Three-dimensional analysis of tooth movement in Class II malocclusion treatment using arch wire with continuous tip-back bends and intermaxillary elastics / 대한치과교정학회지

OBJECTIVE@#The aim of this study was to analyze three-dimensional (3D) changes in maxillary dentition in Class II malocclusion treatment using arch wire with continuous tip-back bends or compensating curve, together with intermaxillary elastics by superimposing 3D virtual models.@*METHODS@#The subjects were 20 patients (2 men and 18 women; mean age 20 years 7 months ± 3 years 9 months) with Class II malocclusion treated using 0.016 × 0.022-inch multiloop edgewise arch wire with continuous tip-back bends or titanium molybdenum alloy ideal arch wire with compensating curve, together with intermaxillary elastics. Linear and angular measurements were performed to investigate maxillary teeth displacement by superimposing pre- and post-treatment 3D virtual models using Rapidform 2006 and analyzing the results using paired t-tests.@*RESULTS@#There were posterior displacement of maxillary teeth (p < 0.01) with distal crown tipping of canine, second premolar and first molar (p < 0.05), expansion of maxillary arch (p < 0.05) with buccoversion of second premolar and first molar (p < 0.01), and distal-in rotation of first molar (p < 0.01). Reduced angular difference between anterior and posterior occlusal planes (p < 0.001), with extrusion of anterior teeth (p < 0.05) and intrusion of second premolar and first molar (p < 0.001) was observed.@*CONCLUSIONS@#Class II treatment using an arch wire with continuous tip-back bends or a compensating curve, together with intermaxillary elastics, could retract and expand maxillary dentition, and reduce occlusal curvature. These results will help clinicians in understanding the mechanism of this Class II treatment.

Investigating the Intrapsychic Factors that Affect Quality of Life in Patients with Schizophrenia / 대한정신분열병학회지

OBJECTIVES: This study was designed to investigate the intrapsychic factors affecting the quality of life of patients with chronic schizophrenia. METHODS: Quality of life was measured using the World Health Organization Quality of Life Scale-Brief (WHOQOL-BREF) in 72 community-dwelling patients with schizophrenia. Demographic status, psychopathology, independent living skill, and insight were examined. Based on this, correlation analysis between each scale and multiple regression analysis was performed to examine the factors that can predict the quality of life. RESULTS: The illness duration was over 10 years in 79.2% of patients. The patients with 10–0 years of illness duration showed lower scores of quality of life than those with less than 10 years or more than 20 years. Anxiety/depressive symptom, hostile/suspiciousness were associated with quality of life scores. Among those, anxiety/depressive symptom was the strongest predictor of quality of life in patients with chronic schizophrenia. CONCLUSION: The management of anxiety and depressive symptoms should be implicated in the treatment of schizophrenic patients to improve the quality of life.

Depression as a Mediator of the Relationship Between Resilience and Posttraumatic Stress Symptoms and Dissociation in Firefighters / 정신신체의학

OBJECTIVES: This study aimed to investigate the effects of resilience on posttraumatic stress symptoms and dissociation and whether depression mediates the relationships between resilience and posttraumatic stress symptoms and dissociation. METHODS: A total of 115 firefighters participated in the study. Data were collected via the Life Events Checklist, Impact of Event Scale-Revised, Dissociative Experience Scale, Beck Depression Inventory, and Connor-Davidson Resilience Scale. Structural equation modeling and path analysis were applied to estimate the relationships between resilience, depression, posttraumatic stress symptoms, and dissociation. RESULTS: Greater resilience was associated with lower posttraumatic stress symptoms and dissociation, and the relationship between them was fully mediated by depression. CONCLUSIONS: Specific aspects of depression may help explain the relationships between resilience and posttraumatic stress symptoms and dissociation. Tailored prevention programs and treatments based on resilience and depression may prevent posttraumatic stress symptoms and dissociation in firefighters and improve treatments outcomes among firefighters with posttraumatic stress symptoms and/or dissociation.

