School of Dental Medicine

Background on the Bolton-Brush Center

The Long View of Health

CWRU's landmark Bolton-Brush Study charted the growth of healthy kids. Decades Later, the original test subjects are coming back to campus to help researchers gain insight on aging. -- Judith Bailey

This is the earliest cephalometer, an instrument developed by Dr. Broadbent's father to position the head during X-rays.

Betty Cope best remembers the Rorschach tests. "I remember thinking that was such an interesting word," she recalls. "I used to love those, because they were fun and you could see all kinds of things in them--which my sister absolutely disagreed with. She thought they were ugly!"

Mrs. Cope, president and general manager of WVIZ, Cleveland's public television station, and her sister, the late Janet Copy Henry, were among more than 4,600 Cleveland-area youngsters who participated in two concurrent studies launched at Western Reserve university some six decades ago. Designed to chart the growth of normal, healthy children, these longitudinal studies measured the progress of the same youngsters year after year.

The annual head-to-toe analysis of each child included a physical exam, a series of X-rays, and a dental exam and impressions, plus a battery of psychological tests, including the Rorschach inkblot tests enjoyed by Ms. Cope. Sleep patterns, nutrition and other behaviors were tracked through a 588-item questionnaire filled out annually by the parents.

The research has entered a new phase that is expected to shed light on the aging process and what it may hold for the baby boom generation. A campaign to recall as many as 1,000 of the original 4,631 subjects, most of whom would now be in their sixties or older, got underway early this year. A major aim of the recall is to learn more about medical problems associated with aging, such as tooth loss, osteoporosis, sleep apnea and Alzheimer's disease.

The Bolton-Brush Study, as it is now known, began in 1928 as two closely aligned research projects in the School of Medicine. The Bolton Study focused on normal development of the facial skeleton and dentition, while the Brush Inquiry was designed to chart the physical and mental progression of the normal, healthy child. The two merged in 1970 and became the Bolton- Brush Growth Study Center in the School of Dentistry.

"The Bolton-Brush Study is probably the largest single longitudinal study that exists," observes Rolf Behrents (DENT '75), head of orthodontics at the University of Tennessee and a former head of the CWRU orthodontics department. "Speaking as an outsider now, I would say the collection is of immense importance, because in its totality, it will never be duplicated."

The Bolton-Brush Study claims a sample in which women outnumber men--2,428 to 2,203. Interestingly, the nearly nine-percent African-American participation in the study is comparable to the seven-to-ten-percent African-American segment of Cuyahoga County's population in 1940.

The current recall is expected to help the medical community predict how baby boomers, Americans born between 1945 and 1964 and who compose the largest population group in the country, will fare as they age. The recall is being conducted by B. Holly Broadbent, Jr. ADL 48, DEN 52), director of the Bolton-Brush Growth Study Center and one of the study's original participants, and Mark Hans (DEN 79 and 81), head of the CWRU orthodontics department and a research associate in the Bolton-Brush Center.

As the researchers explain, the two studies focused on a select group of healthy people with access to good health care, education and nutrition. As such, they effectively mirror today's middle class and its bulging ranks of baby boomers.

"Since many of the original participants are still living, the provides an opportunity to expand the original database and made the collection a cradle-to-grave study," says Dr. Hans. "Based on our detailed records on these people when they were young and as they grew older, we can look at what problems they have now and see if there were any indicators along the way."

A primary goal of the recall is to study the rate of tooth loss versus retention. Studies show that up to forty-two percent of Americans have lost all their teeth by age sixty-five; in a limited Bolton-Brush recall in 1978-1982, however, only two of 113 participants whose mean age was 55.3 had lost their teeth. If the current recall yields comparable findings, the ramifications for the baby boomers--and the dentists who will be caring for them--are enormous. When the baby boomers reach old age, they will still be the largest segment of our population, Dr. Hans points out. "What if instead of up to forty-two percent with no teeth, we have just three or four percent without teeth?" he asks. "That will mean a lot more teeth at risk in the older age group, which is totally different from what people now expect."

