SUMMARY
Objective of research. To analyze features of stomatological status indexes, relative length of telomeres and phenotype of immunocompetent cells of peripheral blood in children with chronological enamel hypoplasia – residents of Ukrainian territories, contaminated with radionuclides after the Chornobyl NPP accident.Materials and methods. The object of research is chronological enamel hypoplasia (CEH) of permanent teeth, and lymphocytes of peripheral blood (PB). The subject of research is the state of oral cavity hygiene, caries intensity, gingivitis severity degree, relative telomere length (RTL), and phenotype of immunocompetent cells (ICC) of peripheral blood (PB). Methods of the research: stomatological, immunological (flow cytofluorometry), molecular genetic (fluorescence in situ hybridization-flow cytometry – flow-FISH), statistical.Results. Two types of the analysis of the stomatologic status, RTL and phenotype of PB ICC were carried out: the first is the comparison of indexes of the combined group of children with anamnesis complicated by radiation (group No. 1 with CEH + group No. 2 without CEH) comparing with the control group No. 3; the second is the analysis of indeces of the group No. 1 comparing with the same markers in children of the groups No. 2 and No. 3. The first stage of the analysis shows thesignificant worsening of oral hygien indices , high DMFTand DMFS in children with permanent dentition, higher degree of gums inflamation and moresignificant RTL shortening in children of the combined group (No. 1 + No. 2) comparing with the control. Changes of the same character, but more expressed observed during the another analysis concerning the children with anamnesis complicated by radiation and CEH comparing with the control. Reliable changes in the content of PB ICC subpopulations in the examined children of all groups were not identified.Conclusions.1. Inchildren with CEH, complicated by ionizing radiation (IR) influence in low doses diapason the highest degree of stomatological status disorders comparing with the examined reference and control groups was determined: unsatisfactory and poor oral cavity hygiene according to OHI-S (1.76±0.41, ??0.0001 and ??0.0001, respectively) and Silness-Loe index (1.73±0.45, ??0.0001 and ??0.0001, respectively); very high intensity of dental caries ((DMFT=7.0±2.29, ?=0.003and ??0.0001; DMFS=8.74±2.58, ?=0.0004 and ??0.0001, respectively); mean degree of gingivitis severity (??? 47.55±14.27 %, ??0.0001 and ??0.0001, respectively).2. At CEH, which occurs due to the complex of negative factors during first years of life, including IR in residents of territories with effective doses more than 1.0 mSv/year, reliable shortening of relative telomeres length of PB lymphocytes comparing with the control group (15.17±3.20, ?=0.0002) was found. Reliable differences in the content of peripheral blood immunocompetent cells when compared the examined groups were not identified.3. Results of indices of the groups No. 1, No. 2 and No. 3 comparison are agreed with the data, obtained in result of dispersive analysis that allowed to separate the most informative indices concerning stomatological examination of children: OHI-S index (F=34.92; ??0.001); Silness-Loe index (F=27.01; ??0.001); dft+DMFT (F=82.23; ??0.001); dfs+DMFS (F=49.41; ??0.001); DMFT (F=13.94; ??0.001); DMFS(F=19.41; ??0.001); ??? (F=41.25; ??0.001); RTL (F=7.53; ?=0.001).