LYON—CONARD—GLASSFORD . . . VOLUME 68, JANUARY 1964 © 55/37
DISCUSSION
The acute effects of significant quantities
of total-body ionizing radiations on human oral tissues have been described.}0-1¢
Postirradiation findings from high radia-
Theinhabitants of Uterik who received
only 14R have remained completely
asymptomatic since initial exposure.
SUMMARY
Initial dental examinations of certain
Marshallese populations who were exposed accidentally to significant quantities of ionizing radiations from radioacbody dose exceeds 250 R. None of the tive fallout were conducted five years
foregoing acute conditions was noted in after primary exposure. Fortunately, neganyof the irradiated Rongelapese.
ative findings far outnumberpositive obAny relation of radiation exposure in servations. The examinations disclosed
the Rongelap people to the somewhat the following:
1. Similar degrees of caries activity
higher levels of periodontal destruction in
this group is purely conjectural. Because were observed in irradiated and nonirof the generally substandard levels of oral radiated children.
2. Although the prevalence of periohygiene amongthe Marshallese, it appears
likely that the disease was prevalent in dontal disease was practically identical in
the Rongelap group at the time of their both the irradiated and nonirradiated
radiation exposure. It is possible to specu- groups, the extent of periodontal destruclate that the period of leukopenia after tion was greater in the irradiated Ronthis group’s exposure might have en- gelapese. This difference may or may not
hanced the progress of periodontal dis- be related to factors such as leukopenia
ease. Clinically, however, they showed no and lowertissue resistance and the presevidence of increased infection, oral or ence of preexisting periodontal disease.
otherwise, nor bleeding tendency during
3. Children born of irradiated parents,
the period of leukopenia and thrombocy- including those children in utero at the
topenia. Nevertheless, it is possible that time of initial exposure, and irradiated
in a subclinical sense radiation exposure children 6 to 18 years old, showed no evimight have resulted in lower tissue re- dence of any morphological effects on
sistance and repair, thereby enhancing oral tissues from total body irradiation
the progress of periodontal disease in this when compared with the nonirradiated
group.
control groups.
Thefact that 64 per cent of the Rongelap irradiated children and 51 per cent
or assertions contained in this article
of the Rongelap nonirradiated children areThetheopinions
private ones of the writer and are not to be
construed
as
official
or reflecting the views of the Navy
had experienced dental caries indicates Department or the naval
service at large.
that caries activity was similar in both
*Captain, Dental Corps, United States Navy; dental
tion levels include hemorrhagic gingivitis,
buccopharyngeal ulceration and necrotizing gingivitis, According to Gerstner,1¢
these lesions develop only when the total
these groups. However,
the available
number of subjects was too small to test
the possible significance of the difference.
A dental survey is planned for the ten
year postexposure examinations, which
will allow further observations of these
dental abnormalities. In addition, the
state of dentition in the children will be
of interest in view of the findings ofslight
retardation of growth and development
in certain exposed Rongelap children.17
division,
Naval
Medical
Research
Institute,
Bethesda,
tHead, Marshall Islands Survey Team, Medical Research Center, Brookhaven National Laboratory, Upton,
Long Island, N. Y.
fLieutenant, j.g., Medical Service Corps, United States
Navy, U.S. Naval Training Station, Great Lakes, HI.
|. Bond, V. P., and others. Hematologic observations.
In Some effects of ionizing radiation on human beings;
report on Marshallese and Americans accidentally exposed to radiation from fallout and discussion of radiation injury in human being, Cronkite, E. P.; Bond, V. P.,
and Dunham, C. L. Washington, D.C., Government Printing Office, July 1954.
2. Conard, R. A., and others. March [957 medical
survey of Rongelap and Uterik people three years after
exposure to radioactive fallout. Washington, 0.C., Government Printing Office, June 1958.