• The korean journal of orthodontics
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• v.46 no.6
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• pp.379-385
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• 2016

Objective: Forced eruption has been proposed for the reconstruction of deficient bone and soft tissue. The aim of this study was to examine the changes in the alveolar ridge width and the vertical levels of the interproximal bone and papilla following forced eruption. Methods: Patients whose hopeless maxillary anterior teeth were expected to undergo severe bone resorption and soft tissue recession upon extraction were recruited. In addition, patients whose maxillary anterior teeth required forced eruption for restoration due to tooth fracture or dental caries were included. Before and after forced eruption, the interproximal bone height was measured by radiographic analysis, and changes in the alveolar ridge width and the interproximal papilla height were measured with an acrylic stent. Results: This prospective study demonstrated that the levels of the interproximal alveolar bone and papilla were significantly increased by 1.36 mm and 1.09 mm, respectively, in the vertical direction. However, the alveolar ridge width was significantly reduced by an average of 0.67 mm in the buccolingual direction. The changes in the level of the interproximal alveolar bone and papilla were positively correlated. Conclusions: Although the levels of the interproximal bone and papilla were significantly increased, the alveolar ridge width was significantly decreased following forced eruption. There was a modest positive and significant correlation between the changes in the height of the interproximal alveolar bone and the papilla. Based on our findings, modification of vertical forced eruption should be considered when augmentation of the alveolar ridge width is required.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.5
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• pp.70-78
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• 2003

From the viewpoint of the importance of the division theory based on topography(pyungsu) derived from the uniqueness in topography, not to mention of the function of ridge in ruban areas, the destroy of ridges should be prevented from the development of hill areas. This study intends to propose the basic concepts and principles to protect the ridge axis with green in open space and landscape planning. The main results are summarized as follows : First, eco-bridge across the ridges will be connected for the purpose of ecosystem restoration. Second, the protection and restoration of green ridge axis can be completed by Green Structure Plan which has principles and standards such as. - layout of development axis and establishment of rules on preservation - the practical use of various preservation methods and the standards suitable to the methods - laying down the standards of restoration according to the height from ground level - the application of zoning such as height district and urban design for preservation Finally, the design of implementation tools must be needed for protection and restoration.

• Journal of Periodontal and Implant Science
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• v.49 no.4
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• pp.237-247
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• 2019

Purpose: To analyze the maxillary sinus anatomy over edentulous ridges in the bilateral posterior maxillary area in Taiwanese patients using cone-beam computed tomography (CBCT). Methods: In total, 101 anatomical sites from 61 patients, including 32 premolar and 69 molar regions, were analyzed using CBCT. Measurements were made of the width and height of edentulous ridges, the thickness of the lateral wall of the maxillary sinus, and the presence of a sinus septum and the posterior superior alveolar artery (PSAA). A statistical analysis of the measurements was performed, and correlations among the measurements were assessed. Results: The average ridge width was $10.26{\pm}3.16mm$, with a significantly greater ridge width in the second molar region than in the premolar region. The mean residual ridge height was $8.55{\pm}4.09mm$, and ridge height showed an opposite trend from ridge width for the premolar and molar regions. A sinus septum was present at 5.9% of the sites, and the PSAA was observed in 24.5%. The average thickness of the lateral wall of the maxillary sinus was $2.08{\pm}0.94mm$, with no significant difference between the tooth position and lateral wall thickness. Conclusions: This study presents the anatomical features of the maxillary sinus, which should be considered in sinus lift procedures for implant placement, in the Taiwanese population. The use of CBCT is recommended to avoid intraoperative complications.

• Journal of Periodontal and Implant Science
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• v.52 no.1
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• pp.3-27
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• 2022

Purpose: This study was conducted to evaluate and compare the effects of different graft materials used in alveolar ridge preservation on dimensional hard tissue changes of the alveolar ridge, assessed using cone-beam computed tomography (CBCT) scans. Methods: A systematic electronic search of MEDLINE and the Cochrane Central Register of Controlled Trials and a manual search were conducted from November 2019 until January 2020. Randomized controlled trials were included if they assessed at least 1 variable related to vertical or horizontal hard tissue changes measured using CBCT scans. After a qualitative analysis of the included studies, subgroups were formed according to the graft material used, and a quantitative analysis was performed for 5 outcome variables: changes in vertical alveolar bone height at 2 points (midbuccal and midpalatal/midlingual) and changes in horizontal (buccolingual) alveolar bone width at 3 different levels from the initial crest height (1, 3, and 5 mm). Results: The search resulted in 1,582 studies, and after an independent 3-stage screening, 16 studies were selected for qualitative analysis and 9 for quantitative analysis. The metaanalysis showed a significantly (P<0.05) lower reduction of alveolar ridge dimensions for the xenogenic subgroup than in the allogenic subgroup, both vertically at the midbuccal aspect (weighted mean difference [WMD]=-0.20; standard error [SE]=0.26 vs. WMD=-0.90; SE=0.22) as well as horizontally at 1 mm (WMD=-1.32; SE=0.07 vs. WMD=-2.99; SE=0.96) and 3 mm (WMD=-0.78; SE=0.11 vs. WMD=-1.63; SE=0.40) from the initial crest height. No statistical analysis could be performed for the autogenic subgroup because it was not reported in sufficient numbers. Conclusions: Less vertical and horizontal bone reduction was observed when xenogenic graft materials were used than when allogenic graft materials were used; however, the loss of alveolar ridge dimensions could not be completely prevented by any graft material.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.401-404
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• 2006