Osteoporosis also is slated for study. A debilitating disease that results in excessive bone fragility, osteoporosis primarily affects postmenopausal women. As Dr. Hans explains, "The research will look at whether there are predictive indicators regarding which women might be at risk for developing osteoporosis. For example, we can compare their X-rays now with those taken when they were young to see if there are any risk factors that could have been identified, such as thickness of bones." If such a correlation is discovered, it might even become a screening test for osteoporosis, he says.

How osteoporosis is related to diet is another question the recall may help answer. "Of great significance is that we have preemptive diet histories of these people when they are young," Peter Scoles, associate professor of orthopedics in the medical school, points out. "A fascinating concept would be to study the relationships of diet in early life to osteoporosis in the women today."

The correlation between diet and chronic disease also intrigues Margaret Cicirella (GRS 73, nutrition), a nutrition instructor in the medical school.

I'm interested in looking at the persistence of diet patterns and food preferences over time, and whether diet-related chronic conditions are found in the recall group," she says. Such research could shed new light on the correlation between fat intake and heart disease, for example, or sodium and hypertension.

The recall may help explain another problem of aging--snoring and obstructive sleep apnea, characterized by temporary interruptions in breathing during sleep. Though generally a problem of overweight, middle-aged men, sleep apnea also tends to affect women after menopause. "In the aging process of women, something is happening in the upper airway so that they tend to develop apnea in later life," says Professor of Medicine Kingman P. Strohl, who will conduct this research with Susan Redline, assistant professor of medicine.

A subject of ongoing interest to Dr. Broadbent is the long-term effects of the diagnostic radiation he and the other participants received over the years. The study's series of X-rays exposed subjects to more radiation that currently recommended. While some radiation is beneficial to living things, Dr. Broadbent says, the recall may help determine the threshold at which radiation becomes detrimental. So far, two limited studies of radiation amounts received by Bolton-Brush subjects have not turned up cause for alarm, and earlier recalls have not shown any related health problems among participants.

In the recall conducted in 1978-1982, Drs. Broadbent and Behrents recruited 113 participants for a study of change in the adult craniofacial skeleton. "These people were healthier than the normal population," Dr. Behrents recalls. "They were normal, well children, and as adults they were still well and normal."

Dr. Behrents was struck by how interested the subjects were in their childhood records--the drawings they had made, their family histories. Since many children were selected for the study through healthy-child contests in schools, it was considered an honor to be a participant, says Dr. Behrents, who is serving in the current recall as a consultant on craniofacial changes. "Judging from my talks with them, they still consider it quite an honor to be involved."

As straightforward as it sounds now, the original Brush Inquiry's aim--to study the growth of normal, healthy children--was, in fact, profoundly different from earlier research on human growth. Previously, such research had been based on skeletal remains and cadavers of those who had dies as a result of disease, neglect, birth defect, accident, or even suicide or murder. As such, they were far from representing the normal and healthy. So the Brush Inquiry was unique for its time and thus generated a fair amount of newspaper coverage at its inception. Also contributing to the study's news value was its funding source, the then brand-new Brush Foundation.

Ironically, the Brush Foundation and its study of normal growth came about as a result of an untimely death. Charles Francis Brush--the renowned inventor and scientist whose electric company eventually was consolidated to form General Electric--established the Brush Foundation in 1928 in memory of his only son and namesake, who had recently died of blood poisoning at age thirty-four.

Through his son, a physician, Mr. Brush had become concerned about possible dire consequences of the population explosion and was a proponent of the then-current eugenics movement, which sought to improve the human species and limit population growth. He established the $500,000 Brush Foundation to work toward these ends. The foundation's main goals were to further scientific research in eugenics and in the regulation of population growth and to educate people regarding the importance of these goals.

The goal of its first project, the Brush Inquiry, however, was simply to chart the physical and mental growth of healthy children. "We expect to establish a record of progress from birth to adulthood, punctuated by observations on the inception and maturation of those powers and qualifications which are of especial significance in the greater progress of our civilization," said the late T. Wingate Todd, first director of the foundation and the Brush Inquiry.

