• 대한기계학회논문집
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• 제11권2호
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• pp.296-303
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• 1987

본 논문에서는 동력전달용 기어에 주로 쓰이는 물림률 1.3 이상일 때, 치면접 촉응력과 공칭굽힘응력이 작게되는 풀림각 1˚로 고정하여 잇수 30∼100개 압력각 14˚∼30˚의 범위에서 최소 원호반경식과 치형 조건을 만족하는 최대 원호반경식에 대하여 고찰하였다.

• 대한치과보철학회지
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• 제37권3호
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• pp.328-342
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• 1999

This study was performed to investigate the factors related to tooth wear. For this study, 78 patients with temporomandibular disorders and 76 dental students without any signs and symptoms of temporomandibular disorders were selected as the patients group and as the normal group, respectively. Preferred chewing side, Angle's classification, lateral guidance pattern, head and shoulder posture were observed clinically. Electromyographic activity of anterior temporalis and masseter muscle were recorded with $BioEMG^{(R)}$ and occlusal status were recorded with $T-Scan^{(R)}$. Wear facet area of each tooth was measured from working model of upper arch corresponding to the occlusal status from T-Scan. Wear facet area were measured with planimeter in $mm^2$. Total area were divided into incisal, canine, posterior tooth area. Anterior wearfacet area was incisor area plus canine area, and unilateral area was anterior area plus posterior area. The data collected were analyzed by SAS statistical program and the results of this study were as follows: 1. There was no significant difference between the two groups in total werafacet area, and male subjects showed tendency to have larger area in the normal group but female subjects showed tendency vice versa. 2. There was no significant difference related to preferred chewing side and Angle's classification, however some difference was observed by lateral guidance pattern. Anterior wear facet area in subjects of canine guidance was the largest in the three subgroups. 3. Subjects with head tilting to right side had larger posterior and total area, and subjects with higher shoulder in right side had larger canine and anterior area than any other subgrous. 4. Electromyographic activity of masseter muscle was more correlated with wear facet area than anterior temporalis muscle, and tooth contact number and force were significantly correlated with wear facet area, but the most important factor affecting tooth attrition was age.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제25권4호
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• pp.311-323
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• 1999

The osteonectin is a sort of glycoprotein which is secreted in human tissues. The osteonectin is generally detected in number of normal or neoplastic human tissues in vivo, but hasn't been studied the role of osteonectin in developing human teeth and odontogenic tumors. We evaluated degree of the expression of osteonectin immunohistochemically in 20 cases of developing tooth germ which growth from fetus 5 to 38 weeks, and total 51 odontogenic tumors whitch has taken from routine biopsy, such as 10 ameloblastomas, 5 cases of adenomatoid odontogenic tumors and odontomas and odontogenic fibromas, 4 cases of cementomas and calcifying epithelial odontogenic cyst and odontogenic keratocyst and dentigerous cysts and periapical cysts, and 3 cases of ameloblastic fibromas and myxomas. The results were as follows: 1. The osteonectin on the bud stage of tooth germ was strongly expressed in the epithelial dental lamina and in the outer dental epithelium on the early bell stage, and also strongly expressed in the inner dental epithelium on the late bell stage of tooth germs. 2. In ameloblastoma, the osteonectin was strongly expressed in the epithelial tumor component and especially in the acanthomatous types. 3. In both of calcifying epithelial odontogenic tumor and adenomatoid odontogenic tumors, the osteonectin was moderately expressed on the duct like spindle cells and epithelial tumor cells around calcification areas. 4. In odontogenic tumors originated from epithelial-mesenchymal tissues, the osteonectin was moderately expressed on the epithelial tumor components and in odontogenic cysts, it was expressed in ghost cells and calcification areas only. These were summaried the osteonectin may be strongly related to the developing tooth germ and odontogenic tumors and could be regulated hard tissue of human tooth in morphogenesis and involved with calcification mechanism in development odontogenic tumors.

• 수산해양기술연구
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• 제50권4호
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• pp.530-541
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• 2014

The dredge gear is dragged along the bottom of the sea to catch targeted edible bottom dwelling species. Species composition and ecological index of the catches of dredge were estimated around Gangneung coastal fishing ground by dredge with different mesh size and tooth space from July to December 2013. Eight different types of dredge including four different tooth space (24.7 mm, 29.9 mm, 34.9 mm, 40.1 mm) and four different mesh size(15.5 mm, 32.7 mm, 51.1 mm, 60.0 mm) were used in the experiment. During the experiment, total catches were collected 31 species as sipunculida 1 species, mollusca 13 species, annelida 3 species, arthropoda 8 species, echinodermata 4 species and others 2 species. The dominant genus were mollusca and echinodermata while the dominant species were Megangulus venulosus, Pseudocardium sachalinensis, Schaphechinus brevis. The richness index was ranged 1.29-1.72, evenness index was 0.6-0.65 and diversity index was 1.65-1.83 according to the tooth space and mesh size of dredge. Richness index, diversity index were high at tooth space 34.9 mm dredge and ecological index showed decreasing tendency with the increasing of mesh size of dredge. Cluster and MDS analysis, based on a Bray-Curtis and similarity matrix of fourth root transformed data of number of species and wet weight, showed division into four different groups as four different tooth space (Group A), four different mesh size Group B (51.1 mm, 60.0 mm), Group C (32.7 mm) and Group D (15.5 mm).

