Effects of low-dose ionizing radiation on the molecular pathways linking neurogenesis and autism spectrum disorders in zebrafish embryos.

Prenatal exposure to environmental factors may play an important role in the aetiopathogenesis of autism spectrum disorder (ASD). We aim to investigate the potential effects of low-dose x-rays from dental diagnostic x-rays on neurodevelopment and molecular mechanisms associated with ASD in developing zebrafish embryos. Zebrafish embryos were divided into four groups and exposed using a dental x-ray unit: control, 0.08, 0.15 and 0.30 seconds, which are exemplary exposure settings for periapical imaging. These exposure times were measured as 7.17, 23.17 and 63.83 mSv using optical stimulated luminescence dosimeters. At the end of 72 hours post-fertilization, locomotor activity, oxidant-antioxidant status, and acetylcholine esterase (AChE) activity were analyzed. Expression of genes related to apoptosis (bax, bcl2a, p53), neurogenesis (α1-tubulin, syn2a, neurog1, elavl3) and ASD (eif4eb, adsl2a, shank3) was determined by RT-PCR. Even at reduced doses, developmental toxicity was observed in three groups as evidenced by pericardial edema, yolk sac edema and scoliosis. Deleterious effects of dental x-rays on neurogenesis through impaired locomotor activity, oxidative stress, apoptosis and alterations in genes associated with neurogenesis and ASD progression were more pronounced in the 0.30s exposure group. Based on these results we suggest that the associations between ASD and low-dose ionizing radiation need a closer look.

Radiological Associations between Posterior Edentulism and Condylar Bony Changes: A Retrospective Study.

This retrospective study aimed to investigate the relationship between posterior edentulism and condylar bone changes in patients aged 35-60 years. The CBCT images of 259 patients, including 131 posterior edentulous and 128 posterior dentulous patients, were analyzed to identify the types of condylar bone changes. The frequency of flattening, sclerosis, erosion, and reduced joint space was found to be higher in posterior edentulous patients. Regression analysis revealed that combined premolar and molar loss and being female were significant predictors of condylar erosion (p = 0.006; OR: 3.264; 95% CI: 1.401 - 7.603, p=0.031; OR: 2.652; %95 CI: 1.095 - 6.424). The study provides support for the domino effect phenomenon in temporomandibular joint pathology, indicating that posterior edentulism can have a significant impact on the occurrence of erosive condylar changes. The findings suggest that prosthetic and temporomandibular joint treatment approaches should consider the association between posterior edentulism and condylar bone changes, particularly in female patients with combined premolar and molar loss. Therefore, close attention should be paid to the management of these patients to minimize the risk of temporomandibular joint pathology.

Attitudes and knowledge of paediatric dentists' on digital radiography and cone beam computed tomography.

OBJECTIVE: To determine the frequency and reasons of digital radiography and cone-beam computed tomography usage among paediatric dental practitioners, and to assess their knowledge and need for specific education.. METHODS: The cross-sectional study was conducted from January to July 2017 and comprised paediatric dentists present at the European Academy of Paediatric Dentistry Interim Seminar in Turin, Italy, and members of the Turkish Society of Paediatric Dentistry who did not attend the event. Data about sociodemographics and their attitude towards, use of, and knowledge of digital radiography and cone beam computed tomography was collected by means of a 20-item questionnaire that was mailed to all the subjects. SPSS 22 was used to evaluate data. RESULTS: Of the 435 questionnaires distributed, 245(56%) were returned, while 194 (45%) were deemed usable. The mean age of the responding paediatric dentists was 35.84±9.10 (range: 24-67 years) and 126(64.9%) were female. Users of digital radiography identified its advantages, such as lower radiation dose 166(85.7%), ease of image storage 150(77.3%), and the possibility to change image settings and to carry out measurements 106(54.5%). Overall, 70(36%) paediatric dentists had no knowledge of cone beam computed tomography. Dental trauma was cited as the reason for using cone beam computed tomography by 70(61.3%) subjects, dental development issues by 138(71%) and pathology in the jaws by 147(75.8%). CONCLUSIONS: Digital radiography and cone beam computed tomography users are increasing in the world.

Improvement of oral health knowledge in a group of visually impaired students.

PURPOSE: The aim of this study was to evaluate the effectiveness of a repeated oral health education programme on oral health knowledge and hygiene of visually impaired students. MATERIALS AND METHODS: The study was conducted at one of the two visually impaired boarding schools of Istanbul, Turkey. The number of subjects was 65, comprising 28 totally and 37 partially visually impaired students between 7 and 17 years of age. A 24-item verbal questionnaire was developed to record their general health, impairment, the socio-economic profile and education level of their parents, oral health knowledge, sources of information about oral health, awareness of sugar in-take/caries risk, frequency of dental check-ups and oral hygiene habits, as well as any difficulties they experienced thereby. They were given individual training on oral care three times with two-month intervals within the nine-month framework of the programme. To measure the oral hygiene status, plaque index (PI) and gingival index (GI) scores were recorded of all teeth at four sites throughout the sessions. After completion of the programme, the oral health knowledge of the students was evaluated using the same questionnaire to determine the effectiveness of the programme. RESULTS: Statistically significant improvements were found at the level of oral health knowledge and oral hygiene status both in totally and partially visually impaired students at the end of the study (p < 0.001) as compared with at the beginning. No significant difference was found between the knowledge of totally visually impaired and partially visually impaired students. CONCLUSION: It was concluded that with an appropriate programme, the oral health knowledge of visually impaired students could be improved. This programme, if conducted on a one-to-one basis, ensures clinical and statistical significance.