https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/issue/feed БИОМЕДИЦИНСКА ИСТРАЖИВАЊА 2021-12-14T14:36:40+01:00 Ана Симовић biomedicinskaistrazivanja@yahoo.com Open Journal Systems <span>"Биомедицинска истраживања" (BII)</span>, часопис Медицинског факултета Фоча Универзитета у Источном Сарајеву објављује оригиналне научне радове, претходна или кратка саопштења, прегледе литературе, приказе случајева, радове из историје медицине, приказе књига, извјештаје са научних и стручних скупова, дописе за рубрику Ин мемориам, новости и писма Уредништву из свих области медицине, стоматологије, дефектологије и здравствене његе. https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8151 Vitamin D and atherosclerosis 2021-12-14T14:34:09+01:00 Vesna Lazić lazicdrvesna@hotmail.com Biljana Mijović ww@email.com Miloš Maksimović ww@email.com Olivera Rašević ww@email.com Maida Mulić ww@email.com Maja Vuković ww@email.com <p>Cardiovascular diseases rank first on the mortality list globally<br>or 31%. The basic measure of prevention in accordance with<br>the recommendations of the World Health Organization is a<br>change in risk lifestyle in terms of diet, physical activity, tobacco<br>and alcohol consumption. Vitamin D was previously recognized<br>as a regulator of calcium and phosphorus ratio, bone<br>remodeling or the main controller of skeletal pathophysiology.<br>However, vitamin D enjoys great interest in clinical and<br>epidemiological research in terms of its possible impact on<br>reducing the risk of cardiovascular diseases. Among other<br>things, vitamin D deficiency is associated with an increased<br>risk of endothelial dysfunction. Although the deficiency has<br>been identified as a risk marker for cardiovascular diseases,<br>the mechanism of action of vitamin D on the path from endothelial<br>dysfunction to cardiovascular diseases has not been<br>fully revealed. The findings in this segment of activity of vitamin<br>D would be significant in terms of reducing morbidity<br>and mortality from cardiovascular diseases.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Vesna Lazić, Biljana Mijović, Miloš Maksimović, Olivera Rašević, Maida Mulić, Maja Vuković https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8138 The function of autophagy as a fundamental process of preserving cell homeostasis 2021-12-14T12:56:23+01:00 Nikolina Elez-Burnjaković nikolinaa85@hotmail.com Lejla Pojskić ww@email.com Sanin Haverić ww@email.com Ajla Smajlović ww@email.com <p>Autophagy is a dynamic process, conserved in all eukaryotes.<br>It is responsible for the degradation of cytoplasmic content.<br>Autophagy is crucial in cell survival and cell death. It plays a<br>significant role in the cell response to stress, nutrient deficiencies,<br>embryonic development, tumor suppression, response to<br>pathogens and aging. The process of autophagy is also involved<br>in the pathology of human diseases, such as cancer, diabetes,<br>cardiomyopathy, and neurodegenerative diseases such as Alzheimer’s<br>and Parkinson’s disease. Autophagy is a mechanism<br>that involves degradation of cells, proteins, damaged organelles<br>and pathogens through the lysosomal mechanisms, thus autophagy<br>supports cell survival during starvation, hypoxia and metabolic<br>stress. However, if extensive and/or excessive, autophagy<br>can promote apoptosis (type I) or function as an alternative celldeath<br>pathway, called autophagic cell death (type II). Autophagy<br>can either promote cancer cell death, or serve as a survival<br>mechanism against apoptosis or necrosis induced by various anticancer<br>treatments. Given the contradictory role of autophagy<br>during tumor initiation and progression, the use of autophagy<br>in therapy depends on the context and must be approached individually.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Nikolina Elez-Burnjaković, Lejla Pojskić, Sanin Haverić, Ajla Smajlović https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8135 The knowledge of nurses about prevention of infections caused by the bacteria Clostridium difficile 2021-12-14T12:45:10+01:00 Ivana Miljković ivanamiljkovic0109@gmail.com Amajla Topuz ww@email.com <p>Introduction. Clostridium difficile is the leading cause of nosocomial<br>diarrhea, associated with the use of antibiotics. The most common<br>ways of transmitting the infection in hospitals are contaminated surfaces<br>of the premises and the hands of medical staff.