The Pterygomandibular Space: A Volumetric Evaluation Using the Novel A-Silicone Injections Method.

Inferior alveolar nerve block (IANB) is one of the most common procedures in operative dentistry, and a deep understanding of the normal anatomical variation of the pterygomandibular space (PM) is essential for its safe and successful administration. This cadaveric anatomical study aimed to use A-silicone injections to evaluate the volume of the PM. This study was conducted using 46 human cadaver heads (25 males and 21 females). A craniometric analysis was performed using the cadavers' ages, the number of silicone cartridges (carpules) used to fill the pterygomandibular space, Izard's Facial Index (FI), and the Cranial Index (CI). A Halstead mandibular block was performed by injecting 1.7 mL A-silicone cartridges (as an equivalent to standard local aesthetic carpules volume) into the PM. The cured silicone was extracted from the dissected mandibles. The volume (length, width, and thickness) of the extracted silicone and the number of silicone cartridges used to fill the space were evaluated. The results showed that there are statistically significant positive correlations between the CI and the width of the right PM, as well as the width and length of the left PM. A statistically significant correlation was found between the width of the left PM and the age of the cadaveric heads; the higher the age, the thicker the space on both sides. The volume of the PM corresponded to 1.5 cartridges on average.

Comparison of Brain Activation According to fMRI Data in Patient with Depression (After Acute Coronary Syndrome and Somatically Healthy) and Healthy Volunteers.

Objective: The present study is devoted to the study of brain activation using fMRI in patients with depression (after acute coronary syndrome and somatically healthy) and in healthy volunteers. Method : The study enrolled a total of 51 patients: 11 with depression after acute coronary syndrome, 16 with primary depressive episode and recurrent depression without prior coronary event, and 24 with ACS without depression. The groups were matched by sex and age. The emotional information processing was evaluated with the Pennsylvania Test of Emotion Recognition. All patients underwent fMRI at the time of this test. The data processing was performed with SPM12 and xjView applications. Results: During the processing of emotional information in the depressed patients after ACS, specific activation zones in the frontal cortex (P < 0.001), right fusiform gyrus (P < 0.001), and right insular lobe were identified (P = 0.017). In the patients with primary depressive episode and recurrent depression without ACS, certain zones of activation were identified in frontal cortex (P < 0.001; 0.001), left fusiform gyrus (P < 0.001), occipital cortex (P < 0.001). In the patients who had ACS, without depression, some zones of activation were specified in the right middle occipital gyrus (P < 0.001), the right superior frontal gyrus (P = 0.088), and the putamen projection on the right (P < 0.001) and on the left (P = 0.009), as well as the left insular lobe (P = 0.015). Conclusion: The pathogenesis of depression is significantly associated with the peculiarities of processing emotionally significant information, regardless of the conditions under which it develops.

Vaccination as a Significant Factor Influencing the Psychoemotional State of Medical Students During the Sars-Cov-2 Pandemic: An International Aspect.

Background: The rapid spread of SARS-COV-2, characterized by its severe course in the absence of effective specific treatment for this infection, may become a significant risk factor for psycho-emotional disorders' emergence during this pandemic. One of the vulnerable groups in the current situation are first-year medical students, whose problems associated with an unfavorable sanitary-epidemiological situation and an increased infection risk are compounded by the difficulties of adapting to specific professional environments. In this situation, along with strict adherence to nonspecific prevention methods, the mass student SARS-COV-2 vaccination acquires particular importance. Objective: To compare the attitudes of first-year medical students in Russia and Azerbaijan toward SARS-COV-2 immunization and to assess the vaccination impact on the student's psycho-emotional state during the SARS-COV-2 pandemic. Materials and Methods: The study involved 594 first-year students at the Moscow and Baku branches of Sechenov University. The Google Forms platform was used to conduct an anonymous sociological survey. To compare the psychoemotional state of vaccinated freshmen and non-vaccinated students, we used the State-Trait Anxiety Inventory, STAI, to assess reactive anxiety and the Beck Depression Inventory test - to diagnose depressive symptoms. The online survey was conducted during the fourth wave of coronavirus infection. WHO official sources were used to analyze the current epidemiological SARS-COV-2 situation during the study data provided by the Russian Federal Service on Customers' Rights Protection and Human Well-Being Surveillance and JHU CSSE. Statistical analysis was carried out using RStudio. Results: The study results showed that vaccination coverage of first-year students at the Moscow branch of Sechenov University during the fourth wave of the SARS-COV-2 pandemic was 42,9±5,13%, at the Baku branch - 69,6±5,86%. The lack of reliable information about anticovid vaccines, indicated by a third of all respondents, may largely determine the motivated participation in the vaccination SARS-COV-2 campaign. The role of medical school in imparting knowledge about active SARS-COV-2 immunization to medical students was found to be insignificant. It was shown that the percentage of students willing to recommend SARS-COV-2 vaccination to the people around them and thereby contribute to increasing collective immunity level significantly depends on the percentage of students vaccinated. It was proved that vaccinated students were characterized by significantly greater psychological stability regardless of their study place. Conclusion: Vaccination is not only a good preventive measure against the infection spread but also a significant factor in stabilizing the psycho-emotional state of first-year students, which significantly affects the quality of their educational process and its effectiveness.

