Mapping the literature of dental hygiene By Ardis Haaland, M.S.L., AHIP Assistant Professor and Head of Reference
Rowvland Medical Library University of Mississippi Medical Center 2500 North State Street Jackson, Mississippi 39216-4505
Despite the long history of the dental hygiene profession, little research has been conducted on the characteristics of its literature. In this study, the bibliometric method was used to identify the core journals in the discipline and the extent of indexing of these journals. The study was a part of the Medical Library Association (MLA) Nursing and Allied Health Resources Section's project to map the allied health literature. Five journals were found to provide one-third of all references studied. Forty-two journals yielded an additional one-third of the references. MEDLINE had the best indexing coverage with 87% of the journals receiving indexing for at least one-half of the articles included. Limited coverage was provided by EMBASE/Excerpta Medica (11%) and the Cumulative Index to Nursing and Allied Health Literature (9%). The findings identified titles that should be added by indexing services as well as those that should have more complete coverage. INTRODUCTION
Dental hygienists work with dentists to provide services that "include dental prophylaxis, radiography, application of medications, and provision of dental education at chairside and in the community" [1]. The origin of the dental hygienist role can be traced back to the oral hygiene movement in nineteenth century dentistry. Dentists wanted to focus on restorative work and other complex procedures while ensuring that their patients received the necessary prophylactic care. Initially, only on-the-job training was available. By 1910, formal course work for "dental nurses" was recommended; the title "dental hygienist" was introduced in 1913. Irene Newman, the first person to be licensed as a dental hygienist, was given license #1 in Connecticut in 1917. She was trained by Dr. Alfred C. Fones in 1906 and worked as his assistant and dental hygienist for nearly thirty years. At first, most dental hygienists worked with the public schools; the trend toward private practice was a major change in the dental hygienists' role [2]. Accreditation standards for dental hygiene were approved by the American Dental Association House of Delegates in 1947 and went into effect five years later in 1952. These standards were developed by the American Dental Hygienists' Association, the National Association of Dental Examiners, and the American Dental Association's Council on Dental Education. The Bull Med Libr Assoc 87(3) July 1999
standards were revised in 1969, 1973, 1979, and again in 1993 [3]. In 1953, the first list of accredited dental hygiene programs consisting of twenty-one programs was published. By 1995, the Commission on Dental Accreditation accredited 212 programs. Most programs grant an associate degree; some lead to a bachelor's degree; and ten universities offer master's degree programs in dental hygiene [4]. Dental hygiene is projected to be one of the top ten growth disciplines in the health care professions through the year 2005. This expansion is due in part to the success of preventive dentistry in helping middle-aged and senior citizens retain their teeth longer. In addition, the field may expand as dentists are expected to hire more hygienists to perform preventive dental care, enabling dentists to concentrate on more
complicated procedures [5]. A review of the literature yielded two studies that were based on content analysis. Nielsen-Thompson, Sisty-LePeau, and Eldredge evaluated manuscripts published in the Journal of the American Dental Hygienists' Association to identify trends in the professional development of dental hygiene [6]. Type and focus of manuscript were the subjects of research by Boyer and Nielsen [7]. Neither of these studies focused on identifying the core journals. The purpose of this study is to identify the core journals in the field of dental hygiene and to determine the extent of indexing coverage for these journal titles. 283
Haaland Table 1 Cited format types by source journal and frequency of citations
Cited format type Journal articles Books Miscellaneous Government documents Total
No. citations in source journals JDH JPH Probe
1,072 290 86 60 1,508
488 88 56 36 668
270 98 52 36 456
Table 2 Cited format types by publication year periods
Citations
Frequency No.
