Mapping out Missouri

Dental hygienists are licensed professionals who provide educational, clinical, research, administrative, and therapeutic services that support optimal oral health.

Feb 1st, 2004
Th 142438

by Debra Henderson, RDH, MPA

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Dental hygienists are licensed professionals who provide educational, clinical, research, administrative, and therapeutic services that support optimal oral health. Because of their comprehensive education and clinical training, licensed dental hygienists are qualified to provide safe and effective preventive oral health care services without the supervision of a dentist.

In Missouri, a project was initiated to demonstrate how effective the use of geographic information systems are in the public policy area of oral health care.

For the past several years, dentists in the state have complained about a shortage of dental hygienists. They evaluated different methods for increasing the number of dental hygienists, including reducing the education level required to be a dental hygienist. Currently, Missouri dental hygienists have to graduate from an accredited dental hygiene program and pass three different tests to be licensed: a written national test, a regional clinical exam, and a state law test.

There are a number of different issues to look at when evaluating if there is a shortage of dental hygienists in the state:

• Is there really a shortage of dental hygienists in Missouri, or is the problem the distribution of where the dental hygienists live?

• What will happen if the numbers of dental hygienists in Missouri are increased and not the number of dentists?

• Is there a shortage of dentists in Missouri?

Nationally, new dental hygiene programs are opening at a remarkable rate. In Missouri, three dental hygiene programs existed in the state for many years in Joplin (Missouri Southern State College), Kansas City (University of Missouri), and St. Louis (Forest Park Community College). Since 2000, additional programs have opened in Springfield (Ozark Technical College) and State Fair Community College in Sedalia.

The dental hygiene programs will graduate 100-plus dental hygienists a year. How can dentists still claim a shortage of dental hygienists?


In the past, a numeric format for showing how many dentists and hygieinsts were in each county was difficult to analyze.
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Dentists even feel there is a need to implement preceptorship, a term given to a form of training dental assistants to perform dental hygiene duties on the job without the benefit of formal education or clinical instruction. Why would dentists want to change the current standards for becoming a dental hygienist? Many dental groups who are in favor of shifting dental hygiene duties to dental assistants state as their primary reason that they believe there is a national shortage of licensed dental hygienists.


By using a geo-coding system, an analyst can quickly discern where the shortages lie for both dentists and dental hygienists.
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However, there is no valid evidence to substantiate this claim. In fact, the number of dental hygiene program graduates has exceeded the number of dental school graduates for the past six years.2 The Missouri Director of Economic Development states the number of new licensees for dental hygienists compensates over and above the number of dental hygienists not renewing their licenses. The average increase in licensed dental hygienists each year is 44, but the number of dentists is declining with an average loss of 67 per year.3


By overlapping sets of data, a viewer of the map can see that the blue areas (dentists) typically have purple areas (hygienists) nearby, suggesting that a claim of a shortage of dental hygienists may be misleading.
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The focus, of course, should be on the challenges oral health faces in rural areas. Many states require the dental hygienist to practice in the immediate presence or supervision of a dentist. Since dental hygienists are restricted from practicing on their own, they are forced to go where the jobs are, instead of where patients need them.4 The Missouri practice act states the following:

"332.311. 1. Except as provided in subsection 2 of this section, a duly registered and currently licensed dental hygienist may only practice as a dental hygienist so long as the dental hygienist is employed by a dentist who is duly registered and currently licensed in Missouri, or as an employee of such other person or entity approved by the board in accordance with rules promulgated by the board. In accordance with this chapter and the rules promulgated by the board pursuant thereto, a dental hygienist shall only practice under the supervision of a dentist who is duly registered and currently licensed in Missouri, except as provided in subsection 2 of this section."

Missouri's dental hygienists believe the problem might not be in the quantity of hygienists but rather the distribution of hygienists in the state. Because the dentists believe there is a shortage of hygienists in the state, a "data set" was chosen to compare the number of dentists and dental hygienists by zip code.

The data set can be demonstrated in ArcGIS because the data can be easily overlapped in a visual representation. ArcGIS is a geographical information system program designed for developing maps from layers of spatial data. The data can be easily interpreted by allowing different colors and symbols to be used to represent different categories or fields.

It is important to consider the location of the dentists and hygienists. If there are no dentists in an area, there is no need for a dental hygienist to be there, since the hygienist has to be employed or supervised by a licensed dentist.


The maps were created to support a policy issue. The first map revealed a side-by-side comparison of where the dentists and hygienists are located by zip code. The map on the left represents where the dentists are located by zip code, while the map on the right a presentation of the dental hygienists.
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The Missouri project downloaded a list of dental hygienists and dentists from the state's department of economic development Web page. The files contained the current information provided by the professional registration directories, including addresses, telephone numbers, and status of license.


The second map places the location of both dentists and dental hygienists on the same map.
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Once the data set was filtered for the necessary information, the information was imported into a geo database in ArcGIS. The files imported were the spreadsheet files of dentists and hygienists, county shape file, zip code shape files, pre-geocoded data set for both hygienists and dentists, and the csv. files. The zip code and county boundary files were obtained from the Center for Agriculture, Resource and Environmental Systems (CARES).


Since the maps above made urban areas difficult to analyze, the third map zoomed in on the St. Louis area.
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By using ArcGIS, the information can be conveyed to the layperson in a few minutes, by using a variation in scales, colors, and symbols. In the example included with this article, the dentists are represented by the yellow stars and the purple dots represent the dental hygienists. By quickly glancing at the map, you can see there is neither a dentist or dental hygienist in Shannon, Carter, or Reynolds counties. One can also note a large number of dental hygienists in the cities where the dental hygiene programs are located — St. Louis, Kansas City, and Joplin.


