• Phonetics and Speech Sciences
• /
• v.6 no.1
• /
• pp.95-101
• /
• 2014

This paper investigated the effects of frequency band limitation on perceptual characteristics of Korean consonants. Monosyllabic speech (144 syllables of CV type, 56 syllables of VC type, 8 syllables of V type) produced by two announcers were low- and high-pass filtered with cutoff frequencies ranging from 300 to 5000 Hz. Six listeners with normal hearing performed perception test by types of filter and cutoff frequencies. We reported phoneme recognition rates and types of perception error of band-limited Korean consonants to examine how frequency distortion in the process of speech transmission affect listener's perception. The results showed that recognition rates varied with the following factors: position in a syllable, manner of articulation, place of articulation, and phonation types. Consonants in the final position were stronger to the frequency band limitation than those in the initial position. Fricatives and Affricates are stronger than stops. Fortis consonants were less stronger than their lenis or aspirated counterparts. Types of perception error also varied depending on such factors as consonant's place of articulation: In case of bilabial stops, they were perceived as alveolar stops with while in cases of alveolar and velar stops, there were changes in phonation types without any change in the place of articulation.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.10 no.1
• /
• pp.15-28
• /
• 1980

The author studied age and sex distribution, etiology, affected site and several radiographic features of osteomyelitis of the jaw. And radiologic classification of osteomyelitis was also done. The material consisted of 118 males and 96 females examined and/or treated under the diagnosis of osteomyelitis during past 11 years (1970-1980.6) in SNUDH. The obtained results were as followings. 1. The incidence is the highest in teenages(22.9%) and the lowest in seventies. (2.8%). 2. 199 cases were found in lower jaw, and 15 cases in upper jaw. 30.8% of all cases were located at the posterior portion of mandibular body comprising alveolar region. 3. Radiographic examination of osteolytic lesion revealed that 21. 5% of all patients had periapical and alveolar bone rarefaction combined with osteoporotic changes and that in most of patients two or more of the above described changes were present at the same time. 4. Sclerotic lesions were seen in 62.2 % of all patients and 21.5% of sclerotic lesion were diffuse or homogenuous type. 5. Based on the radiologic study, classification of the osteomyelitis of the jaw was made. Loclized osteolytic type was the highest in incidence (38.8%) and localized sclerotic type was the lowest (7.0%)

• Korean Journal of Veterinary Service
• /
• v.20 no.1
• /
• pp.55-67
• /
• 1997

The morphological development of lungs in fetuses of 60, 90 and 120 days of gestation and neonates of Korean native goats was investigated by light, scanning and transmission electron mictroscope. The results were summarized as follows ; 1. Gross findings ; In the 60-days-old fetus, the lung was developed and differentiated into six lobes. 2. Light microscopic findings : The gland-like bronchioles were formed in loose mesenchyme at 60 days of gestation and the bronchial wall contained smooth muscles. The loose mesenchyme had been replaced by compact parenchymal tissue at 90 days of gestation and the cartilage plates appeared in bronchial wall which contained blood vessels, submucosal glands and smooth muscles. The lung parenchyma consisted of a fine network of alveoli at 120 days of gestation and the bronchial wall contained well-developed blood vessels, submucosal glands, cartilage plates and smooth muscles. In neonates, the lung tissue was similar to the mature lung tissue and the bronchial wall contained well developed cartilage plates. 3. Scanning electron microscopic findings : The epithelial cells lining the tubules were composed of cuboidal or columnar at 60 days of gestation and the epithelial cells lining the large airways were often ciliated : some were covered with stubby microvilli. The epithelial cells lining the canals were cuboidal at 90 days of gestation and the epithelial cells lining the bronchioles were ciliated cells or nonciliated(clara) cells, The clara cells contained row microvilli. The alvealor development of this stage was rapidly progressed ; the subdivision of canals by alveolar crests and assosiated wall attenuation resulted alveoli at 120 days of gestation and the respiratory bronchioles were lined by ciliated or nonciliated epithelial cells. In neonates, the epithelial cells lining the alveolar walls were mainly covered with pneumocyte type I ; Some were covered with pneu-mocyte type II. 4. Transmission electron microscopic findings : The epithelial cells lining the tubules were adhered with tight junction at apical borders of the adjacent cells at 60 days of gestation, which contained few organells and glycogen. The epithelial cells lining the canals were composed mostly of cuboidal cell at 90 days of gestation and the epithelial cells lining of the bronchioles were ciliated of nonciliated cell, which contained few organelles and abundant glycogen. The epithelial cells lining the alveolar walls were composed of pneumocyte type I and a few pneumocyte type II at 120 days of gestation. The epithelial cells lining of the bronchioles were ciliated or nonciliated cells. In neonates, pneumocyte type I was observed as flat and thin cytoplasmic extension in shape. Otherwise, pneumocyte type II was observed as cuboidal type with apical microvilli and contained osmiophillic lamellar inclusion bodies. Putting these various experiment results together, the lung development was slowly progressed at early stage, which was rapidly progressed in the late stage of gestation.

