Association between Job-related Factors and Musculoskeletal Symptoms in University Hospital Healthcare Workers / 대한산업의학회지

OBJECTIVES: To investigate the prevalence of musculoskeletal symptoms in university hospital healthcare workers and to evaluate the job-related factors that affect musculoskeletal symptoms. METHODS: A questionnaire was administered to health care workers who work at the university hospital. The self-reported questionnaire included the following information: general characteristics, health behaviors, job-related factors, depression symptom, ergonomic factor, job stress, and musculoskeletal symptoms. Ergonomic factor was measured by ANSI Z-365, depression symptom by CES-D, job stress by KOSS-26 and musculoskeletal symptoms by NIOSH questionnaire. RESULTS: A total of 1,198(64.2%) of 1,842 respondents answered and 1,183 were included in the final study population. The prevalence of musculoskeletal symptoms was 53.3%. The prevalence of musculoskeletal symptoms of males and females was 25.6% and 63.9%, respectively. After adjusting for confounding factors, total job stress score(OR=3.05, 95% CI=1.62~5.74), depression symptom(OR=2.18, 95% CI=1.07~4.43), ANSI Z-365 high risk group(OR=5.33, 95% CI=2.08~13.66) in males and total job stress score(OR=2.14, 95% CI=1.53~3.00), three-shift work(OR=1.81, 95% CI=1.26~2.60), nurses(OR=1.82, 95% CI=1.22~2.73), and ANSI Z-365 high risk group(OR=3.33, 95% CI=1.58~7.03) in females were significantly associated with musculoskeletal symptoms. CONCLUSIONS: Shift work, nurses, ANSI Z-365 high risk group, depression symptom and job stress were related with musculoskeletal symptoms. In order to prevent musculoskeletal disorders, ergonomic improvements and stress reduction are required.

A study on the Development of Surveillance System for Agricultural Injuries in Korea / 農村醫學 地域保健

Injury in agriculture is a serious public health issue with a major impact on the lives of Korean farmers. It is one of the leading causes of death and is also a major cause of longand short-term disability. In 2001, the social cost of one accident in agricultural machinery was estimated as 97.7-97.8 million won that is 4 fold of farm household income in Korea. Effective prevention and control of injuries requires a system of surveillance that monitors the incidence of injuries, their causes, treatment and outcomes. This requires an integrated system of data collection, analysis and interpretation and communication. Creating effective injury surveillance system in Korea requires to establish a framework for a national agenda. Discussions regarding the development of the framework should address, but not be limited to issues related to Data Holdings and Linkages; Capacity and Skills; Communication; Interconnection; and Surveillance Products. Ideally, an injury surveillance system would meet the information requirements across all sectors, while allowing each to have the ongoing information it needs for its policy and programming needs. This study was carried out to develop a surveillance system of agricultural injuries in Korea. Study subjects were residents who lived in a typical agricultural area (Yangpyung area in Kyung-gi province). The main data sources were reports of village headmen, compared with data of 'National Emergency Management Agency', 'National Health Insurance Corporation', 'Insurance of National Agricultural Cooperative', and 'Emergency Medical Centers'. Each data were reviewed to validate the strengths and weaknesses.

Early change of C-reactive protein level in TKA : Antibiotic-loaded vs Plain bone cement

PURPOSE: To analyse the level of C-reactive protein (CRP) after total knee arthroplasty (TKA) with antibiotic-loaded bone cement (ABLC) and plain bone cement (PBC). MATERIAL AND METHODS: In the 75 primary TKAs, 35 cases with risk factors for infection were fixed with ABLC and 36 cases without risk factors were fixed with PBC. We did comparative analysis of the changing trends of the level of CRP up to 6 months after TKA in the 2 groups. RESULTS: The CRP levels at 5th,7th, 10th, 14th day and 1.5 th, 3 th, 6 th months after TKA were average 3.03, 1.50, 1.00, 0.60, 0.48, 1.04 and 0.60 mg/dl in the ABLC group, and 3.71, 2.16, 1.08, 0.78, 0.58, 0.27 and 0.31 mg/dl in the PBC group. The results were ALBC group, even having some risk factors for infection, showed the lower levels of CRP in early recovery period after TKA than PBC group. But two group has no significant difference statistically (p=0.08). CONCLUSION: Even though some risk factors for infection, statistically same returning patterns of the CRP levels in the ABLC group compare with the PBC group would be informative for observation about infection in TKA.

