• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.3
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• pp.211-217
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• 2020

In patients with insufficient bone height and width, the successful placement of dental implants is difficult with regards to maintaining an ideal pathway and avoiding important anatomical structures. Vertical and/or horizontal ridge augmentation may be necessary using various bone substitute materials and bone graft procedures. However, effective one-wall reconstruction has been challenging due to its poor blood supply and insufficient graft stability. In this paper, the authors summarize current evidence-based literature based on the author's clinical experience. Regarding bone substitutes, it is advantageous for clinicians to select the types of bone substitutes including autogenous bone. The most important consideration is to minimize complications through principle-based ridge augmentation surgery. Ridge augmentation should be decided with complete consent of the patients due to the possible disadvantages of surgery, complications, and unpredictable prognosis.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.73-89
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• 1991

Impression ragistration is an improtant and difficult phase of prosthodontic treatment procedures and a tray of appropriate size and shape is essential to obtain the accurate impression. Particularly, in edentulous patients, the size and forms of their residual alveolar ridges are different from one another. Therefore, in this study, various measurements were taken on the edentulous models. And the measurements were analyzed and compared with one another. The results were as follows ; 1. The mean of denture bearing area was $32.86cm^2$ in the upper jaws, $24.20cm^2$ in the lower jaws and the variation of denture bearing area was greater in the upper than in the lower jaws and in males than in females. 2. The mean of A-P(anteroposterior) ridge length was 48.72mm in the upper jaws, 53.05mm in the lower jaws and that of males was longer than that of females. 3. The mean of most posterior ridge width was 47.23mm in the upper jaws, 58.03mm in the lower jaws and the difference of that between males and females was least in both jaws. 4. In the upper jaws, the mean of ridge width was 29.66mm on anterior 1/4, 42.79mm on middle, 48.95mm on posterior 1/4 line and the mean of palatal height was 4.56mm on anterior 1/4, 10.01mm on middle, 10.84mm on posterior 1/4 line. 5. In the lower jaws, the mean of ridge width was 33.24mm on anterior 1/4, 50.19mm on middle, 59.16mm on posterior 1/4 line and the mean of lingual ridge height was 5.49mm on anterior 1/4, 9.16mm on middle, 16.72mm on posterior 1/4 line. 6. The correlation coefficient(=r) between denture bearing area and A-P ridge length was 0.83 in the upper jaws and 0.75 in the lower jaws. The corelation between denture bearing area and AP ridge length was statistically significant, but, between denture bearing area and A-P ridge length and between A-P ridge length and the most posterior ridge width was not statistically significant in both jaws. 7. Alveolar ridge forms were classified into three(ovoid, "u" shape, and "v"shape) categories. In the upper jaws, ovoid was 66%, "u" shape was 24%, and "v" shape was 10%, in the lower jaws, ovoid was 66.7%, "u" shape was 20%, and "v" shape was 13.3%.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.22 no.1
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• pp.47-55
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• 2013

There have been a great number of developments in clinical techniques and dental materials in dentistry to date. Looking at these developments, while it could be seen that functional elements such as mastication were prioritized rather than aesthetic aspect in the past, aesthetic needs of patients have steadily increased over time and accordingly the aesthetic has become considered a priority in the development of dentistry. Although the first to be considered in discussing the aesthetic in clinical dentistry will be the white aesthetic that is the tooth part of prosthesis, the pink aesthetic that refers to the harmony of such prosthesis with gingiva can be an important consideration not to be ignored aesthetically. However, the harmony with the gingiva often cannot be obtained only by the beautiful prosthesis, and in particular, the pontic and implant areas have poor conditions to achieve the gingival (pink) aesthetic due to the absorption of alveolar ridge compared to natural teeth. Among the most important elements of the gingival aesthetic are the gingival level and the interproximal papilla height. It is very difficult to make the gingival aesthetic in the case of insufficient alveolar ridge, and the recovery of ridge volume and contour is necessary in order to overcome this condition. To this end, the most widely used method is the "connective tissue graft". Many techniques of the connective tissue graft have already been introduced for the ridge augmentation, and each technique has different purposes, and advantages and disadvantages. Rather, due to the excessive amount of techniques, there is confusion about selecting the right technique at a certain time. However, the goal is clear. Ways to increase the success rates must be found, and at the same time, a more favorable way to the gingival aesthetic is to be chosen. Thus, in this study, considerations for the gingival aesthetic that makes harmony and the techniques to achieve it are discussed.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5_2
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• pp.163-175
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• 2010

