Study on the Development of Training Programs for Standardized Patients of the Practical Examination Portion of the National Dental Licensing Examination

Purpose@#The practical examination portion of the National Dental Licensing Examination (NDLE) is slated to be administered in the latter half of 2021 in the form of a clinical performance examination that comprehensively evaluates the patient-dentist interaction using standardized patients (SPs). The SPs should be equipped with the basic qualities and capacity as evaluators for a fair and reliable administration of the test. @*Materials and Methods@#In this study, we analyzed the existing training materials for SPs who participated in domestic and overseas practical tests for the development of training materials for SPs through seminars and surveys of 11 dentistry schools and colleges.Result: First, SPs should be selected according to the basic quality criteria and capacity, which they must possess, and the preliminary basic training about the details which they must have knowledge of and be provided through videorecorded cases before the implementation of the preliminary field training. Second, the roles of SPs and the calibration process of the evaluation result forms are needed when conducting the preliminary field training for SPs. After watching video-recorded scenario cases, the SPs participate in discussions about the watched videos before proceeding to calibration practices of evaluation result forms. Third, because the Type A questionnaire of the practical examination of the NDLE is dependent on the SPs’ capacity and training, the fairness of the practical test is largely dependent on the SPs. Therefore, practicing the roles as evaluators and evaluation training should be provided using practical test items that can improve the reliability of the test and show a high level of reproducibility about the same case. @*Conclusion@#The findings of this study will be utilized for the development of training materials for SPs, so they can participate in the administration of a fair and reliable practical examination of the NDLE.

Study on the Development of Training Programs for Standardized Patients of the Practical Examination Portion of the National Dental Licensing Examination

Purpose@#The practical examination portion of the National Dental Licensing Examination (NDLE) is slated to be administered in the latter half of 2021 in the form of a clinical performance examination that comprehensively evaluates the patient-dentist interaction using standardized patients (SPs). The SPs should be equipped with the basic qualities and capacity as evaluators for a fair and reliable administration of the test. @*Materials and Methods@#In this study, we analyzed the existing training materials for SPs who participated in domestic and overseas practical tests for the development of training materials for SPs through seminars and surveys of 11 dentistry schools and colleges.Result: First, SPs should be selected according to the basic quality criteria and capacity, which they must possess, and the preliminary basic training about the details which they must have knowledge of and be provided through videorecorded cases before the implementation of the preliminary field training. Second, the roles of SPs and the calibration process of the evaluation result forms are needed when conducting the preliminary field training for SPs. After watching video-recorded scenario cases, the SPs participate in discussions about the watched videos before proceeding to calibration practices of evaluation result forms. Third, because the Type A questionnaire of the practical examination of the NDLE is dependent on the SPs’ capacity and training, the fairness of the practical test is largely dependent on the SPs. Therefore, practicing the roles as evaluators and evaluation training should be provided using practical test items that can improve the reliability of the test and show a high level of reproducibility about the same case. @*Conclusion@#The findings of this study will be utilized for the development of training materials for SPs, so they can participate in the administration of a fair and reliable practical examination of the NDLE.

Osteocalcin Expression and Mineralization in Developing Tooth of Xenopus laevis

Osteocalcin (OC) is the most abundant noncollagenous protein of extracellular matrix in the bone. In an OC deficient mouse, bone formation rates are increased in cancellous and cortical bones. OC is known as a negative regulator of mineral apposition. OC is also expressed in the tooth of the rat, bovine, and human. However, little is known about OC during tooth development in Xenopus. The purpose of this study is to compare the expression of OC with mineralization in the developing tooth of Xenopus, by using von Kossa staining and in situ hybridization. At stage 56, the developmental stage of tooth germ corresponds to the cap stage, and an acellular zone was apparent between the dental papilla and the enamel organ. From stage 57, calcium deposition was revealed by von Kossa staining prior to OC expression, and the differentiated odontoblasts forming predentin were located at adjoining predentin. At stage 58, OC transcripts were detected in the differentiated odontoblasts. At stage 66, OC mRNA was expressed in the odontoblasts, which was aligned in a single layer at the periphery of the pulp. These findings suggest that OC may play a role in mineralization and odontogenesis of tooth development in Xenopus.

Effect of Pdx1 Expression after Sox9 Depletion in the Early Pancreatic Development in African Clawed Frog (Xenopus laevis) / 대한해부학회지

The pancreas is a mixed exocrine and endocrine gland involved in the control of many homeostatic functions.During embryogenesis,the pancreas arises from dorsal and ventral evaginations of the foregut,which subse- quently fuse into a single organ.The characterization of early genes expressed in the developing pancreas is critical to understand its specification and differentiation.Pdx1 is one of the earliest markers of pancreatic development and a key molecule in its development.Sox proteins form a large class of transcriptional regulators implicated in the control of a variety of developmental processes.One member of this family,Sox9,is expressed in the developing pancreas, but little is known about the function of Sox9 in the developing pancreas.We further investigated Sox9 function during pancreatic development in Xenopus .Using a hormone-inducible inhibitory mutant of Sox9 ,we found that Pdx1 expres- sion was reduced in the ventral pancreatic buds in Sox9-depleted embryos.We suggest that Sox9 gene expression may be involved in pancreatic development in Xenopus.

