FLUORIDE-INDUCED DEVELOPMENTAL-CHANGES IN ENAMEL AND DENTIN OF EUROPEAN ROE DEER (CAPREOLUS-CAPREOLUS L) AS A RESULT OF ENVIRONMENTAL-POLLUTION

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.