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Paper: Water Fluoridation & Tooth Decay: Results from
the 1986-1987 National Survey of US Schoolchildren
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Fluoride: Journal of the International Society for Fluoride Research
April 1990 (Volume 23, Issue 2, Pages 55-67)
Water Fluoridation & Tooth Decay: Results
from the 1986-1987 National Survey of US Schoolchildren
by John A. Yiamouyiannis, Ph.D.
SUMMARY: Data from dental examinations of 39,207 schoolchildren,
aged 5-17, in 84 areas throughout the United States are analyzed.
Of these areas, 27 had been fluoridated for 17 years or more (F),
30 had never been fluoridated (NF), and 27 had been only partially
fluoridated or fluoridated for less than 17 years (PF). No statistically
significant differences were found in the decay rates of permanent
teeth or the percentages of decay-free children in the F, NF,
and PF areas. However, among 5-year olds, the decay rates of deciduous
teeth were significantly lower in F than in NF areas.
KEY WORDS: Dental caries; Fluoridation; Schoolchildren;
Tooth decay.
Introduction
It has become widely accepted among dental and
public health professionals that fluoridation reduces tooth decay
by one-half to two-thirds (1,2). However, recent studies by public
health dentists in New Zealand, Canada, and the United States have
reported similar or lower tooth decay rates in nonfluoridated areas
as compared to fluoridated areas (3-6). Moreover, findings in the
United States and worldwide show that, over the last 25 years, reductions
in tooth decay rates in nonfluoridated areas are comparable to those
in fluoridated areas (7-9).
From 1986 to 1987, dentists trained by the US National
Institute of Dental Research (NIDR) performed dental examinations
on 39,207 schoolchildren, aged 5-17, in 84 areas throughout the
United States. This survey allowed a comparison
of tooth decay of large numbers of people from a large number of
areas, some of which have been fluoridated and some of which have
not.
Materials and Methods
Through the United States Freedom of Information
Act, we obtained a printout of the dental records and a list of
the 84 areas used in this survey. From these data, we calculated
the number of decayed and filled deciduous teeth (dft) and the number
of decayed, missing, and filled permanent teeth (DMFT) for each
record and entered the resulting data into a computer. All calculations
were triple-checked before being entered into the computer and all
computer entries were double-checked.
By computer, each record (including the dft and
DMFT scores of each student) was placed in the appropriate age group.
For each of the 13 age groups, average dft and DMFT rates per child
were determined for each of the 84 areas. Age-adjusted DMFT rates
for 5- to 17-year olds were calculated by adding the DMFT rates
for each of the 13 age groups and dividing by 13 (10).
We obtained the data regarding the fluoridation
status of the areas surveyed from Natural Fluoride Content of Community
Water Supplies, Fluoridation Census 1969, Fluoridation Census 1975,
and Fluoridation Census 1985, all published by the US Public Health
Service. In some cases, local authorities were also contacted to
determine the fluoridation status of an area.
Average DMFT (and dft) rates for F, NF, and PF
groups were calculated for each age. Average-age-adjusted DMFT (and
dft) rates for the F, NF, and PF groups were calculated by taking
the average of age-adjusted rates for the respective groups (10).
The percentage of "caries-free" children
was calculated for each age group for each area. Age-adjusted "caries-free"
rates were also calculated. A student was considered to be "caries-free"
so long as they had no DMFT or dft. For example, a child who had
lost all their teeth and no longer had any left to be decayed or
filled would not be recorded as a "caries-free" student.
Through the United States Freedom of Information
Act, we also obtained residence data for each of the above schoolchildren
which allowed us to calculate tooth decay rates for those in F,
NF, and PF areas who had lived at the same residence for their entire
life.
The two-tailed t-test was used to determine 95%
confidence intervals and to determine statistical significance (at
the 95% confidence level). A two-sided Wilcoxon rank sum test (11)
was used to determine whether there was a statistically significant
difference (at the 95% confidence level) in the rank order of DMFT
rates of F and NF areas.
