Obukhov Yu.A.

Relevance. The limited selectivity of antitumor therapy for central nervous system neoplasms entails the risk of dental morbidity in patients.The aim of the study is to assess the severity of damage to the dental hard tissues in patients with tumors of the posterior cranial fossa (medulloblastoma, astrocytoma) and other tumors of the central nervous system.Materials and methods. Three comparison groups were established based on the toxicity profiles of antitumor therapy among 251 patients at the "Russian Field" treatment and rehabilitation scientific center, to assess the characteristics of oral health status. The assessment of oral health status included diagnosing the carious process and calculating the DMFT index. The degree of damage to the dental hard tissues was evaluated on a four-point scale. The clinical manifestations of oral cavity pathology were compared using the Z-criterion for multiple pairwise comparisons of data, with adjustments for multiple testing (Multiple pairwise comparison Z-test for proportions with multiple testing correction) using the free R software version 3.5.2. The null hypothesis of equal indicators in the compared groups was rejected with a 95% confidence probability when comparing groups of patients.Results. Dental hard tissue pathology was significantly more prevalent in patients with medulloblastoma compared to those diagnosed with astrocytomas and other central nervous system tumors. Additionally, the prevalence of dental hard tissue pathology progressively decreased as the observation period following the completion of antitumor remission was extended.Conclusion. The most severe damage to dental hard tissues is observed in patients with medulloblastoma, who undergo more intensive antitumor therapy compared to those with CNS tumors of other histological types.

Aim. To study serum concentrations of trace and macro elements and their correlations in children and adolescents after antitumor therapy, depending on the presence or absence of caries.Materials and methods. The study included 98 patients aged 4 to 17 years who were in remission after an antitumor therapy performed for acute leukemia or lymphomas. Patients with carious tooth lesions were included in group 1 (n = 34) and without caries – in group 2 (n = 64). We used inductively coupled plasma mass spectrometry to calculate the content of essential, conditionally essential and toxic elements in blood serum. The median and interquartile range were calculated, the Mann-Whitney U-test was applied to compare groups, and the Kendall rank correlation coefficient (τ) was calculated for tandem elements.Results. In both groups, the concentrations of the studied elements were within the reference ranges. In group 1, compared with group 2, higher concentrations of potassium, arsenic, iodine and boron and lower concentrations of lithium and tungsten (p < 0.05) were noted. There were no differences in the concentration of phosphorus, calcium, magnesium, manganese, gold, silver, platinum, aluminum, beryllium, bismuth, cadmium, cobalt, chromium, copper, iron, mercury, lithium, molybdenum, nickel, rubidium, antimony, tin, vanadium, zinc, zirconium and thallium between the groups. Significant correlation coefficients in both groups were obtained for the iron/manganese tandem (τ = 0.24, p < 0.05). Different values of τ were got for nickel/ manganese, cobalt/iron, manganese/phosphorus, beryllium/lithium tandems: τ = 0.342 and τ = 0.14; τ = 0.363 and τ = 0.033; τ = –0.111 and τ = –0.326; τ = –0.365 and τ = 0.42, respectively, for groups 1 and 2.Conclusion. In patients in remission after antitumor therapy, an association of caries with an increase (within reference values) in the concentration of essential (potassium, iodine) and conditionally essential elements (arsenic, boron), a decrease in the concentration of lithium and tungsten; as well as a change in the ratio of nickel/manganese, cobalt/iron, manganese/ phosphorus and change the direction of the correlation in the beryllium/lithium tandem was revealed.

Annotation. The authors' study highlights the urgent problem of the development of toxic damage to the dentition under the influence of anticancer therapy in children and adolescents. The aim of the study was to study the violation of the homeostasis of the oral fluid and the severity of the carious process. Materials and methods. As part of a pilot study at the Russian Field Treatment and Rehabilitation Center, 63 children were studied the severity of mineral homeostasis disorders and damage to the dentoalveolar system. Results. In 67% of patients in the main group, there was an increased tendency to form carious cavities. 54.5% of them have complicated caries. One third of patients had more than five carious teeth. In the control group, carious lesions of the teeth in only three patients (20%), with the involvement of 1-3 teeth in the pathological process. Violation of enamel formation was diagnosed in 36% of children of the main group. There is a tendency for the accumulation of the studied microelements in the oral fluid, while in the blood serum there is a normal or insignificant decrease in their content. According to the literature, this may indicate destruction in the oral cavity. Deviations in the homeostasis of chemical elements in children who completed the treatment of malignant neoplasms and children in the control group were revealed. An increased content of osteotrophic microelements was found to correlate with the destructive processes of the teeth. Conclusion. It seems appropriate to study the severity of morphological changes in hard tissues of teeth and the electrolyte composition of mixed saliva in children and adolescents who have been cured of malignant neoplasms. The results of studies of gastric cancer, as an indicator of metabolic disorders, will make it possible not only to reveal the imbalance of macro- and microelements, but also to establish the effectiveness of adaptation mechanisms aimed at normalizing the elemental composition of the oral fluid.

Relevance.The relevance of the literature review presented by the authors is due to the diversity and complexity of the differential diagnosis of tumors of the orofacial zone in children and adolescents. Against the background of the absolute predominance of benign neoplasms, about 10-20% falls on the share of malignant neoplasms in this area. In this regard, polyclinic specialists often do not show sufficient oncological alertness, which leads to an unjustified lengthening of the diagnostic period and late diagnosis of malignant neoplasms.The purposeof the literature review is to discuss the results of studies on the epidemiological, clinical and therapeutic features of the tumor process in the orofacial zone in children and adolescents.Materials and methods.The searching of publications on the subject of the review were performed in the databases: https://www.ncbi.nlm.nih.gov/, https://elibrary.ru/cit_title_items.asp, https://www.researchgate.net/, https://elibrary.ru/. The authors describe the clinical manifestations of tumors depending on the location of the lesion and histological affiliation. The initial symptoms of both malignant and benign neoplasms are often nonspecific. Prevailing benign neoplasms can only be treated by surgery. Much less often in children and adolescents, malignant neoplasms are also found: squamous cell carcinoma of the oral cavity, Langerhans cell histiocytosis and others, which are treated in accordance with the principles of complex / combined anticancer therapy, including courses to minimize the amount of rehabilitation. Results.Timely diagnosis and prevention of the development of neoplasms in the orofacial area can reduce the severity of morphological and functional disorders in children and adolescents. Despite the use of effective methods of surgical or combination therapy, many need rehabilitation measures.Conclusions.The optimal position of a pediatrician, therapist, dentist, or surgeon at the stage of tumor diagnosis should be the implementation of oncological alertness, which implies an active approach without long-term "dynamic observation" of patients. Oncological alertness, especially among dentists, will improve the results of antitumor therapy in patients with Orofacial tumors.