Anti-inflammatory Effects of Flavonoids on TNBS-induced Colitis of Rats

It has been shown that the extracts including eupatilin and quercetin-3-beta-D-glucuronopyranoside had mucoprotective effects on the esophagus and stomach through their antioxidant activities. This study was designed to investigate the anti-inflammatory effect of these flavonoid compounds in an animal model of inflammatory bowel disease induced by 2,4,6-trinitrobenzene sulfonic acid. Experimental colitis was induced by intracolonic administration of 2,4,6-trinitrobenzene sulfonic acid. Extracts including eupatilin or quercetin-3-beta-D-glucuronopyranoside were orally administered to animals 48, 24, and 1 h prior to the induction of colitis and then again 24 h later. The animals were sacrificed 48 h after by 2,4,6-trinitrobenzene sulfonic acid treatment and the macroscopic appearance of the colonic lesions was scored in a blinded manner on a scale of 1 to 10. The inflammatory response to colitis induction was assessed by measuring myeloperoxidase activity, nitric oxide production, tumor necrosis factor-alpha expression, total glutathione levels, and malondialdehyde concentrations in the colon. The results indicated that extracts including eupatilin and extracts including quercetin-3-beta-D-glucuronopyranoside dose-dependently improved the morphology of the lesions induced by 2,4,6-trinitrobenzene sulfonic acid and reduced the ulcer index accordingly. In addition, rats receiving extracts including eupatilin and extracts including quercetin-3-beta-D-glucuronopyranoside showed significantly decreased levels of mucosal myeloperoxidase activity, nitric oxide production, tumor necrosis factor-alpha expression, and malondialdehyde levels, and increased total glutathione levels. Extracts including eupatilin and extracts including quercetin-3-beta-D-glucuronopyranoside ameliorated the inflammatory response and colonic injury in acute colitis by decreasing oxidative stress and neutrophil activation. Extracts including eupatilin and extracts including quercetin-3-beta-D-glucuronopyranoside may inhibit acute colitis.

Finite element analysis of the influence of esthetic posts on incisors / 대한치과보철학회지

STATEMENT OF PROBLEM: Most posts are metallic, but in response to the need for a post that possesses optical properties compatible with an all-ceramic crown, an esthetic post has been developed. Although there have been many studies about the esthetic post materials, 3-dimensional finite element studies about the stress distribution of them are in rare. PURPOSE: The purpose of this study is to investigate comparatively the distribution of stresses of the restored, endodontically treated maxillary incisors with the esthetic post materials and the displacement on the cement layer on simulated occlusal loading by using a 3-dimensional finite element analysis model. MATERIAL AND METHOD: Four 3-dimensional finite element models were constructed in a view of a maxillary central incisor, a post, a core, and the supporting tissues to investigate the stresses in various esthetic posts and cores and the displacement on the cement layer (Model 1; Cast gold post and core, Model 2; Glass fiber post with composite core, Model 3; Zirconia post with composite core, Model 4; Zirconia post with ceramic core). Force of 300N was applied to the incisal edge and the cingulum (centric stop point) with the angle of 135-degree to the long axis of the tooth. RESULTS: 1. The stresses and displacement on the incisal edge were higher than on the cingulum. 2. The stresses in dentin were the highest in Model 2 (Glass fiber post with composite core), and the second was Model 3, the third Model 1, and the lowest Model 4. 3. The stresses in post and core were the highest in Model 4 (Zirconia post with ceramic core), and the second was Model 1, the third Model 3, and the lowest Model 2. 4. The displacement on the cement layer was the highest in Model 2 (Glass fiber post with composite core), and the second was Model 3, the third Model 1, and the lowest Model 4. CONCLUSION: When a functional maximum bite force was applied, the distribution of stresses of the esthetic post and core materials and the displacement on the cement layer were a little different. It seems that restoring extensively damaged incisors with esthetic post and core materials would be decided according to the remaining tooth structure.

Comparison of Resorbable and Nonresorbable Membrane for Guided Bone Regeneration in Implant Dehiscence Defects / 대한치주과학회지

The purpose of this study was to examine the frequency of dehiscence bone defect on peri-implant and to compare the difference between resorbable membrane and non-resorbable membrane in bone regeneration on peri-implant. Amomg the patients, 22 patientswho have recieved an implant surgery at the department of Periodontics in Dankook University Dental Hospital showed implant exposure due to the dehiscence defect and 27 implants of these 22 patients were the target of the treatment. Gore-Tex(R) and Bio-mesh(R) were applied to the patients and treated them with antibiotics for five days both preoperatively and postoperatively. Reentry period was 26 weeks on average in maxilla and 14 weeks on average in mandible. The results were as follows: 1. Dehiscence bone defect frequently appeared in premolar in mandible and anterior teeth in maxilla respectively. 2. Among 27 cases, 2 membrane exposures were observed and in these two cases, regenerated area was decreased. 3. In non-resorbable membrane, bone surface area 9.25+/-4.84 preoperatively and significantly increased to 11.48+/-7.52 postoperatively.(P<0.05) 4. In resorbable membrane, bone surface area was 14.80+/-8.25 preoperatively and meaningfully widened to 17.61+/-10.67 postoperatively.(P<0.05) 5. The increase of bone surface area in non-resorbable membrane was 2.23+/-3.38 and the increase of bone surface area in resorbable membrane was 2.80+/-3.00 ;therefore, there was no significant difference between these two membranes(P<0.05). This study implies that the surgical method using DFDB and membrane on peri-implant bone defect is effective in bone regeneration regardless the kind of the membrane, and a similar result was shown when a resorbable membrane was used.