HISTOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY OF BLOOD VESSELS OF GINGIVAL CONNECTIVE TISSUE IN THE AREA OF THIRD MOLARS OF CHILDREN DIFFERENT AGES

Objective – to study the condition of the vessels of the connective tissue of the gums ofchildren in the area of the third molars, which, according to orthodontic indications, hadto be removed, in order to substantiate further the optimal timing of surgical treatmentof such patients.Material and methods. The operation to remove third molars for orthodontic indicationswas performed on 95 children aged 11 to 18 years. The clinical examination of thechildren was carried out using generally accepted methods. Radiographic assessmentof the state of the third molar buds was performed using the Demirjian method. Threeobservation groups were clinically and radiologically distinguished: I (n=30) – childrenaged 11-13 years, in whom the third molar was at the stage of a weakly mineralized bud(stage D according to Demirjian); II (n=35) – children aged 13-16 years, in whom thethird molar was at the stage of a mineralized bud and the initial stages of root formation (stages E and F according to Demirjian) and III (n=30) – children aged 16-18 years, in whom the third molar was at the fi nal stages of root formation (stages G and H according to Demirjian). The specifi c volume of the vascular bed of the papillary layer of the gums was determined on histological sections of gingival tissues from adjacent areas around third molars, taken during surgery. The content of CD-34 and vimentin antigens in endothelial cells was determined by immunohistochemical methods.Results. As a result of the histological examination, it has been proven that the specifi c volume of the vascular bed of the papillary layer of the gums of children increases with increasing age and stage of formation of the third molar bud, in particular, by 2.24 times in the examined group III stage «H» (p<0.05) and 4.31 times in stage «G» (p<0.05) compared to the data of children of group I. A slight increase in the studied parameters was detected in children of group II and I of the study. There were no signifi cant diff erences between immunohistochemical indicators, however, data were obtained on lower concentrations of CD-34 and vimentin antigens in endothelial cells of children of groups II and III, compared to the indicators of children of group I (p>0.05).Conclusions. The conducted histological and immunohistochemical study of the blood vessels of the connective tissue of the gums in the area of the third molars in children of diff erent age groups revealed that during the formation of the tooth root, changes occur in the circulatory structure of the gingival stroma, in particular: an increase in the volume of the blood vessel of the papillary layer of the gums against the background of a decrease in the concentration of CD-34 and vimentin antigens. In the reticular layer of the gums of children of the study groups, no changes were observed in the specifi c volume of blood vessels and the concentration of CD-34 and vimentin antigens.