Morphometric changes of odontogenesis caused by low-dose ionizing radiation in the experiment

Morphometric methods are increasingly being used to evaluate clinical, pathological and experimental data. A systemic morphometric analysis of the main pathological processes and the most common diseases has been developed. However, these data regarding dental pathology are missing. 
The aim of the study. A morphometric investigation of the effects of low doses of ionizing radiation on odontogenesis in rats.
Objects and methods of the study. The experiments were carried out on albino rats of mongrel gregarious breeding. The irradiation of the rats and their offspring was carried out at the Institute of Radiobiology of the National Academy of Sciences of Belarus on the Gammarid-192/120 installation with an exposure dose rate of 110 mR/h since the 1st day of pregnancy before sampling on the 16th, 18th and the 20th day. The irradiation of the offspring was continued on the 1st and 3rd days after birth. The absorbed dose in all groups did not exceed 0,5 Gy. Histological, histochemical and morphometric methods of investigations were applied.
Results of the study and their discussion. Low doses of ionizing radiation at the early stages of odontogenesis (the 16th and 18th days of antenatal life) caused the greatest decrease in almost all morphometric indexes of tooth germs in experimental animals. Morphometric indexes in the control animals significantly exceeded those in the experimental animals. By the 20th day, almost a complete repair of these changes had occurred. However, in 3-dayold rats some differences were still present, for example in the odontoblast layer thickness in the control animals.
Conclusion. Low doses of ionizing radiation during all periods of odontogenesis affected the structure and development of tooth germs, although they did not disrupt the genetically programmed course of odontogenesis. In our opinion, it can be considered as one of the manifestations of the non-threshold effect of ionizing radiation.

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