Results
Table 1 presents the number of students examined
and the age-adjusted DMFT rate for each of the 84 areas in the order
of increasing tooth decay rate. There is no statistically significant
difference in the rank order of the age-adjusted DMFT rates of F
and NF areas. As can be seen by examination of column 1, there is
no clustering of fluoridated areas at the top of the table. In the
quartile with the lowest age-adjusted DMFT rates, 9 are non-fluoridated,
3 are partially fluoridated, and 9 are fluoridated. In the quartile
with the highest DMFT rates, 5 are nonfluoridated, 10 are partially
fluoridated, and 6 are fluoridated. Table 1 also indicates that
there is no biased geographical distribution of F and NF areas that
is hiding some potential decay preventive effect of water fluoridation.
Table
1
The number of children examined and the average-age-adjusted
DMFT, dft, and "caries-free" rates for 5- to 17-year
olds in each of the 84 areas in the order of increasing age-adjusted
DMFT rate. F refers to areas fluoridated before 1970; PF refers
to areas which are only partially fluoridated; PF(x) refers
to areas fluoridated in the year "x"; NF refers
to areas that are not fluoridated. |
Water |
Area |
No. |
DMFT |
dft |
Caries-free |
NF |
Buhler, KS |
543 |
1.229 |
0.810 |
44.7% |
F |
El Paso, TX |
451 |
1.321 |
0.777 |
43.5% |
NF |
Brooklyn, CT |
410 |
1.420 |
0.693 |
47.6% |
F |
Richmond, VA |
475 |
1.435 |
0.715 |
45.6% |
F |
Ft. Scott, KS |
491 |
1.442 |
0.774 |
38.2% |
F |
Prince George, MD |
443 |
1.491 |
0.539 |
48.0% |
NF |
Cloverdale, OR |
354 |
1.494 |
0.872 |
40.4% |
PF(71) |
Alliance, OH |
467 |
1.584 |
0.549 |
44.6% |
NF |
Martin, Co., FL |
440 |
1.587 |
0.677 |
41.0% |
F |
Andrews, TX |
455 |
1.588 |
0.893 |
35.8% |
NF |
Coldspring, TX |
406 |
1.589 |
1.144 |
33.8% |
F |
Tulsa, OK |
504 |
1.602 |
1.075 |
35.5% |
NF |
Palm Beach, FL |
476 |
1.613 |
0.896 |
34.5% |
PF |
Hocomb, MO |
558 |
1.628 |
0.883 |
40.3% |
NF |
Kitsap, WA |
564 |
1.635 |
0.769 |
42.9% |
F |
St. Louis, MO |
491 |
1.638 |
0.711 |
39.1% |
PF (82) |
Houston, TX |
488 |
1.662 |
0.819 |
41.8% |
F |
Clarksville, IN |
428 |
1.678 |
0.747 |
40.4% |
NF |
Grand Island, NE |
535 |
1.719 |
0.789 |
40.7% |
F |
Ft. Stockton, TX |
415 |
1.722 |
0.891 |
33.4% |
NF |
San Antonio, TX |
422 |
1.736 |
0.895 |
39.3% |
F |
Cherry Creek, CO |
441 |
1.757 |
0.727 |
36.5% |
F |
Tuscaloosa, AL |
475 |
1.809 |
0.963 |
32.0% |
PF |
Marlon Co., FL |
545 |
1.817 |
0.944 |
28.8% |
F |
Cleveland, OH |
486 |
1.819 |
0.715 |
39.9% |
NF |
Allegany, MD |
458 |
1.834 |
0.735 |
38.3% |
PF (78) |
Norwood, MA |
434 |
1.841 |
0.640 |
39.9% |
F |
Alton, IL |
511 |
1.859 |
0.843 |
37.6% |
NF |
Shamokin, PA |
462 |
1.861 |
1.023 |
32.2% |
NF |
Lodi, CA |
573 |
1.878 |
1.197 |
33.0% |
PF |
Bullock Creek, MI |
472 |
1.879 |
0.766 |
36.7% |
PF (82) |
Marlboro, MA |
386 |
1.885 |
0.613 |
40.8% |
PF (81) |
Allen, TX |
445 |
1.905 |
0.674 |
