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.

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.

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).

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.

Alterações idade-dependente nas vias metabólicas de folículos dentários: um estudo piloto / Age-related metabolic pathways changes in dental follicles: a pilot study

Envelhecer não é uma escolha; é nosso destino. O declínio funcional dependente do tempo que afeta a maioria dos organismos vivos está vinculado às alterações em variados processos celulares, incluindo senescência celular, alterações epigenéticas, instabilidade genômica, exaustão de células-tronco, entre outras. As alterações morfológicas relacionadas à idade nos folículos dentários associados a dentes não-erupcionados têm sido investigadas há décadas, principalmente motivado pelo fato de que cistos e tumores podem surgir em associação a dentes inclusos e/ou impactados. Quanto mais entendemos a fisiologia dos folículos dentários, mais nos tornamos capazes de contextualizar eventos biológicos que podem estar associados à ocorrência de lesões odontogênicas cuja incidência aumenta com a idade. Assim, nosso objetivo foi avaliar as alterações metabólicas relacionadas à idade em amostras de folículos dentários associados à terceiros molares inferiores inclusos/impactados de indivíduos adolescentes e adultos. Uma amostra de conveniência de folículos dentários fixados em formalina e embebidos em parafina de indivíduos adolescentes (<16 anos, n= 13) e adultos (>26 anos, n= 7) foi selecionada. As amostras foram preparadas e submetidas à cromatografia líquida de alta eficiência acoplada a espectrometria de massa (HPLC-MS) em análise metabolômica untargeted. Análises uni- e multivariadas foram conduzidas, e a previsão de vias alteradas foi realizada pelas abordagens mummichog e GSEA. Folículos dentários de indivíduos adolescentes e adultos mostraram diferenças nas vias relacionadas à biossíntese do hormônio esteróide C21, biossíntese dos ácidos biliares, metabolismo da galactose, biossíntese de androgênio e estrogênio, metabolismo do amido e sacarose e metabolismo do lipoato. Nossos achados sugerem que, assim como outros tecidos humanos, os folículos dentários associados a dentes não erupcionados apresentam, durante o envelhecimento, alterações em nível metabólico, o que pode abrir caminho para novos estudos sobre biologia, fisiologia e patologia oral.

Aging is not a matter of choice; it is our fate. The 'time-dependent functional decline that affects most living organisms' is coupled with several alterations in cellular processes, including cell senescence, epigenetic alterations, genomic instability, stem cell exhaustion, amongst others. Age-related morphological changes in dental follicles have been investigated for decades, mainly motivated by the fact that cysts and tumors may arise in association with a unerupted and/or impacted teeth. The more we understand dental follicles' physiology, the more we become able to contextualize biological events that can be associated with the occurrence of odontogenic lesions which incidence increases with age. Thus, our objective was to assess age-related changes in metabolic pathways of dental follicles associated with unerupted/impacted mandibular third molars from young and adult individuals. For this purpose, a convenience sample of formalin-fixed paraffin-embedded dental follicles from young (<16 y.o., n = 13) and adult (>26 y.o., n = 7) individuals was selected. Samples were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based untargeted metabolomics. Multivariate and univariate analyses were conducted, and the prediction of altered pathways was performed by mummichog and GSEA approaches. Dental follicles from young and older individuals showed differences in pathways related to C21-steroid hormone biosynthesis, bile acid biosynthesis, galactose metabolism, androgen and estrogen biosynthesis, starch and sucrose metabolism and lipoate metabolism. Our findings support that similar to other human tissues, dental follicles associated with unerupted tooth show alterations at a metabolic level with aging, which can pave the way for further studies on oral pathology, oral biology and physiology.

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.

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.

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.

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.

Update on dentin hypersensitivity: with the focus on hydrodynamic theory and mechanosensitive ion channels

Dentin hypersensitivity is an abrupt intense pain caused by innocuous stimuli to exposed dentinal tubules. Mechanosensitive ion channels have been assessed in dental primary afferent neurons and odontoblasts to explain dentin hypersensitivity. Dentinal fluid dynamics evoked by various stimuli to exposed dentin cause mechanical stress to the structures underlying dentin. This review briefly discusses three hypotheses regarding dentin hypersensitivity and introduces recent findings on mechanosensitive ion channels expressed in the dental sensory system and discusses how the activation of these ion channels is involved in dentin hypersensitivity.

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.

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.

