Although some employees working for Seoul Metropolitan Subway Cooperation are working at the noisy workplaces, they has been excluded from Special Periodic Health Examination Program. And some workers complained of hearing loss or tinnitus. So, this study was carried out to investigate the prevalence rate of Noise Induced Hearing Loss of employees(10,792) working for Seoul Metropolitan Subway Cooperation. The number of subjects were total 10,792 with 10,355 men and 437 women. A questionnaire survey, otological examination, Rinne test, pure tone audiometric tests were performed and through the first and second screening audiometric examination, 605 workers were selected after excluding employees with past otologic problems, recent exposure to high level noise, and under medications. and the results were as follow; 1. Among 10,792 workers, 4 workers(0.037%) diagnosed as NIHL and 601 workers(5.56%) as early NIHL. As workers grew older, the prevalence rate of NIHL and early NIHL became more rising. 2. The prevalence rate of NIHL and early NIHL was different between work site. After age adjustment, The prevalence rate of NIHL and early NIHL was 23.74% in Train repairmen{80dB(A)}, 3.1% in Station staffs{below 70dB(A)}, 2.53% in Train crew{below 70dB(A)}, 2.1% in Office workers. 3. The perception rate of necessities of ear plug in NIHL and early NIHL was below 55% and wearing rate of ear plug in NIHL and early NIHL was 1.1% In conclusion, some employees who was under working environment in Seoul Metropolitan Subway Cooperation should be monitored to prevent hearing impairment and would be needed health education.
Ear ; Female ; Health Education ; Hearing Loss* ; Hearing* ; Humans ; Male ; Mass Screening ; Noise* ; Prevalence ; Railroads* ; Seoul* ; Tinnitus ; Workplace ; Surveys and Questionnaires

BACKGROUND: The purpose of this study was to evaluate the postoperative magnetic resonance imaging (MRI) results of minimal-tying (one medial-row tie among 4 medial-row sutures) on the medial-row in double-row suture-bridge configuration (2x2 anchor with 4x4 suture stands). METHODS: From 2011 March to 2012 July, 79 patients underwent arthroscopic rotator cuff repair using 2x2 anchor double-row configuration. The mean age was 61.3 years (range, 31-81 years). Two double-loaded suture anchors were used for medial-row. Four medialrow stitches were made with only one medial-row knot-tying (the most anterior suture). Lateral-row was secured using the conventional suture-bridge anchor technique; all 4 strands were used for each anchor. Repair integrity was evaluated with MRI at mean 6.2 months postoperatively. Retear and the pattern of retear, change of fatty infiltration, and muscle atrophy of supraspinatus were evaluated using pre- and postoperative MRI. RESULTS: Repaired tendon integrity was 38 for type I, 30 for type II, 6 for type III, 4 for type IV, and 1 for type V, according to Sugaya classification. Considering type IV/V as retear, the rate was 6.3% (5 out of 79 patients). Medial cuff failure was observed in 4 patients. Fatty atrophy of supraspinatus was significantly improved postoperatively according to Goutallier grading (p=0.01). The level of muscle atrophy of supraspinatus was not changed significantly after surgery. CONCLUSIONS: Minimal tying technique with suture configuration of four-by-four strand double-row suture-bridge yielded a lower retear rate (6.3%) in medium to large rotator cuff tears.
Arthroscopy ; Atrophy ; Classification ; Humans ; Magnetic Resonance Imaging ; Muscular Atrophy ; Rotator Cuff* ; Shoulder ; Suture Anchors ; Sutures ; Tears* ; Tendons

Severe tooth wear may lead to pathological changes of pulp, imbalance in occlusion as well as functional and esthetic problems. In this case, 34-year-old male came to the hospital because of generally worn dentition due to attrition and erosion. After evaluation, a full mouth restoration with elevation of the vertical dimension of occlusion was planned. After occlusion was stabilized by an occlusal stabilization appliance, centric relation position was recorded and subsequent provisional restorations were fabricated. After evaluation, a CAD-CAM (computer aided design-computer aided manufacturing) prosthetic restoration was carried out using monolithic zirconia. After 12 months of follow up observation, the patient was satisfied with function and esthetic appearance.
Adult ; Bruxism ; Centric Relation ; Computer-Aided Design ; Dentition* ; Follow-Up Studies ; Humans ; Male ; Mouth ; Rehabilitation* ; Tooth Wear ; Vertical Dimension

