U. Kierdorf et al., FLUORIDE-INDUCED DEVELOPMENTAL-CHANGES IN ENAMEL AND DENTIN OF EUROPEAN ROE DEER (CAPREOLUS-CAPREOLUS L) AS A RESULT OF ENVIRONMENTAL-POLLUTION, Archives of oral biology, 38(12), 1993, pp. 1071-1081
Using macroscopic, microradiographic and scanning electron-microscopic
methods, the effects of increased fluoride exposure on enamel and den
tine formation were studied in fluorosed mandibular premolars and mola
rs of roe deer from the heavily industrialized Ruhr area, Germany. Mac
roscopically, fluorosed teeth were characterized by opaque and stained
enamel and in more severe cases also by enamel surface lesions, reduc
tion or loss of enamel ridges on their occlusal surfaces and increased
wear. Microradiographically, fluorosed enamel exhibited different deg
rees of subsurface hypomineralization, in part apparently indicating a
fluoride effect during enamel maturation. In some specimens, a pronou
nced but varying enhancement of the pattern of Retzius lines was obser
ved throughout the enamel, denoting strongly intermittent fluoride exp
osure during enamel matrix secretion. This variation in exposure was a
lso reflected histologically in dentine, by bands of interglobular den
tine and marked accentuation of incremental lines. Microradiography of
sections through enamel surface hypoplastic lesions showed the enamel
forming the bottom and partly also the walls of the lesions to be hig
hly mineralized. Scanning electron microscopy showed that the outer en
amel along the more pronounced hypoplastic lesions consisted of stacke
d, thin layers of 'aprismatic' enamel, indicating that the ameloblasts
in these areas had lost the distal (rod-forming) regions of their Tom
es' processes. These observations demonstrate that the origin of ename
l hypoplasias in deer clearly differs from that in rodents, where fluo
ride induces the formation of subameloblastic cysts. The differences i
n the degree of fluorotic alteration between the teeth of a single too
th row could be related to the developmental sequence of the dentition
in roe deer. The roe deer is thus considered to be a very sensitive a
nd useful bioindicator of environmental pollution by fluorides.