38.7% |
F |
San Francisco, CA |
456 |
1.908 |
1.031 |
36.3% |
NF |
E. Orange, NJ |
401 |
1.909 |
0.796 |
38.0% |
PF (71/60) |
Lincoln/Sudbury, MA |
436 |
1.923 |
0.758 |
37.8% |
NF |
Conejo, CA |
620 |
1.930 |
0.811 |
41.7% |
NF |
Lakewood, NJ |
450 |
1.933 |
0.698 |
38.0% |
F |
New York City-2 |
336 |
1.953 |
0.812 |
34.9% |
PF |
Bethel, WA |
540 |
1.958 |
1.072 |
34.3% |
F |
Beach Park, IL |
518 |
1.970 |
0.878 |
35.2% |
PF |
Rising Star, TX |
370 |
1.971 |
0.909 |
28.7% |
F |
Philipsburg, PA |
499 |
1.983 |
0.982 |
33.2% |
F |
Lanett, AL |
503 |
1.994 |
0.978 |
31.9% |
PF (82) |
Plainville, CT |
436 |
2.006 |
0.795 |
39.3% |
NF |
Wichita, KS |
496 |
2.036 |
0.878 |
33.5% |
NF |
Newark, NJ |
494 |
2.038 |
0.869 |
35.9% |
PF |
Knox Co., TN |
530 |
2.056 |
1.152 |
31.3% |
NF |
Los Angeles, CA |
540 |
2.063 |
1.039 |
33.0% |
F |
Pittsburgh, PA |
415 |
2.064 |
0.781 |
34.1% |
PF (70) |
Lincoln, NE |
476 |
2.076 |
0.825 |
31.5% |
NF |
Newton, KS |
464 |
2.083 |
1.225 |
31.1% |
PF |
Lakeshore, MI |
486 |
2.088 |
0.781 |
32.6% |
NF |
New Paltz, NY |
350 |
2.110 |
0.751 |
34.8% |
F |
Bemidgl, MN |
485 |
2.124 |
1.001 |
29.3% |
NF |
Alpine, OR |
397 |
2.133 |
0.974 |
34.7% |
NF |
Canon City, CO |
463 |
2.160 |
1.118 |
33.1% |
NF |
Wyandank, NY |
396 |
2.161 |
0.828 |
34.7% |
NF |
Milbrook, NY |
332 |
2.179 |
0.716 |
32.2% |
NF |
Chowchilla, CA |
551 |
2.181 |
1.073 |
33.0% |
F |
New York City-1 |
503 |
2.190 |
0.627 |
37.9% |
PF (82) |
Baltic, SD |
487 |
2.193 |
0.974 |
27.8% |
PF (71/74) |
Blue Hill, NE |
480 |
2.218 |
0.855 |
29.6% |
NF |
Crawford, PA |
492 |
2.222 |
0.996 |
28.5% |
PF (74) |
New Orleans, LA |
459 |
2.251 |
0.953 |
27.4% |
PF (70) |
Memphis, TN |
464 |
2.253 |
0.763 |
33.1% |
PF |
Madison Co., MS |
493 |
2.259 |
1.455 |
26.4% |
F |
Milwaukee, WI |
478 |
2.349 |
0.909 |
32.1% |
NF |
Tooele, UT |
519 |
2.372 |
1.458 |
24.3% |
NF |
Chicopee, MA |
453 |
2.389 |
0.862 |
34.2% |
PF |
Cambria, PA |
532 |
2.460 |
1.039 |
27.1% |
PF (75) |
Springfield, VT |
444 |
2.489 |
0.838 |
32.1% |
F |
Dearborne, MI |
491 |
2.496 |
1.167 |
26.3% |
F |
Maryville, TN |
466 |
2.512 |
1.287 |
22.9% |
PF (81) |
Taunton, MA |
445 |
2.515 |
0.903 |
31.0% |
F |
Greenville, MI |
556 |
2.558 |
1.191 |
25.3% |
PF |
Hart/Pentwater, MI |
455 |
2.584 |
1.344 |
24.1% |
F |
Philadelphia, PA |
463 |
2.649 |
0.824 |
26.0% |
PF |
Sup. Union #47, VT |
487 |
2.710 |
0.907 |
28.1% |
NF |
Cutler/Oroal, CA |
528 |
2.796 |
1.742 |
19.2% |
F |
Brown City, MI |
512 |
2.972 |
1.229 |
22.5% |
PF (83) |
Lawrence, MA |
339 |
3.012 |
1.262 |
17.6% |
NF |
State of Hawaii |
293 |
3.294 |
1.375 |
23.9% |
PF |
Concordia, Co., LA |
424 |
3.767 |
1.508 |
12.4% |
There is no statistically significant difference
between the average DMFT rates for the F and NF groups at any age
(Figure 1). The average DMFT rates of the PF groups are higher than
those of the F and NF groups at every age with the exception of
14-year olds.
