Background: Dental caries is a worldwide spreader infectious decease. According to the present studies, the prevalence of the disease is highly dependent on the developmental of the country and its prevention strategies. By the World Dental Federation and World Health Organization (WHO) criteria, dental caries prevalence is increasing every year in Mongolia, which is becoming one of the main problems in our country. According to studies, the most effective method of decreasing prevalence of caries is to have an oral health knowledge, provide caries treatment on early-stage and focusing more on prevention. Aim: The aim of our study was to determine the oral health status among the groups aged between 5, 12, 35-44, 65-74. Materials and Methods: The study has consisted 3512 subjects who selected from 4 age groups (5, 12, 35-44, 65-74) and from 6 districts of Ulaanbaatar city and 5 provinces of Mongolia. The oral examination of each person was done by calibrated dentists according to recommendation of WHO, 2013. The statistical analysis was processed using statistical software system (Stata version 16.0). Result: The prevalence of dental caries and mean of Decayed, Missed, Filled, permanent teeth (DMFt), decayed filled primary teeth were 87.6%, 6.2±0.14 among 5 years old, 77.0%, 2.2±0.03 among 12 years old, 98.1%, 11.8±0.19 among 35-44 years old, 99.8%, 23.6±0.27 among 65-74 years old. The good oral hygiene index was 51.5%, 46.3%, 49.0% and 65.7%. The prevalence of gingivitis was 2.3%, 9.8%, 34.5%, 17.6% and of calculus 0.8%, 7.6%, 62.8%, 31.6%, respectively above groups. The percent of people with removable dentures among 65-74 years old was higher than among 35-44 years old. Conclusion Across multiple age groups, the prevalence and severity of dental caries remain high. Oral hygiene status is predominantly classified as fair to poor. Among adults, partial or complete tooth loss is common; however, the utilization of dental prostheses is low, indicating inadequate prosthetic rehabilitation and limited adaptation to tooth replacement.

Background: Numerous studies have shown that air pollution is a serious public health threat and risk worldwide. Mongolia is the world leader in outdoor and indoor air pollution, and the morbidity and mortality caused by it are increasing every year. People spend most of their lives indoors, and it is necessary to regularly assess and study indoor air pollution. Aim: To study the concentration of PM2.5 particles in the indoor air of households in Ulaanbaatar and Darkhan cities in relation to some symptoms of respiratory diseases. Materials and Methods: The study was conducted using an analytical cohort design from October 2023 to July 2025, and the 4 districts of the central Ulaanbaatar city and Darkhan cities were included in the study. A total of 240 households were included in the study, including 48 households living in ger and house, 24 households living in apartments, and 48 households living in ger and house, and 24 households living in apartments from Ulaanbaatar city. A direct measurement device (PurpleAir) was installed in the households for 3-4 weeks to measure PM2.5 particles in the indoor air for 24 hours. After measuring PM2.5 particles in the indoor air of the household, data were collected through questionnaires from the participants aged 18-60 who participated in the study and underwent health examinations. The results were processed using STATA-19.0 and R programs. Result: 213-239 households were selected for the study, including households living in 17-26 apartments, 42-58 houses, and 38-50 houses. The 24-hour average concentration of PM2.5 particles in the ambient air of households in Ulaanbaatar city was measured relatively higher in winter and summer than in households in Darkhan city. Among the districts of Ulaanbaatar city, the highest concentration of PM2.5 particles was measured in Songinokhairkhan district, and the lowest concentration was measured in Bayanzurkh district. Considering the cities by heating type, households with stoves are more polluted than households with centralized heating. In Darkhan city, the lowest concentration was measured in apartments (22.78-31.53 μg/m³), houses (44.53-68.17 μg/m³), and the highest concentration was measured in traditional felt houses (houses) (63.20-68.25 μg/m³). In Ulaanbaatar, PM2.5 concentrations were relatively high in all types of housing, including apartments (41.61-58.37 μg/m³), houses (79.22-92.50 μg/m³), and traditional felt dwellings (76.69-86.31 μg/m³). In the summer, PM2.5 concentrations in Darkhan were 3.10-10.03 μg/m³ in apartments, 7.67-14.37 μg/m³ in houses, and 7.98-17.90 μg/m³ in traditional felt dwellings (houses). The concentration of PM2.5 particles in the ambient air of the settlement is statistically significantly associated with shortness of breath, fatigue, weakness, muscle pain, nausea, palpitations, sneezing, runny nose, conjunctivitis, pain in the eye socket, tearing of the eyes, headache, fever, nasal congestion, cough, loss of appetite, sore throat, phlegm, wheezing, and chest pain. Conclusion The 24-hour average concentration of PM2.5 particles in indoor air in households in Ulaanbaatar and Darkhan cities is higher than the Mongolian standard during winter and is statistically significantly associated with some symptoms of respiratory diseases.

