
The bluelight,
up close and personal

A. Ross Kerr,
B.S.C., D.D.S., M.S.D., is Assistant Professor of Oral Medicine
and Director of Special Patient Care and Hospital Dentistry
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Halfway through an
oral cancer examination, Dr. A. Ross Kerr suddenly turns off the
lights and points a glowing blue wand at his patient’s mouth.
“This blue light supplements oral cancer screenings
conducted by plain eyesight under standard room lighting,”
explains Dr. Kerr, an expert in oral medicine. “We are hoping
that the blue light will draw attention to pre-cancerous or cancerous
lesions that might otherwise escape notice.”
A complex chemical
reaction produces this diffuse, low-energy light. When focused on
the mouth, the light may illuminate lesions that could otherwise
be missed under standard lighting. Just before the blue light is
activated, patients rinse with a dehydrating acetic acid that is
believed to make dysplastic lesions become whiter under the blue
light’s glow.
Dr. Kerr is conducting a six-month pilot study to
evaluate the blue light’s usefulness as a screening tool for
oral cancer and pre-cancer. The light has already proved useful
in cervical cancer screening. In a related study, Dr. David Sirois,
Associate Professor and Chairman of the Department of Oral Medicine
and Head of the Division of Reconstructive and Comprehensive Care,
plans to compare the light with other oral cancer detection methods.
Both studies are part of a broad new effort to
enhance early detection of oral cancer and pre-cancer. Better screening
techniques, combined with an understanding of the molecular changes
leading to cancer, may result in an improved outlook for those at
risk. Researchers ultimately hope to identify genetic markers for
oral cancer that could signal a predisposition to the disease long
before lesions occur.
Dr. Kerr’s research also focuses on the study
of recurrent aphthous ulcers (RAU), a condition commonly known as
canker sores. Five to 25 percent of the general population suffers
from canker sores. And in selected groups, such as medical and dental
students, who are subject to predisposing factors like stress, the
rate is between 50 and 60 percent.
“While we’ve been waging a relentless
battle against these extremely painful ulcers for as long as anyone
can remember, we still have no cure,” Dr. Kerr observes. “For
most sufferers, who get a handful of outbreaks a year, treatment
is palliative, and includes the use of mucosal coating agents with
topical anesthetics to relieve the pain. For those patients who
have frequent recurrences or ulcers which take longer to heal, there
are treatments available to reduce or even stop the frequent recurrence
of ulcers, but their long-term use can cause unwanted side effects.”
Dr. Kerr recently completed a six-month study which
found that a topically-applied penicillin troche significantly reduced
healing time for minor RAU, which is generally defined as lesions
less than 10 millimeters in diameter that heal in approximately
a week to two weeks without scarring. On the fourth day of treatment,
43 percent of Dr. Kerr’s subjects who received penicillin
reported that their ulcers had healed completely, compared to 15
percent of those who received a placebo and 11 percent who got no
treatment. On the sixth day, 90 percent of people had completely
healed in the penicillin group, compared to 55 percent and 44 percent
in the placebo and no treatment groups, respectively. A total of
100 people participated in Dr. Kerr’s portion of the multicenter
study. If the penicillin troche proves successful in larger trials,
it may offer a new alternative in the struggle to relieve the pain
of aphthous ulcers. Yet the battle to conquer canker sores is far
from over. While research has established that factors such as allergies
and stress can cause an onset of the condition, the causes of many
canker sores remain unknown.
But for now, any significant relief is welcome news
for canker sore sufferers, who can find chewing and swallowing painful.
And Dr. Kerr points out that pain symptoms disappeared faster in
his penicillin-treated subjects than in those receiving a placebo
or no treatment at all.
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