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Relevance. Tooth extraction is the most common operation in oral surgery practice. For oroantral communication (OAC) treatment and prevention as one of the surgery complications, it is paramount to study the prevalence of anatomical risk factors for OAC in patients based on their facial sk eleton type.Materials and Methods. We analyzed 1629 cone-beam CT scans of patients aged 18 to 85 years of both sexes to determine the potential risk of OAC in patients with different types of the facial skeleton.Results. The overall assessment of OAC potential risk demonstrated a high risk in 29.7% of cases (4514 teeth) (p < 0.01). The high-risk group determined teeth most often in patients with a mesoprosopic type of facial skeleton – 31.2% of cases (2912 teeth), in euryprosopic – 29.46% (914 teeth), in leptoprosopic – 24.96% of cases, (688 teeth), (p < 0.01). The potential risk of the first and second molar OAC was the highest of all teeth in all facial skeleton types (p < 0.01).Conclusion. A potentially high OAC risk of about 30% can be related to the upper teeth, located in the maxillary sinus floor area in patients with any facial skeleton type, though the risk is higher in meso- and euryprosopic types (p < 0.01). Among all groups of teeth, the highest potential risk of OAC (up to 40%, p < 0.01) is in the maxillary 1st and 2nd molar region in any facial sk eleton type.

In the process of evaluating X-ray diagnostic images of the jaw bones of dental patients, foci of altered bone structure and atypical intraosseous inclusions of increased density are often found. The identified inclusions have different etiology, but at the same time a similar and in some cases implicit scialogical picture, which may cause an incorrect radiological conclusion. When analyzing the available literature, limited information was found about the typical radiosemiotic signs of dense intraosseous inclusions of the jaw bones found in everyday medical practice.

In surgical dentistry, the sampling of the biomaterial of the jaws is usually carried out with the help of dental trepans. As a result of osteotomy, a friction force inevitably arises during trepan biopsy, which can lead to local hyperthermia and, as a consequence, coagulation necrosis of both the bone tissue of the jaw itself and damage to the resulting biopsy. Local overheating can lead to complicated healing of a bone wound in the area of a trepan biopsy, lead to difficulties in verifying the morphological picture of the disease and, as a consequence, further treatment of the patient. When conducting a navigational trepan biopsy using a surgical template, the risk of hyperthermic exposure increases, and the question of choosing the rotation speed becomes obvious. The literature presents limited data on osteotomy regimes using a trepan cutter during jaw bone biopsy, including using a navigational surgical template, which determined the relevance of the study. The purpose of the study: to determine the permissible speed of rotation of the trepan cutter during the navigation trepan biopsy of the jaw bones. Materials and methods: 20 (5) micro-preparations were made from trepan biopsies of the femur of cattle, obtained at speeds of 800 rpm, 500 rpm, 250 rpm, 50 rpm in the classical way; 15 (5) micro-preparations were also made from trepan biopsies obtained at speeds of 350 rpm, 200 rpm, 50 rpm using a surgical navigation template. The width of pathological changes in the tectorial properties of ostein due to coagulation damage of the bone matrix in microns was measured using SlideViewer (3DHISTECH), a built-in tool for measuring linear parameters in microns. The statistical significance of the obtained values was determined using the Kraskel – Wallis H-test. Results: with osteotomy at a speed of 50 rpm, the width of the bone matrix damage reached up to 10 microns. As the rotation speed increased, the width of the damage also increased: at 200 rpm – Me = 36.8 microns, 350 rpm – Me = 98.6 microns. Conclusion: when conducting a navigational trepan biopsy using a surgical template, the recommended rotation speed of the instrument is up to 350 rpm.

In this article there are described urgent problems of diagnostics and treatment of xerostomia and established positions in interpretation of the term “xerostomia” and their fundamental provisions are considered. Also there is presented a survey of the different kinds of xerostomia, including discovered. The presence of existing clinical and practical problems and the absence of common exposition of xerostomia create some premises of the further explorations and development of this thematic area.

The article presents the results of the analysis of the success of treatment and survival of dental implants in the treatment of patients with bone deficiency in the framework of multi-stage and single-stage approaches for bone grafting operations using standard-sized dental implants and in the framework of the approach using narrow/short dental implants without bone augmentation surgery. Based on the results obtained, the degree of expediency (p0.05) of choosing an approach to treatment can be selected depending on the type, location of the defect and the number of missing teeth.

An assessment and correlation analysis was performed between the main indicators when using the drug etoricoxib for the removal of third molars.