<br>Methods. The study involved 68 nurses/technicians employed at<br>the University Hospital Foca in the departments of surgery and internal<br>medicine. As a research instrument, we used a specially designed<br>questionnaire, created by the authors for the purpose of this<br>research.<br>Results. The research showed that 61.8% of respondents knew that<br>hand washing with warm water and soap was considered the most effective<br>prevention of the spread of infections, and 55.88% meant that<br>they used chlorine-based preparations and hydrogen peroxide as the<br>only effective disinfectant. Nurses with a work experience of less than<br>5 years showed better knowledge than other groups.<br>Conclusion. The knowledge of nurses about the prevention of C. difficile<br>infection is not at a satisfactory level, which indicates the growing<br>need for education of nurses.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Ivana Miljković, Amajla Topuz https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8128 Relationship between auditory discrimination of Serbian language phonemes and dysgraphia in different forms of written expression 2021-12-14T11:22:59+01:00 Vesela Milankov vesela.milankov@mf.uns.ac.rs Ivana Andjić ww@email.com Jelena Vrućinić ww@email.com Ljiljana Simić ww@email.com Milica Stelkić ww@email.com <p>Introduction. Writing is the most complex human ability and the<br>most direct form of communication. Auditory discrimination is the<br>ability to distinguish different sounds of language. After the age of<br>seven, difficulties in auditory discrimination, even of similar sounds,<br>are considered a pathological phenomenon. The aim of the research<br>was to determine whether difficulties in auditory discrimination of<br>phonemes are related to the manifestation of dysgraphia in children<br>of younger school age.<br>Methods. The research was conducted at the Elementary School<br>“Vuk Karadzić” in Priboj, during 2020, with the previous consent of the<br>school principal, as well as the students’ parents. The research sample<br>included fifty children of the third and fourth grade, aged 9 and 10.<br>For the purpose of this research, two tests were used: the Phonemic<br>Discrimination Test (Kostić, Vladisavljević, Popović, 1983) and the Dysgraphic<br>Handwriting Assessment Test (Ajuriaguerra, Auzias. 1971).<br>Results. There was no significant difference in achievement in the<br>Phonemic Discrimination Test between boys and girls. Half of the tested<br>students achieved the maximum score in the Phonemic Discrimination<br>Test and they were fairly equal in their achievement in the Phonemic<br>Discrimination Test. Girls generally had harmoniously developed<br>handwriting, while more than half of the boys in the categories had<br>inconsistent handwriting or dysgraphic handwriting when it came to<br>the forms of dictation, free topic and transcription. No statistically significant<br>correlations were found between the results in the Phonemic<br>Discrimination Test and the Dysgraphic Handwriting Assessment Test,<br>p &gt; 0.05.<br>Conclusion. Based on the assessment of writing ability and auditory<br>discrimination in young school children, no statistically significant association<br>was found between auditory discrimination of sounds and<br>manifestations of dysgraphic handwriting in all three forms of written<br>expression (dictation, free topic, transcription).</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Vesela Milankov, Ivana Andjić, Jelena Vrućinić, Ljiljana Simić, Milica Stelkić https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8125 The incidence of anxiety in patients with chronic subjective tinnitus 2021-12-14T11:18:01+01:00 Ljiljana Krsmanović ljiljanakrsmanovic85@gmail.com Siniša Šolaja ww@email.com Nenad Arsović ww@email.com Bojan Joksimović ww@email.com Zoran Dudvarski ww@email.com Gabrijela Šolaja ww@email.com <p>Introduction. Tinnitus is a perception of a sound in the ears<br>in the absence of acoustic stimulation whose pathophysiological<br>mechanisms have not been evaluated yet. Approximately,<br>1–2% of people report distress which can negatively affect<br>their daily performance. Our study aimed to assess the incidence<br>of anxiety in patients with tinnitus.<br>Methods. The study was designed as a cross-sectional study.