Background: Speciality choice among graduating students is important for professional development and health workforce planning. Studies of medical graduates in the United Kingdom have reported that speciality preferences may change over time. Evidence concerning speciality choice among final-year dental students in Mongolia remains limited. Identifying students’ preferences and perceived influencing factors may inform curriculum development and career guidance. Aim: To identify the factors perceived to influence speciality choice among final-year dental students graduating from the School of Dentistry, MNUMS, in 2026. Materials and Methods: This cross-sectional questionnaire study included 111 of 136 eligible final-year students (81.6%). A questionnaire adapted from Svirko et al. (2013) collected demographic information, decision status, up to two preferred specialties, and ratings of nine potential influencing factors on a three-point Likert scale (strongly influenced=2, slightly influenced=1, not influenced=0). Descriptive statistics, Pearson’s chi-square test, and Spearman’s rank correlation coefficient were used, with statistical significance set at p<0.05. Result: Of the 111 respondents, 96 (86.5%) were female and 74 (66.7%) were aged 24–26 years. Sixty (54.1%) had not finalized their specialty choice, while 37 (33.3%) had made a definitive decision. Oral and Maxillofacial Surgery and Orthodontics were each mentioned by 48 respondents (43.2%), followed by Prosthodontics (25, 22.5%). Personal motivation and conviction had the highest mean rating (1.58/2.0), whereas family members’ decisions or traditions had the lowest (0.48/2.0). Teaching methodology and faculty attitudes/communication showed a strong positive correlation (Spearman’s ρ=0.72). The reported statistical results for sex-related comparisons require verification against the original dataset. Conclusion More than half of respondents had not finalized their specialty choice. Personal motivation received the highest perceived-influence rating, while family-related factors received the lowest. Teaching methodology and faculty attitudes/communication were strongly correlated. These findings may inform further evaluation of career guidance, training environments, and clinical learning opportunities. The single-institution, cross-sectional design limits generalizability and does not establish causality.

Background: Allergic and atrophic forms of chronic rhinitis are common among the population, characterized by a chronic progressive course with a tendency toward increasing prevalence. Worldwide, allergic rhinitis affects approximately 10–40% of adults and 2–25% of children. According to a study conducted in Mongolia, the prevalence of allergic rhinitis among adults in Ulaanbaatar was reported to be 23.6%, with an increasing trend anticipated in the future. In allergic and atrophic rhinitis, structural alterations occur in the nasal mucosa, including disruption of the normal architecture of the pseudostratified epithelium and ciliated cells, accompanied by changes in goblet cell number and dysfunction of their activity, resulting in a complex pathological process. In otorhinolaryngology practice in Mongolia, there is a relative lack of studies investigating the ultrastructural changes of the nasal mucosa in allergic and atrophic rhinitis. Aim: To compare ultrastructural and histological changes of the nasal mucosa in allergic and atrophic rhinitis. Materials and Methods: Ethical approval was obtained from the Research Ethics Review Committee of the Mongolian National University of Medical Sciences at the meeting held on April 24, 2020 (Protocol No. 2020/З-04). Appropriate ethical permission was also obtained from the EMJJ ENT Hospital. Nasal mucosal tissue samples were collected from surgically resected specimens of patients aged 20–45 years diagnosed with allergic and atrophic rhinitis. The mucosal specimens were processed at the Institute of Biomedical Sciences of the Mongolian National University of Medical Sciences. Samples were fixed and dehydrated according to the protocol, coated with 100 Å gold, and examined using a scanning electron microscope (FEI Quanta FEG 250, USA). In addition, paraffin blocks were prepared, sectioned at 4 μm thickness, stained with Hematoxylin and Eosin, and analyzed histologically. Results: In allergic rhinitis, the pseudostratified epithelium was relatively preserved; however, disorganization of ciliated cells, partial loss of cilia, and goblet cell hyperplasia were observed. In contrast, atrophic rhinitis showed epithelial thinning, near-complete loss of ciliated structures, glandular atrophy, and submucosal fibrosis. Conclusion Allergic rhinitis is associated with relatively mild and predominantly functional mucosal alterations, whereas atrophic rhinitis demonstrates severe structural damage with irreversible impairment of mucosal protective function.