Enseñanza de bioética en la carrera de odontología. reflexiones y prospectivas / Teaching bioethics in odontology. considerations and prospects / Ensino de bioética no curso de odontologia. reflexões e prospectivas

Resumen La conciencia de los formadores del área de la salud para promover la conducta ética en la formación de estudiantes de odontología se constata en los planes de estudio de pregrado. El presente estudio busca develar las diferentes formas utilizadas para enseñar estas materias. Para ello, se revisa manualmente la literatura publicada en bases de datos indexadas en SciELO en los años 1999-2014, que se encuentran bajo el título ciencias de la salud, humanidades, ciencias sociales aplicadas, a las que se puede acceder on-line, a texto completo, gratuito, en forma anónima y también en las siguientes revistas especializadas de educación en salud: Journal of Dental Education (ADEA), Journal of Medical Education (AMM), con los mismos títulos, durante el mismo periodo y a través del motor de búsqueda PubMed vía Medline. Los resultados arrojan 43 artículos de pertinencia temática. Se concluye que la enseñanza de bioética en los planes de estudio de pregrado en las escuelas de odontología es creciente y se diferencia según los entornos educativos y culturales en que se desarrolla; las formas de enseñanza mencionadas como más eficientes son el aprendizaje basado en casos y el aprendizaje basado en problemas; la formación de odontólogos íntegros requiere que la enseñanza de estas materias esté a cargo de equipos profesionales interdisciplinarios suficientemente preparados.

Abstract The awareness of educators in the health sciences with respect to promoting ethical conduct when instructing dental students is reflected in the undergraduate curriculum. This study is intended to discover the different ways these subjects are taught. A manual review of the literature published in databases indexed in SciELO during the years from 1999 to 2014 was done to that end, under the heading health sciences, humanities, applied social sciences, specifically literature that can be accessed in full, free of charge and anonymously. Also reviewed was the literature in two specialized journals in the area of health education; namely, the Journal of Dental Education (ADEA) and the Journal of Medical Education (AMM), with the same titles, during the same period, and through the PubMed search engine, via Medline. The results show 43 articles of thematic relevance. The conclusion is that education in bioethics, as part of the undergraduate curriculum at dental schools, is increasing and differs according to the educational and cultural environment where it is imparted. Case-based learning and problem-based learning are mentioned as being the most efficient methods of instruction. Training dentists to be well-rounded professionals requires these subjects to be taught by interdisciplinary teams that are sufficiently prepared to do so.

Resumo A consciência dos formadores da área da saúde para promover a conduta ética na formação de estudantes de odontologia constata-se nos planos de estudo de graduação. O presente estudo procura revelar as diferentes formas utilizadas para ensinar essas matérias. Para isso, revisa-se manualmente a literatura publicada em bancos de dados indexados em SciELO nos anos 1999-2014, que se encontram sob o título ciências da saúde, humanidades, ciências sociais aplicadas, às quais pode se acessar on-line, a texto completo, gratuito, em forma anônima e também nas seguintes revistas especializadas de educação em saúde: Journal of Dental Education (ADEA), Journal of Medical Education (AMM), com os mesmos títulos, durante o mesmo período e por meio do motor de busca PubMed via Medline. Os resultados mostram 43 artigos de pertinência temática. Conclui-se que o ensino de bioética nos planos de estudo de pós-graduação nas Escolas de Odontologia é crescente e se diferencia segundo os meios educativos e culturais em que se desenvolve; as formas de ensino mencionadas como mais eficientes são a aprendizagem baseada em casos e a aprendizagem baseada em problemas; a formação de odontólogos íntegros requer que o ensino dessas matérias esteja a cargo de equipes profissionais interdisciplinares suficientemente preparadas.

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.

Effect of Royal Jelly on new bone formation in rapid maxillary expansion in rats

BACKGROUND: The aim of this study was to evaluate the effects of long and short term systemic usage of royal jelly on bone formation in the expanded maxillary suture in a rat model. MATERIAL AND METHODS: Twenty eight Wistar albino rats were randomly divided into 4 equal groups: Control (C); Only Expansion (OE), Royal Jelly (RJ) group, Royal Jelly was given to rats by oral gavage only during the expansion and retention period; Royal Jelly plus Nursery (RJN) group, Royal Jelly was given to rats by oral gavage during their nursery phase of 40 days and during the retention period. After the 5 day expansion period was completed, the rats underwent 12 days of mechanical retention. All rats were sacrificed in same time. Histological examination was performed to determine the number of osteoclasts, number of osteoblasts, number of capillaries, inflammatory cell infiltration, and new bone formation. RESULTS: New bone formation, number of osteoclasts, number of osteoblasts, and the number of capillaries in the expanded maxillary sutures were higher in the RJ and RJN groups than in the other groups. Statistical analysis also demonstrated that new bone formation and the number of osteoblasts was also highest in the RJN group. CONCLUSIONS: The systemic administration of Royal Jelly in conjunction with rapid maxillary expansion may increase the quality of regenerated bone