There is no statistically significant difference
in the average-age-adjusted DMFT rates among the F, PF, and NF groups
(Table 2). The average-age-adjusted DMFT rates in F and NF areas
are 1.96 and 1.99, respectively. The 95% confidence interval for
the DMFT rate in F areas minus the DMFT rate in NF areas is (-0.19,
0.25); thus we can rule out, with a certainty of 95%, the possibility
that the DMFT rate in F areas is more than one-fourth of a tooth
less than in the NF areas. We can also rule out, with a certainty
of 95%, the possibility that the DMFT rate in NF areas is more than
one-fifth of a tooth less than in the F areas.
Table
2
Average-age adjusted DMFT rates for 39,207 U.S. schoolchildren
and 17,336 life-long resident schoolchildren in 84 areas throughout
the United States. Standard deviations are given in parentheses. |
|
|
Total |
Life-long |
|
No. of Areas |
No. of Students |
DMFT |
No. of Students |
DMFT |
Fluoridated |
27 |
12,747 |
1.96 (0.415) |
6,272 |
1.97 (0.465) |
Partially Fluoridated |
27 |
12,578 |
2.18 (0.465) |
5,642 |
2.25 (0.470) |
Nonfluoridated |
30 |
13,882 |
1.99 (0.408) |
5,422 |
2.05 (0.517) |
To make certain that the absence of a statistically significant
difference between the DMFT rates of schoolchildren living in F
and NF areas was not the result of the mobility of schoolchildren,
or their sex and racial compositions, DMFT rates were determined
for 1.] those who spent their entire lives in one household
and 2.] for white males and white females. The results in
Table 2 show that for life-long residents, there is no statistically
significant difference in average-age-adjusted DMFT rates in F and
NF areas. In addition, there are no statistically significant differences
in tooth decay rates between permanent residents of F and NF areas
at any age (Figure 2A). If water fluoridation were to have reduced
tooth decay as measured by DMFT, tooth decay rates for lifelong
residents living in fluoridated areas should be lower than residents
who had not spent their entire lives in these areas. This was not
found to be the case. Figures 2B and 2C show that among white males
and white females (which make up about 70% of all the children studied),
there is no significant difference in DMFT rates in the F and NF
areas at any age group.
Table
2
Average-age adjusted DMFT rates for 39,207 U.S. schoolchildren
and 17,336 life-long resident schoolchildren in 84 areas throughout
the United States. Standard deviations are given in parentheses. |
|
|
Total |
Life-long |
|
No. of Areas |
No. of Students |
DMFT |
No. of Students |
DMFT |
Fluoridated |
27 |
12,747 |
1.96 (0.415) |
6,272 |
1.97 (0.465) |
Partially Fluoridated |
27 |
12,578 |
2.18 (0.465) |
5,642 |
2.25 (0.470) |
Nonfluoridated |
30 |
13,882 |
1.99 (0.408) |
5,422 |
2.05 (0.517) |
To make certain that the absence of a statistically significant
difference between the DMFT rates of schoolchildren living in F
and NF areas was not the result of the mobility of schoolchildren,
or their sex and racial compositions, DMFT rates were determined
for 1.] those who spent their entire lives in one household
and 2.] for white males and white females. The results in
Table 2 show that for life-long residents, there is no statistically
significant difference in average-age-adjusted DMFT rates in F and
NF areas. In addition, there are no statistically significant differences
in tooth decay rates between permanent residents of F and NF areas
at any age (Figure 2A). If water fluoridation were to have reduced
tooth decay as measured by DMFT, tooth decay rates for lifelong
residents living in fluoridated areas should be lower than residents
who had not spent their entire lives in these areas. This was not
found to be the case. Figures 2B and 2C show that among white males
and white females (which make up about 70% of all the children studied),
there is no significant difference in DMFT rates in the F and NF
areas at any age group.