The fourth map presented geo-coded information. Purple dots represent dental hygienists, while the yellow stars represent dentists.
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Intensity is demonstrated well by using this map because of the use of different shapes to represent dentist and dental hygienists. This method also allows the user to show the overlapping of hygienists and dentists making the data more meaningful to the intended purpose of the map.


The fifth map demonstrates the geo-coding for the St. Louis area.
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For this project, the layers selected was currently licensed dentists and dental hygienists in the state of Missouri. First, the maps were created based on the number of dentists and hygienists in a zip code. A variation of color was used based on a scale.


The sixth map used more sophisticated techniques to present the Columbia area.
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For example, the white areas represent areas where there is neither a dental hygienist for dentist. The top purple layer represents hygienists and the lower blue layer represents dentists. The areas that show up in blue signify there is at least one dentist, but no dental hygienists.

By overlapping the two data sets, a map can demonstrate that there is not a significant number of areas in the state where there are dentists and no dental hygienists, as previously claimed by the dentists.


The final map was the author's home page in educating visitors about the policy issue of a shortage of dental hygienists in the state.
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To further expand on the location of the dental hygienists and the dentists, the dataset was geo-coded. Geo-coding allows a list of addresses to be displayed on a map as a feature. The value of geo-coding for dentists and dental hygienists is representing the data on the map and having the information readily available.

In the issue of the shortage of dental hygienists and dentists, GIS is a powerful tool to use to tell the story. By geo-coding the dentists and hygienists, a simple map can be used in telling the most accurate story. Is there a shortage of dentists and/or hygienists and what areas of the state does this apply? GIS technology gives the user the ability to tell a realistic and meaningful story to the Missouri Dental Board, as well as city and state officials.

Currently, the Missouri Dental Board has been addressing this issue. This product allows the user to demonstrate visually to the members of the legislature and dental board. The issue is not about the shortage of dental hygienists, but rather the distribution and the shortage of dentists. It is important to show the legislator why more funding needs to be given to increase the size of the dental schools and additional funding for Medicaid reimbursement.

Last year in Missouri, a bill was passed that allows dental hygienists to work unsupervised in public health settings working on children who qualify for Medicaid and SCHIPS. Because of the lack of funding, this legislation was not supported financially in the budget.

The medical field in the years past have experienced the same problem dentistry is facing today — a shortage of medical doctors in the rural areas. To help alleviate this problem, nurse practitioners are utilized to provide the necessary care within the scope of their practice.

Another solution to the current policy problem is to allow dental hygienists to practice within their scope of practice without the supervision of a dentist. A new category of dental hygiene practice could be established called Collaborative Dental Hygiene Practice. This category of dental hygiene is similar to the nurse practitioner. In 1999, New Mexico was experiencing the same problem — the need to provide dental care to Medicaid patients. The collaborative practice dental hygiene category was developed to help with the problem.

There is potential for problems with data presented in such maps. The information, for example, does not indicate if an address is where the dental hygienist or dentist lives or works? When dental hygienist renews a license, a home address is often used because he or she may work in more than one office, or might have had changes in employment that year.

Secondly, the information only indicates if the licenses are active or not. The data should indicate if the licensed dental professional is working full-time, part-time, retired, or not working at all. This information should be obtained for both dentists and dental hygienists. Often, in the larger metropolitan areas, dental hygienists may not work at one office full time; they may have to work two or three offices to equal full time employment.

Third, the information does not depict whether or not the dentists hire a dental hygienist. As indicated earlier, many dentists in the rural area allow dental assistants to perform dental hygiene tasks, or are doing the work themselves.

In addition, some dentists or dental hygienists may reside in the bordering states, but work in Missouri, or vice versa.

There are several methods and programs available for use to present data. To effectively present the data set comparing the locations of dentists and dental hygienists based on zip codes, the ArcGIS program was utilized to make the maps. The maps can easily be incorporated into a PowerPoint program.

The data collected offers the potential for more analysis. The Health Resources and Services Administration defines a shortage area as one dentist per 5,000 people. Further analysis needs to be completed to see where the shortage areas are in the state in regards to dental care. Because of the declining population of dentists, the data could be further analyzed to indicate what areas of Missouri have a shortage of oral health care professionals.

This policy issue is not just relevant to the state of Missouri. This is a national issue. There is an incredible amount of need for oral health care, and the number of dentists is decreasing. Recently, Missouri faced the cut of dental Medicaid for adults on top of the other issues: a shortage of dentists, an inadequate Medicaid reimbursement, and a lack of dentists accepting Medicaid.

The ArcGIS program is an essential tool. In Missouri, the maps demonstrate there simply are no dentists in the rural areas. The maps are quickly understood because of the use of different colors, symbols, lines, and graphs. With greater understanding of the program, the user could create additional maps filtering and buffering the information based on different attributes.

Debra J. Henderson, RDH, MPA, is the president of the Missouri Dental Hygienists' Association. She completed her bachelor's of general studies degree at Missouri Southern State College in May 2000 and earned a master's degree in public administration from the University of Missouri in May 2003. She can be contacted at debrardh@mchsi.com.

References
1. ADHA Access to Oral Health Care Position Paper, October 2001, Online. www.adha.org
2. Center for Agriculture, Resource and Environmental Systems (CARES) http://www.cares.missouri.edu.
3. Department of Economic Development, Division of Professional Registration, Missouri Dental Board. February 2001. Chapter 332 RSMo. Rules and Regulations
4. O'Looney, John. "Beyond Maps GIS and Decision Making in Local Government". 2000. ESRI. Redlands, CA
5. Ormsby, Tim. "Getting to Know ArcGIS. 2001 ESRI. Redlands, CA
6. Department of Economic Development: http://www.ecodev.state.mo.us/pr/.
7. Driskill, Joe: Missouri Department of Economic Development, January 13, 2000

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