A mandibular continuity defect can be repaired using either a prosthetic device or autogenous bone. A titanium reconstruction plate can be used with a localized or vascularized flap over the defect of the mandible. Unfortunately, the plate may fail due to plate exposure, screw loosening, fracture, or infection, and will need to be removed. Plate exposure though the skin or mucosa is one of the main reasons for failure. In the present work, the authors introduced a lingually positioned reconstruction plate fabricated via three-dimensional printed bending support. This custom reconstruction plate can avoid plate re-exposure as well as reduce surgical errors and operation time.

A mandibular continuity defect can be repaired using either a prosthetic device or autogenous bone. A titanium reconstruction plate can be used with a localized or vascularized flap over the defect of the mandible. Unfortunately, the plate may fail due to plate exposure, screw loosening, fracture, or infection, and will need to be removed. Plate exposure though the skin or mucosa is one of the main reasons for failure. In the present work, the authors introduced a lingually positioned reconstruction plate fabricated via three-dimensional printed bending support. This custom reconstruction plate can avoid plate re-exposure as well as reduce surgical errors and operation time.

STATEMENT OF PROBLEM: Porcelain veneers have become a popular treatment modality for aesthetic anterior prosthesis. Fitting porcelain veneers in the mouth usually involve a try-in appointment, which frequently results in salivary contamination of fitting surfaces. PURPOSE: An in vitro study was carried out to investigate the effect of silane treatment timing and saliva contamination on the resin bond strength to porcelain veneer surface. MATERIAL AND METHODS: Cylindrical test specimens (n = 360) and rectangular test specimens (n = 5) were prepared for shear bond test and contact angle analysis. Whole cylindrical specimens divided into 20 groups, each of which received a different surface treatment and/or storage condition. The composite resin cement stubs were light-polymerized onto porcelain adherends. The shear bond strengths of cemented stubs were measured after dry storage and thermocycling (3,000 cycles) between 5 and 55 degrees C. The silane and their reactions were chemically monitored by using Fourier Transform Infrared Spectroscopy analysis (FTIR) and contact angle analysis. One-way analysis of variance (ANOVA) and Dunnett' multiple comparison were used to analyze the data. RESULTS: FT-IR analysis showed that salivary contamination and silane treatment timing did not affect the surface interactions of silane. Observed water contact angles were lower on the saliva contaminated porcelain surface and the addition of 37 percent phosphoric acid for 20 seconds on saliva contaminated porcelain increased the degree of contact angle. Silane applied to the porcelain, a few days before cementation, resulted in increasing the bond strength after thermocycling. CONCLUSION: Within the limitation of this study, it can be concluded that it would be better to protect porcelain prosthesis before saliva contamination with silane treatment and to clean the contaminated surface by use of phosphoric acid.
Cementation ; Dental Porcelain ; Mouth ; Phosphoric Acids ; Prostheses and Implants ; Resin Cements ; Saliva ; Spectroscopy, Fourier Transform Infrared ; Water

STATEMENT OF PROBLEM: An incompatibility between the initiator systems of self-curing composite resins and light-curing adhesives was supposed recently. PURPOSE: The purpose of the study was to evaluate the influence of activators for self/dual bonding on dentin shear bonding strengths. MATERIAL AND METHODS: Fifty human molars were divided into 5 groups. A flat dentin surface was created for each tooth. A self-curing composite resin (Luxacore) was bonded with the following adhesives (n = 10): One-Step, Prime and Bond NT, AdheSE, Prime and Bond NT and AdheSe were also used in combination with activators. Shear bond strengths were measured after 24 hours of water storage. The specimens were loaded in shear in the Instron until failure at a 1 mm/min crosshead speed. Data were compared using one-way ANOVA and Tukey HSD test (alpha = 0.05). RESULTS: The dentin adhesive systems in order of decreasing median bond strength were One-Step > Prime & Bond NT with activator, AdheSe with activator > Prime and Bond NT, AdheSe. Among adhesives, One-Step had the highest bond strength. Prime & Bond NT with activator had higher bond strengths than Prime and Bond NT that was used alone, and so was AdheSe. CONCLUSION: Shear bond strengths were increased in Prime and Bond NT and AdheSe when these were used with activators comparing used without activators. But using activators was not effective clinically comparing One-Step.
Adhesives ; Composite Resins ; Dentin ; Humans ; Molar ; Polymethacrylic Acids ; Tooth ; Water