1,830
(%)
476 194 132
69.5 18.1 7.4 5.0
2,632
100.0
JDH = Joumal of Dental Hygiene. JPH = Joumal of Practical Hygiene.
year
Journal articles (%)
Books (
Miscellaneous (
1990-1995* 1985-89 1980-84 1970-79 1960-69 Pre-1960 Not available
34.4 36.7 15.6 9.5 2.7 1.1 0.0
30.9 35.6 14.5 12.8 2.9 2.7 0.6
55.6 22.7 9.7 1.9 2.9 0.0 7.2
Publication
*
In addition to providing information for producers of indexes and databases, the results of this study may be useful to collection development librarians and dental hygienists.
METHODOLOGY A common methodology was used, as was described previously in the overview of the Project for Mapping the Literature of the Health Sciences [8]. Source journals were selected to provide the references to be studied. A study of the 1996 Brandon/Hill allied health list [9] provided one title in dental hygiene, Journal of Dental Hygiene. To locate other titles for consideration, a list of journals on the subject of dental hygiene was pulled from SERLINE and refereed titles currently being published were reviewed. Two additional titles were selected, Probe and Journal of Practical Hygiene. The Journal of Dental Hygiene is the official publication of the American Dental Hygienists' Association and began publication in 1927 as the Journal of the American Dental Hygienists' Association. In 1973, the title changed to Dental Hygiene and, in 1988, it became the Journal of Dental Hygiene. Probe is the official journal of the Canadian Dental Hygienists' Association. It began publication in 1968 as Canadian Dental Hygienist and changed to its present title in 1986. The Journal of Practical Hygiene, a refereed serial, has been published since 1992. It has a large circulation, making it readily available to dental hygienists in the field. All references appearing in articles in the three source journals for the years 1993 to 1995 were reviewed. Only full articles in the source journals were used; editorials, letters to the editor, news items, continuing education, and self-assessment tests were eliminated. For each cited item in the reference lists, a note was made of the type of format and publication year. For journal citations, the specific journal title cited was also noted. Four format types were used to identify the materials cited in the three source journals: books, journal articles (government serials were grouped into this 284
Government documents
Total citations
53.1 28.0 9.8 1.5 0.0 0.0 7.6
36.4 35.0 14.7 9.1 2.5 1.3 1.0
Includes materials in press.
category), government documents (any governmental group), and miscellaneous (dissertations, interviews, course outlines, personal communications, presentations, abstracts, tests, reports, newsletters, manuals, theses, guidelines, surveys, computer software, work-
shops). Journals were ranked in descending order according to the number of times each journal title was cited. Cited journals with title changes were combined under the current title. Using Bradford's Law of Scattering, three zones were created. Zone 1 consisted of the journals cited most often; Zone 2 consisted of the next most cited titles; and Zone 3 were the least cited literature. Indexing coverage for Zones 1 and 2 was then checked; again, the established methodology was used. Finding indexes that covered the dental hygiene literature was difficult. Four indexing/abstracting tools were consulted: the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Dental Abstracts, EMBASE / Excerpta Medica, and MEDLINE. Each tool included at least some of the titles being studied. The journal titles that were included in Zones 1 and 2 were searched in each of the tools to determine to what extent the titles were indexed. Indexing coverage was rated for each journal title and each index on a scale of 5 to 0 (high to low): 5 (95%-100%), 4 (75%-94%), 3 (50%-74%), 2 (25%-49%), 1 (1%-24%), 0
(< 1%).
