Repairing cleft palates — a common birth defect that
affects roughly one in 700-1,000 births — is a harrowing
experience for the kids afflicted. Not only are they subjected
to several operations; they often have to live with some
disfigurement. Experimenting on hounds, researchers at
the Mayo Clinic are trying an existing orthopedic technique
to close the gap in the split palate.
Current repair, normally done at
nine to 18 months, involves surgery to sew together
the mucosal flaps, without repairing the missing bone.
The surgery sometimes results in interference with subsequent
bone growth, which can in turn cause disfigurement,
poor contact between upper and lower teeth and speech
impairment.
The new method uses distraction
osteogenesis, a technique developed in Russia in the
1950s that applies mechanical force to lengthen soft
tissue and bone, via a device attached to the bone.
Today the method is widely used in orthopedics, "but
it has not yet been used for this," says Dr Bob Tibesar,
chief resident at the Mayo Clinic's Department of Otorhinolaryngology
and lead author of an article on the research that's
slated to run in an upcoming issue of the Archives
of Facial Plastic Surgery.
A
DOG'S LIFE
The procedure has been performed on eight adult hounds,
chosen for the similarity in thickness of bone and overlying
tissue to that in human mouths. A series of small metal
plates are screwed into the roof of the mouth, and a
key in the device is turned slightly every day for four
weeks, lengthening the bone slowly. After wearing the
device for 6-7 weeks, complete closure was achieved
in five of the hounds; two others had some closure.
"There's a lot of controversy still
about what age to repair," notes Dr Tibesar. "If done
later the children don't develop appropriate speech.
Much younger, the mouth is so small it's quite difficult,
and may restrict growth even more." The hounds involved
in the study are hardy, says Dr Tibesar, but he and
his team are concerned about how infants would tolerate
the device, especially for eating and drinking. They're
refining the apparatus to make it flatter and smaller.
So when will they be ready to try
it out on people? "We've begun the next phase of this
experiment," says Dr Tibesar, "and it's just a matter
of getting enough of us with time to spend in the lab
and work on these hounds and work towards progressing
to humans. It's in the order of at least one year."
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