Background: Temporomandibular Disorders (TMD) represent a significant public health concern, heavily impacting the physical and functional well-being of young adults. This cross-sectional study investigates the prevalence and risk factors of TMD among university students, incorporating a targeted sub-cohort of orthodontic patients from dental clinics across Hunan and Inner Mongolia. It consists of ten questions that differentiate the severity of temporomandibular joint disorders, and these questions are divided into three parts. The main part includes questions 1, 2, 3, 6, and 7, which are also called the Fonseca Short Form Index (SFAI). Whether it is the FAI or the SFAI, they are simple, efficient, and accurate. The Fonseca Short Form Index has been translated into several languages and adapted to suit specific cultural needs. Aim: To determine the prevalence and severity of TMD and to evaluate the statistical association between orthodontic history, parafunctional habits, and psychological stress. Materials and Methods: An online survey (N=64) was conducted utilizing the Fonseca Anamnestic Index (FAI). The instrument demonstrated strong internal consistency (Cronbach’s α=0.759). Data analysis employed descriptive statistics and multivariate logistic regression to identify independent risk predictors. Results: The overall prevalence of TMD symptoms was 50.0% (32/64), predominantly classified as mild (45.3%). In the multivariate analysis, individuals with bruxism were 3.56 times more likely to exhibit TMD (OR=3.559, p=0.027). Furthermore, a significant dose-response relationship was established between TMD and psychological stress (OR=2.680, p=0.050). Notably, students with a history of orthodontic treatment exhibited a lower TMD prevalence (40.9%) compared to those without (54.7%), revealing no statistically significant association (p=0.311). Conclusions 1. The prevalence of temporomandibular joint disorders among students was (50.0%). 90.6% of students with temporomandibular joint disorders had mild temporomandibular joint disorders. 2. There was no statistically significant association between previous orthodontic treatment and the prevalence of temporomandibular joint disorders. 3. The results of the study indicate that psychosocial stressors and bad habits such as teeth grinding are risk factors for temporomandibular joint disorders.

Background: Temporomandibular disorders (TMD) are the most common cause of non-dental orofacial pain and affect about one-third of adults. Population-based data obtained with standardized criteria are scarce in Mongolia, particularly outside the capital. Aim: To determine the prevalence of clinical signs of TMD and of examination-based Diagnostic Criteria for TMD (DC/TMD) diagnoses among residents of western Mongolia, and to compare them by sex and age group. Materials and Methods: This retrospective secondary data analysis utilized research data collected in 2020–2021 across Bayan-Ulgii, Govi-Altai, Zavkhan, Uvs, and Khovd aimags. A total of 520 participants were included in the analysis; participants aged from 16 to 71 years, with females accounting for 72.3%. Ethical approval for the secondary use of data was obtained in 2024. Diagnoses that can be established from the examination alone (IIa, IIIa–IIIc) were assigned. Differences were tested with chi-square and Fisher’s exact tests and logistic regression. The study was approved by the MNUMS Research Ethics Committee (№24/3-06) Results: At least one clinical sign was found in 87.1% of participants; deviation on opening (58.1%) and joint sounds (56.2%) were the most common. Muscle and joint pain on opening were found in 16.7% and 18.3%, and muscle and joint pain on palpation in 8.7% and 8.3%, respectively. An examination-based diagnosis was established in 21.5% (95% CI 18.2–25.3); disc displacement with reduction (14.4%) was the most common and Group III diagnoses were found in 8.3%. Pain on palpation at three or more muscle sites was found in only 3.3%. Compared with men, women more often had joint pain on opening (21.0% vs 11.1%; p=0.009) and muscle and joint pain on palpation, and had 2.5-fold higher odds of a Group III diagnosis (OR 2.50; 95% CI 1.02–6.15). Muscle pain on opening decreased with age (from 26.7% to 10.6%; p=0.036), whereas diagnoses did not differ by age group. Conclusions Most residents of western Mongolia had at least one clinical sign of TMD, mainly deviation on opening and joint sounds, and one in five had an examination-based DC/TMD diagnosis. Painful joint conditions were more common in women. The low prevalence of myofascial pain should be interpreted in light of limited standardization of palpation.

