The USPHS initiates dental research

Dentistry and dental research were of minor importance to the U. S. government until after World War I. In March 1919, passage of the War Risk Insurance law assigned the U.S. Public Health Service the responsibility for medical and dental services for war veterans. The Service thus was forced to conduct a hasty recruitment of dentists, particularly specialists to treat injuries to jaws and teeth, and to form dental dispensaries in all its hospitals (1).  One of the dental officers who entered the Public Health Service in 1919 was Clinton Thaddeus Messner, DDS, who took his first assignment in St. Louis, Missouri. Two years later, he was transferred to the USPHS headquarters in Washington, D.C., to become chief of the dental section (2). 

Dental Caries Epidemiology

Around that time there was an increased interest in the physical fitness of school children, which may "be referred to the agitation in favor of health which followed the World War and the publication of the results of physical examinations of drafted men, and part of it is associated with the general development of public health work and the emphasis placed on preventive medical work" (3) probably connected with the sequels of the "industrial revolution". The examination, between October 1919  and April 1920, of 7,059 children in 43 communities of West Virginia revealed 16,151 decayed teeth and 1,822 missing six-year molars, a result which the Surgeon general called "a condition of 'dental neglect' which can be observed in many other average American communities" (4). However, members of a dental unit of the USPHS argued that the problem of finding the real prevalence of carious teeth among children was rather complicated because of (a) the presence of both temporary and permanent teeth with markedly different tendencies to decay, and (b) the fact that a few years difference in the age of a child makes considerable difference not only in the extent to which the teeth decay, but even in the number of teeth that are found in the mouth. With this in mind, they examined over 12,000 white school children from 5 to 19 years of age in Missouri, Illinois, Georgia as well as in Hagerstown, Maryland, during three school years from the fall of 1922 to the summer of 1925. Verna Thornhill Meaker, a dental hygienist with the unit, made most of the examinations. Associated with her were at first Dr. H. B. Butler, a dentist who made some of the earlier examinations, and later Mrs. Mary Knight, a dental hygienist who examined some of the children in Georgia. The data were evaluated by Amanda Stoughton and Selwyn D. Collins, statisticians with the USPHS, and reported, in 1931, as decayed, missing or filled teeth as well as very badly decayed teeth designated as "remaining roots" (5,6).

A research project at the Hygienic Laboratory

What is of interest here, is not primarily the result of these early examinations, but rather the strange situation: the statistical division of the USPHS carried out dental research with the support of dental auxiliary personnnel with diagnostic skills, while the dentists within the USPHS found themselves  confined to dental treatments as they did not show much interest in research work despite their academic education. Yet research is regarded to be the motor of an academic profession.  For this reason the American Dental Association undertook every efforts to get a central research institution installed. Hence, a dental caries research project within the USPHS was proposed by ADA member Clinton T. Messner and approved in 1928. A one-person dental research unit was created at the Hygienic Laboratory (which would become the National Institute of Health (NIH), in 1930, and would later change to multiple Institutes). "The chemical composition of dental enamel in normal and pathological conditions" was choosen as the subject of this investigation. A Dr. Cornwall was envisaged to do the work, but by April 1930 the project had not been undertaken seriously (7).

In 1929, the year when Messner was appointed to the Research Commission of the American Dental Association (ADA) (8), Henry Trendley Dean, DDS, presented at the annual meeting of the ADA a scholarly prepared paper analyzing fifty cases of fractures of the mandible (9). Between June 1929 and March 1930, there was also an investigation on the "Health aspects of radium dial painting" (including dental conditions), in which Dean was involved, and which was carried out  under the general direction of Assistant Surgeon General Lewis R. Thompson, who was then in charge of the Office of Industrial Hygiene and Sanitation (9a).

Having thus shown his research abilities, Dean was finally assigned to the position vacant at the NIH. When the presence of fluoride in water supplies was discovered as the cause of the endemic disfiguring dystrophy called "mottled teeth" (or "mottled enamel"), Dean´s preliminary task was a survey of mottled enamel in the United States, and its relation to the concentration of fluoride in water samples to be analyzed by one of the Service´s chemists, Dr. Elias Elvove (10,11). In April 1931 he told McKay about his assignment (12), but to begin this study he had to wait until late in September, when Messner would have recovered from his first coronary thrombosis (10,11). While Dean was waiting for Messner´s recovery, he started reviewing the literature on the subject available at the University of California, where he was stationed.

McKay was apparently not enthusiastic at first, as he commented in a letter to Frank James McClure: "The U. S. Public Health Service is interested in this subject to a limited extent and I doubt owing to the prevailing situation, that they are very actively engaged on this problem. I think they have a man in the field who is connected with the dental department possibly principally as an observer" (13).

