthetic base that is applied
directly onto the teeth. The treatment is inexpensive and is more
easily used with very small children than other preventive measures,
such as dental sealants and mouth rinses.
Meanwhile, the
Disparities Center at the University of Washington is evaluating the
oral health benefits of gum and candy sweetened with xylitol rather
than caries-promoting sugars. Xylitol, a natural substance found in
certain fruits, has been shown to fight tooth decay. The team is
refining the optimal dose to satisfy taste and fight decay. Xylitol
use exemplifies an easily adopted, self-administered, scientifically
validated approach that may be useful in underserved populations.
IMPROVING THE NATION’S ORAL HEALTH
As these highlights demonstrate, the NIDCR has made a strong
commitment to expand clinical research and to build the evidence base
that will inform better clinical practice. At the same time, progress
in basic science continues to provide new and exciting leads that can
translate into large clinical trials, yielding results with the
potential to transform dentistry and public health. Above all, the
NIDCR seeks to find practical solutions to intractable problems and, in
so doing, improve the Nation’s oral health.