The benefits of incorporating active learning into online, asynchronous coursework in dental physiology.

The COVID-19 pandemic required a shift to online learning that posed particular challenges for the education of dental students. Basic science courses were presented in an online, asynchronous format to facilitate small group rotations through preclinical work. The success of active learning was previously examined in a Dental Physiology course, and it was desired to reassess those methods in an online environment. Students were provided with prerecorded lectures containing learning activities, and the effectiveness was compared with traditional lecture recordings. On surveys, dental students had more positive perceptions of online recordings that incorporated active learning strategies, with higher perceived effectiveness of the lecturer, ability to pay attention, motivation to study, and confidence with the material. This was similar to the previous study, in which face-2-face (F2F) active learning was more positively reviewed than traditional lectures. Compared with these past sections, the online cohort expressed similarly positive perceptions of the active learning sections, but the online traditional lectures were perceived to be less effective than F2F lectures. Despite the differences in student perceptions, unit exam scores were similar for didactic lectures in both online and F2F settings. Unit exam scores were significantly higher when active learning strategies were employed, with the highest performance levels in the F2F cohort. While active learning strategies continue to be effective, further research is needed to optimize these methods and engage students in online coursework. The results suggest the importance of active and collaborative learning opportunities in the education of students in physiology coursework.

A new model of classification of third molars development and its correlation with chronological age in a Brazilian subpopulation.

The present study correlated the mineralization of third molars to chronological age using a modified classification based on Demirjian's stages in a Brazilian subpopulation and compared with the original classification. A total of 1082 patients with age ranging from 6 to 26 years were included in the sample, with at least one third molar on panoramic radiographs. The third molars were classified according to the original Demirjian classification (8 stages) and a new model based on the Demirjian method, where the original stages were grouped into four stages: AB-enamel mineralization; CD-crown dentin mineralization; EFG-root formation; and H-complete development. Statistical analyses were performed by Kruskal-Wallis/Dunn tests (α = 0.05) and the multinomial logistic regression model. Data were analyzed according to percentiles for the probability of an individual being over 18 years old. The mean ages of the stages in both classifications did not present a significant difference between superior and inferior arches (p < 0.05). The differences in mean ages between all the stages of mineralization were statistically significant (p < 0.001) only for the 4-stage classification. Males attained root formation and complete formation earlier than females (p < 0.05) in the 4-stage classification. The modified classification system showed dependence between chronological age and mineralization stages of third molars, simplifying the age estimation process. At stage H, females present a 95.7% chance of being over 18, while for males, this probability is 89.6%. This modified classification system simplifies the dental age estimation process based on third molars and can be used as a reference for future studies.

Dental age estimation in children affected by juvenile rheumatoid arthritis.

Dental root calcification has proven to be a reliable biological evidence to estimate chronological age of children. The development of structures usually examined in the age estimation forensic practice (e.g. skeleton, teeth) is supposed to be influenced by diseases and nutritional, environmental, ethnic, and ultimately even socioeconomic factors. This research aims to study the age estimation in children affected by juvenile rheumatoid arthritis (JRA) with and without steroids treatment and compared with healthy subjects. MATERIAL AND METHODS: Dental age estimations based on 752 OPGs, 420 girls and 332 boys, aged from 3.3 to 15.99 years, were provided by applying Demirjian and Willems' original methods. Of the whole sample, 103 individuals were affected by JRA and 40 received a continuous corticosteroid therapy, over 1 year long. CONCLUSIONS: Willems' and Demirjian's original methods, as methods commonly applied to estimate age for sub-adults with unremarkable medical history, can be used for medico-legal purposes to children affected by JRA. Willems' method tended to underestimate age while Demirjian's method resulted to be prone to overestimation for both healthy and JRA-affected children. JRA showed to have no influence on root calcification process even in children that received steroid treatment for 1 year or longer.

Establishing links between assessments and expected learning outcomes through curriculum mapping in a dental physiology curriculum.