Background: Visual impairment may negatively affect children’s daily activities, educational opportunities, and hygiene practices, including their ability to maintain oral hygiene independently. Therefore, assessing the oral health status of visually impaired children is important for improving access to dental care services and developing preventive oral health programs. Aim: To compare the oral health status of visually impaired and sighted children. Materials and Methods: A total of 174 children from grades 1–12 of School No. 116 for visually impaired children and Logarithm School in Ulaanbaatar were included in this study. Oral examinations were conducted using an examination form developed according to the World Health Organization (WHO, 2013) guidelines. The study was carried out using a descriptive cross-sectional design, and the collected data were statistically analyzed. Result: Among visually impaired children, the prevalence of dental caries was 77%, with a mean DMFT index of 4.4±3.8. Among sighted children, the prevalence of dental caries was 75.9%, with a mean DMFT index of 4.7±3.8. The prevalence of gingivitis was 18.4% in visually impaired children and 11.5% in sighted children. Oral hygiene status was predominantly classified as poor or fair among visually impaired children, whereas a good level of oral hygiene predominated among sighted children. Conclusion 1. The prevalence and severity of dental caries were similar between visually impaired and sighted children. 2. The prevalence of gingivitis was comparable between visually impaired (18.4%) and sighted children (11.5%). 3. Oral hygiene status was generally poorer among visually impaired children, while sighted children predominantly demonstrated good oral hygiene.

Background: Children with disabilities experience long-term impairments in one or more developmental domains, including cognitive, communicative, motor, behavioral, sensory, and self-care functions, often requiring continuous support in daily life. These children are particularly vulnerable to poor oral health due to a combination of factors such as limited motor coordination, dependence on caregivers, longterm medication use, and unfavorable dietary patterns. Consequently, they are at increased risk for dental caries, periodontal diseases, and oral infections. In Mongolia, oral health disparities among children with disabilities remain insufficiently explored, and evidence-based data on their treatment needs are limited. Addressing this gap is essential for planning targeted preventive and therapeutic strategies. Aim: To evaluate the oral health status and determine the dental treatment needs of children with disabilities in Ulaanbaatar, Mongolia. Materials and Methods: A descriptive cross-sectional study was conducted among 888 children with disabilities attending special education schools in Ulaanbaatar. Oral examinations were performed following ethical approval (No. 2023/3-06) from the Research Ethics Committee of the Mongolian National University of Medical Sciences. Dental caries was assessed using dmft/DMFT indices, and oral hygiene status was evaluated using a plaque index. Data were analyzed using Stata 16.0, with statistical significance set at p<0.05. Result: The overall prevalence of dental caries was 85.5%, indicating a substantial disease burden. Caries prevalence and mean experience were 66.7% and 5.28±4.58 (dmft) in primary dentition, 86.2% and 5.23±3.75 (DMFT + dmft) in mixed dentition, and 83.6% and 5.44±4.00 (DMFT) in permanent dentition. Oral hygiene assessment showed that only 9.8% of children had good hygiene, whereas 46.3% exhibited poor oral hygiene, which was consistently associated with higher caries levels across diagnostic groups. Notably, 83.3% of children had at least one untreated decayed tooth or caries-related complication, reflecting a considerable unmet treatment need. Conclusion 1. The prevalence of dental caries among children with disabilities in Ulaanbaatar was 85.5%. Specifically, during the primary dentition stage, the prevalence was 66.7% with a mean caries experience of 5.28±4.58 (dmft). In the mixed dentition stage, the prevalence increased to 86.2% with a mean caries experience of 5.23±3.75 (DMFT+dmft). During the permanent dentition stage, the prevalence was 83.6%, with a mean DMFT score of 5.44±4.00. 2. Assessment of oral hygiene status using the plaque index revealed that 9.8% of the children had “Good” oral hygiene, 43.9% had “Fair” hygiene, and 46.3% had “Poor” oral hygiene. 3. The caries profile was predominantly characterized by untreated decayed teeth, and a strong direct association was observed between dental caries and oral hygiene status. Overall, 83.3% of the children required oral healthcare services and treatment, with the highest needs observed among those with permanent dentition, males, and children with intellectual disabilities.

