Short Communication: Links between Dental Hygiene Curriculum and Dental Hygiene Task Analysis / 치위생과학회지

Background@#The problem with current dental hygienist education is that it operates as an education system based on the national examination rather than on a practical basis; thus, graduates have difficulties in practice after obtaining their license. This study aimed to propose a job-oriented curriculum by analyzing the links between the task analysis of Korean dental hygienists and dental hygiene learning goals. @*Methods@#This study performed a relationship analysis based on a second job analysis study of dental hygienists conducted by the Korea Health Personnel Licensing Examination Institute and the learning goals of the Korean Dental Hygiene Faculty Association. @*Results@#Based on the links between the task and learning goals of the dental hygienist, they were classified into six types: 1) tasks listed in the license exam and learning goal, 2) tasks not listed in the license exam but listed in learning goals, 3) tasks not listed in learning goals, 4) learning goals not related to tasks, 5) learning goals listed in a few tasks, and 6) tasks related to several learning goals. The results showed that most of them correspond to the 5th classification, followed by the 3rd and 4th categories, which are mostly basic science learning goals. Tasks without learning goals are not included in the curriculum; thus, the curriculum needs to be supplemented. The overlapping learning goals of several subjects for one job skill must be reduced in job-oriented education. @*Conclusion@#We suggest that the dental hygiene curriculum be developed based on task analysis and reflected in the national dental hygienist exam. The clinical practice performance of dental hygienists will take further leap forward through task-oriented education.

Successful Localization of Intraoral Foreign Body with C-arm Fluoroscopy / 대한악안면성형재건외과학회지

During surgical procedures, unexpected material, including surgical instruments and tissue segments, may get lost in the surgical field. Most of these should be immediately removed to prevent further complications, such as vital organ irritation, infection, and inflammatory pseudo-tumor formation. However, it is not always easy to define the exact location of the foreign body, especially if the item is very small and/or it is embedded in the soft tissue of the head and neck region. Intraoperative real-time radiological imaging with C-arm fluoroscopy can be useful to trace the three-dimensional location of small and embedded foreign bodies in the oral and maxillofacial area. We describe an unusual case of an embedded micro-screw in the intrinsic tongue muscle that had been dropped into the sublingual space during a lower alveolar bone graft procedure. The lost foreign body was accurately identified with C-arm fluoroscopy and safely removed without any further complications.

Expansile keratocystic odontogenic tumor in the maxilla: immunohistochemical studies and review of literature

Keratocystic odontogenic tumors (KCOT) - previously termed odontogenic keratocysts (OKC) - are characterized by aggressive behavior and a high rate of recurrence. Histopathologically, the basal layer of KCOT shows a higher cell proliferation rate and increased expression of anti-apoptosis genes. Clinically, KCOT is frequently involved in the mandibular posterior region but is not common in the posterior maxilla. However, it should be noted that due to its expansive characteristics, KCOT involved near the maxillary sinus could easily expand to an enormous size and occupy the entire maxilla. To achieve total excision of these expanded cystic tumors in the maxilla, a more aggressive approach would be needed. In this report, we describe two cases of expansile KCOT involving the entire unilateral maxilla and maxillary sinus; they were completely excised using the Weber-Ferguson approach, showing no evidence of recurrence during the follow-up period of more than two years. In immunohistochemical analyses of the tumor specimens, p53 and p63 showed strong expression, and B-cell lymphoma 2 (BCL2) and MKI67 (Ki-67) showed moderate or weak expression, however, detection of BCL2-associated X protein (BAX) was almost negative. These data indicate that expansile KCOT possesses increased anti-apoptotic activity and cell proliferation rate but decreased apoptosis. These properties of KCOT may contribute to tumor enlargement, aggressive behavior, and high recurrence rate.

Isolation of human mesenchymal stem cells from the skin and their neurogenic differentiation in vitro

OBJECTIVES: This aim of this study was to effectively isolate mesenchymal stem cells (hSMSCs) from human submandibular skin tissues (termed hSMSCs) and evaluate their characteristics. These hSMSCs were then chemically induced to the neuronal lineage and analyzed for their neurogenic characteristics in vitro. MATERIALS AND METHODS: Submandibular skin tissues were harvested from four adult patients and cultured in stem cell media. Isolated hSMSCs were evaluated for their multipotency and other stem cell characteristics. These cells were differentiated into neuronal cells with a chemical induction protocol. During the neuronal induction of hSMSCs, morphological changes and the expression of neuron-specific proteins (by fluorescence-activated cell sorting [FACS]) were evaluated. RESULTS: The hSMSCs showed plate-adherence, fibroblast-like growth, expression of the stem-cell transcription factors Oct 4 and Nanog, and positive staining for mesenchymal stem cell (MSC) marker proteins (CD29, CD44, CD90, CD105, and vimentin) and a neural precursor marker (nestin). Moreover, the hSMSCs in this study were successfully differentiated into multiple mesenchymal lineages, including osteocytes, adipocytes, and chondrocytes. Neuron-like cell morphology and various neural markers were highly visible six hours after the neuronal induction of hSMSCs, but their neuron-like characteristics disappeared over time (24-48 hrs). Interestingly, when the chemical induction medium was changed to Dulbecco's Modified Eagle Medium (DMEM) supplemented with fetal bovine serum (FBS), the differentiated cells returned to their hSMSC morphology, and their cell number increased. These results indicate that chemically induced neuron-like cells should not be considered true nerve cells. CONCLUSION: Isolated hSMSCs have MSC characteristics and express a neural precursor marker, suggesting that human skin is a source of stem cells. However, the in vitro chemical neuronal induction of hSMSC does not produce long-lasting nerve cells and more studies are required before their use in nerve-tissue transplants.

Mandibular bone regeneration using autogenous skin-derived precursor cells with a mixed demineralized bone and fibrin glue scaffold in miniature pigs

Evaluation of angiogenic phenotypes in cultured human periosteal-derived cells under high-dose dexamethasone