Background: Mongolia ranks first in the world for liver cancer incidence and mortality, with more than 95% of cases associated with hepatitis B virus infection. Healthcare professionals are considered a priority group for vaccination. Aim: To investigate the level of hepatitis B virus immunization among dental specialist physicians. Materials and Methods: This retrospective, observational, analytical cross-sectional study was conducted with approval from the Research Ethics Committee of the Mongolian National University of Medical Sciences (MNUMS). We analyzed serum test data from 76 dentists officially registered in the Dentistry residency program during the 2025–2026 academic year, assessing hepatitis B virus infection status and immunization levels. Statistical analysis of quantitative data was performed using SPSS version 27. Results: Data from 76 dentists were analyzed. The mean age was 28.5±6.2 years; by age group, 70% (n=53) were aged 20–29 years, 22.3% (n=17) were 30–39 years, and 7.8% (n=6) were over 40 years (p<0.05). By sex, 13.2% (n=10) were male (p>0.05). Among the study participants, 97.4% were HBV-negative with a mean age of 28.2±5.3 years (Median: 27.0, IQR: 24.0–31.0), whereas 2.6% were infected; the mean age of infected physicians was 43.5±2.1 years (Median: 43.5, IQR: 42.0–45.0), indicating a high and statistically significant occurrence of HBV infection in the age group over 40 years (Fisher’s exact test, p=0.05). When classified by immunity level, 29.2% (n=19) had anti-HBs levels below 10 mIU/mL (insufficient), 24.6% (n=16) had anti-HBs levels of 10–99 mIU/mL (weak), and 46.2% (n=30) had anti-HBs levels above 100 mIU/mL (adequate immunity); however, no statistically significant association was observed between age groups and protective antibody levels (Fisher’s exact test, p=0.892). Conclusion Among participants, the prevalence of hepatitis B virus infection was 2.6%, vaccination coverage was 85.5%, and anti-HBs antibody titers were adequate in 46.2%.

Background: The first supposition of a possible relationship between occlusion and TMJ (temporomandibular joint) function was suggested by Costen, who hypothesized that changes in dental condition (loss of vertical dimension) can lead to symptoms of temporomandibular disorders (TMD). Symptoms of temporomandibular disorders are more common in women, with a female-to-male ratio ranging from 2:1 to 8:1. Temporomandibular disorders occur in 25-38% of the general population. The reason for conducting this study is that no research has been conducted in Mongolia on the relationship between malocclusion and TMJ. Aim: This study aimed to investigate the association between malocclusion and temporomandibular disorders. Materials and Methods: The study was conducted using a case-control design, and patients requiring orthodontic treat ment who visited the Orthodontics Department of the Center Hospital of the Dentistry, Mongolian National University of Medical Sciences were included in the case group, while relatively healthy individuals with normal occlusion who had not undergone orthodontic treatment were included in the control group. The sample size for each case and control group was calculated to be 20 people, for a total of 40 people aged 20-30. The need for orthodontic treatment was determined by the IOTN index (Index of Orthodontic Treatment Need). Relatively healthy occlusion was defined according to Andrew’s six keys. The condition of the temporomandibular joint was determined using a questionnaire and physical examination. Results: The mean age of the study participants was 24.4±3.7 years in the malocclusion group and 26.0±3.6 years in the control group, 45% (n=8) of the malocclusion group were male and 40% (n=9) of the control group were male. The indicators of malocclusion, such as increased overjet, decreased overjet, increased overbite and mouth breathing were statistically significantly different between the malocclusion group and the control group (p<0.05). Logistic regression analysis showed that CII (OR=11.66, p=0.007) and CIII (OR=16.33, p=0.017) occlusion, increased overbite (OR=6.87, p=0.025) and mouth breathing (OR=4.22, p=0.042) had an impact on the occurrence of TMJ noise in both vertical and horizontal directions. Conclusions 1. Among the study participants, Angle’s Class I accounted for 50% (the highest percentage), while Angle’s Class III accounted for 20% (the lowest percentage). But Angle’s Class II accounted for 30%. 2. Symptoms of temporomandibular joint disorder were statistically significantly higher in the case group (p<0.05). 3. People with Angle’s Class II and Class III were 11-16 times more likely to develop temporomandibular joint (TMJ) noise, a symptom of TMD, compared to people with normal occlusion.