<br>The participants were divided into two groups: a group of 73<br>patients with tinnitus (with two subgroups in relation to the<br>duration of tinnitus - less than one year and more than one<br>year) and a control group of 43 patients without tinnitus. We<br>examined the presence of anxiety in all patients using the<br>Burns Anxiety Inventory (BAI). The quality of life of all patients<br>was estimated by Tinnitus Handicap Inventory (THI).<br>Results. In the group of patients with tinnitus, 56.2% of them<br>had mild and 24.7% moderate hearing loss, while 27.7% of respondents<br>from control group had mild and 8.5% moderate<br>levels of hearing impairment. THI results showed that patients<br>with tinnitus less than 1 year had a significantly (p= 0.002)<br>higher level of disorders in daily life, compared with the group<br>who had tinnitus for more than 1 year. The 30.8% of respondents<br>had minimal anxiety, 26.7% borderline anxiety, 17.5%<br>mild anxiety, the same percentage of respondents moderate,<br>5% severe, while 2.5% had extreme anxiety based on BAI.<br>Conclusion. Anxiety can be considered as potentially significant<br>modulators of changes in brain structures observed in<br>people with tinnitus.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Ljiljana Krsmanović, Siniša Šolaja, Nenad Arsović, Bojan Joksimović, Zoran Dudvarski, Gabrijela Šolaja https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8091 Effect of using HEART score in patients with chest pain at the emergency department of University Clinical Centre of the Republic of Srpska 2021-12-13T10:26:02+01:00 Bojan M. Stanetić bojan.stanetic@gmail.com Nenad Jaćimović ww@email.com Šemsudin Porčić ww@email.com <p>Introduction. Recent data show that 1/5 of patients with chest<br>pain in emergency room (ER) have an acute coronary syndrome<br>that requires admission and treatment. Current guidelines have<br>endorsed the HEART score for admission, observation or discharge<br>in individual patients. We aimed to assess performance of<br>the HEART score at the University Clinical Centre of the Republic<br>of Srpska.<br>Methods. Between March 1 and March 31, 2019, all patients with<br>chest pain who presented at ER were evaluated. The HEART score<br>for each patient was calculated, and patients were stratified based<br>on the HEART score recommendation, i.e. low-, intermediate- and<br>high-risk. Patients were followed 6 weeks for major adverse cardiac<br>events (MACE).<br>Results. Out of a total of 144 included patients, 23 had low-risk<br>(0−3) HEART scores, while 73 and 48 patients had intermediate-risk<br>(4−6) and high-risk (7−10) HEART scores, respectively. The discordance<br>among intuitive judgments by clinicians and the HEART<br>score advice became typically obtrusive in patients with excessive<br>(7−10) HEART score rankings: 25 out of 48 (52.1%) patients<br>had been discharged, while the remaining 22 patients had been<br>admitted and 1 person was observed. In population with HEART<br>score rankings 4–6, MACE became recognized in 1/73 (1.4%) while<br>in patients with excessive HEART score rankings (values 7–10),<br>MACE befell in 5/48 (10.4%). Only one patient who was discharged<br>experienced MACE. The ROC analysis of the HEART score revealed<br>a value of 0.78, suggesting a good performance in discriminating<br>between low- and high-risk patients.<br>Conclusion. Discordance between clinical decision and HEART<br>score recommendation was not associated with severe clinical<br>consequences.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Bojan M. Stanetić, Nenad Jaćimović, Šemsudin Porčić https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8152 A rare thyroid disorder mimicking mitochondrial disease 2021-12-14T14:36:40+01:00 Adrijan Sarajlija adrijans2004@yahoo.com Sladjana Todorović ww@email.com Biljana Alimpić ww@email.com Maja Čehić ww@email.com <p>Introduction. Patients affected with Allan-Herndon-Dudley syndrome<br>(AHDS) have a deficiency of monocarboxylate transporter 8 (MCT8), a<br>protein primarily responsible for the transport of triiodothyronine (T3)<br>into the brain. This X-linked disorder affects almost exclusively males with<br>clinical presentation encompassing developmental delay, axial hypotonia,<br>dystonia, poor head control, quadriplegia and absence of speech.