Researchers at Case Western Reserve University's School of Dental Medicine want to answer the question by locating the more than 4,000 youngsters from Cleveland, who had head-to-toe x-rays of their bodies as children and were participants in the Bolton-Brush Growth Studies on normal healthy development.
Now adults between the ages of 70-85, the subjects at an early age annually underwent a group of x-rays and physical and mental tests from 1920-1950.
The Bolton-Brush Growth Studies have become one of the world's longest-running studies on what it means to develop normally and to be a healthy child and now adult. The investigation into health combines two longitudinal studies--the Brush Inquiry, that explored the physical and mental health progress of the children, and the Bolton Study that focused on the normal development of the cranial-facial skeleton and dentition (teeth). The studies began at then Western Reserve University (now Case School of Medicine) during the 1920s and moved to the Case School of Dental Medicine in the 1970s.
Information and voluminous records gathered have provided important insights and research data about head development that has aided orthodontists and maxillofacial surgeons in correcting skeletal problems in facial formation, according to Dr. B. Holly Broadbent Jr., a researcher in the study begun by his father Dr. B. Holly Broadbent Sr. and Dr. T. Wingate Todd.
Along with his three sisters, Broadbent Jr., the 76-year-old director of the Bolton-Brush Growth Study Center at the Case dental school, is among the subjects who participated in the study and is leading the search to find others for the follow-up research.
Broadbent particularly would like to find the project's women, who participated in the project and tend to be more difficult to locate because of name changes with marriage and moving away from the Cleveland area.
"It's remarkable that the majority of the people, whom we have found over the years, continue to be in very good health," said Broadbent, who is also interested in the long-term impact of radiation upon their health.
Each child in the studies had as many as 13 radiographs (x-rays) annually of different parts of their bodies to study bone growth. At the time, parents authorized the studies' investigators to administer the annual tests for their children. The parents and teachers answered some 588 questions about the child's nutrition, sleep habits and exercise. Coupled with psychological tests, it gave the studies' investigators an opportunity to understand what it means to be healthy and to develop normally.
Broadbent said he believes the radiation given at the time (approximately six times the amount required for each picture today) has had a beneficial effect upon the individual's health. This is the hormitic effect which considers the stimulatory result of the low-dose radiation, stated Broadbent.
While humans live in an environment filled with radiation from the sun and cosmos and emitted from the earth, Broadbent stated that the extra radiation children received may be within the hormitic range that promotes positive growth without harm to the individuals. As part of the study he and fellow researchers are also examining that impact over time.
"We want to look at these adults throughout their entire life span," said Broadbent.
Broadbent is the son of Dr. B. Holly Broadbent Sr., the original principal investigator on the Bolton Growth Study. Dr. T. Wingate Todd headed the Brush Inquiry. Both doctors recruited "healthy" children primarily from the Cleveland schools and medical offices, who were identified by their teachers and physicians as healthy normally developing children.
Some of the Bolton-Brush participants are among the 125 children who entered the study while they were in their mothers' wombs and had their development chronicled through x-rays and then were followed after their births throughout childhood and later in recall studies in the 1980s and 1990s.
While it may seem that we stop growing, Broadbent said that the body continues to grow and change over time, such as women develop more bone mass during pregnancy or that cranial-facial features change over time. Findings from the study have produced important information on bone development for orthodontists and oral surgeons, who need an understanding of how the cranial-facial bones develop to assist in correcting overbites, under bites or other facial development problems.
To contact the Bolton-Brush Growth Study for the follow-up survey, call 216-368-6715 or bhb@case.edu.