28
those
- 35, exposed and unexposed. were free of
clinteally detectable peridontal disease Un the
agcd, many of che rematning teeth were stmptv
held in position by the gingival attachment
Almost all the Rongelapese exhibited marked
xerostomia, The oral mucosa felt damp but not
wet During the dental examination, manipulatron of the tissues by mouth ourror and explorer
faited to stunulate the flow_of saliva. For pH read-
Ings, the paper strip had to remain in contact with
the floar of the mouth for 25 to 30 see in order to
absorb suffictent saliva. [n most instances it was
difhieult for the subject to produce the > ml of
saliva necessary for pH determination in a period
« 10to £5 min. Phe pH values ranged from 6.0 ¢0
7, with an average ol 6 3
Utirik Population
The Utirik population exhibited oral findings
similar to those of the Rongelapese. Their stand-
ards of oral hygiene were somewhat superior, but
the incidence of peridontal disease and caries in
adults was practicaily identical In the Utirik
(open circles, exposed people: closed circles, unexposed people) to show the spread of the data, and
the mean salues are also plotted (squares) for each
d-year age group with exposed and unexposed
people combined The trend ofeach criterion with
Increasing age is represented bya line of approximate best fit hy eve. Che values of the criteria
generally either increase or decrease with increasing age. Manv changes. such as greving of the
hair, bakding, arterrosclerosis (peripheral and
retinal), and skin looseness and retraction, are not
appeciahly manifest in the Marshallese until after
age 35 to FO. Phere ts a tendency for values of
criteria such as blood pressures, greving of the
hair, loss of visual acutny. and accommodation to
level off. or even to showslightly reduced values
in the oldest groups. The number of people in
these groups 1s too smail to make this observation
certain. However, American statistics on blood
pressure (systolte and diastolic) also show a plateau
effect bevond about 60 vears of age and evena
slight tendency to lowering of blood pressures be-
children fess evidence was seen of bunching ofthe
vond this age." By the age of 65 to 70, arcus
sents in all Marshallese showed a ++ change
and, therefore. the plateau was at a maximum.
Some curves showed lower maxima. For example,
Conclusions
and artertosclerosis of the retina only 45%. The
lower antertor teeth, and jaw development was in
harmony with general body growth
These examinations led to the following con-
clusions.
1 There was no significant difference in etther
caries rate or incidence of peridontal! disease between the exposed and the unexposed people of
Rongelap. Thelevel of oral hygtene appeared to
be somewhat better tn the chtldren examined at
Majuro and at Utirik, but the incidence of caries
was about the same in the two groups. and higher
than in the Roneelapese children.
2. The peor oral hygiene generally observed in
the Marshallese people had its usual results: a
high caries rate in teen-age children: severe peridontal lesions tn adults (heavy calcutus, loss of alve-
baldness in women showed only a 35% maximum,
differences in maxima probably were due largely
to differences in the degree of changeassociated
with the various criteria but also partly to the
arbitrary nature of the scoring. The sexual differences in hand strength and baldness were expected. In the neuromuscular function test, slight
muscle fatigue may have been a factor in the lower
female scores, necessitating separate evaluation.
Or
.
~EKPOSEO
» UNEXPOSED
' MEAN BOTH GROUPS
oo
oe
olar bone}: and edentulous mouths in the aged.
3. No difference was perce ptble tn the clinical
appearance of developing dentition among the exposed children, the nonexposed, and those born to
irradiated parents.
Wt
The results of aging criteria studies are plotted
in Figures | 3 to 31. Individual readings are plotted
1225
.
ig!
0 per
STUDIES OF AGING CRITERIA
.
20 |
a
I
It
®
.
»
7)
BO
Figure 13. Skin retraction ume, 1958-1959
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