• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.83-91
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• 2004

2-piece 임플란트에서는 초기 치유 기간 동안 0.9-1.6mm의 골 소실이 일어나는데 2-piece 임플란트의 미세 간극과 그에 따른 생물학적 폭경의 형성이 중요한 원인이다. 최근 수직적으로 미세 간극의 위치를 변화시킴으로 골 소실의 양을 줄일 수 있다는 보고가 있다. 이번 실험의 목적은 미세 간극의 수평적 위치 변화에 따른 골 소실의 양을 비교하는데 있다. 하악에서 인접하여 최소 2개의 임플란트를 식립할 수 있는 7 무치악 부위에 총 15개의 Osseotitie XP 4/5를 식립하였다. 이때 임플란트의 상연이 주위 치조골과 일치하게 식립하였고 무작위로 선택하여 한 그룹(W군)에서는 wide diameter healing abutment를 연결하였고 다른 한 그룹(S 군)에서는 standard diameter healing abutment를 연결하였다. 3개월의 치유 기간후 보철 과정을 시작하였으며 이 때 healing abutment와 같은 크기의 prosthetic component를 이용하였다. 임플란트 식립 직후, 3개월의 치유 기간이 지난 보철 직전(Interval I)에, 보철 과정 직후(Interval II)에 각각 치근단 방사선 사진을 찍어 각 단계에서의 골 소실 양을 비교하였다. W 군의 경우 골 소실의 양이 Interval I에서 $1.60{\pm}0.78$, Interval I+II에서 $2.36{\pm}0.29$이었고 S 군에서는 Interval I에서 $1.5810{\pm}0.3030$, Interval I+II에서는 $1.7346{\pm}0.4199$이었다. W군에서는 Interval I와 I+II에서의 골 소실 양이 통계학적으로 유의할 만한 차이를 보였으며, Interval I+II에서의 W 군과 S 군에서의 골 소실 양도 통계학적으로 유의할 만한 차이를 나타내었다. Interval I에서는 두 그룹에서 골 소실의 차이가 없었는데 이는 1 stage surgery시 healing abutment 주위로 mucoperiosteal flap 접합의 어려움 때문으로 생각된다. 한편 Interval II에서는 abutment manipulation 등의 과정이 추가적인 골 소실을 야기한 것으로 생각된다. Interval I+II에서 W 군과 S 군 사이의 골 소실 양 차이는 미세 간극의 수평적 위치 변화의 양과 유사한 결과를 나타내었는데 이로 미루어 미세 간극의 수평적 이동은 임플란트 주위의 골 소실 양에 영향을 미칠 수 있다고 생각된다.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.49-59
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• 2004

The goal of periodontal treatment is not only to arrest the progression of the disease but also to promote the functional, esthetic regeneration of the periodontium. Flap operation, bone graft, guided tissue regeneration, growth factors and bone morphogenetic protein have been used for this purpose. Among these techniques of regeneration, alloplastic graft, especially calcium phosphate is getting more attention recently. The purpose of this study was to evaluate the effects of calcium phosphate glass on mouse calvarial cell in vitro. The toxicity of calcium phosphate glass was measured using MTT assay, the synthesis of collagen was measured using collagen assay, and ALP activity was measured. The experimental groups were cultured with calcium phosphate glass(both AQ-, and HT-CPG) in concentration of 0.01, 0.02, 0.1, 0.2g/ml. The results are as follows 1. In concentrations not exceeding 0.02g/ml, both the groups(AQ-CPG, HT-CPG) didn't show any toxicity on mouse calvarial cell(p<0.05). 2. In both the experimental groups are the concentration of 0.02g/ml, collagen expressions were significantly up-regulated (p<0.05). 3. In both the experimental groups are the concentration of 0.02g/ml, ALP activity was not significantly up-regulated, but ALP activity in both experimental groups were greater than control group(p<0.05). The results suggested that the use of calcium phosphate glass may promotes periodontal regeneration. Ongoing studies are necessary in order to determine their regeneration effects.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.127-138
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• 2004

