• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.550-568
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• 1995

The purpose of this study was to observe the effects of early functional on bone formation around titanium plsama sprayed IMZ implants. 15 IMZ implants were inserted on the mandibular premolar areaa in 5 mondgrel dogs. The inplants were divided into 4 groups according to it’s loading schedule : Temporary abutments were connected for functional loading 6weeks, 9weeks, and 12weeks after implants installation in group I, II, and III, respectively. Abutments were not connected in the control group. After polyfluorochrome sequential labeling, all animals were sacrificed and bone sections includig implants and the 1st. molar were removed and processed for histologic evaluation. From light and fluorescence microscopic evaluation as well as histomorphometric and EPMA analysis, following results were obtained : 1. Light microscopically, the osteoid tissues were observed much in the compact bone of unloaded group, and cancellous bone formation observed more in early loaded group. 2. Calcification and remodeling of bone took place faster in loaded group, especially in 6 weeks group. 3. Moderate to severe marginal bone resorption was observed in 6 weeks group, mainly on buccal crest. 4. There was no difference in the percentages of bone-to-metal contact among the experimental groups. 5. In quantitative analysis using EPMA, there was no difference in the content of calcium and phosphorus among the experimental groups, regardless of distance.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.639-650
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• 2000

The purpose of this study was to evaluate clinical changes in graft size after treatment with connective tissue autograft in human. 40 premolar teeth in 23 patients having the following mucogingival problemswere selected. The width of extension, attached gingiva including free marginal gingiva, width of transplant and clinical sulcus depth were measured at the initial examination, 2, 12 and 24 weeks following the connective tissue autograft and free gingival autograft. The change of width of extension, attached gingiva including free marginal gingiva, width of transplant and clinical sulcus depth according to healing process in both graft procedures was statistically analyzed by ANOVA test and independent ttest using SPSS program. The results were as follows : 1. The change of keratinized gingiva in both grafting procedures was increased significantly at 24 weeks post-op. 2. The clinical sulcus depth exhibited no marked changes throughoutthe entire investigation in both grafting procedures. 3 . After 12 weeks, no dimensional variation was seen in graft size in both grafting procedures. 4. Shrinkage differs significantly in both grafting procedures. From the day of graft to 24 weeks after surgery the percentages of shrinkage were connective tissue autograft 55% and free gingival autograft 29%.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.797-809
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• 1998

The purposes of this study were to develop the computer program for the contrast and geometric correction in digital subtration radiography with the IDL (Interactive Data Language) and compare the results with this program for the correction of the non-standardized radiographs to those of standardized radiographs and those with "Emago" software, the commercial program for the correction. The procedures were written for the contrast correction and subtraction with the geometric correction, using IDL. 32 pairs of periapical radiographs of premolar and molar portion of two dry human mandibles were taken at two different occasions with XCP film holder(nonstandardized films) and another 32 pairs with customized XCP film holder(standardized films). Subtraction of standardized film pairs was performed. Subtraction after the contrast and geometric correction of non-standardized films was performed using the newly developed program and Emago software. Standard deviations of grey levels of the subtracted images by the newly developed program were compared with those of the standardized group and Emago-corrected group. Standard deviations of grey levels of new program-corrected group were much smaller than those of the Emago-corrected group (p<0.001) and slightly larger than those of standardized group (p<0.05). However, the difference was very minute. This study indicates that the newly developed program written with IDL may substitute the mechanical standardization for digital subtraction radiography.

• The Journal of Korean Academy of Prosthodontics
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• v.11 no.1
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• pp.15-21
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• 1971

The prime objective of this study was to analyze the positional relationship of the lips to the anterior teeth according to age, sex, and both sides of the dental arch in 381 healthy Korean adults with normal occlusion ranging from 17 to 70 years over old. The results were as follows; 1. In the position of the corner of the mouth to the teeth, the range from center of canine to mesial side of first premolar was revealed the incidence of 81~87%, the distal side of canine was the hiqhest frequency of 39~43%. 2. A straight type (76~79%) of lip line was prevailed against the curved type in rest position. 3. In the exposed type of anterior teeth to upper lip in rest position, type III(50~52%) Grade 2 (26~29%) was revealed the highest frequency of occurences. 4. No significant difference in both sexes and sides of the dental arch was observed. 5. Lip position to the teeth with aging was showed the tendency toward straight type in lip line and toward reduction of the number of exposed type of upper anterior teeth to upper lip, and the corner of the mouth was placed posteriorly.

• Journal of Periodontal and Implant Science
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• v.46 no.2
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• pp.128-134
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• 2016

Purpose: This article describes a case of the successful non-surgical management of a periodontally compromised maxillary premolar. Methods: A combination therapy, including root planing, occlusal adjustment, and tooth splinting, was applied. Clinical and radiographic examinations were performed during the 16-month follow-up period. Results: All periodontal parameters were improved. There were dramatic decreases (3-6 mm) in the probing pocket depth, tooth mobility, and marginal bone loss. Interestingly, gradual resolution of the periapical radiolucency and alveolar bone regeneration were observed in the radiographs, and the periodontal condition was maintained during the follow-up period. Conclusions: Within the limits of this study, these results demonstrate the importance of natural tooth preservation through proper periodontal treatment and occlusal adjustment of the periodontally compromised tooth, which is typically targeted for tooth extraction and dental implantation.