Background: According to the World Health Organization (WHO), 6.7 million people die annually due to air pollution caused by solid fuel use, with the majority of deaths resulting from respiratory diseases and cardiovascular conditions. In Mongolia, air pollution ranks as the fourth leading risk factor contributing to mortality, following hypertension, diabetes, and other major health risks. Although there have been numerous studies on outdoor air pollution in Mongolia, research linking indoor air pollution at the household level with the health status of residents remains limited. Aim: To compare indoor PM2.5 concentrations in households of Ulaanbaatar and Darkhan and examine their association with hypertension during the winter season. Materials and Methods: The study was conducted during November and December 2023, and January 2024, involving 240 households in Ulaanbaatar and Darkhan. Indoor PM2.5 concentrations were measured using Purple Air real-time sensors continuously for 24 hours over approximately one month. After measuring indoor air pollution, individuals aged 18–60 years living in the selected households were recruited based on specific inclusion criteria. Blood pressure was measured three times and the average value was recorded. Information on respiratory illnesses was collected through structured questionnaires. Statistical analysis was performed using STATA version 19.0. Results: A total of 241 households participated in the study, with 116 from Ulaanbaatar and 125 from Darkhan. Of the participants, 46.5% were male and 53.5% were female. In terms of housing type, 96 households (39.8%) lived in gers, 97 (40.2%) lived in stove-heated houses, and 48 (19.9%) lived in apartments. Among all participants, 66.0% (n=159) had hypertension and 34.0% (n=79) had normal blood pressure. Among participants aged over 40, 69.9–88.5% had hypertension, which is statistically significantly higher compared to younger individuals (p=0.0001). By body mass index, 75.3% (n=72) of overweight individuals and 78.4% (n=58) of obese participants had hypertension, showing a statistically significant difference compared to participants with normal weight (p=0.0001). The 24-hour average concentration of indoor PM2.5 was measured using the Purple Air device, and the levels in gers and stove-heated houses exceeded the limit set by the MNS 4585:2025 standard (37.5 µg/m³) Conclusion This study identified a relationship between environmental factors, such as air pollution and housing type, and the prevalence of hypertension. The indoor PM2.5 concentration in gers and stove-heated houses was above the standard limit, indicating a negative impact on the health of those residents. Furthermore, the high prevalence of hypertension among participants over the age of 40 and those who are overweight suggests a possible link to lifestyle and environmental conditions.

Background: Particulate matter with an aerodynamic diameter of 2.5 micrometers or smaller (PM2.5) penetrates deep into the alveoli through the respiratory tract and is characterized by its ability to induce oxidative stress, systemic inflammation, and vascular inflammation. Mongolia ranks among the countries with the highest levels of air pollution. In Ulaanbaatar, where more than half of the country’s population resides, wintertime PM2.5 concentrations often exceed 200 μg/m³, which is about eight times higher than the World Health Organization (WHO) guideline value. A study involving 1,200 adults in Ulaanbaatar showed that quality of life deteriorated sharply during periods of high air pollution, with effects more pronounced among individuals who already had impaired respiratory function. Aim: To examine the relationship between indoor household PM2.5 concentrations and lung function indicators among adults in Ulaanbaatar and Darkhan. Materials and Methods: This analytical cross-sectional study recruited adult participants from Ulaanbaatar and Darkhan through targeted sampling. Household air quality was measured using PurpleAir sensors, which were installed in participants’ homes for one month. After exposure measurement, lung function was assessed via spirometry. Statistical analyses were conducted using SPSS version 25.0. Results: A total of 236 participants were included: 114 (48.3%) from Ulaanbaatar and 122 (51.7%) from Darkhan. The sample consisted of 111 men (47.0%) and 125 women (53.0%). The mean indoor PM2.5 concentration was 66.24 μg/m³ (SD 44.87 μg/m³), ranging from a minimum of 7.79 μg/m³ to a maximum of 264.55 μg/m³. Stratification by housing type showed the highest PM2.5 levels in gers (82.34 μg/m³), followed by detached houses (67.34 μg/m³), while apartments had the lowest concentrations (32.24 μg/m³). Correlation analysis revealed statistically significant negative associations between PM2.5 levels and measures of expiratory function, including the FEV1/FVC ratio, peak expiratory flow (PEF), and mid-expiratory flow (FEF25–75). Reduced forced vital capacity (FVC) was observed in 9.4% of participants, reduced forced expiratory volume in one second (FEV1) in 15.3%, and a decreased FEV1/FVC ratio in 3.8%. Conclusion Indoor household PM2.5 concentrations were highest in gers, and expiratory flow-related lung function parameters showed significant negative associations with particulate exposure. This suggests that indoor PM2.5 primarily affects airflow limitation rather than overall lung volumes in this population.