Background: . The relevance of curriculum mapping to determine the links between expected learning outcomes and assessment is well stated in the literature. Nevertheless, studies confirming the usage of such maps are minimal. Methods: . We assessed links through curriculum mapping, between assessments and expected learning outcomes of dental physiology curriculum of three batches of students (2012-14) at Melaka-Manipal Medical College (MMMC), Manipal. The questions asked under each assessment method were mapped to the respective expected learning outcomes, and students' scores in different assessments in physiology were gathered. Students' (n = 220) and teachers' (n=15) perspectives were collected through focus group discussion sessions and questionnaire surveys. Results: . More than 75% of students were successful (≥50% scores) in majority of the assessments. There was moderate (r=0.4-0.6) to strong positive correlation (r=0.7-0.9) between majority of the assessments. However, students' scores in viva voce had a weak positive correlation with the practical examination score (r=0.230). The score in the assessments of problem-based learning had either weak (r=0.1-0.3) or no correlation with other assessment scores. Conclusions: . Through curriculum mapping, we were able to establish links between assessments and expected learning outcomes. We observed that, in the assessment system followed at MMMC, all expected learning outcomes were not given equal weightage in the examinations. Moreover, there was no direct assessment of self-directed learning skills. Our study also showed that assessment has supported students in achieving the expected learning outcomes as evidenced by the qualitative and quantitative data.

The micro-CT evaluation of enamel-cement thickness, abrasion, and mineral density in teeth in the postmortem interval (PMI): new parameters for the determination of PMI.

OBJECTIVE: The estimation of time of death or the determination of the postmortem interval (PMI) is one of the most important issues in forensic medicine and odontology. However, evaluation of bone and dental hard tissues in PMI could be challenging due to the lack of objective methods with high accuracy. In this respect, micro-CT analysis which has not been used for postmortem evaluation would be beneficial in evaluating hard tissues such as bones and teeth. Therefore, the aim of the present study was to determine the alterations in the hard dental tissue, mineral density of enamel, and the surface abrasion of hard dental tissues of rats in the PMI period with a relatively novel method, micro-CT. METHODS: The present study included 60 female Wistar rats which were divided into six study groups. The rats were sacrificed at the baseline and were left into nature putrefaction process. The study groups were created based on the PMI period as week-0, week-1, week-2, week-4, week-8, and week-12, which included 10 rats in each group. All hemi-mandibles were collected in the determined timelines and the micro-CT analysis was carried out on each group. Mineral density of enamel and the surface abrasion of hard dental tissues were determined. RESULTS: The enamel and cement thickness remained the same in the examined PMI periods. Mineral density of the enamel tissues were also similar until the 8th week but the decrease was significant at 12th week (2.313 gHAp cm3). Surface abrasion of the dental tissues on weeks 4, 8, and 12 were 0.006, 0.024, and 0.024 mm, respectively. CONCLUSION: The present study indicated that surface abrasion and enamel mineral density evaluation via micro-CT can be considered as objective and precise parameters in PMI evaluation in forensic medicine and odontology.

Curriculum mapping of dental physiology curriculum: The path towards outcome-based education.

INTRODUCTION: Curriculum mapping provides a clear picture of curriculum content, learning opportunities and assessment methods employed to measure the achievement of learning outcomes with their interrelationships. It facilitates educators and teachers to examine the extent to which the curricular components are linked and hence to find out gaps in the curriculum. The objective of the study was, therefore, to evaluate the physiology curriculum of Bachelor of Dental Surgery (BDS) programme through curriculum mapping. MATERIALS AND METHODS: In this study, mapping of the physiology curriculum of three batches of BDS programme was conducted retrospectively. The components of the curriculum used for mapping were expected learning outcomes, curriculum content, learning opportunities, assessments and learning resources. The data were gathered by reviewing office records. RESULTS: Descriptive analysis of the data revealed reasonable alignment between the curriculum content and questions asked in examinations for all three batches. It was found that all the expected learning outcomes were addressed in the curriculum and assessed in different assessments. Moreover, the study revealed that the physiology curriculum was contributing to majority of the programme outcomes. Nevertheless, the study could identify some gaps in the curriculum, as well. CONCLUSION: This study revealed that majority of the components of the curriculum were linked and contributed to attaining the expected learning outcomes. It also showed that curriculum mapping was feasible and could be used as a tool to evaluate the curriculum.

