Background: Reconstruction of mandibular and maxillary defects resulting from malignant tumors has remained a complex challenge in recent years. Defects caused by tumors—as well as trauma, inflammatory diseases, and congenital anomalies—lead to impaired essential functions such as mastication, swallowing, and speech. Prior to the 1950s, reconstruction of maxillofacial hard tissue was not commonly performed. Instead, metal plates were used to reestablish bony continuity, and surrounding tissues were utilized to close soft tissue defects, without effectively restoring function. With modern advances in three-dimensional (3D) virtual planning, it is now possible to accurately plan free bone flaps for reconstructing jaw defects. During surgery, manually bending reconstruction plates to fit donor bone precisely is often not feasible. Preoperative 3D planning allows for precise fabrication of surgical guides and fixation plates, improving accuracy and significantly reducing operative time. Additionally, incorporating dental implant planning into the reconstruction process facilitates restoration of both structural and functional outcomes. Aim: To evaluate the outcomes of mandibular defect reconstruction using scapular free flaps in Mongolia and explore potential approaches to optimize the technique. Materials and Methods: This was a case study series. Data from reconstructive surgeries performed at the National Cancer Center of Mongolia, Central Dental Hospital, and the Mongolia-Japan Hospital were collected. Variables included patient age and sex, etiology of the mandibular defect, size of the scapular bone segment, operative time, ischemia time of the free flap, number of vascular anastomoses performed, and pedicle length. For 3D planning, CT scans of the patient's head and lower limb (slice thickness <1 cm) were used to generate 3D models via the 3D Slicer software. Cutting guides for the mandible and scapula (ASIGA), as well as the reconstruction models (AMS), were printed using a 3D printer. Results: A total of 400 free flap reconstructions were performed during the study period. Of these, 29 cases involved reconstruction of mandibular defects using scapular free flaps. The mean age of patients was 40.0 ± 18.3 years, with 52% (15 patients) being female. The etiologies of the defects included malignant tumors (13 cases, 45%), benign tumors (6 cases, 21%), and pre-existing defects (10 cases, 34%). In one case, tumor resection and mandibular reconstruction were performed using 3D planning. The total operative time was 9 hours and 30 minutes, and the ischemia time was 2 hours and 40 minutes. Conclusion Between 2012 and 2025, a total of 29 mandibular reconstructions using scapular free flaps were performed in Mongolia. Traditional reconstruction methods were associated with prolonged ischemia time. The use of 3D surgical planning has shown potential in significantly reducing ischemia time and improving surgical outcomes.

: We report a case of a 1-year-6-month old baby presenting with classic clinical of Prader-Willi syndrome, a rare congenital disorder. Early identification and multidisciplinary management are critical to improving outcomes. Case presentation: Patient U is a 1.5-year old male. Due to his inability to breastfeed for the first day after birth, diagnostic tests were initiated. He was dependent on tube feeding for over two months. At 9 months, the child was able to hold their head up and began sitting independently around 11 months. His eyes are slightly slanted, the bridge of his nose is narrow, the upper lip is thin, and the corners of his mouth are downturned.The skin soft texture. Muscle tone is noted to be weak. The size of the arms and feet is small. Additionally, the neck is of short stature. Cytogenetic Analysis: November 2023. The analysis identified a microdeletion in the 15q11-q13 chromosomal region. He was discharged from the hospital upon demonstrating the ability to suck effectively, achieving consistent weight gain, and having his sucking and swallowing activities adequately controlled. Discussion and Conclusion Prader-Willi syndrome is a genetic disorder resulting from the non-expression of a gene located on chromosome 15 at the 15q11.2–q13 region. The prevalence of corresponding to an approximate global total of 350,000 to 400,000 cases. The sex ratio is equivalent at 1:1. In the initial year of life (0–1 year), affected infants commonly present with muscle weakness, difficulties in feeding, reduced sucking capabilities, absence of crying or vomiting, diminished motor activity, poor muscle strength, and low weight. For individuals aged 1 to 10 years, symptoms encompass increased appetite, obesity, delays in speech and psychomotor development, a long facial structure, narrow forehead, downturned mouth and eyes, small hands and feet, along with other distinctive facial features. In adolescence and adulthood, prevalent symptoms may include behavioral changes, irritability, uncontrolled eating habits, diabetes, and depression. From infancy onward, holistic care may include nutritional interventions (such as tube feeding and specialized diets), strategies for heat retention, enhancement of sucking abilities. Cardiovascular and respiratory monitoring, weight management, physical activity support, health education for families and caregivers, growth hormone therapy, psychological counseling, sex hormone replacement therapy, and assistance with movement, psychomotor skills, cognitive and intellectual development, alongside speech therapy. Timely diagnosis, integrated multidisciplinary care, and proactive family involvement have the potential to markedly enhance the quality of life for affected individuals.