This study is based on the viewing characteristics of mountain landscapes. It investigates whether the current landscape management-related regulations are efficient in terms of the viewing characteristics of the mountain landscape against Bukhansan Mountain in which the conventional landscape management techniques were used. In addition, some viewing characteristics of mountain landscapes, such as distance from the view point to the target mountain, angle of elevation, altitude, gradient, have been analyzed and 3 cases of viewing condition have been simulated. The following results were obtained: i) Mountain landscapes can be managed up to 7~8 times of the mountain height with a $5{\sim}9^{\circ}$ of elevation angle. ii) In the Natural Landscape District which is situated on the hillside, it is reasonable to include altitude, gradient as criteria for regulation. iii) According to a simulation of the construction permit height by viewing distance, it was confirmed that buildings can be constructed up to 111.55m when viewing the 20% ridge, 150.75m when viewing the 50% ridge and 189.05m when viewing the 70% ridge. iv) The construction permit height varies depending on the landscape analysis method that is used and the application conditions. It is therefore unfair to apply height limit regulations to all buildings without considering the geographical features or viewing characteristics. v) It is unreasonable to apply 2~3 management techniques to the same area for landscape management. Therefore, we recommend the Focused Landscape Management Area based on the landscape master plan as a integrating mountain landscape management techniques.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.3
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• pp.139-151
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• 2003

This study was to evaluate and to compare the compressive strength and the displacement effecting the abutment or the residual ridge which are transformed by the angle and the heights of the konus denture inner crown when restorating the unilateral konus denture by using the mandibular canine and the 1st premolar as an abutment. The author made 9 different models for different inner crown heights and konus angles. The inner crown height were divided to 5mm, 6mm, and 7mm and konus angles was divided to $4^{\circ}$, $6^{\circ}$, and $8^{\circ}$. And then in each model, 5kg of $15^{\circ}$ mesial load was stressed on the central fossa of the 1st premolar and the 1st molar. The stresses and displacement were measured using the finite element analysis. The results were as follows 1. The maximum compressive strength was shown on the connective area of the abutment and the denture base. 2. As the angle of the inner crown becomes increased, the compressive strength was shown smaller. 3. As the height of the inner crown becomes increased, the maximum compressive strength was shown smaller while the compressive strength of the root apex and the residual ridge showed larger. 4. When the stress was loaded only on the 1st premolar, the more compressive strength was concentrated on the root apex area of the 1st premolar. 5. When the stress was loaded only on the 1st premolar, the compressive strength was concentrated uniformly on the abutment and the residual ridge. 6. When the stress was loaded only on the 1st molar, the maximum displacement was shown on the distal part of the residual ridge.

• Ocean and Polar Research
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• v.32 no.4
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• pp.337-350
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• 2010

This study conducted sedimentological and geophysical surveys for 3 years (2006-2008) in southern Gyeonggi Bay, Korea to elucidate temporal changes in subaqueous dune morphology on a sand ridge trending northeast to southwest that has been excavated by marine sand mining. The sand ridge (~20 m in height, ~2 km in width and 3~4 km in length) has a steep slope on the NW side and a gentle slope on the SE side, creating an asymmetric profile. Large (10~100 m in length) and very large (>100 m in length) dunes occurring on the SE side of the ridge show a northeastward asymmetrical shape, whereas dunes on the NW side destroyed by marine sand mining display a southwestward asymmetry. The comparison between Flemming (1988)'s correlation and the height-length correlation of this study indicates that tidal current and availability of sand sediment are major controlling factors to the development and maintenance of dunes. Depth and sedimentary characteristics (grain size) are not likely to be major controlling factors, but indirectly influence dune growth by hydrological and sedimentary processes. The length and the height of dunes decrease toward the southeastern trough away from the crest of the ridge. These features result from the decrease of tidal current and sediment availability. The length and the height of dunes on the southeast side decrease gradually over time. This is a result of the interaction between tidal current and the decrease in sediment availability due to sediment extraction by marine sand mining. Marine sand mining has destroyed the dunes directly, causing irregular shapes of shorter length and lower height. The coarse fraction of suspended sediments is transported and deposited very close to the sand pit. By contrast, relatively fine sediments are transported by the tidal current and deposited over a wide range by the settling-lag effect, resulting in a decrease of sediment grain size in the area where suspended sediments are deposited. In addition, marine sand mining, decreases the height of dunes. Therefore, morphological and sedimentological characteristics of dunes around the sand pits will be significantly changed by future sand mining activities.

