Prosthetic reconstruction of maxillary defect resulting from a traumatic fall in an elderly patient: A case report / 대한치과보철학회지

Fall is the most common cause of trauma in the elderly and a major reason of dental injury. Maxillary anterior region is the most vulnerable area to the traumatic fall. Loss of teeth and adjacent tissue in this area results in maxillofacial defects and inappropriate maxillomandibular relationship. Reconstruction of the loss requires comprehensive and careful planning to fulfill not only functional but also esthetic demand. Prosthetic approach can avoid surgically extensive intervention, reducing both treatment cost and time. This clinical report describes a 78-year-old woman with the loss of teeth and alveolar bone in maxillary anterior region due to a traumatic fall, rehabilitated with a metal-ceramic fixed dental prosthesis using gingival porcelain.

Complete denture rehabilitation of a fully edentulous patient with unilateral facial nerve palsy: A case report / 대한치과보철학회지

Bell's palsy is an acute-onset unilateral peripheral facial neuropathy. For patients with sequelae of facial paresis, the successful rehabilitation of fully edentulous arches is challenging. This case report described the treatment procedures and clinical considerations to fabricate complete dentures of a patient who showed unilateral displacement of mandible, unilateral chewing pattern and parafunctional jaw movement due to sequelae of Bell's palsy. Gothic arch tracing was used to record reproducible centric relation and lingualized occlusion was performed to provide freedom to move between centric relation and the patient's habitual functional area in fabricating satisfactory dentures in terms of function and esthetics.

Effect of Age on Cortical Activation during Swallowing: An fMRI Study / 대한연하장애학회지

OBJECTIVE: Understanding the neural functional organization of swallowing in the elderly is essential when diagnosing and treating older adults with swallowing difficulties. While brain-imaging studies in young adults have implicated multiple cortical regions in swallowing, only a few investigations were performed on older subjects. In this study, we aimed to compare neural activation in regions for swallowing between healthy young and older adults and to better understand neural control of deglutition, complex sensory-motor process which occurs as a result of old age. METHOD: Fifteen young and fifteen older healthy individuals without a swallowing problem were examined with functional magnetic resonance imaging (fMRI) during voluntary saliva swallowing. Functional image data was obtained with a T2 gradient-echo, echo planar imaging (EPI) pulse sequence optimized for blood-oxygen level dependent (BOLD) contrast. Two samples t-test was conducted to perform group comparison (younger adults versus older adults) for the areas in which the activation was larger for the swallowing condition than the non-swallow condition. RESULT: Both groups showed activations in areas involved in the motor control and execution. In both groups, main regions of activation included bilateral prefrontal cortex, primary somatosensory cortex, insula, basal ganglia, and cerebellum. Between-group comparisons revealed statistically stronger activations in the prefrontal cortex and middle temporal gyrus of older adults during swallowing. CONCLUSION: This study provides evidence that swallowing requires larger and more widespread areas of neural control in older adults group, especially in prefrontal cortex and inferior frontal gyrus. These findings suggest that more demanding swallowing tasks are necessary for elderly patients because of their inefficient neural network due to their age.

A root submergence technique for pontic site development in fixed dental prostheses in the maxillary anterior esthetic zone

PURPOSE: This case report discusses the effect of a root submergence technique on preserving the periodontal tissue at the pontic site of fixed dental prostheses in the maxillary anterior aesthetic zone. METHODS: Teeth with less than ideal structural support for fixed retainer abutments were decoronated at the crestal bone level. After soft tissue closure, the final fixed dental prostheses were placed with the pontics over the submerged root area. Radiographic and clinical observations at the pontic sites were documented. RESULTS: The submerged roots at the pontic sites preserved the surrounding periodontium without any periapical pathology. The gingival contour at the pontic site was maintained in harmony with those of the adjacent teeth, as well as the overall form of the arch. CONCLUSIONS: The results of this clinical report indicate that a root submergence technique can be successfully applied in pontic site development with fixed dental prostheses, especially in the maxillary anterior esthetic zone.

Chondrogenesis of periodontal ligament stem cells by transforming growth factor-β3 and bone morphogenetic protein-6 in a normal healthy impacted third molar / 国际口腔科学杂志·英文版

The periodontal ligament-derived mesenchymal stem cell is regarded as a source of adult stem cells due to its multipotency. However, the proof of chondrogenic potential of the cells is scarce. Therefore, we investigated the chondrogenic differentiation capacity of periodontal ligament derived mesenchymal stem cells induced by transforming growth factor (TGF)-β3 and bone morphogenetic protein (BMP)-6. After isolation of periodontal ligament stem cells (PDLSCs) from human periodontal ligament, the cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with 20% fetal bovine serum (FBS). A mechanical force initiated chondrogenic differentiation of the cells. For chondrogenic differentiation, 10 µg·L⁻¹ TGF-β3 or 100 µg∙L⁻¹ BMP-6 and the combination treating group for synergistic effect of the growth factors. We analyzed the PDLSCs by fluorescence-activated cell sorting and chondrogenesis were evaluated by glycosaminoglycans assay, histology, immunohistochemistry and genetic analysis. PDLSCs showed mesenchymal stem cell properties proved by FACS analysis. Glycosaminoglycans contents were increased 217% by TGF-β3 and 220% by BMP-6. The synergetic effect of TGF-β3 and BMP-6 were shown up to 281% compared to control. The combination treatment increased Sox9, aggrecan and collagen II expression compared with not only controls, but also TGF-β3 or BMP-6 single treatment dramatically. The histological analysis also indicated the chondrogenic differentiation of PDLSCs in our conditions. The results of the present study demonstrate the potential of the dental stem cell as a valuable cell source for chondrogenesis, which may be applicable for regeneration of cartilage and bone fracture in the field of cell therapy.

A Comparative Study on Mechanical and Biochemical Properties of Bovine Pericardium After Single or Double Crosslinking Treatment

BACKGROUND AND OBJECTIVES: Glutaraldehyde (GA) has been used as a representative method of tissue preservation in cardiovascular surgery. However, GA has showed limited durability including calcification, mechanical failure and toxicity. To overcome those unsolved problems, we analyzed the crosslinking differences of primary amines, GA and genipin in their mechanical and biochemical properties with a single or double crosslinking agent for clinical application. MATERIALS AND METHODS: Samples were divided into 3 groups; control, single crosslinking fixation and double crosslinking fixation after decellurarization using bovine pericardium. For analysis of the biochemical and mechanical properties of each crosslinking method, tensile strength, percentage strain, thermal stability, resistance to pronase, nynhydrin and cytotoxicity test were studied. RESULTS: Combined hexamethylene diamine and suberic acid in the carbodiimide hydrochloride/N-hydroxysucinimide solution (EDC/NHS) after decellurarization, tensile strength and strain percentage were not statistically significant compared to the single crosslinking treated groups (p>0.05). Tissue crosslinking stability was weak in single treatment of diphenylphosphoryl azide, suberic acid, low concentration of EDC, hexamethylene diamine and procyanidin groups, but thermal stability and resistance to the pronase and ninhydrin were markedly increased in concentrated EDC/NHS or after combined double treatment with low concentration of GA or genipin (p<0.001). CONCLUSION: Single or double crosslinking with low concentration of carbodiimide, diphenylphosphonyl azide, procyanidin, suberic acid and hexane diamine were not as effective in mechanical, biochemical, cytotoxic and crosslinking properties compared to GA or genipin fixation, but their mechanical and chemical properties were much improved when combined with low concentrations of GA or genipin in the double crosslinking process.