The impact of premature birth on dental maturation in the permanent dentition.

OBJECTIVES: To evaluate tooth development and calculate dental maturity score in prematurely born children and to compare the findings with full-term born children. MATERIAL AND METHODS: Nine-year-old preterm children were selected from the Swedish Medical Birth Register. One group consisted of 36 extremely preterm children (born before week 29), and the other included 38 very preterm children (born during weeks 29 to 32). Panoramic radiography was performed on each child and the preterm children were compared with 42 full-term born children. Five observers independently assessed the tooth development stages for all teeth in the left mandible (31-37) on the panoramic radiographs according to the method described by Demirjian et al. (Hum Biol 45:211-227, 1973). Data from tooth development stages were compiled and converted into a dental maturity score for each group. Kappa values were calculated for intra- and inter-observer agreement. RESULTS: When the different development stages for each individual tooth were compared, all observers presented a significant delay in the maturity of tooth 37 for the extremely preterm group (p ≤ 0.002). The extremely preterm group had a significantly lower dental maturity score than the full-term group, as assessed by each observer (p ≤ 0.006). Kappa values for inter-observer agreement varied between 0.31 and 0.71 depending on tooth and intra-observer agreement was between 0.16 and 1.0. CONCLUSIONS: At age 9, the extremely preterm children had a general delay in tooth development. CLINICAL RELEVANCE: The increased survival rate of extremely preterm babies adds a new group of children to society. Dental clinicians should be aware that the delay in tooth development could impact the timing of orthodontic diagnostics and potential treatment.

Preterm infants--odontological aspects.

Preterm birth is associated with medical complications and treatments postnatally and disturbances in growth and development. Primary and permanent teeth develop during this postnatal period. The overall aim of the present thesis was to elucidate the effects of preterm birth and postnatal complications on oral health and the dentoalveolar development during adolescence, and to study the effects of preterm birth on caries during childhood, in a well-defined group of preterm infants. In the same group, explore the development of the primary and permanent teeth and compare the results with a matched control group and control teeth. The subjects consisted of 40 (45) of 56 surviving infants, born < 29 weeks of gestational age (GA), and matched healthy children born at term. The material consisted of 44 teeth from 14 of the preterm adolescents and 36 control teeth from healthy children. Clinical examinations and dental cast analysis were performed during adolescence and morbidity was noted. Retrospective information from medical and dental records was obtained. Dental enamel was analyzed in a polarized light microscopy, and scanning electron microscopy. Further, chemical analyses of enamel and dentin were performed with X-ray microanalysis. The results showed that during adolescence, more preterms had plaque and gingival inflammation, lower salivary secretion, more S. mutans and severe hypomineralization. Retrospectively, less caries was noted at six years of age, but more children had hypomineralization in the primary dentition. Angle Class II malocclusion, large over-bite and deep bite associated with medical diagnoses were frequent. Furthermore, smaller dental arch perimeters in girls, at 16 years of age, and smaller tooth size in the incisors, canines and first molars were found. The morphological findings were confirmed in the XRMA analyses. In postnatal enamel, varying degrees of porosities > 5% and incremental lines were seen. Lower values of Ca and Ca/C ratio and higher values of C were found. Ca/P ratio in both enamel and dentine indicates normal hydroxyapatite in both groups. No single medical diagnosis, postnatal treatment or morbidity in adolescents could explain the findings. As a conclusion, there are indications for poor oral outcome in this group of preterm infants during adolescence, and disturbed mineralization in primary teeth.

microRNA-875-5p plays critical role for mesenchymal condensation in epithelial-mesenchymal interaction during tooth development.

