Global Health Nexus, Spring 1999

Examining the Genetic Roots of Tooth Development

Building on her discovery of a gene that accounts for the abnormal development of teeth, Dr. Heleni Vastardis is continuing her quest to determine how permanent teeth develop.

Dr. Vastardis, an assistant professor of basic sciences and growth and developmental sciences, has identified the gene MSXI that is responsible for partial anodontia -- the condition of developing fewer than the normal number of adult teeth. Her research indicated that MSXI affects selectively the second premolars and wisdom teeth. "I'm trying to find more genes causing the condition," said Dr. Vastardis, who discovered the gene in 1996. She hypothesizes that many genes are responsible for the disorder, but finding them is difficult.

She likens her job of finding genes to the tedious task of searching for one misspelled word among volumes of books. To find the word one must search each book page by page. The first gene took her four years to find, and the next one could take even longer. Yet she never doubts the importance of her quest.

"With this knowledge we will eventually be able to replace the mutant gene with a correct one," said Dr. Vastardis. That procedure, however, depends on future advances in genetic research.

In the short-term, knowledge of the mutant genes will enable dentists to advise parents on the best treatment for their children. For adults whose permanent teeth have already grown in, little can be done. But for children, advance warning of the abnormality can make a profound difference.

"Tooth agenesis may be a marker for a more pronounced anomaly," said Dr. Vastardis. "Research in mice showed that lack of the same gene can affect other areas of the face. In addition to missing teeth, these mice displayed a cleft palate and a distortion of the face and ear."

Since treatment for the disorder sometimes involves extensive therapeutic intervention (e.g., orthodontics, implants, and oral and maxillofacial surgery), parents who know that their children eventually will need a corrective procedure can make plans early to provide the care.

Dr. Vastardis' findings have been published in Nature Genetics and Molecular and Cellular Biology. She is a recipient of the 1999 Basil O'Connor Starter Scholar Award from the March of Dimes Foundation, the Biomedical Research Award from the American Association of Orthodontists Foundation, and the National Hellenic Scholarship Foundation Award.

Dr. Vastardis was born in Piraeus, Greece. She attended the University of Athens School of Dentistry. In 1992, she left Greece to attend Harvard University, where she earned both a Doctor of Medical Sciences degree in oral biology from the Harvard Medical School and a Certificate in Orthodontics from the Harvard School of Dental Medicine. Following postdoctoral training in oral biology at the Harvard Medical School from 1996 to 1997, she joined the NYU dental faculty. She is also a visiting lecturer at the Harvard School of Dental Medicine.