An Englishman, Dr. Todd had come to WRU in 1912 as the first Henry Wilson Payne Professor of Anatomy. He pursued his interest in anatomy, especially pediatric, through research involving thousands of cadavers. Based on this research, Dr. Todd was considered ideally suited to head the Brush Inquiry. After years of studying cadavers, which nearly always were the products of disease or deformity, here at last was his opportunity to study anatomy based on healthy children.

Also beginning in 1928 in the School of Medicine, the Bolton Study was an independent but coordinated study in conjunction with the Brush Inquiry. Funded by the late Frances Payne Bolton and her son, Charles Bingham Bolton, the Bolton Study focused on the normal development of the head, face and neck. The study was an outgrowth of the work of B. Holly Broadbent, Sr., (DEN 19), an orthodontist who had been doing research in the anatomy department under Dr. Todd; Dr. Broadbent, Sr., was named the study's director. The two studies were conducted cooperatively with most subjects participating in both.

Mrs. Bolton, for whom the CWRU nursing school is named, was keenly interested in health and nursing. "Her son was an orthodontic patient of my father's. When he was nineteen, he broke his neck in a swimming accident and became a paraplegic," Dr. Broadbent, Jr., explains. The accident left Charles Bolton without the use of his legs and limited use of his arms. Partly through the encouragement of Dr. Broadbent, Sr., he became interested in visiting the Bolton Study and doing work in animation photography.

"Part of his recovery and resuming interest in other things had to do with his participation here in the early years," say Dr. Broadbent, Jr. An outgrowth of Charles Bolton's work was the animated motion picture Normal Dentofacial Growth, which illustrated the dental and facial changes that occur from birth to young adulthood.

When Dr. Broadbent, Sr., became ill in 1967, his son took over as director of the Bolton Study. It seemed a natural transition. He had become a study participant as a toddler, and, except for a year in the Army paratroops, was close to it ever since.

Growing up, he never considered any career but dentistry. "I worked in my father's laboratory at a very early age," Dr. Broadbent recalls. "I did everything from waxing floors to making retainers--things that didn't require a lot of background knowledge, just the technical skills one could learn along the way." After graduating from the School of Dentistry in 1952, he began a preceptorship in orthodontics under his father and at the same time joined the Bolton Study as a researcher. Since 1956, a year after he completed his orthodontic preceptorship, he has been on the dental school faculty as well.

In 1930, two-year-old Holly Broadbent became a Bolton-Brush Study subject along with his sisters, Ann, Jane (FSM 46) and Frances. Over the years, the four chalked up more than 170 study visits, including about fifty-five for Dr. Broadbent. "What sticks in my mind most graphically was the restricting almost painful, aspect of the cephalometer," Dr. Broadbent says, recalling the instrument developed by his father to position the head during X-rays. "The most interesting aspects were the intelligence tests and the eye-hand coordination tests. And the Rorschach tests, too. We had fun with those."

Like the Broadbent youngsters, the subjects of the study were normal, healthy, "well-born" children who were referred by pediatricians or school groups or were winners of healthy-child contests in schools. "Life in Our Hands," a 1946 pamphlet about the Brush Foundation, touches on the "well-born" qualification. "Please note," it says, "that this was a study of the best normal children--not of the richest. Dr. Todd set up only two requirements: that the child be free of gross defects in make-up and behavior, and that the parents be sufficiently interested in the child to carry out the program faithfully through the years."

Throughout the 1930s, the study continually recruited additional participants, including babies, adolescents and some adults. Some of the adult subjects, in fact, were born as long ago as the late 1800s.

Testing included physical examinations and X-rays of the head--frontal and side views-- plus the hand-wrist, elbow, shoulder, chest, pelvis, knee and foot. Researchers also took dental impressions, assessed motor skills, and tracked diet, sleep patterns and other behavioral factors.