In contrast, notably lower tooth decay rates were
observed in the deciduous teeth of young children living in F areas.
The 5-, 6-, and 7-year-olds in the F group have dft rates 22%, 9%
and 6% lower than those of the NF group, respectively (Figure 3).
Although the average-age adjusted dft rates for F, NF, and PF groups
were not significantly different statistically, they were higher
for the NF groups (0.96, +0.25) for the PF groups (0.93, +0.24),
which in turn is slightly higher than the F group (0.89, +0.19).
To focus in on dft rates among children 5-8, the
eight areas which commenced water fluoridation between 1970 and
1978 were removed from the PF group and added to the F group. The
5-, 6-, and 7-year-olds in the new F (F*) group have dft rates 24%,
10%, and 10% lower than those of the NF group, respectively, and
the dft rate of 5-year-olds in the F* group is significantly lower
(p < 0.05) than that of the NF group.
Moreover, among 5-, 6-, and 7-year-old lifelong
residents in the F* group, dft rates were 42%, 18% and 11% lower
than those of the NF group, respectively, and the dft rate of 5-year-olds
in the F* group was significantly lower (p < 0.002) than that
of the NF group (Table 3). If water fluoridation were to have reduced
tooth decay as measured by dft among 5-year-olds, tooth decay rates
for lifelong 5-year-old residents living in fluoridated areas should
hav been lower than those of residents who had not spent their entire
lives in these areas. This was found to be the case. From Table
3, it can also be seen that this large and significant reduction
disappears after a couple of years.
Table
3
Percentage change in dft rates in all residents and life-long
residents of F and F* areas in comparison to NF areas. |
|
Total |
Life-long |
Age |
(NF-F)/NF |
(NF-F*)/NF |
(NF-F)/NF |
(NF-F*)/NF |
5 |
22% |
24% (p < 0.05) |
36% (p < 0.02) |
42% (p < 0.002) |
6 |
9% |
10% |
14% |
18% |
7 |
6% |
10% |
5% |
11% |
8 |
-4% |
1% |
-5% |
1% |
Fluoride may have caused a reduction in
dft by delaying deciduous tooth eruption. This is consistent with
the fact that the dft rate in the F and F* groups reaches a maximum
later than in the NF group. Fluoride-induced delays in tooth eruption
have been reviewed elsewhere (12, 13) with contradictory conclusions,
but more recent studies examining 5-year-olds have indicated delayed
eruption that could account for such a difference in tooth decay
rates (14).
The percentage of decay-free children in F, PF,
and NF areas is 34.5%, 31.9%, and 35.1% respectively. There is no
statistically significant difference between the average "caries-free"
rates for the F and NF groups at any age (Figure 4).
Discussion
The data presented here are consistent with data
reported elsewhere in large US surveys. In 1977, the Rand Corporation
examined the tooth decay rate of 25,000 children in (5F and 5NF)
nonrandomly selected areas (15). In the three areas in their study
that were included in the present study, we compared the tooth decay
rates of 12-year-olds. There was good agreement between this study
and theirs with regard to tooth decay rate, after converting DMFS
(decayed, missing and filled permanent tooth surfaces) to DMFT (16)
and considering the acknowledged 36% decrease in DMFS from 1979-1980
to 1986-1987 (17).
In 1983-84, Hildebolt et al. (4) examined the tooth
decay rates of over 6500 Missouri rural schoolchildren from grades
2 (average age 7.5) and 6 (average age 11.5). Among 6th graders
living in the most intensively studied regions, the average DMFT
+ dft rate was 2.07 for those drinking nonfluoridated water and
2.17 for those drinking fluoridated water, compared to the DMFT
+ dft rate of 2.00 reported for 11-year-olds living in Holcomb,
Missouri in our study.
In 1986, Kumar et al. examined 1446 schoolchildren
aged 7-14 from Newburgh, New York (fluoridated in 1945) and cohorts
from nonfluoridated Kingston, New York (18). The sample selection
was nonrandom and had a response rate of only 50-65%. Nonetheless,
the age-adjusted DMFT rates observed (1.5 for fluoridated Newburgh
and 2.0 for nonfluoridated Kingston) were in line with the corresponding
values obtained in this study for communities in the area (1.5 for
nonfluoridated New Paltz, New York and 1.7 for fluoridated New York
City).