<br>Case reports. Patient 1 is a male child referred to a hospital investigation<br>at 11 months due to severe developmental delay and elevated<br>blood ammonia level (163 mcmol/L). Hypotonia and dystonic movements<br>were noted at admission, with facial dysmorphic features. Laboratory<br>findings revealed increased blood lactate (17.2 mmol/L), alanine<br>(533 mcmol/L) and ammonia (391 mcmol/L) concentrations. Serum<br>creatine-kinase levels showed substantial increase over the course of<br>hospitalization up to 6,855 IU/L. Clinical exome sequencing detected<br>a novel hemizygous frameshift insertion c.1456insC in gene SLC16A2,<br>predicted to cause loss of normal protein function either through protein<br>truncation or nonsense-mediated mRNA decay. Segregation genetic<br>testing of the family members revealed that mother, maternal<br>uncle and maternal grandmother carry the same mutation in SLC16A2.<br>The boy`s mother experienced learning difficulties through childhood<br>while maternal uncle is severely affected by AHDS. Patient 2 is a boy<br>referred to clinical geneticist due to severe psychomotor delay of unknown<br>etiology. Moderate serum lactate elevation was the only laboratory<br>abnormality during initial investigations. Diagnosis of AHDS was<br>established by clinical exome sequencing, and subsequent hormonal<br>evaluation revealed increased triiodothyronine (T3) level which corresponds<br>well to genetic diagnosis.<br>Conclusion. Presence of lactic acidosis and/or hyperammonemia in<br>children with severe developmental delay is not specific for inborn disorders<br>of energy production, such as mitochondrial disease. Clinicians<br>should consider thyroid hormones profiling in cases of unexplained<br>severe developmental delay in male children, especially if associated<br>with axial hypotonia and dystonic movements.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Adrijan Sarajlija, Sladjana Todorović, Biljana Alimpić, Maja Čehić https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8150 Puberphonia: from classic to modern approach 2021-12-14T14:30:18+01:00 Bojana Vuković bvukovic75@yahoo.com Sladjana Ćalasan ww@email.com <p>Voice is a significant component of communication that allows us to<br>express information and emotions, so it is the foundation of verbal<br>communication. Maturation of the body involves dilation of the larynx<br>and lower positioning of the larynx in the neck, resulting multiple<br>changes in voice quality. The rapid changes in the human larynx<br>during puberty are more evident in males. Such changes can result<br>in voice mutation – puberphonia. Puberphonia, also called mutational<br>dysphonia or mutational falsetto, is the failure of a natural decrease in<br>fundamental frequency or pitch. We can also defined puberphonia as<br>persistent adolescent voice even after puberty in the absence of organic<br>cause. This functional voice disorder can have multiple consequences<br>on the personality and quality of life of an individual that often<br>encounters problems that include psychological, emotional, social,<br>and professional difficulties. This article aims to review the relevant<br>and accessible literature on puberphonia in a comprehensive concise<br>manner, highlighting the etiology, prevalence, clinical manifestation,<br>consequences on quality of life, as well as evolution of the approach<br>and attitude to its treatment.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Bojana Vuković, Sladjana Ćalasan https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8136 Late postoperative complications of arteriovenous fistula for hemodialysis 2021-12-14T12:47:28+01:00 Zlatko Maksimović zlatko.maksimovic@gmail.com Nenad Lalović ww@email.com Siniša Maksimović ww@email.com <p>The vascular approach is a prerequisite for performing hemodialysis,<br>but their “weak points” are different and frequent complications. Modern<br>guidlines recommend native arteriovenous fistula (AVF) as the first<br>choice of vascular approach, because it is characterized by the longest<br>survival and the least complications compared to other vascular approaches.<br>All complications of AVF can be divided into intraoperative,<br>early, and late postoperative. This paper presents the late postoperative<br>complications of AVF, their frequency, causes, diagnosis and treatment.