65 Non-bacterial originated tooth wear is a normal process which occurs throughout lif. If the rate of loss is likely to prejudice the survival of the teeth, or is a source of concern to the patient, then it may be considered ‘pathological’. Robb reported that the prevalence of pathological loss of tooth tissue in patients less than 26 years of age was greater than in many older age groups. Tooth surface loss was classified into 4 groups: attrition, erosion, abfraction and abrasion. To find the prevalence of four different types of tooth wear among patients visited Digital Dental Office, Ulaanbaatar, Mongolia and investigate their dental attrition severity. Methods: From total of patients visited Digital Dental Office clinic between September 2016 and September 2017 adults aged 16-62 who was found with any type of tooth wear were explored by 4 types. Those patients with attrition were chosen and severity was determined by Bardsley’s simplified tooth wear index (TWI). There were total of 5432 patients examined and treated during this period of time. From them total of 1002 patients aged 16-62 presented some degree of tooth hard tissue wear/dental attrition. Most of the patients were with combination of 4 types of tooth wear: attrition, abrasion, abfraction and erosion. Attrition (At) was found in 68 patients which was only 6.7%, Abrasion (Ab) in14 people-1.3%, Abfraction (Abf) in 4-0.3%, Erosion (Er) in 2 -0.1% alone. The combination of these types of tooth hard tissue was dominant. At+ab+abf+er in 59 patients of total 1002 (5.8%). At+ab+er in 58 (5.7%). Ab+abf in 29 (2.8%). At+er in 25 patients (2.4%). Er+ab in 27 (2,6%). At+abf+er in 264 people (26.3%). At+abf in 452 (45.1%), which was the most prevalent combination. Dental attrition severity in these 1002 patients were shown as following: -0-0- No loss of contour. -1-229 people (22.8%) - Loos of enamel surface characteristics. Minimal loss of contour. -2- 505 people (50.3 %) - Loss of enamel exposing dentine for less than one third of surface.Loss of enamel just exposing dentine. Defect less than 1 mm deep. -3- 211 people (21 %) - Loss of enamel exposing dentine for more than one third of surface.Loss of enamel and substantial loss of dentine. Defect less than 1-2 mm deep. -4-57 people (5.6%) - Complete enamel loss - pulp exposure - secondary dentin exposure.Pulp exposure or exposure of secondary dentine. Defect more than 2mm deep - pulp exposure - secondary dentine exposure. In this descriptive study showed patients with some degree of tooth wear were around 19% from total patients visited during 1 year of period. Four types of tooth hard tissue wear shown as a different combination, very low percentage was in these types alone. Most of the attrition patients were with mild to moderate degree of enamel loss. This kind of study should be continued to explore harmful dentofacial change

To analyze the results of the forensic psychiatric examination in the period of time from 2006 to 2013 year.We analyze retrospectively 7180 material of clients attended to forensic mental examination in the National center of mental health from 2006 to 2013 year.From all 7180 clients that attended to forensic mental examination in the 2006-2013 the 1165 clients or 16.2% were with mental disorders. The 543 clients or 7.5% of all attended to examination were with mental retardation and 59.8% of mentally retarded clients were with mild mental retardation, 33.8% with moderate, 5.3% with severe and 0.9% with profound mental retardation. The 97.3% (n=6989) of all clients investigated first time, 158 or 2.2% second time, and 33 or 0.45% third or fourth time. From 7062 criminal cases 4.98% or 352 investigated clientsdeemed incompetent and from 115 civil cases 57.3% or 66 clients deemed incompetent. From the clients with mental retardation deemed incompetent in criminal cases the 23.5% and 7.5% in civil cases.Results of the analysis show that about 16.2% of all investigated clients have some mental disorders and 46.6% of them have mild mental retardation.

The term ‘‘learning styles’’ refers to the concept that individuals differ in regard to what mode of instruction or study is most effective for them. There are some types of learning style model in the world and one of them is VARK model which was developed by N.Fleming. Teaching willbecome more effective when determine learning styles of students and teach them suitable way with their learning styles. The main goal of our study is to determine learning styles of nursing students. A descriptiveconfidential questionnaire survey was conducted on 100 students who are learning at Nursing School of MNUMS. They filled VARK questionnaire with 16 question.There are most common learning style was kinesthetic one and it means teaching will be more effective when simulation, close handed and practical sets are used and increased practice hours in the curriculum.

BACKGROUNDThe term ‘‘learning styles’’ refers to the concept that individuals differ in regard to what mode of instruction or study is most effective for them. Assessment of learning styles has significant importance in a sense that trainers can update their curriculum and teaching methods by taking learning styles of learners into account.The main goal of our study isto determine learning styles of resident doctors.METHODSWe used descriptive methods and quantitative analysis for our study. Honey and Mumford learning style questionnaire was used to determinelearning styles of residents. 144resident doctorsout of 475 agreed to participate in the study and completed questionnaires.RESULTSAnalysis of learning styles revealed that most common styles for residents are reflector (63.9%) and theorist (16.7%) followed bypragmatist (10.4%) and activist (9.0%). CONCLUSIONSBased on our results, we must consider increasing the mutual study and behaviour changing activities in our curriculum to helpresidents to be more independent and productive by promoting their skills of self-expression, critical and creative thinking.