Conclusions
Does water fluoridation reduce tooth decay?
i] This study and other recent studies (3-8) show that there
is currently no significant difference in tooth decay rates in F
and NF areas and that decreases in tooth decay rates over the last
25 years have been comparable regardless of fluoridation status;
if this is true, there was no significant difference in the tooth
decay rates between these areas 25 years ago. ii] From 1970
to the present, total fluoride intake studies indicate an average
intake of 1-2 mg per day in nonfluoridated areas and 3-5 mg per
day in fluoridated areas (19,20); thus, it is difficult to claim
that the reason tooth decay differentials between fluoridated and
nonfluoridated areas have disappeared is because the fluoride intakes
in these areas are now similar. Furthermore, the substantially higher
incidence of dental fluorosis in fluoridated areas confirms that
residents in these areas are consuming substantially higher levels
of fluoride than those living in non-fluoridated areas (21-23).
iii] Dramatic reductions in tooth decay have occurred in developing
countries where there is no water fluoridation (see
World Health Organization data) and there is little reason to
suspect that there would be elevated levels of fluoride in the food
chain (7,9,24,25). iv] In addition to recent studies, a number
of early studies have also shown no significant reduction in tooth
decay as a result of water fluoridation (7, 26-28). v] Serious
questions have been raised regarding the reliability of earlier
studies claiming that fluoridation causes a reduction in tooth decay
(29).
Acknowledgments
I thank Kimberly Close-Hittle, Jerry Putnam, Margot
Yiamouyiannis, and Opal Kuhn for their help in the calculation and
verification of summary data as well as Jill Pitts and Chris Hiatt
for their lightning fast speed in entering data into our computer.
Without the generosity of Dr. Leo Roy, Dr. Reuben Benner, Dr. H.
Charles Kaplan, Dr. Gerald Judd, Richard Barmakian, John C. Justice,
Len Greenall, Mr. and Mrs. Andrew Yimoyines, Wini Silko, AIM International,
Inc., and other patrons of the Center for Health Action and the
Safe Water Foundation, the preparation and publication of this article
would not have been possible. Finally, I thank Ray Fahey for correcting
an error we had made in assigning the fluoridation status of E.
Orange, NJ.
Addendum
Recently Brunelle (30), using the same database
that we used, reported 26% fewer dfs (decayed and filled deciduous
tooth surfaces) in children who had always resided in F communities
than those who never lived in F communities. This finding agrees
reasonably well with the data outlined in our Table 3, which shows
a statistically significantly lower dft rate in lifelong 5-year-old
residents of fluoridated areas. However, by omission of age-specific
data, the Brunelle study covers up the fact that this difference
in tooth decay is no longer significant in 6-year-olds and disappears
entirely among 8-year-olds.
Another recent study by Brunelle
and Carlos (31), which also uses the same database that we used,
reports a 17% lower DMFS rate in the F areas. This study has a number
of major deficiencies which render the study of little or no value.
1. It contains extremely serious errors. For example,
by a cursory inspection, we found two values that are off by 100%
or more. In their Table 9, the DMFS figure for lifelong F exposure
residents of Region VII should be about 3, not 1.46 as reported.
From their Table 3, the percent of 5-year-olds who have caries is
1.0%, not the 2.7% that can be calculated from the Table (100%-97.3%).
When I pointed out this error to Dr. Carlos, he admitted that only
19 out of the 1851 5-year-olds had caries: 19/1851 = 1%, but refused
to make the correction (32).
2. It fails to report the tooth decay rates for
each of the 84 geographical areas surveyed. This covers up the fact
that there is no difference in the tooth decay rates of the fluoridated
and nonfluoridated areas surveyed. The Brunelle/Carlos study even
fails to list the area studied. As a result, they produce misleading
illustrations; for example, their Figure 3 implies that Arizona
and New Mexico have the lowest tooth decay rates, when, in fact,
not a single area was surveyed in either of the two states.
3. It fails to control for geographical differences
in tooth decay rates by indiscriminately and disproportionately
bunching children from all parts of the country into 2 groups, F
and NF.