Early on, many of the mental-testing results had to be discarded, as researchers found that standards then in use did not apply to healthy kids. A prime example is the Rorschach test, in which the subject tells what is suggested to him or her by a standard series of inkblot designs. The test was originally based on the responses of adults with psychiatric problems. The futility of applying this scoring to normal children soon became obvious to Brush Inquiry researchers, who subsequently spent over five years revising the Rorschach.

Some subjects returned for retesting every three months, until age one, every six months to age five and then every year--usually on their birthdays--through adolescence. Of the 4,631 subjects, just under half were tested once, and the rest tallied two or more visits, including the fifteen percent or so who returned for ten or more visits. Examples of the latter are CWRU Board of Trustees Chairman Allen Ford and his brothers David and Amasa. Today associate dean for geriatric medicine and professor of epidemiology and biostatistics in the School of Medicine, Amasa Ford serves as a consultant in the current recall.

"I think we were in the we were in the study because of my mother's interest in health issues," Allen Ford recalls, noting that there is now a professorship in her name (Elizabeth Brooks Ford) in the nursing school. "Once a year, near our birthdays, we were scheduled to visit the foundation. My mother would drive us down to the medical school. I would be taken out for a hamburger or something afterwards, so going to the Brush Foundation was a very distinct event every year."

Testing for the Brush Inquiry ended in 1942, while the Bolton Study continued recruiting new subjects until 1959. The two collections were officially merged in 1970, but each has retained its autonomy. Over the thirty years of active research, a vast pool of information had been collected, including 22,000 physical examination reports, 90,000 mental and psychological reports, and well over 50,000 X-rays of the head and neck, plus many others of the major bones of the body.

Until now, research involving the collection has been done manually with the actual X-rays and dossiers--up to four inches thick--on each participant. A computerization project, partially funded by an IBM grant and the American Association of Orthodontists, is now underway to protect the collection while making it more convenient to researchers.

So far, fourteen elements of basic information about each participant--such as sex, race, birthdate and orthodontic treatment--have been entered into the computer. Also thirty of the X-ray images have been computerized (or "scanned") in a pilot project to demonstrate two ideas: that the scanned image is as useful to researchers as the original, and that the text information about each participant can be linked to the computerized image.

"We want to be able to search through the database to find, for example, all the ten-year- olds that had a particular X-ray at ten and again at twelve," Dr. Hans says. "Then we want to be able to show these X-rays on the computer screen."

Work is also underway to develop a system that will allow researchers to measure images on the computer screen, plus take computerized notes on their findings. "Right now, we're working all this out with the thirty scanned X-rays," Dr. Hans says. "When it works for them it will work for three hundred or three thousand." The Bolton-Brush center is searching for funding to scan all the X-rays in the collection--a total of 300,000 to 400,000.

Tough computerization will take years to complete, eventually it will make the collection even more valuable to researchers. Yet even in its present state, the collection is an international resource, attracting one or two outside researchers each month.

The collection is also used by CWRU researchers, such as Dr. Scoles of the medical school. Initially, he used it to establish maturation standards for the radiographic appears of the hip joint in children. "These provide guidelines radiographically for what is normal and not normal in healthy children," he explains.

His latest project is a longitudinal study of the development of the cervical spine (neck) from the birth through age twenty-two. Based on measurements of the X-rays of fifty normal boys and fifty normal girls from birth through maturation, this study will produce "the definitive reference standard for the morphology of the cervical spine," predicts Dr. Scoles, who is planning further research based on the recall. "There is no other available standard for children under the age of three," he explains, and existing standards for older children are based on different children at each age, not a longitudinal study such as the Bolton-Brush.

The early years of the Bolton Study and the Brush Inquiry generated significant achievements as well. In the Brush Inquiry, for instance, the method of charting a woman's body temperature to predict ovulation was developed in the 1940s under Dr. Todd's successor, William W. Gruelich.

B. Holly Broadbent, Sr., developed a special X-ray technique that, with modifications, is still in use internationally. To assure accurate measurements of head growth, Dr. Broadbent adapted a device--ordinarily used by anthropologist to hold dry skulls in a fixed position--to hold dry skulls in a fixed position--to hold the head of a living subject while X-rays were taken. The Broadbent-Bolton Roentgenographic Cephalometer, as it is called, made it possible to create precise, comparable X-rays of a child's growing face and head at intervals to adulthood.

