Obstructive sleep apnea patients with the oral appliance experience pharyngeal size and shape changes in three dimensions

Pharyngeal size and shape differences between pre- and posttrials of a mandible-protruding oral appliance were investigated using cine computerized tomography (CT). Fourteen patients diagnosed with obstructive sleep apnea whose apnea-hypopnea index was higher than 5 and arousal index higher than 20 underwent a second overnight sleep study to evaluate the effectiveness of the oral appliance. Three-dimensional changes in pharyngeal shape measured on cross-sectional CT images during two respiratory cycles after oral appliance delivery were estimated by three variables: (1) lateral dimension, (2) anterior-posterior dimension, and (3) cross-sectional area at five vertical levels. Apnea indices improved significantly when the appliance was used. During apnea, measurements at retropalatal and retroglossal levels decreased most. However, the cross-sectional area of these levels appeared to increase significantly (P < .05) with the appliance in place during wakefulness. The oral appliance appears to enlarge the pharynx to a greater degree in the lateral than in the sagittal plane at the retropalatal and retroglossal levels of the pharynx, suggesting a mechanism for the effectiveness of oral appliances that protrude the mandible.ope

환경친화적인 산업입지를 위한 제도개선 방안(Policy directions for the environment-friendly industrial location in Korea)

노트 : 이 연구보고서의 내용은 국토연구원의 자체 연구물로서 정부의 정책이나 견해와는 상관없습니다

해외직접투자에 따른 산업입지 대응방안 연구(Industrial location policy on the outbound foreign direct investment in Korea)

노트 : 이 연구보고서의 내용은 국토연구원의 자체 연구물로서 정부의 정책이나 견해와는 상관없습니다

Evaluation of mandibular cortical bone thickness for placement of temporary anchorage devices (TADs).

OBJECTIVE: In this study, we measured the cortical bone thickness in the mandibular buccal and lingual areas using computed tomography in order to evaluate the suitability of these areas for application of temporary anchorage devices (TADs) and to suggest a clinical guide for TADs. METHODS: The buccal and lingual cortical bone thickness was measured in 15 men and 15 women. Bone thickness was measured 4 mm apical to the interdental cementoenamel junction between the mandibular canine and the 2nd molar using the transaxial slices in computed tomography images. RESULTS: The cortical bone in the mandibular buccal and lingual areas was thicker in men than in women. In men, the mandibular lingual cortical bone was thicker than the buccal cortical bone, except between the 1st and 2nd molars on both sides. In women, the mandibular lingual cortical bone was thicker in all regions when compared to the buccal cortical bone. The mandibular buccal cortical bone thickness increased from the canine to the molars. The mandibular lingual cortical bone was thickest between the 1st and 2nd premolars, followed by the areas between the canine and 1st premolar, between the 2nd premolar and 1st molar, and between the 1st molar and 2nd molar. CONCLUSIONS: There is sufficient cortical bone for TAD applications in the mandibular buccal and lingual areas. This provides the basis and guidelines for the clinical use of TADs in the mandibular buccal and lingual areas.ope

A Macroprudential Approach to Financial Supervision and Monetary Policy in Emerging Economies

This paper attempts to define, construct a policy framework, and analyze interactions with monetary policy of macroprudential policy. The available pieces of evidence suggest that the effects of the LTV and DTI regulations for financial stability are rathⅠ. Introduction 　Ⅱ. Role and Scope of Macroprudential Policy 　Ⅲ. Effectiveness of Macroprudential Policy in Leaning againstFinancial Cycle 　Ⅳ. Korea’s Experience with Macroprudential Policy: 2001-2011 　Ⅴ. Making Operational a Macroprudentia

The efficient use of midpalatal miniscrew implants

The midpalatal suture area with thin, keratinized soft tissue and sufficient cortical bone is an optimal site for miniscrew implantation. Even though the midpalatal area has its own anatomical limitations, it can be overcome by bonding extension arms to the miniscrews. This technique also enhances screw stability, thus producing a successful outcome. Among many applications, midpalatal miniscrew implants can be effectively used for intrusion of upper molars with reduced treatment time and enhanced patient comfort

Effects of Mechanical Properties of Lingual Lever Arm on the Displacement Pattern of Anterior Segment: A Finite Element Analysis

Purpose: The purpose of this study was to investigate the effects of mechanics properties of lingual lever arm on the displacement pattern of maxillary anterior segment. Methods: A finite element model was constructed based on average dental study model. The lever arm was designed as 20 mm in length, with or without splinting wire. Wire stiffness was set as .016×.022 stainless steel, .018×.025 stainless steel or structure with indefinite rigidity. The mechanical property of PDL was simulated based on recent studies. Point of force application was simulated as that of either midpalatal or palatal interradicular miniscrews. Initial tooth displacement was compared depending on the presence of the splint wire, stiffness of the main archwire and the property of periodontal ligament. Results: Compared to the non-splint lever arm, splinted lever arm decreased the lingual tipping of incisors and buccal displacement of canine, inducing translation of 4 anterior teeth at lever arm length 16.85 mm (palatal slope miniscrews) and 19.01 mm (midpalatal miniscrew). When the wire stiffness was increased, buccal displacement of canine was decreased. Differences in the mechanical properties of PDL affected not only the pattern of displacement, but also the amount of displacement at each condition. Conclusion: The results indicate that splinting of lever arms and wire stiffness of main arch provides additional resistance to deformation of the main archwire, implicating predictable tooth movement during anterior retraction.ope

A Simultaneous Mobilization of Four Impacted Upper Incisors in a Case of an Adolescent Patient with Cleidocranial Dysplasia (CCD)

Introduction: Cleidocranial dysplasia (CCD) is often attended by a considerable number of supernumerary teeth combined with impaction of sometimes all permanent teeth. To help these patients obtain an esthetically pleasing and functional dentition, eruption of an appropriate number of permanent teeth should ideally be brought about, while all other teeth should be removed. The simultaneous traction of several neighboring teeth into the same direction is associated with biomechanical challenges. This report illustrates how these difficulties were solved in a specific treatment case. Findings and diagnosis: A 9-year-old boy presented with delayed tooth eruption. Major concern of the patient was the edentulous maxillary anterior segment. Clinical manifestation was confined to all deciduous canines and molars in both jaws and to the permanent mandibular central incisors. Radiographic examination revealed the impaction of all remaining permanent teeth as well as 20 supernumerary teeth and four third-molar buds. Cephalometric analysis revealed a tendency for skeletal class III in conjunction with a horizontal growth pattern. Treatment progress and outcomes: Utilizing a custom-planned appliance, four completely impacted maxillary incisors could be moved to esthetically and functionally acceptable positions within 8 months. The appliance used was supported exclusively by the maxillary deciduous teeth and the palate. Thanks to biomechanical considerations, the position of the anchor teeth could be fully preserved. Conclusions: Simultaneous mobilization of multiple teeth requires a customized approach that does justice to each patient’s individual situation. Meticulous treatment planning can prevent adverse effects even without the use of skeletal anchorage methods.ope