<br>The most important late postoperative complications are: stenosis,<br>thrombosis, aneurysm or pseudoaneurysm formation, infection, hand<br>edema, hematoma, ischemic steal syndrome, ischemic neuropathy,<br>congestive heart failure. Large differences in the frequency of each<br>complication in earlier studies can be explained by differences in surgical<br>technique, localization of AVF, diagnostic methods, but, above all,<br>differences between the presented groups of patients. It is described<br>that the age of patients, sex, underlying disease, the presence of comorbid<br>conditions and various metabolic and immune disorders characteristic<br>of chronic renal failure, as well as the way of using and caring<br>for AVF significantly affect the occurrence of AVF complications. One<br>of the main predictors of AVF success and survival is the quality of the<br>patients’ blood vessels, and therefore careful examination of blood<br>vessels before approaching AVF creation is of particular importance.<br>The creation, use and care of AVF is the task of the team of health professionals<br>who take part in the treatment of these patients, and successful<br>treatment requires their good cooperation, as well as cooperation<br>with patients.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Zlatko Maksimović, Nenad Lalović, Siniša Maksimović https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8134 Knowledge and frequency of contacts as factors in forming primary school children attitudes towards peers with developmental disabilities 2021-12-14T12:43:05+01:00 Sladjana Djorem djorem7@gmail.com Gordana Odović ww@email.com Ana Lukić ww@email.com Jelena Milić ww@email.com Bojan Joksimović ww@email.com Milena Božinović ww@email.com <p>Introduction. Higher level of knowledge and frequent contacts with<br>peers with disabilities can influence the emergence of more positive<br>attitudes of students towards peers with disabilities. In regard to that,<br>our aim was to test the importance of knowledge, contact frequency<br>and other possible factors influencing attitudes of students toward<br>disabled peers.<br>Methods. The study included 140 students of 4th and 5th grade of<br>primary schools. The research was conducted in the period from December<br>2020 to March 2021 in two primary schools. The Chedoke<br>McMaster scale was used to examine students’ attitudes toward peers<br>with disabilities, while Contact with Disabled Persons Scale and the<br>Children’s Knowledge about Handicapped Persons Scale were used<br>to assess frequency of contact and knowledge about disabilities.<br>Results. Girls showed a significantly higher level (25.21±6.21) of frequency<br>of contacts with students with disabilities compared to boys<br>(19.66±7.30) (p=0.043) and higher level of knowledge (27.88±5.88)<br>about disabilities compared to boys (25.50±4.69) (p=0.009). Respondents<br>who attended school together with children with disabilities<br>(31.07 ± 8.41) showed a significantly higher level of frequency of<br>contacts with students with disabilities compared to respondents<br>who did not attend school with peers with disabilities (13.72±6.32)<br>(p=0.001).<br>Conclusion. Higher level of knowledge and frequent contacts with<br>peers with disabilities does not have influence on the emergence of<br>more positive attitudes of students towards peers with disabilities.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Sladjana Djorem, Gordana Odović, Ana Lukić, Jelena Milić, Bojan Joksimović, Milena Božinović https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8127 Expression of tumor necrosis factor alpha, interleukin-1 and matrix metalloproteinase-9 and pathomorphological changes in acquired middle ear cholesteatoma 2021-12-14T11:20:15+01:00 Dalibor Vranješ dalibor.vranjes@yahoo.com Predrag Špirić ww@email.com Mirjana Gnjatić ww@email.com <p>Introduction. The inflammatory mediators play a central role in the<br>pathogenesis of the inflammatory process of the middle ear and cholesteatoma<br>from the aspect of initiating and maintaining the inflammatory<br>response to infection and lesion. The aim of the study was to<br>examine if the presence of acquired cholesteatoma could predict pathomorphological<br>changes of the tympanic cavity mucosa in relation to<br>the control tissue of the inflamed middle ear mucosa and to examine<br>and compare the expression levels of tumor necrosis factor-alpha<br>(TNF-α), interleukin-1 (IL-1) and matrix metalloproteinase 9 (MMP-9)<br>with pathomorphological changes in the middle ear mucosa in chronic<br>otitis media (COM), with and without acquired cholesteatoma (AC).