Background: Sleep is a complex neuropsychological, biological, and physiological process essential to human health. Obstructive Sleep Apnea (OSA) is a highly prevalent disorder worldwide. In Asian countries, 12–40% of the population, and in the United States, 35.8% of the population are estimated to be at high risk for OSA. In Mongolia, however, there is limited research on the prevalence of OSA, which led to the initiation of this study. Aim: To determine the prevalence and risk level of OSA among the Mongolian population. Materials and Methods: A total of 1,405 individuals aged 18 and older from the clinical Mon-Timeline cohort study were assessed using the Berlin Questionnaire (BQ). The BQ evaluates three categories: snoring and witnessed apneas, daytime sleepiness, and high blood pressure and obesity. Individuals who met criteria in any two of the three categories were classified as being at high risk for OSA. Data on educational attainment and lifestyle behaviors were collected using the Food Frequency Questionnaire and the Global Physical Activity Questionnaire. Statistical analysis was performed using Student’s t-test, Pearson’s chi-square test (χ²), and ANOVA. Results: The mean age of participants was 42 ± 14.3 years, and 42.5% were male. A total of 24.3% (n=341) were found to be at high risk for OSA. The risk increased with age: 6.7% in individuals under 30, 28.3% in those aged 30–50, and 39.4% in those over 50. Participants at high risk for OSA tended to be older and more physically inactive. Additionally, 41.7% of all participants reported snoring, and 39.3% of those stated that their snoring disturbed others. Conclusion A significant portion (24.4%) of the Mongolian population is at high risk for OSA. These individuals are more likely to be older and physically inactive. The high prevalence of snoring and associated disturbances suggests a need for increased awareness, early detection, and age-targeted prevention strategies in Mongolia.

Background: Implant restoration necessitates meticulous attention to the profile, and texture of gingival soft tissue. The healing abutment plays a critical role as a gingival shaping tool, with its neck design significantly impacting soft tissue profile and crown aesthetics. Aim: This study explores the impact of a modified anatomic healing abutment (MAHA) on morphological changes in gingival soft tissue and patient satisfaction following mandibular first molar implant restoration. Materials and Methods: Thirty patients with a single missing mandibular first molar undergoing implant repair were randomly assigned to either the control group (n=15) or the experimental group (n=15). The experimental group received a MAHA post-dental implantation, while the control group received a standard healing abutment. Both groups underwent crown restoration after 2 months. Peri-implant soft tissue index, Pink Esthetic Score (PES), and patient satisfaction were assessed at postoperative day (T0), 1 month (T1), 3 months (T2), and 6 months (T3). Independent sample t-tests were conducted with a significance level of α=0.05, where P < 0.05 indicated statistical significance Results: No significant differences in peri-implant soft tissue index were observed between the experimental and control groups at T0, T1, T2, and T3 (P>0.05). The mean PES value in the experimental group exceeded that of the control group at T0, T1, and T2 (P < 0.05). VAS scores showed no significant differences between the groups at T0, T1, and T3 (P>0.05), but at T2, the experimental group exhibited higher satisfaction levels than the control group (P < 0.05) Conclusion The modified anatomic healing abutment for a mandibular first molar implant demonstrates superior soft tissue contouring compared to the standard healing abutment, leading to heightened patient satisfaction during prosthesis wear. Clinical Significance: The use of a MAHA in mandibular first molar implant restorations can enhance soft tissue contour and improve early esthetic outcomes without compromising peri-implant health. This approach also contributes to increased patient satisfaction during the prosthetic phase, supporting its clinical application for optimizing both functional and esthetic results in implant dentistry.