The aim of the study was to evaluate the effectiveness of antibiotic chemotherapy regimens and the dynamics of the nature of microbial associations of the operating area at the surgical stages of treatment of patients using dental implants in conditions of limited bone tissue. The study involved 37 patients (17 m and 20 w, from 32 to 68 years). According to the tactics of the treatment and the type of antibacterial effect, the patients were divided into 3 groups. Per os was prescribed antibiotics as a step therapy: amoxicillin (flemoxin 500 mg 1 tablet 2 per day for 7 days) and amoxicillin / clavulanate (flemoclav 625 mg 1 table 2 per day 7 days), doxycycline (unidox 100 mg 1 table 1 per day 5 days). The 1st group of patients (n1=12; 31.9%) — a multi-stage approach (MA), where the 1st operation is bone grafting (BG) (Flemoxin 500 mg), after 6—9 months, the 2nd dental implantation (DI) (flemoklav 625 mg), after 3—6 months the 3rd — installation of gingival formers (GF) (unidox 100 mg). The 2nd group of patients (n2=14; 36.2%) — a one-stage approach (OA), where the 1st operation is BG with simultaneous DI (flemoxin 500 mg), after 6—9 months — the 2nd — installation of GF (flemoklav 625 mg). 3rd group — narrow/short implants (N/S) without BG were installed (n3=11; 31.9%). The 1st operation — DI (Flemoxin 500 mg), the 2nd — installation of GF (Flemoklav 625 mg). A bacteriological study with the identification of pure cultures of bacteria and determination of sensitivity to antibacterial drugs was performed for all patients before treatment and in dynamics. In MA, there was a suppression of the growth of certain types of bacteria and an increase in the number of species resistant to this antibiotic. In the framework of the OA, when prescribing antibiotics, the results were comparable. With N/S implants, growth inhibition of a number of species present at the beginning of treatment was noted. In multi-stage operations, we consider it reasonable to use beta-lactamase-protected drugs, or drugs of another group that include representatives of parodontopathogenic species and potential carriers of multiple resistance genes in their spectrum of action.

The article presents the analysis of possible options of dental implant surgical treatment of partially edentulous patients with insufficient alveolar bone volume in the period from 2008 to 2017 (n=1004). Highlighted are three main options for surgical treatment: a staged approach, including alveolar ridge augmentation, subsequent dental implantation (n=562); dental implantation with simultaneous alveolar ridge augmentation (n=362); using of 'narrow/short' dental implants (n=80). The data on the frequency of intra - and postoperative complications before prosthetics are given. Over the past period, there has been a declining tendency in the number of staged procedures with an increase in the number of simultaneous operations installations of 'narrow/short' implants.В статье представлены результаты анализа возможных вариантов хирургического этапа реабилитации пациентов с частичным вторичным отсутствием зубов в условиях дефицита костной ткани альвеолярного отростка/части челюсти в период с 2008 по 2017 г. (n=1004). Выделены три основных варианта хирургической реабилитации: поэтапный подход, включающий проведение костно-реконструктивной операции, последующее проведение дентальной имплантации (n=562); дентальная имплантация с одномоментным проведением костно-реконструктивной операции (n=362); установка 'узких/коротких' дентальных имплантатов (n=80). Приведены данные по частоте встречаемости интра- и послеоперационных осложнений до этапа протезирования. За прошедший период отмечена тенденция к сокращению количества операций по поэтапному подходу, с увеличением количества одномоментно проводимых операций и операций по установке 'узких/коротких' имплантатов.

Was to investigate the efficiency of decoding teleradiological studies using an algorithm based on the use of convolutional neural networks - a simple convolutional architecture, as well as an extended U-Net architecture.For the experiment, a dataset was prepared by three orthodontists with over 10 years of clinical experience. Each of the orthodontists processed 100 X-ray images of the lateral projection of the head according to 27 parameters, 2700 measurements were made. The coordinates of the control points found by orthodontists in the images were compared with each other and a conclusion was made about the consistency of experts in the data obtained.The results of convolutional neural network CNN were not satisfactory in 17 (62.96%) features, satisfactory in 10 (37.04%). The assessment of orthodontists resulted in non-satisfactory evaluation in 6 (22.22%), satisfactory in 8 (29.63%), good in 8 (29.63%), and excellent in 5 (18.52%) coordinates. Neural networks with U-Net architecture showed satisfactory results in 9 (33.3%) cases, good in 16 (59.3%) and excellent in 2 (7.4%) cases, with no non-satisfactory results.The neural network of the U-Net architecture is more effective than a simple fully convolutional neural network and its results of determining anatomical reference points on two-dimensional images of the head are relatively comparable with the data obtained by medical specialists.Оценка эффективности расшифровки телерентгенологических исследований с использованием алгоритма, основанного на применении сверточных нейронных сетей — простой сверточной архитектуры, а также расширенной архитектуры U-Net.Для проведения эксперимента подготовлен набор данных тремя врачами-ортодонтами с опытом клинической работы более 10 лет. Каждым из врачей было обработано по 100 рентгенологических снимков боковой проекции головы по 27 параметрам, произведено 2700 измерений. Координаты опорных точек, найденные специалистами на снимках, сравнивались между собой.Результаты работы простой полностью сверточной нейронной сети были признаны неудовлетворительными по 17 (62,96%) параметрам, удовлетворительными — по 10 (37,04%). Работа врачей-специалистов оценена как неудовлетворительная в 6 (22,22%) координатах, удовлетворительная — в 8 (29,63%), хорошая — в 8 (29,63%), отличная — в 5 (18,52%). Нейронная сеть с архитектурой U-Net в 9 (33,3%) случаях дала удовлетворительные результаты, в 16 (59,3%) — хорошие, в 2 (7,4%) — отличные, при этом неудовлетворительных получено не было.Нейронная сеть архитектуры U-Net эффективнее простой полностью сверточной нейронной сети и ее результаты определения анатомических ориентиров на двухмерных изображениях головы относительно сопоставимы с данными, полученными врачами-специалистами.