Clinical Evaluation about the Immediate Implant Replacement after Tooth Extraction / 영남의대학술지

BACKGROUND: Immediate implant placement has become an acceptable treatment for the edentulous area. The advantages of the immediate implant placement include considerable decrease in time from tooth extraction to placement of the finial prosthesis, fewer surgical procedures, and better acceptance of the overall treatment plans. But the success is dependent on the quantity and quality of the extraction socket. The purpose of this study is to evaluate the success of the immediate implant placement. MATERIALS AND METHODS: Twenty-one sites in 16 patients were selected for the evaluation of the immediate implant placement. All of the cases were followed using clinical and radiographic examinations. Criteria of success were the absence of peri-implant radiolucency, mobility, and persistent pain or sign of infection. RESULTS: Of the 21 implants, 13 implants have been succeeded. Of the 13 implants, 10 implants were replaced for the periodontal disease and 3 implants were replaced for the trauma. CONCLUSION: The criteria of the success in immediate implant placement are as follows. 1) Implants placed into fresh extraction sockets have a high rate of survival. 2) Implant should be placed as close as possible to the alveolar crest. 3) Implant placed into available bone beyond the apex have a high success rate.

Non-Surgical Treatment of Mandibular Condylar Fracture with Functional Appliance: Clinical and Radiographic Analysis of 1 Case / 영남의대학술지

Mandibular condylar fracture is common in mandibular fractures. Unlike other facial, skeletal fractures, most of mandibular condylar neck or head fractures are treated with closed reduction and subsequent functional therapy is essential for preventing complications including ankylosis, arthrosis and growth disturbance. From January, 2000 to September, 2002, we have treated 15 cases of mandibular condylar fractures with closed reduction by using functional appliance with bite block. Among these cases, we report a case of 14-year-old female with mandibular condylar neck fracture, resulted in good clinical and radiographic progress.

Factors Associated With the Personal Protective Equipments(PPEs) Wearing of Workers in Small Scale Industries / 대한산업의학회지

OBJECTIVE: The aim of this study was to identify the factors associated with the wearing of Personal Protective Equipment (PPE) in small scale industries. METHODS: In a cross-sectional study, the data were obtained from self-administered questionnaires, a special health examination and the industrial hygiene records. The study included 230 workers in small-scale industries (the print industry and automobile repair shops), which were provided with a subsidiary occupational health program funded by government in 1998. The authors used the Precede-Proceed model. RESULTS: Among the subjects who were recommended to wear a PPE, 32.7% (35/107) wore the gas/vapor respirators, 43.9 % (101/230) wore the particulate respirators, and 44.3 % (102/230) wore hearing aids. Among them, 64.3 % (148/230) wore one of the above PPE. The wearing of PPE wearing was associated with knowledge (OR=2.34), the value of prevention (OR=3.46), social support (OR=2.78), the type of task (OR=2.18-4.47), and income level (OR=7.64). CONCLUSIONS: In small scale industries, the proportion workers wearing PPE was low. To increase this proportion, the reinforcing, enabling, and environmental factors as well as the predisposing factors need to be modified.

