Dean, H. Trendley (Henry Trendley), 1893-1962

Biographical sketch: Dr. Henry Trendley Dean (1893-1962) was the first director of the National Institute of Dental Research and a pioneer investigator of fluorine in the prevention of tooth decay. In 1921, he entered the United States Public Health Service and was stationed in several U.S. Marine Hospitals until 1931 when he was placed in charge of dental research at the National Institute of Health. Detailed to the Army for temporary duty in 1945-1946, he studied the epidemiology of Vincent's infection (trench mouth) in the European Theatre of Operations (Germany). When the National Institute of Dental Research was established in June of 1948, Dr. Dean was appointed by the Surgeon General to be its first director. At the urging of Dr. Frederick McKay and others concerned with the brown-staining of teeth in certain regions of the country, Dr. Dean was asked to make this his first assignment at the Institute. With the help of his fellow investigators and the cooperation of dentists and other health workers in the field, it was established that fluorine in the drinking water was not only the cause of the mottled enamel (brown stain) but also at optimal levels prevented dental caries. The rest of Dean's professional life was spent in determining the level, safety, and efficacy of fluorine in drinking water. When he retired from the United States Public Health Service in 1953, he joined the American Dental Association as Secretary of its Council on Dental Research. In this role, he continued to advocate and defend the optimal level of fluorine in public drinking water.

Henry Trendley Dean (1893-1962), the first director of the National Institute of Dental Research and a pioneer investigator of fluorine in the prevention of tooth decay, was born in Winstanley Park, Illinois on August 25, 1893. He received his dental degree from St. Louis University in 1916 and entered private practice that year in Wood River, Illinois. During World War I, he served with the Army until 1919 when he returned to his practice in Wood River. In 1921, he entered the United States Public Health Service and was stationed in several U. S. Marine Hospitals until 1931 when he was placed in charge of dental research at the National Institute of Health. Detailed to the Army for temporary duty in 1945-1946, he studied the epidemiology of Vincent's infection (trench mouth) in the European Theatre of Operations (Germany). When the National Institute of Dental Research was established in June of 1948, Dr. Dean was appointed by the Surgeon General to be its first director.

At the urging of Dr. Frederick McKay and others concerned with the brown-staining of teeth in certain regions of the country, Dr. Dean was asked to make this his first assignment at the Institute. With the help of his fellow investigators and the cooperation of dentists and other health workers in the field, it was established that while fluorine in drinking water was the precipitated mottled enamel (brown staining of the teeth). However, at optimal levels fluorine also helped prevent dental caries (cavities). The rest of Dean's professional life was spent in determining the level, safety, and efficacy of fluorine in drinking water.

When he retired from the United States Public Health Service in 1953, he joined the American Dental Association as Secretary of its Council on Dental Research. In this role, he continued to advocate and defend the addition of fluorine to public drinking water. He was frequently called to speak on the subject in this country and abroad, to assist in the preparation of Congressional testimony, and to refute the arguments of those who opposed water fluoridation. His many awards and honors attest to the significance of his contribution to good oral hygiene.

Dr. Dean was married to Ruth Martha McEvoy on September 14, 1921, and they had three daughters; Ruth Celestine, Dorothea Virginia, and Mary Harriet. A long-time victim of asthma and emphysema, he died in 1962, three days after responding as a juror for the Albert Joachim International Prize for that year.