A related achievement was the 1975 publication of the Bolton Standards of Dentofacial Developmental Growth , a book written by Dr. Broadbent, Jr., using the collection of records amassed by his father. The Bolton Standards are a series of averages that represent optimum facial and dental developmental growth. As a clinical yardstick or as a baseline for comparative research, the Bolton Standards are considered an invaluable tool for understanding and assessing the growth of the craniofacial complex.

Over the years, researchers involved in the Brush Inquiry--including the late S. Idell Pyle (GRS 50, anatomy) a research fellow in the anatomy department who spent most of her career working with the Brush records--have produced numerous skeletal atlases and thousands of related articles and publications.

A decade ago, the 1979-1982 recall yielded surprising new knowledge regarding human growth, including the observation that the face and skull continue to grow and change, albeit modestly, throughout life. The researchers also learned that women go through a little growth spurt during pregnancy due to hormonal changes, says Dr. Behrents. Though this growth was evidenced in measurements of the head an jaw bones, he adds, it validates the common observation of women that, at the other end of the skeleton, their feet grow a half size or so during pregnancy. Since that recall, researchers have maintained contact with about 200 participants, who will be invited to take part in the new recall. IN all, researchers hope to track down about 1,000 subjects who had at least two previous visits.

The recall began after Christmas with a mailing to the last known address of each of the 444,631 participants. For those who didn't reply, national death records are being accessed to try to determine those who have died and their cause of death. After this step, volunteers or a search firm may be used to pare down the list of those still unlocated.

All recall subjects will be sent a preliminary questionnaire on their health history. As questionnaires are returned, the subjects will be invited to the Bolton-Brush center for retesting at the rate of about ten subjects a week for a total of 1,000 over two years.

Testing visits will include X-rays of the head and hand-wrist, physical and dental exams, dental impressions, and complete medical histories--via interviews-to obtain information relevant to the planned research. The physical exam will include items such as blood pressure, temperature, pulse rate and lung function. Researchers may conduct in-home testing for those unable to come to CWRU. Planned research will proceed as soon as adequate numbers of suitable recall subjects are identified.

The Bolton-Brush Growth Study Center has been supported almost entirely by Dr. Broadbent and other individuals and by the Department of Orthodontics in recent years. Outside funding is now being sought to help fiance the recall and allow for the hiring of additional staff to conduct the retesting.

Like Betty Cope and Holly Broadbent, many of the original participants still live in Cleveland and have become prominent in a variety of professions. Among them is Alva T. )Ted) Bonda, businessman, former president of the Cleveland Indians and the Cleveland School Board, and former chairman of the Ohio Board of Regents. As a seventh-grader at Cleveland's Patrick Henry Junior High School, he was invited by school officials to take part in the study.

In those days, Mr. Bonda recalled, people mostly stayed within their own neighborhoods-- in his case, around East 105th Street and Superior Avenue. "We didn't know what the world was like beyond the neighborhoods," he says. "There was no television, and my family didn't even have a radio. Just by chance I was chosen to participate in the study, and I went over to Western Reserve. I was from a poor family--totally unsophisticated and naive. Western Reserve showed me that there was another world. Just my being over there--this was one of the factors in my life that made my life different." CWRU

Judith Bailey is a media relations representative in CWRU's Office of University Communication.

Anyone who participated in either study or knows the whereabouts of someone who did may call Lyda Mumaw, curator at the Bolton-Brush Growth Study Center, at 216-368-6715.

(Reprinted from CWRU The Magazine of Case Western Reserve University Vol. 4, No. 2, pp 26-31, Feb. 1992, with permission from Roberta Hubbard, Editor.)

A Chronological Account of the Bolton-Brush Growth Studies – In Search of Truth for the Greater Good of Man
Rolf G. Behrents, D.D.S., Ph.D. and B. Holly Broadbent, Jr. D.D.S. Copyright (c) 1984, All rights reserved.