Epithelial-mesenchymal interaction has critical roles for organ development including teeth, during which epithelial thickening and mesenchymal condensation are initiated by precise regulation of the signaling pathway. In teeth, neural crest-derived mesenchymal cells expressed PDGF receptors migrate and become condensed toward invaginated epithelium. To identify the molecular mechanism of this interaction, we explored the specific transcriptional start sites (TSSs) of tooth organs using cap analysis of gene expression (CAGE). We identified a tooth specific TSS detected in the chromosome 15qD1 region, which codes microRNA-875 (mir875). MiR875-5p is specifically expressed in dental mesenchyme during the early stage of tooth development. Furthermore, PRRX1/2 binds to the mir875 promoter region and enhances the expression of mir875. To assess the role of miR875-5p in dental mesenchyme, we transfected mimic miR875-5p into mouse dental pulp (mDP) cells, which showed that cell migration toward dental epithelial cells was significantly induced by miR875-5p via the PDGF signaling pathway. Those results also demonstrated that miR875-5p induces cell migration by inhibiting PTEN and STAT1, which are regulated by miR875-5p as part of post-transcriptional regulation. Together, our findings indicate that tooth specific miR875-5p has important roles in cell condensation of mesenchymal cells around invaginated dental epithelium and induction of epithelial-mesenchymal interaction.

Vibrational monitor of early demineralization in tooth enamel after in vitro exposure to phosphoridic liquid.

The Raman spectroscopic method has been applied to quantitatively assess the in vitro degree of demineralization in healthy human teeth. Based on previous evaluations of Raman selection rules (empowered by an orientation distribution function (ODF) statistical algorithm) and on a newly proposed analysis of phonon density of states (PDOS) for selected vibrational modes of the hexagonal structure of hydroxyapatite, a molecular-scale evaluation of the demineralization process upon in vitro exposure to a highly acidic beverage (i.e., CocaCola™ Classic, pH=2.5) could be obtained. The Raman method proved quite sensitive and spectroscopic features could be directly related to an increase in off-stoichiometry of the enamel surface structure since the very early stage of the demineralization process (i.e., when yet invisible to other conventional analytical techniques). The proposed Raman spectroscopic algorithm might possess some generality for caries risk assessment, allowing a prompt non-contact diagnostic practice in dentistry.

Defectos bucodentales en personas con síndrome de Down: una prioridad en salud bucal / Oral-dental defects in people with Down's syndrome: a priority in oral health

RESUMEN El síndrome de Down con frecuencia se acompaña de defectos bucodentales que comprometen la función masticatoria y fonatoria del paciente. Las acciones de prevención y promoción de salud bucal, el diagnóstico precoz y seguimiento de estas enfermedades, contribuyen al logro del verdadero enfoque interdisciplinario que demandan estos pacientes, para lograr una plena inclusión social. Se realizó una búsqueda bibliográfica sobre el tema, con el objetivo de estructurar los referentes teóricos relacionados con los principales defectos bucodentales -congénitos y adquiridos- que afectan a la población con síndrome de Down, para lograr la prevención de estos defectos y el incremento de la calidad de vida de los pacientes. Los defectos bucodentales congénitos más frecuentes encontrados en la trisomía 21, fueron la microdoncia, la macroglosia y la erupción dental tardía. La enfermedad periodontal fue el defecto adquirido de mayor presentación, al que se asocian diversos factores de riesgo, muchos modificables. Las intervenciones tempranas en salud bucal pueden incrementar la calidad de vida de los niños y adultos que padecen este trastorno, ayudándolos a lograr un pleno desarrollo como seres humanos (AU).

ABSTRACT Down's syndrome is frequently accompanied by oral-dental defects compromising the masticatory and phonatory function of the patients. Oral health promotion and prevention actions, precocious diagnosis and follow-up of these diseases contribute to achieving the true interdisciplinary approach these patients demand to reach their full social inclusion. A bibliographic search on the theme was carried out, with the objective of structuring the theoretical referents related to the main oral-dental defects -congenital and acquired-, affecting the population with Down's syndrome to reach these defects prevention and increasing these patients' life quality. The congenital oral-dental defects more commonly found in trisomy 21 were microdontia, macroglossia, and delayed tooth eruption. Periodontal disease was more frequently found acquired defect, to which several risk factors are associated, many of them modifiable. Early interventions in oral health may improve the life quality of these children and adults, helping them to achieve a full development as human beings (AU).