A New Way to Model Periodontitis in Laboratory Animals.

The prevalence of periodontal diseases is increasing, tends to increase with age and is considered as one of the main causes of tooth loss. To assess the effectiveness of new methods of treatment of periodontal diseases, studies on laboratory animals can be promising. THE AIM OF THE STUDY: to develop a new method of accelerated modeling of experimental periodontitis on laboratory animals. MATERIAL AND METHODS: The study was carried out on 22 female rats. A wire ligature was applied to the cervical area of the incisors of the animals in an eight-shaped manner. Plaque obtained from a patient with periodontitis was placed under the wire, and nicotine and ethyl alcohol solutions were injected under the gingival mucosa. A complex index has been proposed to assess inflammation. At the end of the experiment the animals were euthanized, their jaws were dissected into dentoalveolar blocks and further descriptive histologic analysis was performed. RESULTS: On the second day the gingiva of the rats acquired a cyanotic-pink color, on the fourth day the consistency of the gingiva became friable, mobility appeared in the lower incisors. Complex index of inflammation in animals of the main group: before the study-9, on the 7th day-195. Gingival preparations showed signs of exudative inflammation. In alveolar processes-irreversible resorption of bone structures. The difference of indicators in animals before and after the experiment was statistically significant (p < 0.05). CONCLUSION: The new experimental model of periodontitis is reproduced in a short period of time, provides intensive development of inflammation, leads to disruption of the integrity of epithelial and connective tissue attachment, destruction of alveolar bone.

Comparative Analysis of Mechanical Properties and Microbiological Resistance of Polyfilament and Monofilament Suture Materials Used in the Operation "Tooth Extraction".

In surgical dentistry, suture material is the only foreign body that remains in the tissues after surgery, and it can lead to several negative reactions, for example, infection of the wound. The purpose of this study was to compare the mechanical properties and microbiological resistance of mono- and polyfilament suture materials used in tooth extraction operations. The study of elongation and knot force was carried out on an Instron 5969 Dual Column Testing System device. The capillarity of the materials was studied on a setup assembled by the authors manually by immersing the ends of the filaments in a colored manganese solution. A microbiological study was carried out on the threads taken for the experiment immediately after wound suturing, and on day 7, at which time they were removed. The comparison was made according to Rothia mucilaginosa, Streptococcus sanguinis, Staphylococcus epidermidis. Results: monofilament suture materials (Prolene and Glycolon), after calculating the Kruskal-Wallis and Mann-Whitney indices, showed better performance in all experiments compared to polyfilament sutures (Vicryl and PGA). In capillarity comparison, there was a significant difference between groups (p = 0.00018). According to the sum of the results of three microbiological studies on day 7, monofilament suture materials absorbed less of the studied bacteria on their surface compared to the polyfilament ones (p < 0.05). Conclusions: Of the studied suture materials, Prolene had the best microbiological resistance and good mechanical properties.

Recognition of Facial Emotion Expressions in Patients with Depressive Disorders: A Functional MRI Study.

BACKGROUND: The present study evaluated the cortical activation during emotional information recognition. METHODS: The study group included 16 patients with depression, and 16 healthy subjects were enrolled as a control group. Patients received eight weeks of antidepressant therapy. Functional MRI evaluated the cortical activation twice in the patient group and once in the control group. The fMRI task processed the emotional information with face demonstration from the PennCNP test battery. RESULTS: During the processing of emotional information, patients showed activation in the middle and the inferior frontal gyri, the fusiform gyrus, and the occipital cortex. After treatment, patients showed a significant decrease in the frontal cortex activation for negative face demonstration and no frontal activation for positive emotion recognition. The left superior temporal gyrus activation zone appeared in patients after treatment and in the control group. Healthy subjects showed more intense frontal cortex activation when processing neutral emotions and less when showing happy and sad faces. Activation zones in the amygdala and the insula and deactivation zones in the posterior cingulate cortex were revealed in the controls. CONCLUSION: This study confirms the hypothesis that anomalies in the processing of emotional stimuli can be a sign of a depressive disorder.

The onset of functional movement disorders after COVID-19: A case series.