• 대한소아치과학회지
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• 제28권1호
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• pp.142-145
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• 2001

소아치과에 내원한 환아 중에서 치아의 수에 따른 이상을 많이 관찰할 수 있는데 그 중의 하나가 과잉치이다. 과잉치는 정상 치판 (dental lamina)의 과도한 증식의 결과로 발생되며 유치열에서 $0.3\sim0.8%$, 영구치열에서는 $1.0\sim3.5%$의 발생빈도를 보인다. 2 : 1로 남자에게 호발하고 9 : 1로 상악에 호발하며 구치부보다 전치부에 많이 발생한다. 가장 호발하는 것은 상악 정중 과잉치로 상악 중절치 사이에 위치하며 하악 전치부에서는 2%로 낮은 빈도를 보인다. 본 증례는 파노라마 사진 촬영 결과 하악 좌우측 유중절치의 선천적 결손과 4개의 영구 절치외에 2개의 과잉치가 전치부에 관찰되어 발치와 교정치료를 통해 양호한 결과를 얻게 되어 보고하는 바이다.

• 한국표면공학회지
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• 제37권5호
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• pp.249-252
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• 2004

Effects of HA and TiN coating on the electrochemical characteristics of Ti-6AI-4V alloys for bone plates were investigated using various test methods. Ti-6AI-4V alloys were fabricated by using a vacuum induction furnace and bone plates were made by laser cutting and polishing. HA was made of extracted tooth sintered and then tooth ash was used as HA coating target. The TiN and HA film coating on the surface were carried on using electron-beam physical vapor deposition (EB-PVD) method. The corrosion behaviors of the samples were examined through potentiodynamic method in 0.9% NaCI solutions at $36.5\pm$$1^{\circ}C$ and corrosion surface was observed using SEM and XPS. The surface roughness of TiN coated bone plates was lower than that of tooth ash coated plates. The structure of TiN coated layer showed the columnar structure and tooth ash coated layer showed equiaxed and anisotrophic structure. The corrosion potential of the TiN coated specimen is comparatively high. The active current density of TiN and tooth ash coated alloy showed the range of about $1.0xl0^{-5}$ $A\textrm{cm}^2$, whereas that of the non-coated alloy was$ 1.0xl0^{-4}$ $A\textrm{cm}^2$. The active current densities of HA and TiN coated bone plates were smaller than that of non-coated bone plates in 0.9% NaCl solution. The pitting potential of TiN and HA coated alloy is more drastically increased than that of the non-coated alloy. The pit number and pit size of TiN and HA coated alloy decreased in compared with those of non-coated alloy. For the coated samples, corrosion resistance increased in the order of TiN coated, tooth ash coated, and non-coated alloy.

• 대한치위생과학회지
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• 제1권1호
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• pp.37-46
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• 2018

This study conducted a 'specialist tooth brushing' method against the severely disabled once every other week. The purpose of this study is to analyze and validate the effectiveness of maintaining healthy periodontal management when consistent oral hygiene lasts with minimum stimuli for 24 - months. The conclusions were as follows. Table 2 compares the difference between group 1 and 2 from the 1^st to 11th management and verifies the actual difference in measurement of each index. Group 1 used a professional tooth brush while Group 2 used a general brush. There were found many significant differences in dental index. As for PHP, Oral Malodor index and gingival bleeding, it was found that one or two times of dental care can make substantial differences in dental health condition. These results show that as the number of toothbrush method has been increased, gingival bleeding and periodontal index are significantly improved, not to mention the improvement of gingivitis and periodontal disease. This is because periodontal tissue is affected by brushing method, brushing time and consistency of dental care. During the 6-month period, 20 minutes of active periodontal care was intensively conducted, and for 18-months the effect of consistent care was verified by 10-minute periodontal care once every other week. As a result of the test, it was found that there was no complete regression in the basic periodontal treatment and the periodontal health condition had been maintained for 24 months. Also this test shows that, despite of inconsistent dental hygienic care, regular plague control can prevent dental diseases and maintain the dental health. This study proved that periodontal condition can be maintained by periodontal care once every other week as the tooth brushing properly stimulates the gums with positive effect. Therefore, professional dental healthcareworkers should be designated for each facility for the disabled, and dental health of the disabled should be professionally cared on a regular basis, and consistent and repetitive management by the dental care specialist are required.