Background: Crestal bone loss known as saucerization is a frequently observed phenomenon. Recent studies have shown that implants with micothreaded crest module reduced the force concentration in the crestal region thus resulting in no or reduced crestal bone loss. This study presents a clinical, histologic, and histometric evaluation of implants with microthreaded crest module and SLA surface. Methods: The implants were placed in the mandible of 5 beagle dogs weighing 10-15kg. Four premolars were bilaterally extracted 8 weeks prior to implant placement. Mucoperiosteal flap was elevated and drilling with increasing diameter was performed under saline irrigation. After countersinking 2 implants were placed in each side resulting in 4 implants per dog. Healing period of 8 weeks was allowed before sacrificing the animals. Histologic preparation was performed for histologic and histometric analysis. Bone to implant contact as well as percentage of bone area inside threads were measured. T-test was used for statistical analysis with pvalue p<0.05. Results: 1. Healing was uneventful without any cover screw exposure. New bone formation around the implants was observed without any inflammatory infiltration. 2. Bone to implant contact in the microthread and thread were 43.90 ${\pm}$ 20.30 %, and 53.19 ${\pm}$ 20.97 % respectively. The overall bone to implant contact was 48.54 ${\pm}$ 20.95 %. 3. Percentage of bone area inside threads were 54.43 ${\pm}$ 10.39 %, and 38.44 ${\pm}$ 16.44 % for the microthread and thread respectively. There was statistically significant difference(p<0.05). The overall percentage of bone area inside threads was 46.67 ${\pm}$ 15.68 %.

• Journal of Periodontal and Implant Science
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• v.46 no.5
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• pp.303-319
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• 2016

Purpose: The purpose of this animal study was to perform a 3-dimensional micro-computed tomography (micro-CT) analysis in order to investigate the influence of root surface distance to the alveolar bone and the periodontal ligament on periodontal wound healing after a guided tissue regeneration (GTR) procedure. Methods: Three adult Sus scrofa domesticus specimens were used. The study sample included 6 teeth, corresponding to 2 third mandibular incisors from each animal. After coronectomy, a circumferential bone defect was created in each tooth by means of calibrated piezoelectric inserts. The experimental defects had depths of 3 mm, 5 mm, 7 mm, 9 mm, and 11 mm, with a constant width of 2 mm. One tooth with no defect was used as a control. The defects were covered with a bioresorbable membrane and protected with a flap. After 6 months, the animals were euthanised and tissue blocks were harvested and preserved for micro-CT analysis. Results: New alveolar bone was consistently present in all experimental defects. Signs of root resorption were observed in all samples, with the extent of resorption directly correlated to the vertical extent of the defect; the medial third of the root was the most commonly affected area. Signs of ankylosis were recorded in the defects that were 3 mm and 7 mm in depth. Density and other indicators of bone quality decreased with increasing defect depth. Conclusions: After a GTR procedure, the periodontal ligament and the alveolar bone appeared to compete in periodontal wound healing. Moreover, the observed decrease in bone quality indicators suggests that intrabony defects beyond a critical size cannot be regenerated. This finding may be relevant for the clinical application of periodontal regeneration, since it implies that GTR has a dimensional limit.

• Archives of Plastic Surgery
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• v.40 no.4
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• pp.359-366
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• 2013

Background Pedicled transverse rectus abdominis musculocutaneous flaps typically sacrifice the entire muscle. In our experience, the lateral strip of the rectus abdominis muscle can be spared in an attempt to maintain function and reduce morbidity. When the intercostal nerves are injured, muscle atrophy appears with time. The severed intercostal nerve was reinserted into the remnant lateral strip of the rectus abdominis muscle to reduce muscle atrophy. Methods The authors retrospectively reviewed 9 neurotized cases and 10 non-neurotized cases. Abdominal computed tomography was performed to determine the area of the rectus muscles. Electromyography (EMG) was performed to check contractile function of the remnant muscle. A single investigator measured the mean areas of randomly selected locations (second lumbar spine) using ImageJ software in a series of 10 cross-sectional slices. We compared the Hounsfield unit (HU) pre- and postoperatively to evaluate regeneration quality. Results In the neurotization group, 7 of 9 cases maintained the mass of remnant muscle. However, in the non-neurotization group, 8 of 10 lost their mass. The number of totally atrophied muscles in each of the two groups was significantly different (P=0.027). All of the remnant muscles showed contractile function on EMG. The 9 remaining remnant rectus abdominis muscles showed declined the HU value after surgery but also within a normal range of muscle. Conclusions Neurotization was found to be effective in maintaining the mass of remnant muscle. Neurotized remnant muscle had contractile function on EMG and no fatty degeneration by HU value.