The Preventive Programs for the Work-related Musculoskeletal Disorders in a Telephone Directory Assistance Workplace

OBJECTIVES: This study evaluated the effect of an in-house work-related musculoskeletal disorders (WMSDs) preventive programs in a telephone directory assistance workplace. METHODS: The subjects (N=177) were divided into four groups (nonparticipants, 41; preventive exercise, 31; self-physical therapy, 40; both, 65) by program participation type. The results of WMSDs program were obtained by questionnaire, which consisted of upper extremities'(neck, shoulder, arm, hand) symptom prevalence, self-rating symptom severity, and before-after symptom change between 1995 and 1998 data and workers'satisfaction by program participation. RESULTS: The prevalence of symptoms related WMSDs was only reduced in neck region of nonparticipants, other groups not in significant. The pain scale (5-likert) of each region was significantly decreased in neck, arm and hand of nonparticipants. In other groups, there was no significant change in the prevalence of WMSDs. The change of visual analogue scale was decreased by 21.7% in self-physical therapy group (p=0.043). The subjects mostly were satisfied with this in-house programs. Above all, preventive exercise and both program groups showed content over 80%. CONCLUSIONS: The results of before-after symptoms change was not inconsistent, but subjects were showed high satisfaction about the preventive programs. In attempts to improve the WMSDs related symptoms, the best results will be achieved with ongoing in-house preventive programs practice and periodic outcomes assessments.

Radiologic variables affecting extraction of impatcted mandibular third molars

Complications Associated With Open Reduction Of Mandibular Fractures

PURPOSE: The aim of this study was to evaluate the complications of open reduction and internal fixation of mandibular fracture with miniplates. PATIENTS AND METHODS: A total of 134 patients who presented with 196 fractures were analyzed retrospectively. Complications were evaluated for factors such as age, the site of fracture, the severity of fracture, delayed operation, preoperative wound contamination, the site and disposition of teeth in the fracture line and midfacial fractures. Statistical analysis was used to compare complications to risk factors. RESULTS: Of the 134 patients, 20 patients had some form of postoperative complications and complication rate was 14.9%. These complications included infection, plate fracture, malocclusion, wound dehiscence, nerve injury and nonunion. There was a significant correlation between complication rate and the severity of fracture, preoperative wound contamination and the site of the fracture and disposition of teeth(p<0.05). CONCLUSION: The occurrence of postoperative complications in the treatment of mandibular fractures was related to the severity of fracture, preoperative wound contamination and the site of the fracture and disposition of teeth.

Running Title: Apoptotic Effect of Mycolactone in SCC15 Cells

The effect of mycolactone, a recently reported apoptosis-inducing factor, was investigated in SCC15 oral squamous cell carcinoma (OSCC) cell line. Mycolactone rapidly induced cell death in OSCC cells in 2days, which was similar to that found in apoptotic cell such as detaching from culture plate and rounding-up of cells. Apoptotic cells were increased 4hrs after mycolactone treatment and more than half of cells showed apoptosis after 72hrs. Caspase 3 activation, a biochemical evidence of apoptosis, was determined by Western blotting. Caspase 3 activation was started at 2hrs that lasted until 8hrs after mycolactone treatment. The expression of bcl-2 family genes was determined to explain the mechanism of apoptosis found in OSCC cells. The expressions of bad, bak, and bax (pro-apoptotic genes) and bcl-w and bcl-2 genes (anti-apoptotic genes) were not changed by mycolactone treatment. The expression of bcl-XL was decreased 8 hrs after mycolactone treatment. Mcl-1 expression was initially increased at 2 hrs which was decreased 8 hrs after mycolactone treatment. The down-regulation of these two anti-apoptotic genes might explain the mycolactone-induced apoptosis in OSCC cells. In this study, mycolactone was revealed to induce cell death in OSCC cells via apoptosis and the apoptosis mechanism of OSCC cells was shown to be down-regulation of anti-apoptotic genes, bcl-XL and mcl-1. These results suggested the applicability of mycolactone for the development of an anti-cancer drug candidate by inducing apoptosis of OSCC cancer cell.