<br>Methods. The immunohistochemical study included 178 patients of<br>both sexes, aged 5 to 75, who underwent microsurgical treatment<br>of COM from 2015 to 2018. Patients were divided into two groups<br>based on the presence or absence of AC of the middle ear: 97 with<br>cholesteatoma (CCOM) and 81 without cholesteatoma (COM). Samples<br>of the perimatrix of AC and inflamed middle ear mucosa were<br>taken intraoperatively. The condition of the tympanic cavity mucosa<br>was examined by otomicroscopy exploration intraoperatively. The<br>expression levels of TNF-α, IL-1 and MMP-9 were determined by immunohistochemical<br>analysis.<br>Results. The difference in the percentage distribution of patients according<br>to the condition of the tympanic cavity mucosa between both<br>groups was statistically significant (p &lt;0.01) where in the COM group<br>the highest frequency was 43.2% of patients with mucosal hypertrophy,<br>and in the CCOM 56.7% with granulations. With highly positive<br>expression of TNF-R2 and IL-1, a higher probability of the presence<br>of mucosal hypertrophy and granulations can be expected, and with<br>highly positive expression of MMP-9 the presence of granulations.<br>Conclusion. Acquired middle ear cholesteatoma is a statistically<br>significant predictor of the occurence of mucosal hypertrophy and<br>granulations in the tympanic cavity in relation to the control tissue of<br>the inflamed middle ear mucosa. The high expression of TNF-R2, IL-1<br>and MMP-9 shows a statistically significant association with the presence<br>of granulations and mucosal hypertrophy in acquired middle<br>ear cholesteatoma which may have clinical significance in the evaluation<br>and prognosis of the disease.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Dalibor Vranješ, Predrag Špirić, Mirjana Gnjatić https://doisrpska.nub.rs/index.php/biomedicinskaistrazivanja/article/view/8124 Analysis of anatomy and configuration of the canal system of the maxillary second premolar in the population of Bosnia and Herzegovina 2021-12-14T11:14:32+01:00 Brankica Davidović davidovicbrankica@yahoo.com Ljiljana Bjelović ww@email.com Igor Radović ww@email.com Bojana Davidović ww@email.com Svjetlana Janković ww@email.com Smiljka Cicmil ww@email.com <p>Introduction. Successful endodontic treatment depends upon the<br>clinician’s knowledge and ability to recognize and diagnose the presence<br>of anatomical and morphological variations of the root and<br>canal system. The aim of this study was to establish the number of<br>roots and root canal configurations of the maxillary second premolar<br>in the population of Bosnia and Herzegovina.<br>Methods. The study sample was comprised of 150 maxillary second<br>premolar teeth extracted for orthodontic or prosthetic reasons. Endodontic<br>drills were used for trepanation of cavum dentis, and the<br>number and patency of each root canal were determined by K- expander<br># 15. Then, the samples were decalcified, made transparent<br>and colored, to enable 3D viewing of the canal system. Decalcified<br>teeth were observed from two projections (clinical and approximal)<br>and analyzed in detail with a magnifying glass under 3 × and 5 ×<br>magnification in order to determine the number of roots, number<br>of canals, root canal configuration using Vertucci’s classification and<br>number of anastomoses between canals. Statistical significance was<br>obtained using Chi-square test.<br>Results. The results obtained by decalcification of the teeth showed<br>that, by radiographic analysis from the clinical projection, all the<br>teeth had a single root. While, by the analysis from the approximal<br>projection, 94.0% had one, 6.0% two roots. From the approximal<br>projection, 70.7% with a single root canal and 29.3% with two root<br>canals are visualized. The most common type of root canal configuration<br>in the maxillary second premolars was Type I in both clinical<br>(87.9%) and approximal projection (40.7%).<br>Conclusion. These results emphasize the importance of knowing the<br>variations in root canal morphology, because excluding the possibility<br>of morphological variations can lead to failure of endodontic therapy.</p> 2021-12-14T00:00:00+01:00 Copyright (c) 2021 Brankica Davidović, Ljiljana Bjelović, Igor Radović, Bojana Davidović, Svjetlana Janković, Smiljka Cicmil