4. It fails to do the statistical analysis (or
even provide the data, i.e. the standard deviation and sample number)
necessary to determine whether the values found for F and NF areas
are significantly different. Our calculations show that even if
their data were accurate, the 17.7% figure does not reflect a statistically
significant difference between the F and NF groups.
5. It fails to report the data for approximately
23,000 schoolchildren who were not life-time residents of either
the F or NF areas (the PF group). If fluoridation reduced tooth
decay, the DMFS rate of the PF group should have been greater than
that of the F group and less than that of the NF group. Our data
indicate that the PF group would have had a DMFS rate higher (although
not significantly higher) than either the F or NF groups.
6. It fails to report the data for the percentages
of decay-free children in F and NF areas. Our data indicate that
had these calculations been done by Brunelle and Carlos, the results
may have actually indicated better (although not significantly better)
dental health in the NF areas.
Brunelle and Carlos, as well as their employer,
the NIDR, have recently come under attack for presenting erroneous
data and designing poor experiments which promoted the fluoride
mouthrinse program (33). The apparent poor quality of their research
regarding the 1986-87 survey (30, 31) is not an isolated case.
Read the Chemical and Engineering News
(1989) article "New Studies Cast Doubt
on Fluoridation Benefits" which discusses this study.
References and Notes
1. Green, J.C., Louie, R. and Wycoff, S.J.: Preventive
Dentistry I. Dental Caries. J. Amer. Med. Assn., 262:3456-3463,
1989.
2. Szpunar, S.M. and Burt, B.A.: Dental Caries,
Fluorosis and Fluoride Exposure in Michigan Schoolchildren. J. Dent.
Res., 67:802, 1988.
3. Colquhoun, J.: Influence of Social Class and
Fluoridation on Child Dental Health. Community Dent. Oral Epidemiol.,
13:37-41, 1985.
4. Colquhoun, J.: Child Dental Health Differences
in New Zealand. Community Health Studies, 11:85-90, 1987.
5. Gray, A.S.: Fluoridation: Time for a New Baseline?
J. Canadian Dent. Assoc., 53:763-765, 1987.
6. Hildebolt, C.F., Elvin-Lewis, M., Molnar, S.,
McKee, J.K., Perkins, M.D. and Young, K.L.: Caries Prevalences Among
Geochemical Regions of Missouri. Amer. J. Physical Anthropol., 78:79-92,
1989.
7. Diesendorf, M.: The Mystery of Declining Tooth Decay. Nature,
322:125-129, 1986.
8. Johnston, D.W., Grainger, R.M. and Ryan, R.K.:
The Decline of Dental Caries in Ontario School Children. J. Canadian
Dent. Assoc., 52:411-417, 1986.
9. Luoma, A-R. and Ronnberg, K.: Twelve-Year Follow-up
of Caries Prevalence and Incidence in Children and Young Adults
in Espoo, Finland. Community Dent. Oral Epidemiol., 15: 29-32, 1987.
10. Hill, A.B.: Medical Statistics. Hodder and
Stoughton, London, 1977, p. 183. While the numerous age-specific
comparisons of dental health of children at different ages provide
the best evidence, it is occasionally desirable to have a summary
rate to enable an overall comparison of different populations. For
this purpose, we have used the age-standardized or age-adjusted
rates, in order to avoid giving disproportionate weighting to larger
numbers of children from one particular age-group that would tend
to distort the summary figure. In using these rates, a standard
population must be chosen. The one most commonly used is the hypothetical
population with equal populations at each age group, which merely
results from taking an arithmetic mean of the age-specific tooth
decay rates measured. In the above reference, Austin Bradford Hill
addresses this method in a discussion of the handling of mortality
rates under a section titled "The Equivalent Average Death-Rate."
Analogously, equal weights were given to each of the 84 geographical
areas to prevent a distortion which might be induced by the variation
of the area sample sizes, since certain geographical areas have
characteristically higher (or lower) tooth decay rates than others.
11. Wilcoxon, F., Katti, S.K. and Wilcox, R.A.:
Critical Values and Probability Levels for the Wisconsin Rank Sum
Test and the Wilcoxon Signed Rank Test. Selected Tables in Mathematical
Statistics, Markham Publishing Co., Chicago, 1:197, 201, 1970.