A Lateral Cephalometric Study of Maxillofacial Morphologic Features in Class III Malocclusion Children / 영남의대학술지

BACKGROUND: When we make treatment plan of class III malocclusion children, it is difficult to determine whether we treat it with orthognathic surgery or without orthognathic surgery. To determine that, we must consider many factors, such as cephalometric analysis, growth pattern, family history, and skeletal age. A Harvold cephalometric analysis is useful in determining the amount of discrepancy by comparing the maxillary unit length with mandibular unit length. We tried this study to help the decision of treatment planning in class III malocclusion children by comparison in class III malocclusion and normal occlusion children using a Harvold analysis. MATERIALS AND METHODS: The materials for this study consisted of 20 class III malocclusion children. Cephalometric tracing and measurements were performed by one investigator. The control group consisted of 18 normal occlusion children and lateral cephalograms were obtained from 8.5 to 14.5 years old children biannually. The relationships between class III malocclusion group and normal occlusion group were evaluated statistically. RESULTS: The lower anterior facial heights between two groups were not significantly different, although the lower anterior facial heights of class III malocclusion group was higher than those of normal occlusion group in all age groups. The Maxillary-mandibular unit length differences of class III malocclusion group were significantly higher than those of normal occlusion group(p < 0.05). CONCLUSION: A Harvold analysis was useful to make treatment planning for class III malocclusion children.

A Cephalometric Study of Lateral Morphologic Features in Adult Cleft Lip and Palate Patients / 영남의대학술지

BACKGROUND: Cleft lip and palate deformity have unknown patterns of maxillofacial growth and development. The maxillofacial growth can be affected either by congenital or environmental factors such as infection and trauma. Surgical repair of cleft lip and palate may interfere the subsequent growth and development of maxillofacial region. The purpose of this study is to evaluate the characteristics of maxillofacial growth patterns in adult cleft lip and palate patients. MATERIALS AND METHODS: The material for this study consisted of 17 adult male patients with cleft lip and palate. Cephalometric tracing and measurements were done by one investigator. The relationship between 17 cleft lip and palate patients and Korean norms were evaluated statistically. RESULTS: There were statistically difference in Na, perpendicular to point A, SNA angle, effective maxillary length, maxillofacial differencial, Wit's appraisal and upper incisor to point A (p < 0.01). Pogonion to Na. perpendicular also statistically differed (p < 0.05). Other measurements didn't statistically differ. CONCLUSION: It was evident that in adult cleft lip and palate patients, maxilla was retruded and short. Careful cleft lip and palate repair and treatment are recommended for facilitating normal growth of maxilla.

Comparative Analysis of Accuracy between Computerized Tomography and Cephalogram for 3-Dimensional Measurement of Maxillofacial Structure / 영남의대학술지

BACKGROUND: The purpose of this study is to evaluate the accuracy of measurements obtained from 3-dimensional computerized tomography and 3-dimensional cephalogram constructed by using the frontal and lateral cephalogram of six human dry skulls. MATERIALS AND METHODS: After CT scans and each cephalograms were taken, 3-dimensional coordinates (X, Y, Z) of landmarks were obtained using computer programs. In this study, the accuracy of both methods were determined by means of 14 linear measurements compare with caliper measurements. RESULTS: The standard deviation of landmarks of 3-dimensional CT and 3-dimensional cephalogram were 0.23 mm and 0.30 mm in X axis, 0.27 mm and 0.25 mm in Y axis, and 0.27 mm and 0.31 mm in Z axis. In both methods, the standard deviation were less than 0.5 mm in all landmarks, and the most of landmarks showed less than 1 mm in range. Concerning the accuracy, the mean difference between 3-dimensional CT and manual measurements was 0.33 mm, and 1.13 mm between 3-dimensional cephalogram and manual measurement. The distance between RGo and LGo showed the largest difference (2.23 mm). There were highly significant, and large correlation with manual measurements in both methods (p<0.01). CONCLUSION: It is concluded that closeness of repeated measurements to each skulls reveal the precision of both methods. Computerized tomography and cephalogram for 3-dimensional measurement of maxillofacial structure are equivalent in quality to caliper measurements.