• Applied Microscopy
• /
• v.33 no.4
• /
• pp.275-282
• /
• 2003

This study was undertaken to investigate paraquat-induced pulmonary injuries and effects of colchicine on pulmonary fibrosis by paraquat. Fifteen Sprague-Dawley rats were intraperitoneally injected 10 mg/kg of paraquat and repeatedly with 2 days interval. Another 15 rats were injected paraquat as same manner and simultaneously injected 10 mg/kg of colchicine in a week. Five rats in each group were sacrificed 1, 2, and 4 weeks after initial injections, and lungs extracted were observed by light and electron microscopes. On light microscopy, there was mild infiltration of neutrophils, macrophages, and lymphocytes in alveolar spaces and walls at 1 week after paraquat injection. The cellularity of alveolar wall was increased with time. However, the cellularity was not so prominent in paraquat and colchicine simultaneously injected group. On electron microscopy, there was marked swelling or excoriation of type I epithelial cells and alveolar capillary endothelium with infiltration of neutrophils, macrophages and monocytes, and lymphocytes in alveolar walls. Such findings were persisted with time. In addition, fibroblastic proliferation and deposition of collagen fibers were prominent at 4 weeks after paraquat injection. Fibrosis also occurred at 4 weeks after paraquat and colchicine simultaneous injection. It was not proninent than that of paraquat injected group. According to the above result, it would be concluded that the type I pneumocytes and alveolar capillary endothelial cells are most vulnerable on paraquat poisoning, and that the colchicine is effective on inhibition of paraquat-induced pulmonary fibrosis.

• Tuberculosis and Respiratory Diseases
• /
• v.52 no.4
• /
• pp.411-418
• /
• 2002

Pulmonary alveolar proteinosis(PAP) is a disorder in which an insoluble, proteinaceous material, rich in phospholipids, is deposited in the alveoli and bronchioles. The deficiency in the clearance and degradation of the intra-alveolar phospholipoproteinaceous material in PAP most likely represents a dysfunction of the type II pneumocytes. Although the pathogenesis and causative treatment of PAP is unclear a whole lung bronchopulmonary lavage is a relatively safe and effective treatment. Here we experienced a case of pulmonary alveolar proteinosis in a 62 year old female patient who had pulmonary tuberculosis approximately 20 years ago. She complained of aggravated dyspnea and chronic cough, and presented fine inspiratory crackles at both lung fields, diffuse ground glass opacity with some area of consolidation and smooth interlobular septal thickenings in both upper, right middled lobes, and a portion of right lower lobe. Optical microscopy of the lung tissue obtained by and open lung biopsy revealed many granulomas containing acid-fast smear positive bacilli and diffuse homogeneous PAS-positive fluid in the alveolar space. Immunohistochemical stain showed surfactant. A in the alveolar space. Antituberculosis drugs with bronchoalveolar lavage were used to treat the disease. Thereafter she showed improvement in her symptoms and a partial improvement in the chest X-ray and HRCT findings. We present a case of PAP associated with pulmonary tuberculosis.

• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.5
• /
• pp.567-578
• /
• 2007

Statement of problem: The endodontically treated tooth is generally restored with post and core, owing to the brittle and the loss of large amount of tooth structure. As periodontal treatment was developed, there are many cases that periodontally involved teeth used in prosthetic treatment. Purpose: The purpose of this study was to analyze the stress distribution in the dentin and post structures by the various post materials and the amount of remaining alveolar bone height. Material and method: The 3-dimensional finite element models of mandible 1st premolars were divided into six types according to the various amount of remaining alveolar bone and post type. All types were modeled using equal length, diameter and shape of the post. Three types of post and core materials were used: prefabricated titaniumpost and amalgam core, prefabricated stainless steel post and amalgam core, and cast gold post and core. 300 Newton force was applied to functional cusp of mandible 1st premolar. Results: The results were as follows: First, there was no apparent difference in the pattern of stress distribution according to the alveolar bone condition concentrate on the post middle area. Second, there was difference in pattern of stress distribution according to the core materials, gold post and core generated same than amalgam core. Third, there was no apparent difference in the pattern of stress distribution within the dentin according to the post and core materials. But a cast gold post and core generated the lowest maximum stress value, a stainless steel post generated the highest maximum stress value. Fourth, in the reduced alveolar bone model, maximum stress value is 1.5 times than that of the normal alveolar bone model. Conclusion: Within the limitations of this study, to provide minimal stress to the root with alveolar bone reduced, the post length may be as long as apical seal was not destroyed. To prevent fracture of tooth, it is rational to use gold alloy which material was good for stress distribution for post materials.