• 대한치과교정학회지
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• 제22권3호
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• pp.579-589
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• 1992

Non-steroidal anti-inflammatory agents are used to relieve pain and to reduce swelling in dental clinics. This experiment was performed to study the effect of non-steroidal anti-inflammatory agents in Sprague-Dawley rats on orthodontic tooth movement. Thirty rats were used and divided six groups of five rats each. The first group, administered saline and no orthodontic force, served as a normal group. The second group, administered saline and applied experimental force, was control group. The other four groups were administered Aspirin, Pontal, Tyrenol and Indomethacin each, and applied experimental orthodontic force by 1/4 inch elastic, inserted into the interproximal space between maxillary first and second molar in rats. All experimental rats were sacrificed after three days, and the specimens were sectioned horizontally five times serially, and counted the number of osteoclasts appeared at the compressed surface of interradicular bone on first buccal root of first molar on light microscope. The obtained results were as follows: 1. The number of osteoclast on the compressed surface of the interradicular bone on first buccal root of the first molar in the four non-steroidal anti-inflammatory agents groups decreased in contrast to control group. 2. In non-steroidal anti-inflammatory agents group, the number of osteoclast in Indomethacin group was least among the all non-steroidal anti-inflammatory agents groups. From the above results, it was believed that the non-steroidal anti-inflammatory agents may have the inhibitory effect of tooth movement during orthodontic treatment.

• 한국학교보건학회지
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• 제15권1호
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• pp.83-92
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• 2002

This study was undertaken to verify various relations between dental health belief and related behaviors in mothers and children. Data for this study were obtained by 264 pairs of 1st and 3rd grade elementary school children and their mothers by self developed questionnaire, The questionnaires are made on the general socio-economical characteristics, the oral health knowledge and the behaviors relative to the oral health and oral health education as to how mothers implement the oral health related activities for their children, while for the children, the questionnaires have been measured relative to the oral health beliefs and health behaviors for the children. The obtained results have shown that mothers become with more ages, the usefulness to prevent children's oral diseases becomes lower, and as much as mothers have higher education level, the sensitivity relative to the oral diseases has been measured low. To the degree that the students live well in economical respect, it has been found that they placed more importance on the oral health. As much as the number of mothers tooth brushing becomes made more in a day, the tooth brushing of the children becomes more that much, and also has higher level of oral health beliefs. The number of children to see dentists has been found high, and to the extent of increasing frequency of visiting dental clinics. As the number of mothers tooth brushing education becomes made more frequent for the children. Also, as mothers put more restriction on the sugar intakes by the children, they placed higher importance on the oral health for their children. In conclusion oral health behavior in mothers' influence on dental health belief of their children, it has been reviewed necessary to activate more the mother-children joint oral health education and oral health projects that mothers and children take part together, as well as to study more in accurate and systematic approaches through more comprehensive and various subjects and elements further in the future.

• 치과방사선
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• 제22권2호
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• pp.185-193
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• 1992

경북대학병원 치과에 내원한 8세에서 27세까지의 환자 6,531명의 파노라마 X선사진에서 제3 대구치를 제외한 선천성 결손치, 제3대구치의 선천성 결손, 과잉치의 발생율, 성별분포, 호발 부위 및 수에 따른 분포를 조사하여 다음의 결과를 얻었다. 1. 제3대구치를 제외한 선천성 결손치의 발생율은 10.8%였으며, 남성이 44.6%, 여성이 55.4%였다. 하악 제2소구치가 23.2 %로 가장 많았으며, 상악 측절치 18.4%, 하악 측절치 18.3%, 상악 제2소구치 15.4%의 순으로 나타났다. 결손치의 수는 1개 인 경우가 48%로 가장 많았으며, 2개인 경우가 35.4%, 3개인 경우가 6.6%로 나타났다. 2. 제3대구치 선천성 결손의 발생율은 39.7%였으며, 남성이 48.6%, 여성이 51.4%였고, 상악 60.3%, 하악이 39.7%였다. 결손치의 수는 1개인 경우가 28.7%, 2개인 경우가 37.2%, 3개인 경우가 12.5%, 4개인 경우가 21.6%로 나타났다. 3. 과잉치의 발생율은 4.2%였으며, 남성이 65.7%, 여성이 34.3%였다. 상악 중절치부가 64.8%로 가장 많았으며, 상악 측절치부 13.2%, 상악 제3대구치 후방부 8.7%의 순으로 나타났다. 과잉치의 수는 1개인 경우가 79.9%로 가장 많았고, 2개인 경우가 18.9%, 3개인 경우가 1.2%로 나타났다.