The aim of the study was to assess the stress-strain state of «short dental implant - lower jaw bone tissue» system in the its osseointegration area under different stress options, of an experimentally developed bone tissue model. Using the finite element analysis method, we investigated a three-dimensional model of an implant with 5.0 mm diameter and 6.5 mm height integrated into the quasi-elastic model of the lower jaw segment with a total deformation modulus of 14 400 MPa and a Poisson's ratio of 0.24 for the cortical layer, for the spongy layer, the general deformation module of 0.2 MPa, Poisson's ratio 0.4. The values of equivalent stresses according to the Genki-Mises criterion for the implant body amounted to 50-76 MPa in the cervical region from the end and inner sides of the implant interface and along the upper edges of the thread edges in the upper third of the implant. Minimum values of 0.1-20 MPa are distributed over the implant body from its cervical part to the top in the lower 2/3. The equivalent von Mises stresses in the bone at the joints of the threaded implant part are minimal - 5-15 MPa. Values of shear stresses in the bone - 2 - 3 MPa, normal vertical stresses - up to 5-13MPa, main tensile stresses - up to 20 MPa, compressive stresses - up to 30-40 MPa. Thus, installing this implant in such model, should not occur irreversible deformations. In our opinion, the structural stability is ensured by the bone tissue features architectonics within 3 mm of the cortical layer, where the maximum stress is redistributed in the future throughout the cortical bone, which can expand the indications for short dental implants use, especially in patients with a limited alveolar bone volume.Цель исследования — оценить напряженно-деформированное состояние в системе «короткий дентальный имплантат — костная ткань нижней челюсти» в зоне его остеоинтеграции при разных вариантах напряжения, в условиях экспериментально разработанной модели костной ткани. Методом конечно-элементного анализа исследовали трехмерную модель имплантата диаметром 5,0 мм и высотой 6,5 мм, интегрированную в квазиупругую модель сегмента нижней челюсти с модулем общих деформаций 14 400 МПа и коэффициентом Пуассона 0,24 для кортикального слоя, для губчатого слоя модуль общих деформаций 0,2 МПа, коэффициент Пуассона — –0,4. Значения эквивалентных напряжений по критерию Генки—Мизеса по телу имплантата составили до 50—76 МПа в пришеечной области с торцевой и внутренней стороны интерфейса имплантата и по верхним краям кромок резьбы в верхней трети имплантата. Минимальные значения 0,1—20 МПа распределены по телу имплантата от пришеечной части и до верхушки преимущественно в нижних 2/3 тела имплантата. Эквивалентные напряжения по Мизесу в кости минимальны, в участках стыка резьбовой части имплантата — 5—15 МПа. Значения сдвигающих напряжений в кости — 2—3 МПа, нормальных вертикальных напряжений — до 5—13 МПа, главных растягивающих напряжений — до 20 МПа, сжимающих — до 30—40 МПа. Таким образом, при установке имплантата в подобной модели не должно возникать необратимых деформаций. На наш взгляд, стабильность конструкции обеспечивается особенностями архитектоники костной ткани в пределах 3 мм кортикального слоя, где концентрируется максимальное напряжение, перераспределяемое в дальнейшем по всей кортикальной кости, что может расширить показания для использования коротких дентальных имплантатов, в особенности у пациентов с ограниченным объемом альвеолярной кости.

The article presents clinical case of a patient with partial secondary absence of teeth and maxillary defect because of vertical alveolar bone atrophy. Vertical alveolar ridge augmentation by osseous flap rotation and xenogenous bone block with 10% collagen was performed. Eight months later 4 dental implants with modified surface were placed in the augmentation area. After 3 months 3 implants showed no signs of osteointegration and were removed. Three week later the patient was admitted to ENT department because of maxillary sinusitis symptoms.В статье представлен анализ клинического случая лечения пациентки с частичным вторичным отсутствием зубов и деформацией верхней челюсти вследствие вертикальной атрофии костной ткани альвеолярного отростка. Пациентке была выполнена операция по увеличению объема костной ткани методом ротации костного лоскута с применением ксеногенного костного блока с 10% содержанием коллагена. Через 8 мес в области аугментации было установлено 4 дентальных имплантата с модифицированной поверхностью. Через 6 месяцев на этапе установки формирователей десны у 3 имплантатов отсутствовала остеоинтеграция. Имплантаты были удалены. Через 3 нед у пациентки возникла клиника гайморита, лечение было продолжено в условиях стационара.

The method of mathematical planning of sandwich bone plasty is proposed. Displacement level of the bone flap is calculated in advance with regard to prosthetics size, shape and position as well as occlusal relationships. This makes it possible to accurately simulate the bone "basis" improving the prognosis of dental implantation.