Bullying or peers violation is one of adolescent`s truly urgent issue but it is not public discussion topic. We conducted a study in 3 different schools which began from 6th of October, 2014 to 13th of October, 2014. There are total 167 subjects aged between 13-18 were from classes of junior and senior- high at: Orchlon school, School of 1 and School of 13. We used 53- item Questionnaire consisted of 4 sections for our study. We concluded 98(58.7%) participants from School of 1, 26(15.6%) participants from School of 13 and 43(25.7%) participants from Orchlon school who were aged between 13-17 (M=14.7±0.1) which comprise of 84 (50.3%)male and 83 (49.7%) female in our study We assessed correlation of depression and bullying by linear regression. The result of it shows 1 more score of depression measuring scale-CES-D can rise score of Aggression scale 1 by 0.33 point and also it can rise score of Aggression scale 2 by 0.84 point. There is a positive correlation between bullying and depression which confirms high risk of bullying is associated with majordepression in significantly. (p value 0.000) The findings of the study reveals that high levels of bullying associated with high levels of depression.

Background: Mastication is a biomechanical process that involves the jaws and teeth working together to effectively break down food through the contraction of masticatory muscles. The efficiency of this process is influenced by factors such as bite force, the integrity of the dental arch, and individual characteristics, including age, gender, and body weight. Previous research has investigated the bite force of natural teeth, comparing the differences between removable and fixed denture teeth. For instance, Gibbs et al. estimated the bite force of Eskimo individuals to be 348 lbs (138 kg), while Al-Za rea et al. reported a bite force of 580.9 N for fixed partial dentures. Additionally, J. Urangua estimated the bite force of first permanent molars to be 472 N. Although studies have explored the bite force of Mongolian individuals with removable dentures, there has been no investigation into the bite force of fixed partial dentures, highlighting a significant gap in the literature that the current study aims to address. Aim: This study aims to assess the bite force following the restoration of teeth with Zirconia and Porcelain-Fused-to-Met al crowns. Materials and Methods: The study involved 20 individuals aged 18 to 34 years, each of whom had their mandibular molars restored with Zirconia and Porcelain-Fused-to-Metal (PFM) crowns on one side, while the other side retained their natural teeth, which had not undergone root canal treatment and exhibited no significant alveolar bone loss. A sin gle-instance design was employed to measure occlusal force using the Occlusal Force Meter GM10. Statistical analysis was conducted using SPSS 26.0 software, with results considered statistically significant at a probability level of p < 0.05. Results: The cohort comprised 20 subjects aged 18 to 34 years, with 65% (13) male and 35% (7) female, yielding a mean age of 28.2 ± 3.5 years. The mean bite force for teeth covered with crowns was (393.2±0.3 N), compared to (445.5±70 N) for natural teeth. Notably, the bite force of the Zirconia crown (407.0±0.7 N) was higher than that of the Porce lain-Fused-to-Metal (PFM) crown 367.7±0.9N. When analyzed by gender, the bite force of natural teeth in men averaged 484.1±46.2N, while that of crowns was 445.3±43.7N. In women, the bite force of natural teeth averaged 373.7±15.4N, compared to 296.4±19.6 N for crowns. Conclusion 1. The bite force of zirconia porcelain crowns was 407.0±76N, while the bite force of metal porcelain crowns was 367.7±97N. 2. When determining the bite force of crowns and natural teeth, the bite force of crowns and natural teeth was 296.4±19.6N, and the bite force of uncoated teeth was 445.5±70N, respectively. 3. When compared by gender, the bite force of uncoated teeth in men was 484.1±46.2N, the bite force of coated teeth was 445.3±43.7N, and the bite force of uncoated teeth in women was 373.7±15.4N, and the bite force of coated teeth was 296.4±19.6N, and the bite force was significantly related to gender (p<0.0001).