12. Waldbott, G.L., Burgstahler, A.W. and McKinney,
H.L.: Fluoridation, the Great Dilemma. Coronado Press, Lawrence,
Kansas, 1978, 423 pp.
13. El-Badrawy, H.E.: Dental Development in Optimal
and Suboptimal Fluoride Communities. J. Canadian Dent. Assoc., 50:761-764,
1984.
14. Krylov, S.S. and Pemrolyd, K.: Deciduous Tooth
Eruption and Fluorosis in the Case of Increased Fluorine Content
in the Drinking Water. Stomatologiia (Mosk), 61: 75-77, 1982.
15. Bell, R.M., Klein, S.P., Bohannan, H.M., Graves,
R.C. and Disney, J.A.: Results of Baseline Dental Exams in the National
Preventive Dentistry Demonstration Program. R-2862-RWJ. Rand Corporation,
Santa Monica, CA, 1982.
16. Jarvinen, S.: Epidemiologic Characteristics
of Dental Caries: Relation of DMFS to DMFT. Community Dent. Oral
Epidemiol., 11: 363-366, 1983.
17. Johnson, S. HHS News (U.S. Department of Health
and Human Services: National Institutes of Health) June 21, 1988.
18. Kumar, J.V., Green, E.L., Wallace, W. and Carnahan,
T.: Trends in Dental Fluorosis and Dental Caries Prevalences in
Newburgh and Kingston, NY. Amer. J. Pub. Health, 79:565-569, 1989.
19. Rose, D. and Marier, J.R.: Environmental Fluoride,
1977. NRCC No. 16081. National Research Council of Canada, Ottawa,
Ontario, 1977, pp. 75-83.
20. Featherstone, J.D.B. and Shields, C.P.: A Study
of Fluoride Intake in New York State Residents. 0114Uc1288-1, Eastman
Dental Center, Rochester, NY, 1988.
21. Segreto, A.S., Collins, E.M., Camann, D. and
Smith, C.T.: A Current Study of Mottled Enamel in Texas. J. Amer.
Dent. Assoc., 108:56-59, 1984.
22. Leveret, D.: Prevalence of Dental Fluorosis
in Fluoridated and Nonfluoridated Communities - A Preliminary Investigation.
J. Pub. Health Dent., 46:184-187, 1986.
23. Colquhoun, J.: Disfiguring Dental Fluorosis
in Auckland, New Zealand. Fluoride, 17: 234-242, 1984.
24. Poulsen, S., Amaratunge, A. and Risager, J.:
Changes in the Epidemiological Pattern of Dental Caries in a Danish
Rural Community over a 10-year Period. Community Dent. Oral Epidemiol.,
10:345-351, 1982.
25. Backman, B., Crossner, C-G. and Holm, A-K.:
Reduction of Caries in 8-Year-Old Swedish Children between 1967
and 1979. Community Dent. Oral Epidemiol., 10:178-181, 1983.
26. Scrivener, C.: Unfavorable Report from Kansas
Community Using Artificial Fluoridation of City Water Supply for
Three-Year Period. J. Dent. Res., 30:465, 1951.
27. Galagan, D.J.: Climate and Controlled Fluoridation.
J. Amer. Dent. Assoc., 47:159-170, 1953.
28. Schroeder, P.: Dental Health in Children in
Rural Regions without School Clinics. J. Dent. Res., 50(Supplement
Part 1):1231, 1971.
29. Yiamouyiannis, J.: Fluoride, the Aging Factor.
Health Action Press, Delaware, Ohio, 1986m pp. 94-110.
References for Addendum
30. Brunelle, J.A.: Caries Attack in the Primary
Dentition of U.S. Children. J. Dent. Res., 69(Special Issue):180
[Abstr. No. 575], 1990.
31. Brunelle, J.A. and Carlos, J.P.: Recent Trends
in Dental Caries in U.S. Children and the Effect of Water Fluoridation.
J. Dent. Res., 69(Special Issue):723-728, 1990.
32. Carlos, J.P.: Personal communication, 1989.
33. Disney, J.A., Bohannan, H.M., Klein, S.P.,
and Bell, R..M.: A Case Study in Contesting the Conventional Wisdom:
School Based Mouthrinse Programs in the USA. Community Dent. Oral
Epidemiol., 18:46-56, 1990.
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