Odontoblasts or odontocytes, expression of stem cells markers and differentiation markers among human adult odontoblasts.

Despite that, the odontoblasts of the dental pulp are considered a terminally differentiated type of cell. We were interested in investigating if they express any embryonic, mesenchymal, or neural stem cell markers, along with other differentiation markers they were reported to express previously. Methods: An immunohistochemistry study was performed on wisdom teeth extracted from healthy donors aged between 17 and 19 for dental reasons. Nine markers were tested: c-Myc, SOX2, MCAM, CD73, NCAM1, STRO1, osteocalcin, S100, and Thy1. Results: Odontoblasts expressed the following markers: embryonic stem cell markers SOX2, c-Myc, mesenchymal stem cell marker MCAM, the neural differentiation marker S100, and the osteogenic differentiation marker osteocalcin. Odontoblasts did not express the following markers: mesenchymal stem cell markers CD73, STRO1, Thy1, and neural stem cell marker NCAM1. Conclusion: These findings suggest that odontoblasts' expression of these stem cell markers may enable them to dedifferentiate under certain conditions. Further investigation is needed into whether dental materials could induce such dedifferentiation for functional dentin regeneration.

Patients satisfaction with the dental treatment provided at the University of Jordan's student clinics.

INTRODUCTION: To assess patients' satisfaction with the dental care provided to them by the undergraduate students at Jordan University Hospital. In addition, to investigate whether the age or gender of patients had any correlation with the level of satisfaction. MATERIALS AND METHODS: The Dental Satisfaction Questionnaire (DSQ) developed by the RAND Corporation was used to measure patient satisfaction. The questionnaire was translated to Arabic the native language of the country and it consisted of 14 questions, which measure the overall satisfaction and the subscales of access, convenience and availability, continuity of treatment and quality of dental care provided. RESULTS: A total of 94 patients (58.5% female, 41.5% male) answered the DSQ, the Overall Dental Satisfaction Index (DSI) was found to be 86.2%, and there was no correlation between gender or age groups and the DSI (p < .05). All 14 questions scored above 4/5 except the question about whether the schools' building and dental units being modern and well equipped (3.7/5), and the general satisfaction question (3.2/5). CONCLUSIONS: Patients who were treated at the student clinics at the University of Jordan, School of Dentistry were found to be satisfied about both the quality of treatment and the dental environment, while reporting some negative aspects related mainly to the clinics building which they found to be very old and crowded. This study found no correlation between patients' satisfaction and the age or gender of the participants.

Blended Learning with Video Demonstrations Enhances Dental Students' Achievements in Tooth Carving.

Background: Learning fine motor skill is central to preclinical dental education. Dental students are introduced to anatomical tooth carving to facilitate the development of their fine motor skill and manual dexterity. Various carving technique exists, such as wax build-up, and geometric (block carving technique). Since substantial laboratory Time and instructors' effort are required to teach students the desired techniques, blended learning approach via pre-recorded demonstration may improve the teaching and learning efficiency of anatomical tooth carving. For years, we used the Geometric method to teach preclinical dental students to carve down tooth sculptures after performing live demonstrations for them. Multiple practical laboratory demonstrations are necessary to deepen the student's comprehensive understanding of dental anatomical features and teach them correct instrumentation; this is time-consuming and challenging due to limited laboratory hours and limited view field. Accordingly, in 2016 the teaching staff created videos for tooth drawing, carving, and identification, and uploaded them to the students' university platform. Years later, we decided to perform this retrospective study. Objective: To assess the enhancement in students' tooth carving skills after implementing blended learning with video demonstrations. Methods: The student's total grades were used for comparative purposes. The students' total grades between 2010 and 2019 were collected and categorized into two groups: Group 1 (n=858), which learned tooth carving by the Geometric method after live demonstrations, and Group 2 (972), which benefited from blended learning with video demonstrations in learning. The two groups' mean, median, mode, Percentile 75, and Percentile 90 were compared. Results: Group 2 showed higher grades than group 1, and the differences between the two groups' mean and median were statistically significant p<0.001. Moreover, the mode, P75 and P90 favored group 2. Conclusion: Results show that blended learning with video demonstrations enhanced the achievements of dental students in tooth carving.

Age of the donor affects the nature of in vitro cultured human dental pulp stem cells.