Patients with post-acute sequelae after coronavirus disease (COVID-19) report a variety of non-specific neurological complications (e.g., myoclonus, limb weakness). In particular, they manifest scenarios as medically unexplained symptoms and are known as functional movement disorders (FMDs). We present three cases of FMDs in patients of the Institute of Clinical Medicine named after N. V. Sklifosovsky (Sechenov University). All patients had a history of COVID-19 infection and reported fatigue, weakness, and jerks of upper and lower limbs. In conclusion, there might be a major possibility of the virus negatively affecting the central nervous system, including such rare neuropsychiatric complications.

COVID-19 Vaccinating Russian Medical Students-Challenges and Solutions: A Cross-Sectional Study.

Background: The role of preventive measures increases significantly in the absence of effective specific COVID-19 treatment. Mass population immunization and the achievement of collective immunity are of particular importance. The future development of public attitudes towards SARS-CoV-2 immunization depends significantly on medical students, as future physicians. Therefore, it seemed relevant to determine the percentage of COVID-19-vaccinated medical students and to identify the factors significantly affecting this indicator. Methods: A total of 2890 medical students from years one to six, studying at nine leading Russian medical universities, participated in an anonymous sociological survey. The study was performed in accordance with the STROBE guidelines. Results: It was found that the percentage of vaccinated Russian medical students at the beginning of the academic year 2021 was 58.8 ± 7.69%, which did not significantly differ from the vaccination coverage of the general population in the corresponding regions (54.19 ± 4.83%). Student vaccination rate was largely determined by the region-specific epidemiological situation. The level of student vaccination coverage did not depend on the gender or student residence (in a family or in a university dormitory). The group of senior students had a higher number of COVID-19 vaccine completers than the group of junior students. The lack of reliable information about COVID-19 vaccines had a pronounced negative impact on the SARS-CoV-2 immunization process. Significant information sources influencing student attitudes toward vaccination included medical professionals, medical universities, academic conferences, and manuscripts, which at that time provided the least information. Conclusion: The obtained results make it possible to develop recommendations to promote SARS-CoV-2 immunoprophylaxis among students and the general population and to increase collective immunity.

Cross-Sectional Study on the Comparative Assessment of Mandibular Anesthesia (Inferior Alveolar Nerve Blockage) Manual Skills Shaping among Dentists on Plastic and Biomaterial Models.

BACKGROUND: Providing regional anesthesia skills shaping remains relevant nowadays. A number of studies show that dentists have difficulties with these working independently. The study aim is the comparative analysis of the results of mandibular anesthesia (IANB) manual-skills shaping among dentists on plastic models and cadavers. METHODS: In total, 999 participants were training in the skills of mandibular anesthesia from 2017 to 2021. The participants were divided in a random way into two groups: 700 participants were trained on plastic models, and 299 were trained on the cadaver material. After a lecture on the clinical and anatomical guidelines for IANB, a demonstration of the technique was provided, with subsequent testing of the injection technique. Satisfaction with the aspects of the training was assessed using the Likert scale. RESULTS: the analysis of average values showed that participants from the group in which the manual skills were practiced on cadavers were more satisfied with the main aspects of the training, according to the sum of the main criteria of the modified scale. CONCLUSIONS: The important advantages of cadaver educational technology are that the sensations of tissue resistance are identical to natural ones, the individuality of each object, and the possibility of the visual study of the anesthesia technique, by dissection of the needle course and the location of the anesthetic depot.

Identification of Different Profiles of Illness Perception in COPD Patients: Results of Cluster Analysis.

Background: Chronic obstructive pulmonary disease (COPD) is a widespread, late-diagnosed, and difficult-to-treat disease that influences the quality of life. Despite the availability of a wide range of drugs for the treatment of COPD, none of them provides a complete cure, while the leading risk factors (primarily, smoking) persist. In this regard, illness perception and medical behavior play a key role. Methods: The study design was cross-sectional and included 143 stable outpatients (107 men, mean age 66 ± 7.5, FEV1 51.5 ± 16.5%) who attended the faculty therapy clinic of Sechenov University. The patients were examined pulmonologically and psychiatrically (Hamilton depression and anxiety rating scales). Illness perception was assessed by a brief version of the Illness perception questionnaire (brief IPQ). Results: There were no significant demographic differences and differences in the clinical severity of the disease between the selected groups. Patients in the distressed group had a longer duration of illness, a higher prevalence of anxiety and depression, and more severe dyspnea after a 6-minute walk test. In contrast, patients in the disregarding group had a significantly higher prevalence of smokers and a higher number of cigarettes smoked daily, and a lower prevalence of anxiety and depression. The harmonic had the most optimal profile with low severity of anxiety and depression, but with a healthier attitude to smoking. Conclusion: Perception of illness in COPD patients has a significant impact on medical behavior and levels of anxiety and depression. As such, the perception of illness deserves routine monitoring in clinical practice.