Histochemical Characteristics and Ultrastructure of Mast Cells in Pheasant (Phasianus colchicus) / 대한해부학회지

This study describes the histochemical characteristics and ultrastructure of mast cells from tongue, proventriculus, ileum and fabricius bursa, in pheasant (Phasianus colchicus) by light and electron microscopy. We compared the stainability of 4 different methods, toluidine blue, alcian blue, congo red and alkaline Giemsa, to stain mast cell granules from fixed pheasant organs in three different fixatives, 10% neutral buffered formalin, Carnoy's solution or half-strength Karnovsky's solution. Mast cells in all experimental organs were not stained with 4 different staining methods after fixation in 10% neutral buffered formalin but well stained in fixed organs with half-strength Karnovsky's solution. The mast cells had many metachromatic granules stained with toluidine blue or alkaline Giemsa and orthochromatic granules stained with alcian blue or congo red in tissues fixed in half-strength Karnovsky's solution. In electron microscopy, pheasant mast cells were oval, triangular, spindle-like or irregular and had a few finger-like cytoplasmic processes. There were the membrane-bounded secretory granules and the well-developed organelles in mast cells. Internal large granules were oval or irregular, and had variable shape; some higher or lower electron density with homogeneous appearance; some had a particular appearance, and a few showed reticular or spongy-like structure. This indicates that 10% neutral buffered formalin or Carnoy's fixation may be inadequate for detection of mast cells in pheasant, whereas the half-strength Karnovsky's fixation provides metachromatic or orthochromatic staining of mast cell granules.

Effect of Retinoic Acid on the Expression of PDGF Receptors During Palatogenesis / 대한해부학회지

Although cleft lip and palate are one of the most common craniofacial malformation, little is still known about the mechanism of the palate formation. Retinoic acid (RA) is known a teratogen, and cleft palate is induced by retinoic acid administration in the secondary palate formation stage. Many growth factors and their receptors are involved in the formation of the secondary palate. Here, we investigated the expression of PDGFR-alpha, and PDGFR-beta during palatogenesis after retinoid acid administration in mice by RT-PCR and immunohistochemistry. At E15.5, the opposing palatal shelves fused with one another in the control group, but the palatal shelves were not elevated and cleft palate was induced in the RA-treated group. In RT-PCR, PDGFR-beta was downregulated during palatogenesis after RA administration. In immunohistochemical experiment, PDGFR-alpha and PDGFR-beta were reduced in RA-induced group. Taken together, we suggest that PDGF receptors may be molecules involved in palate formation.

The effects of estrogen on experimental tooth movement in ovariectomized rats / 대한치과교정학회지

The purpose of this study was to evaluate the effect of estrogen on the periodontium and alveolar bone tissue response during experimental tooth movement in ovariectomized rats. Eighty female rats, 250gm in body weight, were classified into four groups ; sham operated group(NN), ovariectomized group(ON), ovariectomized & estrogen injected group(OE), sham operated & estrogen injected injected group(NE), Rats were ovariectomized before 3 weeks to begin the experiment, which resulted in estrogen-deficient osteoporosis. In OE group & NE group, estrogen was injected 50microgramg/kg B.W. every other days. The left maxillary 1st molar was moved mesially with 60g force. Each four rats were sacrificed after 1, 3, 7, 15 days from application of orthodontic appliance and after additional 7 days from removal of orthodontic appliance. Histological findings on mesial roots of upper 1st molar in pressure and tension side are observed. The results were summarized as follows ; 1. In pressure side of alveolar bone, the number of osteoclasts and Howship's lacuna of ON group was significantly more than that of NN group from 1 day to 15 days(P0.05). The amount of tooth movement of ON group between 7 days and 15 days was significantly greater than those of other groups(P0.05).

Morphological Characteristics of the Atrium as an Endocrine Organ: I. Luminal Structure of Atria in Various Animals Using Corrosion Casting Method / 체질인류학회지

The internal morphology of the right and left atria of rabbit, cat, pig, and human, particularly on the luminal structures of the auricle, were observed by stereomicroscope improving corrosion casting method using latex. Structures of the right auricular casts markedly differ from those of the left side, consisting of defined surface sturctures with distinct folds and branching patterns. The main atrial region consists of smooth surfaced single mass of the latex, and the auricular region is characterized by well developed branching patte and delicate small folds. The results of this study indicate that auricula have well organized duct-like luminal structures and many small pouches (out-pocketings) expanding the internal wall of the duct-like structures and small pouches. The endocardial nuclear imprints on the surface of the folds in the auricular region appeared larger and deeper than those on the atrium proper region of the atrial cast. These morphological observation will be aid in understanding structures of auricular lumen, regional differences of the endocardium and their function to the secretory process of atrial natriuretic peptide (ANP) release.