Consultants in Dental Research

Dean was not alone in his task. Five dentists were appointed as consultants in dental research in 1931 by Surgeon General Cumming to function with the Service (13a). This board, consisting of Drs. Homer C. Brown, Weston A. Price, Thomas Hartzell, Russell W. Bunting, and Thomas J. Hill, met on January 2, 1932, for a first conference. According to Dean's report of January 6 to the surgeon general, they were "of the opinion that the major problem in dental research is that of dental caries. The mottled enamel study however should be continued. It was the consensus of the opinion that the Public Health Service should detail a dental officer qualified for this work to those institutions where some of the major researches on dental caries are at present being carried on. These institutions are the University of Michigan, Iowa University, Columbia University, the University of Chicago, Dental Research Laboratories of Cleveland (Dr. Weston A. Price), and others. This officer should work with these investigators and go over their work thoroughly, after which a meeting should be called of this group of dental research workers, the work reviewed, and one of the plans, or a modification thereof selected, for investigation by this Service. This it was thought would help in clearing up the chaotic conditions which exist at the present time because of the many and varied theories advanced by men held in high repute by the dental profession" (10). Thus, Dean was soon on tour visiting the dental research laboratories and sent his reports on the caries research work being done there to the Surgeon General.

After the death of W. D. Miller, Professor Russell Welford Bunting (later assisted by Philip Jay) had performed considerable research work at the University of Michigan on the role of sugar and certain Lactobacilli in dental caries. Bunting was a favorite of Dean´s, the two "became warm and mutually inspiring friends" (14). Furthermore, Bunting was one of the coauthors of the 1925 paper by McCollum et al. on the bad effects of fluoride on the teeth of rats (15). "To his chagrin", however, Bunting had not then seen the relationship of the effects observed in rat teeth to mottled teeth as they occurred in humans (16). But the McCollum et al. paper also contained many references to earlier European work done on the fluoride - caries relationship which prompted McCollum's experiment, i. e. to see whether fluoride in food would do any good to the teeth of rats. Now that fluoride had become known as the cause of mottled teeth, Bunting remembered the early work cited in the McCollum paper. His change of mind becomes obvious in his descriptions of the Minonk examinations: In 1928, he and a group of dentists had examined children of Minonk, Illinois, a community afflicted with mottled teeth. The published original report said: "In regard to the prevalence of dental caries among these children the percentage of those affected was about the same as would be found in any other community, but although caries occurred in the mouths of most children, its extent and activity were remarkably limited. The great majority of cases consisted of small pit and fissure lesions in the molars and seldom did caries extend beyond that stage" (18). Now, with the possible role of fluoride in mind the picture suddenly became a bit different: "The caries rate seemed much less than had been observed in children of other communities. There were fewer cavities, and those that did occur were small, slow-growing lesions quite similar to caries in older persons who chew tobacco" (19).

A visit to Minonk, Illinois

On February 5, 1932, during one of his visits to McCollums Laboratory at Johns Hopkins University, Baltimore, Bunting invited Dean for a trip to Minonk, Illinois, to show him the special features of dental caries observed in that community where mottled enamel did occur to some extent (17). Under the impression of this invitation, and before he had seen any of the children there, Dean wrote in his report of February 6, 1932, to the Surgeon General: "Mottled enamel bears an important relationship to dental caries. Although these teeth erupt showing the most defective calcification known histologically, nevertheless these same individuals in an endemic area show a lower incidence of caries than individuals in some near-by non-endemic area. Consequently, the study of mottled enamel may disclose some lead applicable to the vastly more important problem, dental caries" (10). 

At the time of Dean´s visit to Minonk, on February 18, 1932, not much time was left for detailed examinations, as Dean wrote in his report to the Surgeon General: "Thirty-nine children were examined and fifty-three per cent showed mottled enamel. There was a widespread interest in mottled enamel in Minonk and the small number examined was due to the frequent interruptions by interested physicians, dentists, parents, citizens, etc., upon whom much time was spent explaining the various types and answering questions. On the night of the 18th, the local medical and dental societies had a joint dinner to which was invited members from the surrounding medical and dental societies. Delegations came from Peoria and Bloomington. There were 81 physicians and dentists present. I spoke for about an hour on mottled enamel and was followed by Dr. Bunting who spoke on diet and its relation to dental caries, and Dr. Jay on some of the newer work in bacteriology of dental caries" (20).

But there was another important impression which Dean took home fom Minonk: "Following the Minonk examination, a new phase of this question seems ripe for further study. Is mottled enamel merely an oral manifestation of a general toxicity, or something similar? The hair of some of these mottled enamel cases is unusually coarse, almost like horse hair. Finger nails are apparently not normal. Two of the three local physicians state that there is apparently an unusually large amount of skin disorders among those using the city water supply. Future surveys will attempt to obtain this additional dermatological data in order to determine whether it correlates with the mottled enamel" (20). Apart from this he would take notes on the caries prevalence from then on.