Bisphosphonates: Pharmacokinetics, bioavailability, mechanisms of action, clinical applications in children, and effects on tooth development.

Bisphosphonates (BPs) avidly bind to calcium crystals and inhibit osteoclastic bone resorption, making them useful for treatment of skeletal disorders such as osteoporosis, Paget's disease, osteogenesis imperfecta and metastatic bone diseases. BPs therapeutically act by causing toxic effects on osteoclasts or interfering with specific intracellular pathways in those cells. BPs that possess nitrogen in their composition are called nitrogen-containing BPs (NBPs) and include alendronate, pamidronate, risedronate, ibandronate, and zoledronate. Simple BPs or non-NBPs do not have nitrogen in their composition, include etiodronate and clodronate, and were the first to be tested in animals and clinically used. Because BPs may be administered to pregnant women or children during deciduous and permanent teeth development, it is expected that they might disturb tooth eruption and development. A review of current literature on pharmacokinetics, bioavailability, mechanisms of action, and clinical applications of BPs in children, and their effects on tooth eruption and development is presented.

Age estimation of Malawian adults from dental radiographs.

BACKGROUND: Previous studies have shown that with advancing age the size of the dental pulp cavity is reduced as a result of secondary dentine deposit, so that measurements of this reduction can be used as an indicator of age. Age estimation is one of the indicators used in forensic identification and teeth are biological markers for human age estimation. METHODOLOGY: We measured the height (mm) of the crown (CH = Coronal Height) and the height (mm) of the coronal pulp cavity (CPCH = Coronal pulp cavity height) of premolars and molars of 134 adult Malawians (77 males, 57 females) aged 20 - 80 years from dental radiographs. The Tooth-Coronal Index (TCI) was computed for each tooth and regressed on real age. RESULT: The correlation coefficients ranged from r -0.650 to -0.799 and were significant in both gender, in premolars and molars (P < 0.01). The equations obtained allowed estimation of age with an error of +/- 5 years in our studied population, the molar equation estimated age better for males while the premolar equation was for female and combined samples. The percentage accuracy levels of our sample population were higher than Caucasians previously reported using similar methods. CONCLUSION: Our study demonstrates the potential value of this method of age estimation which is precise, simple, non invasive and applicable to both living individuals and skeletal materials of unknown age.

Autonomic neural signals in bone: physiological implications for mandible and dental growth.

Signals derived from the autonomic nervous system exert potent effects on osteoclast and osteoblast function. A ubiquitous sympathetic and sensory innervation of all periosteal surfaces exists and its disruption affects bone remodeling. Several neuropeptides, neurohormones and neurotransmitters and their receptors are detectable in bone. Bone mineral content decreased in sympathetically denervated mandibular bone. When a mechanical stress was superimposed on mandibular bone by cutting out the lower incisors, an increase in bone density ensued providing the sympathetic innervation was intact. A lower eruption rate of sympathetically denervated incisors at the impeded eruption side, and a higher eruption rate of denervated incisors at the unimpeded side were also observed. A normal sympathetic neural activity appears to be a pre-requisite for maintaining a minimal normal unimpeded incisor eruption and for keeping the unimpeded eruption to attain abnormally high velocities under conditions of stimulated incisor growth. These and other results suggest that the sympathetic nervous system plays an important role in mandibular bone metabolism.

Sexual dimorphism in primate evolution.

