[tt] Los Angeles Times: X-rays could tell Chinese Olympic gymnasts' ages, scientists say

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X-rays could tell Chinese Olympic gymnasts' ages, scientists say
http://www.latimes.com/news/science/la-sci-gymnasts23-2008aug23,0,6797635,print.story
[Thanks to Sarah for this.]

Is He Kexin 16 or 14? Doctors and forensics experts say bone growth
could reveal how old the Olympic medalists really are.
By Karen Kaplan and Alan Zarembo
Los Angeles Times Staff Writers

August 23, 2008

How do you tell the age of a Chinese gymnast?
Don't bother with those government-issued passports or birth
certificates.
Go for the X-rays.
For all the global hand-wringing over how international gymnastics
officials will ever figure out whether three members of the Chinese
women's team were old enough to compete, doctors and forensics
experts said it's actually not too difficult.
The science of determining age is has been honed by decades of
treating patients with growth disorders, identifying youthful
homicide victims and determining the deportation status of illegal
immigrants.
"It would be relatively easy," said Dr. David Senn, a forensic
odontologist at the University of Texas Health Sciences Center who
has analyzed numerous X-rays of immigrants apprehended at the
border.
The science is based on measuring the growth of bones and teeth as
children mature. Decades of data have been distilled into detailed
tables recording the precise size and shape of skeletal components
broken down by age, sex and race.
The task is so straightforward that Dr. Peter Hampl, president of
the American Board of Forensic Odontology, said the Chinese
government should just consent to X-rays and let the films speak for
themselves.
"If there is nothing to be afraid of, let their kids be X-rayed," he
said. "It's almost incriminating if they don't."
It may seem strange that amid the outsized pageantry of the Beijing
Games, the biggest controversy has surrounded three tiny Chinese
gymnasts whose combined weight is 216 pounds.
The ages of He Kexin, Yang Yilin and Jiang Yuyuan came into question
weeks ago after the discovery of online registration records listing
birth dates that would make all three girls 14 years old. Olympic
rules require that a gymnast be at least 16 during the year the
Games are held. The government attempted to put the issue to rest by
producing passports that declared the girls met the age requirement.
The controversy reached Olympian proportions after the Chinese team
beat the American gymnasts in the team competition. In addition to
the team gold, He edged American Nastia Liukin for the top prize in
uneven bars by a tiebreaker, and Yang won the bronze medal in that
event and in the all-around competition.
After new complaints surfaced, the International Olympic Committee
announced Friday that it was asking the International Gymnastics
Federation to reexamine the Chinese gymnasts' age.
Instead of searching through documents, the matter could be settled
with X-rays, said Dr. Gil Brogdon, a professor emeritus of radiology
at the University of South Alabama in Mobile and author of the
textbook "Forensic Radiology."
Bones fuse together according to a well-documented schedule. For
girls between the ages of 13 and 17, the best places to look are the
knee, wrist, elbow and iliac crest on the pelvis, he said. The
younger they are, the more obvious the evidence.
"A Caucasian girl is going to fuse her knee centers at about age 15;
they're going to fuse their iliac crest at about age 16; and part of
the elbow will start fusing around 13 or 14," he said. "That's the
way you do it."
For the Chinese gymnasts, investigators would have to consult growth
tables for Asian girls, Brogdon said.
One complication with teenage girls is that strenuous exercise can
suppress estrogen production, delaying bone development and making
them appear to belong to a younger person, said Dr. Vicente Gilsanz,
a professor of radiology and pediatrics at USC.
But Brogdon said that by comparing multiple bones, "you could come
pretty close" to distinguishing a 14-year-old from a 16-year-old.
Teeth are also useful. U.S. immigration authorities often rely on
dental X-rays to determine for deportation purposes whether an
illegal immigrant is an adult or a minor.
"Of course, everybody who gets arrested says they are 17," Senn
said.
He said he can pinpoint ages within 18 months using images of a
person's wisdom teeth, which start forming around age 9 and are not
fully developed until around 19. For the Chinese gymnasts, Senn
said, he would also look at their second molars, which grow until
age 15 or so.
Dr. Michael Baden, chief forensic pathologist for the New York State
Police, said that with both teeth and skeletal X-rays, "you should
be able to get within 12 months" of someone's age.
All this science probably won't mean much because Chinese
authorities are not likely to agree to let independent doctors take
X-rays of their gymnasts.
In that case, sports fans will be left to contemplate the girls'
physical appearance.
"I must say, they do look kind of young," Baden said.

karen.kaplan at latimes.com
alan.zarembo at latimes.com

Times staff writers Mary Engel and John Johnson Jr. contributed to
this report.