Dental caries is prevent problem, not only Mongolia, but also world wide. According to World Health Organization’s report in 1976 the mean DMFT of 12 years old of Mongolian children was 1.48 and in 1990 was 2.6. According to Mongolian research studies, the prevalence of caries and mean DMFT children within the age range of 3-17 years old was 79.2% and 3.88 and in 3-5 years old children were 4.9 correspondingly. Several investigators have reported increasing caries rate among Mongolian children, especially those living in cities. The aim of this study to access dental caries status among preschool, children of Ulaanbaatar city, Mongolia.The study covered 294 preschool children who were 3 - 5 years randomly selected from 2 kindergartens of Ulaanbaatar city. Design: Cross – sectional study, oral epidemiological survey based on World Нealth Organization methodology clinical examination.The caries prevalence of all preschool children was 85%. The caries prevalence in 3 years old children was 75.6%, in 4 years old, it was 85.78% in 5 years old, it was 93.8%. The caries prevalence was high among 5 years old children. The mean dmft score was 6.2±0.2 all children.Only 15% of the children were caries free. The caries prevalence of the preschool children was 85%, and the mean dmft (decayed, missing, filled tooth) were 6.2±0.2. The dental caries prevalence and mean dmft score among preschool children of Ulaanbaatar city were “VERY HIGH” stage which is determined by criteria World Health Organization.

The aim of this study to assess dental caries status and some growth indices among preschool children of Ulaanbaatar city, Mongolia. The study population consisted of 499 preschool children aged 3-5 years old randomly selected from 6 kindergartens of Ulaanbaatar city. The all children were examined oral examination and body weight and height by anthropometric methods. 1. The caries prevalence of all preschool children was 92.9%. The mean dmft and dmfs score were 8.2±4.8 and 11.7±8.6 of all children, 8.4±4.6 and 12.9±9.1 of 5 years old, 7.8±5.4 and 10.9±9.1 of 4 years old, 8.4±4.7 and 11.3±7.7 of 3 years old, respectively (p<0.01).2. The average body weight and height were 15.8±2.2 кg and 97.7±5.8 cm of 3 years old, 17.2±1.8 kg and 103.4±4.7 cm of 4 years old, 18.5±2.3 kg and 108.1±5.5 cm of 5 years old, respectively (p<0.001).The dental caries prevalence and mean dmft score among preschool children of Ulaanbaatar city were “VERY HIGH” stage, which is determined by criteria WHO. The body height and weight of preschool children of Ulaanbaatar city are increasing year by year. There is not observed significantly the relationship between dental caries status and body growth indices

Purpose: To study some growth indices and dental caries status of twins of kindergarten, Ulaanbaatar city.Methods: The study group consists of 7 pairs or 14 twins and control group consist of 14 children, who were same aged and same classmates of twins. The body weight and height of all children was measured by anthropometric methods and dental examination was done by WHO criteria 2003. The plaque index was determined by Pederov-Volodkini and caries activity was determined by Shimono (1974).Results: 1. The average body weight of study group was lower than control group, but the average body height of study group was higher than control group (p<0.01). 2. The mean deft score 6 dft, 7 dfs in study group and 8 dft, 12 dfs in control group, respectively (p<0.05). 3. Satisfactory of oral hygiene index was 64% in study group and 57% in control group (p<0.05). 4. When we determined the caries activity, high caries activity group was 50% in study group and 57% in control group (p<0.01). Conclusion: The risk factors and scores of dental caries of twin were lower than the control group. In the future we have to carry detailed study to relationship between body weight and mean dft score.