Sexual dimorphism is a pervasive phenomenon among anthropoid primates. Comparative analyses over the past 30 years have greatly expanded our understanding of both variation in the expression of dimorphism among primates, and the underlying causes of sexual dimorphism. Dimorphism in body mass and canine tooth size is familiar, as is pelage and "sex skin" dimorphism. More recent analyses are documenting subtle differences in the pattern of skeletal dimorphism among primates. Comparative analyses have corroborated the sexual selection hypotheses, and have provided a more detailed understanding of the relationship between sexual selection, natural selection, and mating systems in primates. A clearer picture is emerging of the relative contribution of various selective and nonselective mechanisms in the evolution and expression of dimorphism. Most importantly, recent studies have shown that dimorphism is the product of changes in both male and female traits. Developmental studies demonstrate the variety of ontogenetic pathways that can lead to dimorphism, and provide additional insight into the selective mechanisms that influence dimorphism throughout the lifetime of an animal. Evidence from the fossil record suggests that dimorphism probably evolved in parallel twice, and the dimorphism in some extinct hominoids probably exceeded that of any living primate. Our advances in understanding the behavioral/ecological correlates of dimorphism in living primates have not improved our ability to reconstruct social systems in extinct species on the basis of dimorphism alone, beyond the inference of polygyny or intense male-male competition. However, our understanding of the behavioral/ecological correlates of growth and development, and of the expression of dimorphism as a function of separate changes in male and female traits, offers great potential for inferring evolutionary changes in behavior over time.

Designing post-graduate Master's degree programs: the advanced training program in Dental Functional Analysis and Therapy as one example.

INTRODUCTION: The decision to consolidate European higher education was reached by the Bologna Conference. Based on the Anglo-American system, a two-cycle degree program (Bachelor and Master) has been introduced. Subjects culminating in a state examination, such as Medicine and Dentistry, were excluded from this reform. Since the state examination is already comparable in its caliber to a Master's degree in Medicine or Dentistry, only advanced Master's degree programs with post-graduate specializations come into consideration for these subjects. In the field of dentistry numerous post-graduate study programs are increasingly coming into existence. Many different models and approaches are being pursued. METHOD: Since the 2004-2005 winter semester, the University of Greifswald has offered the Master's degree program in Dental Functional Analysis and Therapy. Two and a half years in duration, this program is structured to allow program participation while working and targets licensed dentists who wish to attain certified skills for the future in state-of-the-art functional analysis and therapy. AIM: The design of this post-graduate program and the initial results of the evaluation by alumni are presented here. CONCLUSION: Our experiences show that the conceptual idea of an advanced Master's program has proved successful. The program covers a specialty which leads to increased confidence in handling challenging patient cases. The sharing of experiences among colleagues was evaluated as being especially important.

Hábito parafuncional e disfunção temporomandibular, uma questão de gênero? / Oral parafunction and temporomandibular disorders, a matter of gender?

Introdução: as disfunções temporomandibulares (DTM) são caracterizadas por dor na região da articulação temporomandibular e região pré auricular, nos músculos mastigatórios, limitação da mobilidade articular e ruídos articulares. Fatores biomecânicos, neuromuscular, biopiscossocial e neurobiológico podem contribuir para esta disfunção. Objetivo: o propósito deste trabalho foi demonstrar a associação de hábitos parafuncionais entre os gêneros portadores da DTM. Método: realizou-se um estudo transversal com 150 sujeitos com questões estruturadas sobre hábitos parafuncionais e o Índice Anamnésico de Fonseca para classificação da DTM. Resultado e discussão: dos sujeitos tinham como pratica o habito parafuncional, 70% apresentavam algum grau de DTM sendo 82% destes do sexo feminino (p< 0,05); os hábitos orais mais prevalentes foram roer unha (34%) e mascar chicletes (30%). Considerações finais: as diferenças fisiológicas e de os papéis ocupados na sociedade deveexplicar associação do hábito parafuncional com o gênero feminino.

Introduction: Temporomandibular disorders (TMD) are characterized by pain in the region of the temporomandibular joint and pre-auricular region, in the masticatory muscles, limitation of joint mobility and articular noises. Biomechanical, neuromuscular, biopisco-social and neurobiological factors may contribute to this dysfunction. Objective: the purpose of this study was to demonstrate the association of oral parafunction among patients genres of Temporomandibular Disorders (TMD). Method: we conducted a cross-sectional study with 150 subjects with structured questions about parafunctional habits and the Fonseca Anamnesic Index for TMD classification. Results and Discussion: the subjects had to practice the parafunctional habit, 70% had some degree of TMD and 82% of females (p <0.05). The most prevalent oral habits were nailbiting (34%) and chewing gum (30%). Final remarks: physiologicaldifferences and the roles occupied in society should explain the association parafunctional habit with females.