OBJECTIVES: The dental pulp stem cells (DPSCs) of six donors (three young donors aged < 19 years and three adult donors aged > 25 and < 30 years) were characterized for their stem cell marker expression and differentiation potential to study the effect of donor age on DPSCs in vitro. METHODS: DPSCs were cultured in αMEM supplemented with 20% fetal calf serum (conventional conditions) or on fibronectin-coated flasks with neurobasal medium supplemented with B27, bFGF and EGF (alternative conditions). DPSCs were characterized by immunofluorescence staining to detect the neural crest/mesenchymal stem cells markers P75 and CD146, respectively. The differentiation potential was tested by the induction of DPSCs into osteogenic, adipogenic and glial lineages and then by detecting the corresponding markers osteocalcin, lipidtox and S100ß, respectively. RESULTS: The DPSCs of the young donors expressed CD146 only under the conventional conditions and expressed P75 regardless of the culture conditions. However, the DPSCs of adult donors expressed CD146 only under the alternative conditions and expressed P75 only under conventional conditions. Only the DPSCs of the young donors differentiated into the glial linage. The DPSCs of the adult donors differentiated more efficiently into the adipogenic linage. Osteogenic differentiation was comparable. CONCLUSION: Donor age affects the expression of stem cell markers and differentiation potential of DPSCs. Moreover, the effect of culture conditions on DPSCs is age dependent.

Assessment of the dental morphological pattern of living Jordanian Arabs suggesting a genetic drift from the Western-Eurasia pattern: A cone beam computed tomography study.

The objectives were to determine the expression frequency and sexual dimorphism of 15 dental morphological traits on the permanent dentitions of living Jordanians, and to compare the dental morphological pattern of this sample with those of 22 groups representing the various geographic regions of the world, for the purpose of assessing the population structure and genetic history of this group. Cone beam computed tomography images for the dentitions of 150 adult Jordanians (67 males, 83 females; age range = 18-58, mean ages 28.2, sd = 10.0 years) were studied in 2017. The traits were classified using the Arizona State University dental anthropology system, counted with the individual count method, and dichotomized according to the criteria of Scott & Turner for the purpose of group comparisons. Fisher's exact test for dichotomized scores was used to assess sexual dimorphism in these traits. Smith's Mean Measure of Divergence was used to measure all pairwise distance values among the groups. Statistically significant sexual dimorphism was found in two traits (i.e., UI1 shoveling and 4-cusped LM1), and apparent but statistically insignificant difference was found in three traits (i.e., UC canine mesial ridge, 3-rooted LM1, and 1-rooted LM2), all in favour of females. This study revealed that the dental pattern of Jordanians is distinct from the other reported Western Eurasian patterns and all other known dental patterns. This differentiated dental pattern suggests a genetic drift for this population from the Western Eurasian Ancestry.

Unexpectedly low levels of dental morphological asymmetry suggesting developmental resilience amongst living Jordanians: A cone beam computed tomography study.

The objective was to determine the degree of fluctuating asymmetry in the expression of 13 dental morphological traits among adult Jordanians. Cone beam computed tomography images for the dentitions of 150 adult Jordanians (67 males, 83 females; age range = 18-58, mean ages 28.2, SD = 10.0 years) were studied in 2017. The traits were classified using the Arizona State University dental anthropology system, and dichotomized according to the most widely accepted criteria to define trait presence. Asymmetry was assessed using three different methods: percentage of discordance including bilateral absence cases (PDIBAC), percentage of discordance excluding bilateral absence cases (PDEBAC), and inter-side correlation (ISC) using Kendall's tau coefficient. Fisher's exact test was used to assess sexual dimorphism in the degree of asymmetry. The mean PDIBAC and the mean ISC for all the traits considered are 4.1% and 0.837, respectively. For traits observed on key teeth (mesial members of teeth districts) the mean PDIBAC and the mean ISC are 3.0% and 0.860, respectively; and for those observed on variable teeth (distal members of teeth districts) the mean PDIBAC and the mean ISC are 6.5% and 0.783, respectively. No statistically significant difference was found in the degree of asymmetry between sexes. The overall low degree of asymmetry found in the present sample (4.1%) compared to the world range of 5-15% may indicate great ability of its individuals to buffer the adverse effects of environmental stresses affecting the living Jordanians during early tooth development.