STATEMENT OF PROBLEM: The use of small diameter implants having less than 3 mm in diameter were restricted because of lack of bonding strength to bone. PURPOSE: The purpose of this study was to observe how much resorbable blast media pin implants increase the binding force to the bone compared to machined transitional pin implants by measuring removal torque, and whether they can be used as final implants for replacement of small diameter teeth. MATERIAL AND METHOD: Fifteen rabbits were used in this study. Two kinds of implants (resorbable blast media pin implants and machined transitional pin implants) were inserted in each tibia bicortically. After healing time of 2, 4 and 8 weeks, the removal torque values were recorded and the rabbits were sacrificed for histological analysis. Linear finite element method analyses were conducted to compare bicortical fixation with monocortical fixation. RESULT AND CONCLUSION: Within the limitation of this in vivo study, the following conclusions were drawn: 1) The removal torque value of RBM pin implants showed statistically significant increase compared to machined pin implants at 2, 4, and 8 weeks respectively (p<0.05). 2) The removal torque value of RBM pin implants at 2, 4, and 8 weeks was increased statistically significantly with time (p<0.05). 3) Bicortical fixation showed better stress distribution compared with monocortical fixation in a linear finite element method analysis. 4) RBM pin implants are not recommended as transitional implants because they showed a lot of bone fracture in histologic specimens.
Fractures, Bone ; Rabbits ; Tibia* ; Tooth ; Torque*

Kissing aneurysms are the rare type of multiple aneurysms. They are adjacent aneurysms of different origin arteries in the same region, which require great care in diagnosis and treatment. We report a case of kissing aneurysms at the anterior communicating artery (AcomA) which were treated by endovascular coil embolization.
Aneurysm ; Arteries ; Subarachnoid Hemorrhage

Bony fixation of implants during the early phase of healing is important in order to get secondary stability of the implant assuring the success of the treatment. Because the successful placement of the implant is limited by the quality and quantity of bone, other agents which stimulate bone formation in the peri-implant spaces has been illustrated. Platelet-derived growth factor (PDGF) has been shown to regulate DNA and protein synthesis in bone cells in vitro and to interact synergistically to enhance soft tissue wound healing in vivo. The purpose of this study was to evaluate bone promotion around implants which were augmented with sagittal split osteotomy or autogenous veneer bone graft using the platelet derived growth factor(PDGF). After placement of newly designed twenty four screw-type implants, which were 12mm in length and 4mm in diameter in 6 dogs. 4microgram of PDGF B/B was applied with surgicel carriers. The dogs were sacrificed at 3 days, 1, 2, 3, 6, and 12 weeks after implantation. Specimens were examined clinically, radiographically, histologically, and histomorphometrically. The results were as follows: 1. Clinically and radiologically, there was no significant difference in bone formation and healing pattern between experimental and control group. 2. In autogenous veneer bone graft group, bone formation was observed at 1st week in the experimental groups but 2nd week in the control groups. At 3rd week, the expeimental groups showed more bone formation comparing to the control groups. 3. In sagittal split osteotomy group, bone formation was observed at 1st week in both groups. But the experimental groups showed more bone formation comparing to the control groups after 2nd week. 4. The bone growth rate of experimental group was more rapid than that of control group. These results indicated that PDGF did not affect the initiation of new bone formation, but it accelerated the bone formation at the early period.
Animals ; Blood Platelets ; Bone Development ; Dental Implants* ; DNA ; Dogs ; Osteogenesis* ; Osteotomy ; Platelet-Derived Growth Factor* ; Transplants ; Wound Healing