Evaluation of the accuracy and reliability of 3-dimensional computerized tomography for measurement of maxillofacial region

A Case of Dysbaric Osteonecrosis in Commercial Diver

Chronic complication of diving and working in compressed air is dysbaric osteonecrosis. Dysbaric osteonecrosis could be diagnosed by simple bone x-ray, in the case of exposure history to dysbaric atmosphere. The case is 44 years old man who worked as a shell fish diver for 20 years. He was exposed dysbaric atmosphere during diving. He had bone necrosis in both femur head, both distal femur and proximal tibia. He had multiple attacks of decompression sickness. Other causes of bone necrosis are ruled out. We conclude that diver's bone necrosis is dysbaric osteonecrosis.

THE PROGNOSIS OF THE TEETH IN THE MANDIBULAR FRACTURE LINES

OBJECTIVE: The purpose of this study is to evaluate the vitality of the teeth in and adjacent to the mandibular fracture line according to variable conditions of fracture and to establish the protocol of treatment of fracture line teeth. MATERIALS AND METHODS: The vitality of 97 teeth in fracture line and 104 teeth adjacent to fracture line of 52 patients were invested preoperatively. Of these, 66 teeth in fracture line and 72 teeth adjacent to fracture line were monitored at least 6 months after operation. An electric pulp tester was used to measure pulpal response. The relationships between the vitality of teeth in variable time(preoperation, immediate post-operation; within 1 week after operation, and 6 months after operation) and variable conditions of fracture(horizontal, vertical gap of fracture line, the number of fracture line)were evaluated statistically. RESULT: The vitality of fracture line teeth in the 6 months after operation statistically differed by the vertical gap of fracture line and the number of fracture line. The vitality of fracture line adjacent teeth in the immediate post-operation only statistically differed by the vertical gap of fracture line. There were statistically differences between preoperative EPT value and vitality of fracture line teeth on 6 months after operation. There were 5 cases of complications including periapical and periodontal abscess. Of these, only one tooth was extracted and the others were well treated with endodontic treatment and subgingival curettage. CONCLUSION: It is recommended to retain teeth and to monitor the vitality of teeth in and adjacent to fracture line, unless there is an absolute indication for extraction.

Hearing Threshold Shifts Among Female Communication Workers Wearing Monaural Headset

BACKGROUND: This study was designed to evaluate the effect of monaural headset to the hearing threshold shifts of the female communication workers. METHODS: Hearing threshold shifts of total 642 subjects, selected after excluding workers with history of ear disease, of ototoxic drug administration, and of neuropsychiatric disease, were determined by pure tone audiometric tests. Each worker's personal and work history was taken by the self-administrative questionnaire. In addition, occupational noise exposure levels in the workplace were assessed by noise dosimetry and each worker's noise exposure from the headset was measured by placing the microphone of a noise dosimeter to the external portion of the headset which was coupled by a silicon tube. The hearing threshold shifts were compared between groups of the alternate and the fixed headset user. RESULTS: The results were as follows: 1> The noise levels in the workplace ranged from 62.1 dBA to 63.9 dBA. The mean equivalent sound levels (LEQ) by the headset volume (minimum, middle, and maximum) were 90.8 dBA, 94.6 dBA, and 97.8 dBA, respectively. The maximum sound level (Lmax) of the headset was from 109.1 to 128.6 dBA. 2> The degree of hearing difference of the one side users was higher than that of the alternate users. Comparing the hearing loss of two groups of subjects, hearing loss was statistically significantly higher in the left-ear fixed and in the alternate headset users with more than 15 years than those with less than 15 years of headset taking duration. 3> Based on the hearing loss evaluation criteria by the Korean Ministry of Labor, 25 required follow-up cases (3.89%) and 16 suspected cases (2.49%) out of the 642 subjects were screened. Although statistically not significant, the required follow-up cases were higher among fixed users (4.3%) than those of alternate users (3.7%). CONCLUSION: The results of this study ascertained the possibility of hearing loss due to monaural-headsets among female workers. Thus, it is recommended that an effective hearing conservation program should be provided for the headset-wearing communication workers.