In order to select the seeding machine for mechanizing cultivation of rapeseed in southern areas of Korea, three different seeding machines, ridge rotary, power tiller ridge rotary, tractor ridge rotary were used for sowing one of the high yielding rapeseed cv. Hybrid with five different seeding methods. Seeding of ridge rotary was reduced the seeding effort with 45% and yield components such as plant height, ear length, number of branches and pods, pod length and seed setting rate were higher. The seeding of ridge rotary also was showed highest seed yield. On the basis of time requirement for seeding, vegetative and yield parameters ridge rotary seeding machine was a suitable seeding machine for rapeseed cultivation at the southern area of Korea.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.1
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• pp.83-85
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• 2000

The purpose of this study is to evaluate the effect of $HTR^{TM}$ (hard tissue replacement, Bioplant Inc, U.S.A) polymer on short-term healing as a grafting material for alveolar ridge augmentation. A 48-year-old female presented insufficient bone height and width for the placement of implants. $HTR^{TM}$ polymer was used for ridge augmentation. Bone biopsy was harvested 8 months after the ridge augmentation procedure. $HTR^{TM}$ polymer displayed rapid bone regeneration and mature lamellar and trabecular bone redevelopment. Clinical and histologic observation from the treatment of the patient presented suggest that $HTR^{TM}$ polymer seems to be a appropriate material for alveolar ridge augmentation.

• FLOWER RESEARCH JOURNAL
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• v.16 no.4
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• pp.255-259
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• 2008

This study was conducted to investigate the effect of ridge height (10 cm, 20 cm, 30 cm, and 40 cm) on the soil physical property, the growth and flowering characteristics of Gypsophila paniculata (cv 'Bristol Fairy') in the subalpine area. As ridge height got higher, the daily soil temperature, the soil moisture content, soil hardness, bulk density, and solid phase ratio were decreased, but porosity ratio was a little increased. In summer and autumn cultivation the blooming of ridge height 30 cm and 40 cm was slightly delayed, but their root activity, cut flower width, and yield were better than those of 10 to 20 cm ridges. And the mortality ratio of plants, rosette formation rate, and nonpaniculata inflorescence rate became lower.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.4
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• pp.295-302
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• 1993

The nature of the cavity region and dispersion around trianglular ridge was investigated using model. The artifical neutral boundary layer was simulated in water channel. Two dimensional trianglar ridges, having height of 1.2 cm and various width were placed normal to the flow. Mean velocity with many dimensionless parameters were measured and compared with wind tunnel results by other studies. Using vorticity generator and roughness, the neutral boundary layer was well represented by the water channel. concentration patterns resulting from dye source placed 0.2 cm height above were examined. Narrower the trianglar ridge width resulted in increased amplification factor and the larges amplification factor was observed near downward top of the ridge.

• Journal of Periodontal and Implant Science
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• v.44 no.2
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• pp.50-56
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• 2014

Purpose: The aims of this study were to measure the distance of the intraosseous vascular anastomosis in the anterolateral wall of the maxillary sinus from different reference points, and to correlate the location of the intraosseous vascular anastomosis with the tooth position and the residual bone height of the maxilla. Methods: Computed tomography (CT) images were taken from 283 patients undergoing dental implants placement in the posterior maxilla. Three horizontal lines were drawn at the ridge crest, maxillary sinus floor, and the position of the anastomosis. A vertical second line at the center of each tooth was drawn perpendicular to the horizontal lines. The distance from the ridge crest to the maxillary sinus floor and the distance from the maxillary sinus floor to the bony canal were measured from the intersections of the horizontal and vertical lines. The residual alveolar bone height was used to categorize three groups: group 1,<4 mm; group 2, between 4 and 8 mm; and group 3, >8 mm. Results: The residual bone height values of different tooth positions were significantly different (P=0.0002). The distance from the maxillary sinus floor to the intraosseous vascular anastomosis was significantly different between groups 1 and 3 (P=0.0039). At the molar sites, a moderate negative correlation was found between the residual bone height and the distance from the maxillary sinus floor to the intraosseous anastomosis. The distances of the alveolar ridge crest and the maxillary sinus from the intraosseous vascular anastomosis were not significantly different between sexes. Conclusions: Within the limitations of this study, sites with a higher residual bone height in the molar regions were at a relatively high risk of artery damage during window osteotomy preparation; therefore, we recommend taking more precautions when using a lateral approach for sinus elevation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.2
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• pp.143-149
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• 2005

Objects : With the advancement of tissue engineering techniques, the effort to develop bioartificial mucosa have been actively delivered. The problem we met with this technique is the lack of mechanical strength between kerationocyte layer and dermal layer, where in the normal skin and mucosa, they are tightly bound with rete ridge structure. The purpose of this study is to understand the 2D and 3D structure of rete ridge of mucosa and skin paddle for rendering more biomimetic structure to the artificial mucosa. Materials and Methods : Oral mucosa and skin from the patients who received the oral surgery and maxillofacial reconstruction were harvested. The epidermis was separated from the dermis after treating with dispase for 12-16 hours. H&E staining was performed for 2D(dimensional) structure study and confocal LASER and SEM study were performed for 3D structure. Mean height(Sc) and arithmetic mean deviation(Sa) of all surface height were calculated. Results : The average height of rete ridge of skin flap was between $67.14{\mu}m$ and $194.55{\mu}m$. That of oral mucosa was between $146.26{\mu}m$ and $167.51{\mu}m$. Pressure bearing area and attached gingiva of oral mucosa showed deeper rete ridges. Conclusion : To obtain the adequate strength of artificially cultured keratinocyte skin and mucosa flap, it is necessary to imitate the original skin and mucosa structure, especially rete ridge. Through this study, 2D and 3D rete ridge structure of normal mucosa and skin was obtained. These results can be used as basis for substrate morphology for keratinocytes culture.