• Phonetics and Speech Sciences
• /
• v.6 no.2
• /
• pp.73-79
• /
• 2014

Alveolar fricative sounds /s/ and /s'/ are learned last for normal children in the speech development process for Koreans. These are especially difficult to articulate for hearing-impaired children often causing articulation errors. The acoustic phonetic evaluation uses testing tools to provide indirect and object information. These objective resources can be compared with standardized resources on speech when interpreting the results of a test. However, most previous studies in Korea did not consider acoustic studies that used the spectrum moment values of hearing-impaired children. Therefore, this study was conducted to compare the characteristics of hearing-impaired children's pronunciation of fricative sounds using spectrum moment values. For this purpose, the study selected a total of 10 hearing-impaired children (5 boys and 5 girls) currently in 3rd or 5th grade and attending one of the elementary schools in Seoul or Gyeonggi-do. For the selection process, their age, type of hearing aid, implantation of hearing aid (CI) before two years of age, hearing capacity (dB) before and after wearing the hearing aid, duration of speech rehabilitation, and time of learning alveolar fricative sounds were all considered. Also, 10 normal children (5 boys and 5 girls) were selected among 3rd or 5th grade students attending one of the elementary schools in Seoul or Gyeonggi-do. The subjects were asked to read the carrier sentence, "I say _______," including a list of 12 meaningless syllables composed of CV and VCV syllables, including alveolar fricative sounds /s/ and /s'/ and vowels /a/, /i/, and /u/. The recorded resources were processed through the Time-frequency Analysis Software Program to measure M1 (mean), M2 (variance), M3 (skewness), and M4 (kurtosis) of the fricative noise. No significant differences were found when comparing spectrum threshold values in the acoustic phonetic characteristics of hearing-impaired children and normal children in alveolar fricative sound pronunciation according to vowels /a/, /i/, and /u/, alveolar fricative sounds /s/ and /s'/, and syllable structure (CV, VCV) other than, for M3 in the comparison of groups according to disability. In the comparison of syllable structures, there were statistically significant differences in M1, M2, M3, and M4 with clinical significance. However, there was no significant difference in results when comparing the alveolar fricative sounds according to the vowels.

• Korean Journal of Cleft Lip And Palate
• /
• v.9 no.2
• /
• pp.71-78
• /
• 2006

The case records of 24 patients in Seoul National University Hospital who had bone grafting of 29 alveolar clefts between 2001 and 2004 were examined. Details were recorded of age, sex, preoperative orthodontictreatment, the time of bone grafting, the type of donor site, cleft width, functional load applicationand the success of grafting as established by lowest marginal bone levels. Using this results and review of literature, we concluded that secondary bone graft with iliac bone before canine eruption with root development of 1/2 to 1/3 provide more favorable results and the functional load introduced to the grafted bone lower the resorption rates.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.19 no.3
• /
• pp.135-141
• /
• 2019

Background: The fear of needle insertion and pain during anesthesia is a source of patient dissatisfaction in dentistry. Inferior alveolar nerve block (IANB) remains the most common type of block and is in itself painful. Computer-controlled local anesthetic delivery (CCLAD) has been proven to reduce the pain associated with injection of anesthetics in various blocks. However, the efficacy of CCLAD for IANB in adults remains unknown. Methods: Sixty-four adult patients requiring bilateral IANB were selected and divided into two groups: group A (50 patients receiving IANB via CCLAD) and group B (50 patients receiving IANB using a conventional cartridge syringe). Pain perception and patient comfort were assessed using the visual analog scale and the 5-point semantic scale, respectively. Results: The pain perception was compared between the two groups using the Mann-Whitney U-test, and the P value was 0.003. The patient comfort was also compared using the same test, and the P value was 0.484. Conclusion: A significant difference was observed in the pain perception of the patients during CCLAD. The patient comfort was grossly equal for both techniques.

• Journal of Korean Dental Science
• /
• v.14 no.1
• /
• pp.1-11
• /
• 2021

Purpose: The alveolar ridge preservation (ARP) is widely conducted for implant placement. However, experimental results using deproteinized porcine bone mineral (DPBM) have been scarce. This retrospective study evaluated factors affecting the primary stability of implants in an area where ARP was performed using DPBM. Materials and Methods: Thirty-eight patients were divided into two groups based on the primary stability, with torque value of 30 Ncm as borderline. To determine the factors that affect the primary stability of implants, we collected data from patients' medical records including age, sex, reentry time, socket location, remaining bone wall at the time of extraction, and type of collagen membrane, as well as from radiographs and histomorphometric analysis. Result: The results showed statistically significant difference for the remaining extraction socket wall (P=0.014), residual graft (P=0.029), and fibrovascular tissue (P=0.02) between the two groups. There was an insignificant tendency toward the time of reentry surgery (P=0.052) and location (P=0.077). All implants placed in sites using DPBM functioned well up to 3 years. Conclusion: Within the limitations of the present study, extraction socket wall, residual graft, and fibrovascular tissue can affect the primary stability at the time of implant placement on grafted sites using DPBM and collagen membranes. In addition, reentry time and locations can be considered. In future studies, comparative experiments in quantified models will be required to supporting the findings.