• Journal of the korean academy of Pediatric Dentistry
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• v.7 no.1
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• pp.53-61
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• 1980

The purpose of this study was to statistically evaluate the spacing of primary dentition according to whether or not a space existed and measurement of amount of space in 205 children (male 114, female 91) from 2 to 6 years of age. The results were as follows; 1. In the incidence of interdental space on each region, spacing between the primary lateral incisors and primary canine in maxilla and between the primary canine and 1st primary molar in mandible showed the highest percentage, on the other hand, spacing between the 1st and 2nd primary molars in both jaw showed the lowest percentage. 2. In the kinds of interdental space, the state of primate space and other space together showed the highest percentage, and in the degree of spacing, $S_2$ showed the highest percentage in both jaw. 3. In the incidence of primate space, maxillary primate space showed higher percentage than mandibular primate space in bilateral case. 4. In the type of arch form, spaced arch showed higher percentage than closed arch and about the half of closed arch showed crowding. 5. In both Jaw, available space showed incisor segments, canine segments, and premolar segments in order of amount, and there were not statistically significant differences of sex or jaws in the amount of available space.

• The Journal of the Korean dental association
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• v.48 no.11
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• pp.819-828
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• 2010

Activator is a removable functional appliance used for correcting the skeletal Class II malocclusion in children with the mandibular deficiency. Berlin standard activator modified from Andresen activator has following characters; do not cover the palatal surface for tongue space, relief on lingual surface of mandibular incisors and resin capping 1/3-1/2 of crown height on mandibular incisors for preventing labioversion of mandibular incisors, L-hook between maxillary lateral incisor and canine for anterior high pull headgear, relief on mandibular posterior bite block for differential eruption of posterior teeth. Two cases presented here had a mandibular deficiency and slight maxillary protrusion. First case (an 11-year-old girl) treated with Berlin standard activator and anterior high pull headgear for 13 months followed by fixed orthodontic appliance for another 29 months. Second case (a 12-year-old boy) treated with Berlin standard activator for 6 months followed by fixed appliance for another 24 months. Treatment results showed a significant improvement in sagittal skeletal and occlusal relationship without premolar extraction. Mandibular condyles were concentric in TMJ [ossa, and masticatory muscle activities were normalized after treatment. In the retention period facial harmony and occlusal stability was maintained.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.4
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• pp.349-352
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• 2009

Cementoblastoma is a benign ectomesenchymal odontogenic neoplasm that forms a mass of cementum or cementum-like tissue continuous with the tooth root. Cementoblastoma represents 1% to 6.2% of all odontogenic tumors, and occurs more than 75% arise in the mandible, with most cases arising in the molar and premolar regions. About 75% arises before the age of 30. Radiographically, it appears as a radiopaque mass with a thin radiolucent rim attached to the roots of a tooth. The recurrence rate is 37% in the current study and cortical expansion and perforation of the cortex are common findings in lesions that subsequently recurred. It is apparent that recurrence rate depends largely on the completeness of removal than any other factor. Here we present a 20 year old, female case of an unusual multiple recurrent cementoblastoma around a previous lesion which had been surgically excised 2 years ago.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.145-153
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• 1989

The causes of the missing teeth are classified as congenital missing, trauma and extraction due to dental caries, variable problems are occured clinically by the missing teeth. The missing of the upper incisors especially would assume a serious aspect, and could be treated by three methods of orthodontic treatment, prosthodontic treatment and autotransplantation of the premolar teeth. The patient of this report had the skeletal class II malocclusion with the left upper central incisor missing, and have been treated with the fixed appliance after extraction of the right upper central incisor and both lower second premolars. The results were obtained as follows: 1. Treatment was done for 1 year 6 months. 2. Normal overbite and overjet were achieved. 3. Cuspal interdigitation was obtained normally. 4. Space problem was resolved with resin restoration of the upper lateral incisors. 5. The upper canines were used as the upper laterals after cuspal contouring. 6. Retention would be required with adequate retainers for a long time to prevent relapsing after treatment.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.151-160
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• 1981

The purpose of this study was to compare the retentive values of various dental cements used for cementing the orthodontic bands on the teeth. Sound freshly extracted human premolar teeth were selected for the study. Eleven commercial dental cements (Zinc phosphate, reinforced Zinc-oxide eugenol, Carboxylate and Glass ionomer cements) were handled under standardized conditions. All cemented speciments were then kept in a thermostatic humidor cabinet regulated at $23{\pm}2^{\circ}C$ and more than $95\%$ relative humidity and tested after 24 hours and 1 week each. The force required to remove the cemented orthodontic bands from the teeth was determined on an Instron Universal Testing Machine using a modified specimen holding device with a cross-head speed of 0.20mm/min. The results obtained were as follows: 1, The retentive values of the band cemented with zinc phosphate cements and carboxylate cements were considerably higher than those of the reinforced zinc oxide-eugenol and glass ionomer cements. 2. There was no significant difference between the retentive value of carboxylate cements as compared with zinc phosphate cements. 3. The retentive value of the reinforced zinc oxide eugenol cements was lowest all of the coements. The retentive values expressed for all cements up to at least one week were highly but no significant difference was found between the 24-hour and 7 day time intervals.