Waiting for questionnaires to be returned from district dental societies reporting on the occurrence of mottled enamel in their localities, interrupted by trips to communities in fluorspar and rock phosphate strata, and several personal visits to mottled enamel areas, enough time was left to Dean for a major public relations stroke useful to his profession.

Report on the costs of medical care

The sequels of the world economic crisis, which started in 1929, were increasingly felt. "With the depression, which threw upwards of ten million wage earners out of work, dentistry was confronted with a populace that desired dental service but did not have the wherewithal to pay for it. This situation generated a new facet in the profession designated socio-economics, the study of how best to provide dental service to the mass of people who could not finance such service for themselves. Even before the depression struck, federal government agencies had begun to give thought to the status of the nation´s health, after the bad experience with draftees during World War I. As early as May 1927 a committee, known as the Cost of Medical Care Committee, was organized to study the costs to the people of all aspects of disease and health care", with Ray Lyman Wilbur, M.D., as its chairman (21).  Thus, there were all the ingredients of impending change ready to hand: large groups of job-less or low-paid dissatisfied workers unable to afford medical and dental care turning to political action for relief. Industrial leaders and governments were interested simply because these workers would make up the bulk of the army in case of war. Social workers and lay leaders urged compulsory sickness insurance, which met the disapproval of the health professions. What to do? The final report of the Committee on the Cost of Medical Care caused quite a stir when it proposed in a "fatuous footnote": "We commend the growing tendency in the practice of dentistry toward a division of labor in which a dentist who is also a physician assumes larger responsibilities for the diagnosis and treatment of conditions arising from or related to the teeth, while much of the routine performed by the dentist in the past is delegated to dental hygienists and other technicians working under his direction" (22,23).

In one of the responses to this proposal, William John Gies rejected (with arguments comprising 45 pages of his jounal) this "master - servant" plan, wherein a "master" (physician-dentist = stomatologist) would supervise "uneducated" servants while the profession of dentistry would be discontinued (24). One of his arguments against such plans was the "scientific" progress of dentistry, with special emphasis on the mottled enamel research. "No physician participated in this useful discovery. After important preparatory clinical and scientific work by dentists, the facts were ascertained under industrial and agricultural auspices. ... The prevention of mottled enamel, while primarily within the scope of scientific dentistry, has become largely a matter of water-works engineering and public sanitation under the guidance of the dental profession" (24). His additional remark that "this is one of the many instances that emphasize the importance of dental membership in health boards" was taken up by the American Dental Association at its annual convention, September 1932, in Buffalo.

A survey of dental activities in state boards of health

At the Buffalo meeting a resolution was passed to appoint a Committee for Dental Health Survey, supposedly to make an actual survey of dental health activities throughout the country as well as of the needs for dental health work in the interest of the public (25). According to a report by the Reference Committee of the ADA the actual intentions were the future check-mating or offsetting of potential menacing threats which confront the profession of dentistry, i.e. "... to make a thorough survey of all dental activities in state, county and municipal health organizations; and to recommend a policy ... in order that organized dentistry may be prepared, if and when the time ever comes that we are confronted with state, panel or insurance dentistry ... that dentistry may be efficiently represented in state, municipal and county health organizations" (26). "Realizing that the results of such a survey would more firmly establish dentistry in public health activities throughout the nation, the Surgeon General gave his approval and agreed to authorize experienced dental officers of the U. S. Public Health Service to make the survey, working in cooperation with a committee of the American Dental Association of which C. T. Messner, D.D.S., Washington, D.C., has been appointed chairman" (26). Furthermore, the Surgeon General agreed to designate an officer of the Public Health Service to work with the ADA in developing a nation-wide educational campaign (27). After several meetings of the committee members, among them Clinton T. Messner and Trendley Dean, some of the results were published, in part with the financial support from the Rockefeller Foundation, in two Public Health Bulletins: No. 226 (1936), "Dental Survey of school children, ages 6-14 years, made in 1933-34 in 26 states", (eds.: C. T. Messner, W. M. Gafafer, F. C. Cady, H. T. Dean), which soon became of major importance for Dean´s first fluoride - dental caries studies, and No. 227 (1936), "A survey of dental activities of state departments and institutions of the United States" (eds.: F.C. Cady, H. T. Dean, C. T. Messner), which served as a basis to expand dental activities in the state boards of health.

Clinton T. Messner died on May 28, 1936, two days after submission of the report on the nation-wide survey of children, from a second coronary thrombosis (28). Trendley Dean and Frank C. Cady continued to push for more institute dental projects. In 1937 the Roosevelt administration reorganized the Institute and gave additional autonomy to dental studies. Dean´s Dental Hygiene Unit moved to a new Division of Infectious Diseases, while Frank Cady, as consultant to the state dental directors, headed a new Dental Public Health Section within the Division of Domestic Quarantine (29).