Table 3 Distribution by zone of cited journals and references
Zone
Cited journals No. (%)
Cited journal references No. (%)
Zone 1 Zone 2 Zone 3 Total
5 42 342 389
630 631 569 1,830
1.3 10.8 87.9 100.0
34.5 34.5 31.0 100.0
Cumulative total 630 1,261 1,830
Bull Med Libr Assoc 87(3) July 1999
Mapping the literature of dental hygiene Table 4 Distribution and indexing coverage of cited journals in Zones 1 and 2 Cited journal Zone 1 1. J Dent Hyg (formerly Dent Hyg, J Am Dent Hyg Assoc) 2. J Am Dent Assoc 3. J Periodontol (formerly J Periodontol-Periodontics) 4. J Dent Educ 5. J Clin Penodontol Zone 2 6. J Public Health Dent 7. J Dent Res 8. MMWR Morb Mortal Weekly Rep 9. Oral Surg Oral Med Oral Pathol Oral Radiol Endod (formerly Oral Surg Oral Med Oral Pathol) 10. Community Dent Oral Epidemiol 11. RDH 12. Br Dent J 13. J Prosthet Dent 14. Quintessence Int (formerly Quintessence Int Dent Dig) 15. Compend Contin Educ Dent (formerly Compendium, Compend Contin Educ Dent) 16. Prob (formerly Can Dent Hyg) 17. J Pract Hyg 18. Fed Regist 19. Gen Dent 20. Educ Dir Dent Hyg (formerly Educ Dir Dent Aux) 21. ASDC J Dent Child (formerly J Dent Child) 22. Int J Oral Maxillofac Surg (formerly Int J Oral Surg) 23. JAMA (formerly J Am Med Assoc) 24. N Engl J Med 25. Access 26. J Oral Pathol Med (formerly J Oral Pathol) 27. J Periodontal Res 28. Acad Med (formerly J Med Educ) 29. Am J Orthod Dentofacial Orthop (formerly Am J Orthod) 30. Am J Public Health (formerly Am J Public Health Nations Health) 31. Dent Clin North Am 32. J Allied Health 33. Clin Prev Dent (formerly J Prev Dent) 34. Dent Teamwork 35. J Am Diet Assoc 36. Swed Dent J 37. J Dent Pract Adm 38. Aust DentJ 39. Cancer 40. Community Dent Health 41. Dent Manage 42. Dent Today 43. nt J Oral Maxillofac Implants 44. Int J Periodontics Restorative Dent 45. J Allergy Clin Immun 46. J BoneJointSurg Am 47. Spec CareDent
No. of citations
CINAHL
Dental abstracts
EMBASE
MEDLINE
209
5
0
0
2
129 120
0 0
2 1
0 1
5 5
88 84
0 0
1 1
0 0
5 5
44 43 41 34
0 0 0 1
1 1 0 1
0 0 0 0
5 5 5 5
24 23 21 20 20
0 0 0 1 0
1 0 1 1 2
0 0 0 0 0
5 0 5 5 5
18
0
2
0
5
18 17 16 16 15 14 14
0 0 0 0 0 1 0
0 0 0 2 0 1 1
0 0 0 0 0 0 0
4 0 0 5 5 5 5
14 13 12 12 12 11 11
4 1 5 0 0 0 1
0 0 0 1 0 0 1
2 4 0 0 0 2 0
5 5 0 5 5 5 5
11
1
0
4
5
11 11 10 9 9 9 8 7 7 7 7 7 7 7 7 7 7
0 3 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 23
0 0 0 0 0 0 0 1 0 0 0 0 1 1 0 0 1 25
0 0 0 0 1 0 0 0
5 5 5 5 5 5 5
Total indexing coverage score
4 0 0 0 0 0 4 5 0 27
5 5 5 5 0 5 5 5 5 5 206
Indexing coverng scale: 5 (95%-100%); 4 (75d/6-94%); 3 (50%/6.74%); 2 (250/o-49%); 1 (1%-24%); 0 (< 1%).