Surgical result of velopharyngeal insufficiency Background: The main purpose of primary cleft palate (CP) repair is to reconstruct anatomical structure with minimal impairment of maxillary growth and normalize velopharyngeal function and feeding process. One of the most common complications after the primary CP repair is velopharyngeal insufficiency (VPI), which leads to the subsequent surgery. The velopharyngeal function assessment characterizes speech development in children. Researches noted that VPI causes in 5-86% after primary CP repair. Early diagnosis of VPI and prompt surgical treatment are essential to prevent the development of speech disorders in children. Methods and Material: A retrospective longitudinal study was completed. The patients who diagnosed VPI after primary CP repair in the Department of Maxillo-facial surgery of the National Center for Maternal and Child Healt and had velopharyngeal function assessment were recruited to the study. The results were compared with pre and postoperative nasopharyngoscopy ratio. Results: A total of 133 patients with VPI were included: 75.9% had Furlow Z plasty, 24.1% had pharyngeal flap surgery. The patients ranged in age from 3 years 6 months to 17 years. VPI ratio was 17.3% - severe, 19.5% - moderate. Postoperative VPI ratio were 97.0% normal in the Furlow group and 84.4% in the pharyngeal surgery group (p=0.02). Nasal emission was 94.0% before surgery and 31.6% after surgery, a statistically significant difference (t = -14.2, p <0.0001). Conclusions: The Furlow Z plasty and pharyngeal flap surgeries were superior for maintaining velopharyngeal function.

Background: The main purpose of primary cleft palate repair is to reconstruct anatomical structure with minimal impairment of maxillary growth and normalize velopharyngeal function and feeding process. One of the most common complications after the primary cleft palate repair is velopharyngeal insufficiency, which leads to the subsequent surgery. The velopharyngeal function assessment characterizes speech development in children. Researches noted that velopharyngeal insufficiency causes in 5-86% after primary cleft palate repair. Therefore, it is essential to choose an adequate primary surgical method for each particular type of cleft palate. Objective: To compare velopharyngeal function using nasopharyngoscopy after primary CP repair Materials and Methods: The patients who with congenital cleft palate and, underwent primary cleft palate repair in the Department of Maxillo-facial surgery of the National Centre for Maternal and Child Health and had velopharyngeal function assessment were recruited to the study. Patients with wound dehiscence and oronasal fistula postoperatively were excluded from the study.
Cleft palate was classified according to the Veau system and Golding-Kushner scale of nasopharyngoscopy was used to assess patient’s velopharyngeal function in order to associate with cleft types and the primary palatoplasty techniques. Pearson’s chi-squared analysis and Fisher exact test were used for statistical analysis. Results: A total of 335 patients were included in the study. The mean age at primary palate repair was 22.9±13.6 months. There were 56, 42, 177, and 60 patients with Veau-I type, Veau-II type, Veau-III type and Veau- IV type respectively, whereas for primary palatoplasty 65 patients underwent Furlow technique, 148 patients – Mongolian technique, 108 patients – Two flap technique, 34 patients – Von Langenbeck technique.
Nasopharyngoscopy assessment of adequate velopharyngeal function was as followed as by “Furlow” technique in 89.4% cases, ”Mongolian” technique in 62.2% cases but by “Two flap” technique only in 48.1% and Von Langenbeck technique in 47.1% cases. Conclusion The Furlow and Mongolian techniques were superior for maintaining velopharyngeal function after primary palatoplasty.