References:

(1) R. R. Harris: "Dental Science in a new age. A history of the National Institute of Dental Research", Bethesda, Md., 1992, p.35; (2) R. R. Harris, Ref. 1, p.51; (3) Wilson C. et al, "A study of illness among grade school children", Public Health Rep. 46 (1931) 1801; (4) R. R. Harris,  Ref. 1, p.35; (5) Stoughton AL, Meaker VT: "Dental decay and corrections among school children of different ages", Publ. Health Rep. 46 (Oct. 30, 1931) 2608; id.: "Sex differences in the prevalence of dental caries", Publ. Health Rep. 47 (Jan. 1, 1932) 26; (6) Collins SD: "The health of the school child", Public Health Bulletin No. 200 (Aug. 1931); (7) Memorandum Dr. George Walter McCoy to Prof.  C. S. Hudson, Division of Chemistry, April 11, 1930, in the H.T. Dean papers, Natl. Library of Medicine, History of Medicine Division; (8) ADA transactions, Oct 8, 1929  ; (9) R. R. Harris, Ref. 1, p. 51; (9a) Schwartz L., Knowles F.L., Britten R.H., Thompson R.L. (et al.): "Health aspects of radium dial painting", parts I to IV, J. Ind. Hyg. 15 (1933) pp. 362-82, 433-55;  (10) Dean H. T. to Surgeon General, re: Report of progress of dental studies during the past calendar year, Feb. 6, 1932, in the H. T. Dean papers; (11) McNeil DR: "The fight for fluoridation", Oxford University Press, New York, 1957, p. 35; (12) H. T. Dean to F. S. McKay, June 30, 1931, in the H. T. Dean papers; (13) F. S. McKay to F. J. McClure, May 9, 1932, in the Ruth Roy Harris papers, Natl. Library of Medicine, History of Medicine Division; (13a) Brown HC: Historical review of the research activities of organized dentistry", J. Am. Dent. Assoc. 22 (July 1935) 1172; (14) Jay P.: "In memoriam: Russell W. Bunting. President of the IADR, 1932-33", J. dent. Res. 42:1 (1963) p. 2; H. T. Dean to D. P. Smithwick, March 5, 1932, in the H. T. Dean papers; (15) McCollum E.V., Simminds N., Becker E., Bunting R. W.: "The effect of additions of fluorine to the diet of the reat on the quality of the teeth", J. Biol. Chem. 63 (1925) 553; (16) Bunting RW: "The story of dental caries", Ann Arbor, MI, 1953, p. 83; (17) H. T. Dean to R. W. Bunting, Feb. 9, 1932, in the H. T. Dean papers; (Unfortunately, Bunting's important letter to Dean of February 5, 1932, appears to be no longer in the Dean papers, at the National Library of Medicine, but Dean´s short reply to Bunting is still there.); (18) Bunting RW et al.: "Further studies on the relation of Bacillus acidophilus to dental caries. III", Dental Cosmos 70 (Oct. 1928) 1002; (19) Bunting RW: "The story of dental caries", Ann Arbor, MI, 1953, p. 84; (20) H. T. Dean to the Surgeon General, March 4, 1932, in the Ruth Roy Harris papers; (21) Morrey LW: "Part 3. 1923-1959", pp. 41-76, in "The first Century. A synoptic history of the American Dental Association", J. Am. Dent. Assoc. 58 (June 1959); (22) Editorial: "That fatuous footnote", J. Am. Dent. Assoc. 20 (1933) 1721; (23) Gies WJ: "The final report of the Committee on the Costs of Medical Care. Comment on a misrepresentation of conditions in the practice of dentistry", J. dent. Res. 13 (1933) 81; (24) Gies WJ: "The status of dentistry. Notes on the question whether dental practice should be included in medical practice, with comment on a substitute for state medicine", J. dent. Res. 12 (1932) pp. 945-990; (25) Surgeon General H. S. Cumming to Stanley Osborn, Feb. 27, 1933, in the R. R. Harris papers, National Library of Medicine; (26) Editorial: "A fact-finding committee of the American Dental Association and the U. S. Public Health Service", J. Am. Dent. Assoc. 20 (1933) 716; (27) Editorial: "A tie-up with the U. S. Public Health Service in the matter of dental educational publicity", J. Am. Dent. Assoc. 20 (1933) 524; (28) C. T. Messner: "Progress of nation-wide survey of children to determine dental needs", Abstract 110, J. dent. res. 15 (1935/36) 368; (29) R. R. Harris, Ref.1, pp. 66-67;