A CEPHALOMETRIC COMPARATIVE STUDY OF SKELETAL CLASS III MALOCCLUSION AND CLASS I NORMAL OCCLUSION BY RICKETTS' ANALYSIS

The purpose of this study was to evaluate the parts of discrepancy on orthognathic surgical cases with skeletal Class III malocclusion. For this study, Ricketts' analysis that has suggested visual treatment objective, as named for growth predictable blue print, was used. The results of this study were as follows: 1. In the denture problem, mandibular incisor and molar was positioned more anteriorly in Class III malocclusion. 2. The location of A point was characteristically posteriorly positioned in the Class III group, and mandible plane angle was within normal range in the groups. 3. Position of upper and lower anterior teeth to A-Pogonion line was anteriorly positioned, and angulation of upper anterior tooth was lingually positioned in the Class III group, but angulation of lower anterior tooth was not significant in the both groups. 4. Esthetic line of Ricketts' analysis was not significant statistically. 5. Facial depth and axis was larger, but facial taper(facial plane mandible plane) was smaller in the Class III group. So, protruded and concave profile was seen in the Class III group. 6. Cranial deflection was larger in the Class III male group, ramus location was anteriorly positioned and mandibular length was enlarged in the male and female of Class III group.

PHARYNGEAL AIRWAY WIDTH AND MANDIBULAR POSIT10N RELATIVE OT HYOID BONE POSIT10N IN CLASS I NORMAL OCCLUSION AND CLASS IIIMALOCCLUSION

Various studies have documented a variability of hyoid bone position in relation to changed mandibular position or head position. The aim of this study was to evaluate the hyoid bone position and inclination on the lateral cephalometric radoigraphs of two group of patients exhibiting Class I normal occlusion and Class III maloccluslon, so to verify the relatlonships between hyoid bone position, pharyngeal airway and relative mandibular position In the class I group, there were 16 femailes, while the Class III group consisted of males and females. The results were as follows 1. By the length of A-Aph, N-APH, and GoP-PPH, the hyoid of Class IIIgroup was more anteriorly and inferiorly positioned than Class I group 2. On the analysis of soft tissue airway, the measurement(PNS-ad) of Class III group were smaller than Class I group 3. In the comparison of the variances betwwen male and female, hyoid bone was inferiority positioned and showed sinificantly more lager pharyngetal with of haled tissue in the Class I male and In the Class III male, same tendancy about hyoid position and pharyngeal wldth was seen and more anteriorly positioned 4. There was no statiscally significances between pharyngeal airway measurements and relative mandidular position, but statistical significance between wits appraisal and hyold bone position was seen. 5. The S-N-Pog which shows relative mandibular protrusion inverse ratio in the in the analysis with A-APH , N-APH and Facial ratio with LAH-Mp also showed Inverse ratio.

Clinical Features of the Temporomandibular Disorder Patients with Occlusal Splint Therapy / 영남의대학술지

This study was performed to evaluate the clinical features and treatment results on 55 temporomandibular disorder patients who had treated by conservative treatment using occlusal splint. The results were as follows; 1. The ratio of men to women was about 1:2.2 and most of the patients were second and third decades. 2. Pain was the most frequent symptom, followed by clicking and mouth opening limitation. 3. The number of acute and chronic groups on the basis of 6 months duration of symptoms were similar. 4. Most of patients had Angle's Class 1 molar relationships(78.2%), followed by Class 3 and Class 2. 5. Centric Relation splints were used alone for treatment of 34 patients and 21 patients were treated with Centric Relation splints and Anterior Repositioning splints. The treatment duration of the patients who had complained pain was average 9.8 weeks and 6 patients of them had slight pain continuously during follow-up. 6. Eleven patient's maximum mouth opening who had mouth opening limitation was improved from 30.7mm to 43.0mm during procedures.