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Dental researcher studies Mayan Indians (4/27/98)

When Vincent A. Segreto, DDS, professor and head of dental diagnostic science research at The University of Texas Health Science Center at San Antonio, was chief of dental research for the Air Force, one of his young officers went to Guatemala for three weeks to perform dental work on the Mayan Indians. During this project the dentist and his colleagues noticed that healthy bone surrounded the teeth of the Indians they were treating, even though their patients suffered from severe dental caries (tooth decay) and gingivitis (inflammation of the surrounding gums).

"This finding didn't fit with the theory, at that time, that bone loss is usually a result of gingivitis and a function of poor oral hygiene," says Dr. Segreto. "We deducted it must be diet that was responsible for the low prevalence of chronic destructive periodontal disease (inflammation of the tissue surrounding the teeth) among these Indians."

Later Dr. Segreto was recruited by Dr. Charlie Morris, then chairman of the department, to join the dental research division at the Health Science Center. "With the help of the dean and other executive officers at the Health Science Center, we again ventured into Guatemala to try to prove our theory," says Dr. Segreto. "Unfortunately, our second study didn't produce significant results, except to establish that phytate, found in the Indian's basic diet of corn, prevents the absorption of calcium to a high degree."

The researcher hopes eventually to return to Guatemala and re-investigate the Mayan civilization, now that more knowledge on nutrition is available.

Dr. Segreto has spent more than 20 years developing specialized methods and unique skills in conducting clinical trials at the Health Science Center. The division he heads is recognized as one of the premier sites in the country for managing and performing diverse clinical trails.

"Much work is still necessary to pinpoint the influence of environmental factors, including diet, on oral disease patterns," says Kenneth L. Kalkwarf, DDS, dean of the Dental School. "Dr. Segreto and his research team are a vital part of this continuing effort."

Stephen R. Matteson, DDS, professor and chairman of the department of dental diagnostic science, states, "Dr. Segreto's laboratory is a valued component of this department and has contributed significantly to clinical dental research. His work on dental fluorosis and the potential impact of diet on resistance of progression of gingivitis to periodontitis has been remarkable."

Dr. Segreto's first long-term research study after joining the Health Science Center was the Environmental Protection Agency's Fluoride Report, to determine the significant dental changes (mottled enamel) that occurred when people continually drank water containing fluorides.

"We also identified the level at which these changes occurred," says Dr. Segreto. "This study was conducted from 1979 through 1982.

"Our most difficult job in research is in finding subjects for these studies," he continues. "We spend hours and hours recruiting through radio ads, by phone and by placing flyers in universities, hospitals and businesses, after everything has been approved by the Institutional Review Board."

In addition to his research studies at the Health Science Center, Dr. Segreto and his colleagues have, to date, successfully completed nine sponsored research projects in Guatemala.

"These projects couldn't have been completed without our exceptional research team, including Drs. Ed McDaniel, John Pfeiffer and Bill Baker.

"In late 1985 or early 1986, Dr. Morris introduced me to Dr. Luis Archila, a young dentist who was also a Fulbright Scholar," Dr. Segreto continues. "Dr. Archila had done graduate training in radiology, so he is really classified as a dental radiologist. He was interested in learning how to plan and run dental clinical investigations, and joined our Central America research group. Dr. Archila now manages the dental research program in Guatemala.

"Our clinical studies there have resulted in an affiliation agreement between the Universidad de Mariano Galvez of Guatemala City and the Health Science Center," says Dr. Segreto, "which, in turn, has been instrumental in establishing a clinical research core in Guatemala that has provided a springboard for many diverse research projects."

Our affiliation has also offered additional instruction to Central American dentists in the areas of dental hygiene and general dentistry, and several health professionals have been trained in research procedures and grant funding, according to Dr. Segreto.

"Our ongoing work in Guatemala is important," says Dr. Segreto, "and I'm still hassling with the healthy bone and diseased gum problem down there. I hope to go back soon and try to solve it."

Contact: Jan Elkins (210) 567-2570