• The Journal of the Korean dental association
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• v.54 no.5
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• pp.328-341
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• 2016

An overall reduction in the horizontal and vertical dimensions occurs following tooth extraction and the resorption of the buccal part of the ridge is more pronounced than the lingual part. Thus, the resulting morphology of the healed alveolar ridge is often presenting with a discrepancy in bone height between the buccal and lingual aspects of the ridge. The implant with a sloped marginal configuration that is designed to match the sloped contour of the alveolar ridge provides the opportunity to maintain the buccal-lingual bone discrepancy and soft tissue around the implant. This paper introduces the OsseoSpeed TX Profile implants with sloped marginal configuration and explains the characteristics and clinical meanings of those implants.

• The Journal of the Korean dental association
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• v.40 no.9 s.400
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• pp.709-715
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• 2002

Two patients with sufficient vertical bone height but insufficient bone width in the anterior mandibular edentulous area, less than 6mm in the buccolingual aspect, for implant placement were chosen for treatment with a ridge splitting procedure. The surgical technique involving greenstick fracture is described. This ridge splitting procedure could be simple placement of implants into ideal restorable positions in severely atrophic, knife-edged ridges and predictable for narrow edentulous alveolar ridge augmentation associated with implant placement. We experienced two cases to place implant with insufficient bone width in the anterior mandibular edentulous area for overdenture be ridge splitting technique. Thus, we will report two cases and review of the literature.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.2
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• pp.116-123
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• 1994

The E- $\varepsilon$ turbulence numerical model was applied to a flow around triangular ridge in neutral boundary layer. Scale of cavity region, mean velocity, Reynolds stress and eddy diffusivity were investigated. The height of cavity region was in satifactory agreement with the wind tunnel data while the length of cavity region was underestimated. The man wind velocities outside the cavity region were well Predicted by the model, however in cavity region the mean wind velocities of wind tunnel data were larger than the model results Reynolds stress of cavity region was overestimated by the model. The eddy diffusivity of wake region was strongly modified under the influence of triangular ridge. The local minimum of the eddy diffusivity was occured in the lee of the ridge top.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.4
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• pp.329-334
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• 2005

Polymethyl-methacrylate(PMMA; Artecoll$^{(R)}$) microspheres suspended 1 : 3 in a 3.5% collagen solution has been used as an injectable implant for long lasting correction of wrinkles and minor skin defects. The patients with mandibular prognathism have increased necessity for nasal augmentation. Usually these patients usually get an additional rhinoplasty after orthognathic surgery. The purpose of this study is to evaluate the result of PMMA injection for nasal ridge augmentation simultaneously with the orthognathic surgery. PMMAs were injected to the nasal dorsum of 13 patients with mandibular prognathism to augment the nasal ridge at the end of the orthognathic surgery. The cephalometric X-ray and clinical facial photograph were taken at 2, 4 and 6 months after operation. Using S-N line, we calculated the change of soft tisuue on the nasal ridge and also investigated the degree of patients satisfaction at 6 months after operation. Most of the patients were satisfied with their nasal ridge height status from moderate to good degree. The average amount of nasal ridge augmentation was $1.4{\pm}0.5$ mm immediately after operation, $1.2{\pm}0.4$ mm at 2 months after operation. The postoperative nasal ridge height seemed to be remained stable after 2 months. Intraoperative PMMA injection is considered to be simple and effective technique which can be used for the minor augmentation of nasal ridge in the orthognathic patients.