Background The Internet as a communication tool is an essential component of daily life. Nowadays, problematic Internet use (PIU) has led to various psychosocial problems that can indirectly lead to oral diseases due to neglect of healthy behaviors. Also, college students are a large proportion of Internet users. The present study aimed to determine the association between problematic Internet use and oral health-related quality of life (OHRQoL) among medical and dental students. Methods A cross-sectional descriptive-analytical study was conducted on medical and dental students in the first and second years of education (basic sciences courses) at the Golestan University of Medical Sciences, Iran, between January and July 2020. The data collection process was carried out in the following sequence: questionnaire on demographic characteristics (age, gender, marital status, academic field, and year); Problematic Internet Use Questionnaire (PIUQ); and Oral Health Impact Profile (OHIP-14) questionnaire. Results Among 268 medical and dental students, 171 students (63.81%) [95% confidence interval: 58.02%- 69.60%] had problematic Internet use. The mean PIU score in the first-year was significantly higher than the second-year students. In addition, 65% of single students and 25% of married subjects were dealing with PIU. The statistical difference between mean OHIP scores among PIU students (12.5 ± 2.9), with average Internet usage (7.39 ± 6.6), was significant. The Spearman correlation coefficient between PIU and OHIP was 0.309 and significant (P-value < 0.000001). It indicates that students with higher PIU showed higher OHIP scores. Conclusion The present study showed that problematic Internet use was significantly associated with oral health-related quality of life (OHRQoL) among first and second-year medical and dental students. Thus, the students with problematic Internet use experienced a poorer oral health-related quality of life than average Internet users. Furthermore, appropriate preventive and interventional strategies need to be developed to encourage rational use of the Internet to protect the users' oral health, especially among medical and dental students.

In forensic medicine, it is important to identify whole or fragmented bodies. This aim can be particularly challenging in mass disasters. Palatal rugae patterns can be used as a surrogate parameter in forensic medicine. This stems from the difficulty in falsifying these patterns, their resistance to trauma, to decomposition for several days postmortem, and to combustion under high-temperatures, as well as being distinguishable among different races. The present study aimed to analyze the differences in the palatal rugae patterns among three Iranian ethnicities (Fars, Turkmen, and Sistani). This retrospective study involved the use of archived materials. The study casts were selected from the database of patients who visited a private orthodontics clinic. A total of 309 dental casts (103 Fars, 103 Turkmen, and 103 Sistani) were assessed, which belonged to 181 females and 128 males aged between 12 and 30 years (mean: 16.86 ± 3.18 years). The difference in the mean number of palatal rugae in women between the three ethnicities was statistically significant. Also, the differences in the total number of straight rugae were significant between the three ethnic groups. The most common rugae shapes in the three ethnic groups were the straight and wavy shapes. The length of the palatal rugae in the primary and secondary rugae among the study subjects younger than 18-years-old was significantly different between the three ethnic groups. Thus, the present research highlighted the differences in palatal rugae patterns among three Iranian ethnicities. Therefore, palatal rugae can be used in forensic medicine as a complementary approach to human identification.

Objective: This study evaluated the effectiveness of preventive strategies on caries risk reduction in patients undergoing orthodontic treatment, using the Cariogram program. Methods: In this quasi-experimental study, samples were selected using a convenience quota sampling technique, in a public dental school. At first, caries risk profile was determined for each subject using the Cariogram before brackets bonding. The sample size consisted of 36 patients. The intervention group (n = 18) received preventive programs, and the control group (n = 18) was trained based on the routine oral health education by means of pamphlets. Then, Cariogram parameters were calculated for patients in both groups after six months. Results: The age range of participants was from 12 to 29 years. The mean percentage of the “Actual chance of avoiding new cavities” section in the intervention group increased from 45.72 ± 21.64 to 62.50 ± 17.64. However, the mean percentage of other parameters - such as “Diet”, “Bacteria” and “Susceptibility” - decreased after six months (p< 0.001). Besides, the differences in the mean percentage between intervention and control group at the end of the study period (T1) related to the Cariogram parameters were statistically significant (p< 0.001). Accordingly, the mean percentage of ‘Actual chance of avoiding new cavities’’ parameter in the intervention group (62.50) was statistically higher than in the control group (42.44) (p< 0.001). Conclusion: Implementing different preventive approaches is able to reduce the caries risk in patients undergoing fixed orthodontic treatment, which can be clearly demonstrated using Cariogram program.