RESULTS There were 149 articles from the three source joumals during the three year period from 1993 to 1995. These articles had a total of 2,632 cited items, distributed as Bull Med Libr Assoc 87(3) July 1999
follows: 1,830 or 69.5% of the citations were to journals; 476 or 18.1% of the cited items were to books; 194 or 7.4% were to miscellaneous formats; and 132 or 5% were government documents. These results are shown in Table 1. 285
Haaland
Age of citation, as represented by publication year, is shown for each format type in Table 2. Government documents, although the least cited overall (5.0%), were the most current with 81.1% having publication dates from 1985 to 1995. Books represented the oldest material used, with only 66.5% having publication dates during the most recent eleven years. The focus of this study was on joumal literature, and the results showed that over two-thirds (71.1%) of the citations to the joumal articles were published from 1985 to 1995. The currency of the miscellaneous materials was approximately the same as that of government documents with 78.3% having publication dates for 1985 to 1995. Overall 71.4% of the literature cited was published from 1985 to 1995. A total of 389 journals were cited as shown in Table 3. However, only 5 joumals (1.3%) accounted for 34.5% of the citations (630), and 42 joumals accounted for another 34.5% of the citations (631). The remaining 31.0% of the citations (569) were provided by 342 journals (87.9%). The five joumals that account for 34.5% of the articles are the Journal of Dental Hygiene, Journal of the American Dental Association, Journal of Periodontology, Journal of Dental Education, and Journal of Clinical Periodontology. These journals and the forty-two titles of Zone 2 cited joumals appear in Table 4 in descending order of the number of citations. DISCUSSION Not surprisingly, the majority of the references cited were joumal articles, and more than two-thirds of these were published between 1985 and 1995. This heavy reliance on current joumal literature is characteristic of the health care literature in general. The literature for dental hygiene indicated that a small core of titles provided a major portion of the literature. Five
titles included 34.5% of the citations, and 69% of the citations were published in 12.1% of the journal titles. Of the joumal titles in Zone 1, only MEDLINE provided adequate indexing coverage. In fact, MEDLINE provided the best overall indexing. It was surprising that CINAHL, which includes allied health literature, provided only minimal coverage. In Zone 1, CINAHL provided full coverage of only one title; in Zone 2, CINAHL provided full coverage of one journal title
286
and covered three other titles at the 50% or better rate. Indexing coverage by Dental Abstracts and EMBASE / Excerpta Medica was minimal. Four titles: RDH, Journal of Practical Hygiene, Federal Register, and Dentistry Today were not covered by any database in the study. Federal Register was selectively indexed by HealthSTAR but the other three titles were not indexed by any of the indexing services.
CONCLUSION
The majority of the references cited were journal articles and more than two-thirds of these were published from 1985 to 1995. Only MEDLINE provided adequate indexing coverage. Database producers who index the allied health literature should be encouraged to review the core journals in Zones 1 and 2. The findings identify titles that should be added by indexing services as well as those that should have more complete coverage. REFERENCES 1. ANDERSON KN. Mosby's medical, nursing, and allied health dictionary. 4th ed. St. Louis, MO: Mosby-Year Book,
1994. 2. MOTLEY WE. History of the American Dental Hygienists' Association 1923-1982. Chicago, IL: The American Dental Hygienists' Association, 1986. 3. AMERICAN MEDICAL ASSOCIATION. Allied health and rehabilitation professions education directory. 24th ed. Chicago, IL: The Association, 1996. 4. UNITED STATES DEPARTMENT OF LABOR, BUREAU OF LABOR STATISTICS. Occupational outlook handbook. 1996-1997 edition. Washington, DC: United States Government Printing Office, January 1996:202-3. 5. IBID., 203. 6. NIELSEN-THOMPSON N, SISTY-LEPEAU N, ELDREDGE JB. Measuring professional growth: analysis of dental hygiene manuscripts, 1927-1959. Dent Hyg 1988 Mar;62(3):118-24. 7. BOYER EM, NIELSEN NJ. Content analysis of original manuscripts in dental hygiene: 1975-1981. Dent Hyg 1982 Nov; 56(11):27-31. 8. SCHLOMAN BE Mapping the literature of allied health: project overview. Bull Med Libr Assoc 1997 Jul;85(3):271-7. 9. BRANDON AN, HILL DR. Selected list of books and journals in allied health sciences. Bull Med Libr Assoc 1996 Jul; 84(3):289-309.
Received September 1998; accepted November 1998
Bull Med Libr Assoc 87(3) July 1999