• Archives of Plastic Surgery
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• v.47 no.6
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• pp.574-582
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• 2020

Background Several oncoplastic approaches have been implemented in recent years to enhance cosmetic results and to reduce complications. The round block technique is a volume displacement technique for breast reconstruction after breast-conserving surgery (BCS). However, its indications are currently limited according to tumor location, and its cosmetic results and complications have not been clearly established. We hypothesized that the round block technique could produce favorable cosmetic results without major complications regardless of tumor location or nipple-tumor distance, below a certain resected tumor volume and tumor-breast volume ratio. Methods All breast reconstructions using the round block technique after BCS were included in this analysis. Patients' data were reviewed retrospectively to investigate complications during follow-up, and clinical photos were used to evaluate cosmetic results. The relationships of tumor location, nipple-tumor distance, tumor volume, and the tumor-breast volume ratio with cosmetic results were investigated. Results In total, 108 breasts were reconstructed. The mean resected tumor volume was 30.2±15.0 mL. The cosmetic score was 4.5±0.6 out of 5. Tumor location, nipple-tumor distance, tumor volume, tumor-breast volume ratio, radiotherapy, and chemotherapy had no significant effects on cosmetic results or complications. There were no major complications requiring reoperation. Conclusions Breast reconstruction using the round block technique after BCS can lead to good cosmetic results without major complications regardless of the tumor location, nippletumor distance, radiotherapy, or chemotherapy. Below the maximum tumor volume (79.2 mL) and the maximum tumor-breast volume ratio (14%), favorable results were consistently obtained.

• Archives of Plastic Surgery
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• v.35 no.6
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• pp.698-702
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• 2008

Purpose: Basal cell carcinoma is one of the most common cancers in the western population and the annual incidence rate is still on an increasing course. In Asian countries such as Korea, the incidence of basal cell carcinoma is reported to be remarkably low but is estimated to be in a steep increase nowadays. This study was to analyze the recent clinical trends of basal cell carcinoma in Korea by reviewing a single institution's experience. Methods: Throughout an 11-year period, the surgical excision of 143 cases of basal cell carcinoma was performed in our department. General data of these cases such as the primary site of cancer, age and sex of the patient, operative methods, recurrence rate were reviewed retrospectively. Results: Among the 143 patients included in this study, 82 patients were men and 61 patients were women. The ages ranged from 27 to 89 years with a mean age of 64.0 years. The head and neck region was the most frequently involved primary site for the cancer as 95.1% of the total cases occurred in this area. Especially the nose and perinasal area were the most frequent region, which was followed by the periorbital area, cheek, and perioral area. During this study period, 9 cases showed recurrence of the cancer as the overall recurrence rate was 6.3%. Conclusion: Gradual increase in the incidence of basal cell carcinoma was demonstrated in this study. Basal cell carcinoma showed high incidence in the old-age population as 68.5% of the total patients were more than 60 years of age. High recurrence rate was noted in the nasal region especially after local flap reconstruction. A more cautious approach is to be required when handing such high risk lesions. Multiple factors such as extended life span, increased outdoor leisure activity and exposure to sunlight, higher accessibility to medical services and increased understanding of the public about skin cancer are assumed to be the main reasons for this increase of basal cell carcinoma.

• Archives of Plastic Surgery
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• v.38 no.3
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• pp.295-299
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• 2011

Purpose: It is generally believed that alopecia is caused by various factors such as scars, stress, genetical factors, androgens, etc. Androgenic alopecia is one of the most common cause of alopecia and found mainly in males. Propecia (Merck & Co., USA) and Minoxidil (McNEIL-PPC, Inc, USA) were the drugs approved from FDA for treatment of androgenic alopecia. Surgical treatments such as flap, tissue expansion, scalp reduction and hair transplantation can be considered if necessary. Hair micrograft techniques were developed for natural hair shapes and minimal adverse effect. There were attempts to measure the length of the forehead of the Korean young adults. However attempts to classify the shape and location of forehead hairline were rare. This study attempted to find out standard hairlines of young adults in their 20s & 30s and the result would be the guideline of the hairline in hair replacement surgery of male patients in their 40s & 50s. Methods: 200 male adults in 20s and 30s were photographed and measured the length of 11 vertical index lines to determine hairline. The indexes are the distances from hairline to intercanthal midpoint (A), to medial canthus (B), to upper eyelid fissure (C), to lower eyelid fissure (D), to lateral canthus (E) and distance from lateral highest point to medial lowest point, if the hairline is M-shape (F). Additionally, we classified the hairlines into 4 groups, M, horizontal, inverted U and irregular shapes. Results: The most common hairline of male adults in their 20s is inverted U-shape (53.3%), followed by horizontal-shape, M-shape, irregular-shape. In their 30s, inverted U-shape (59%) is followed by irregular-shape, M-shape, horizontal-shape. The M-shape is more frequently found in males in 30s than those in 20s. The mean values of the indexes in their 20s are as follows: A (76.14 mm), B (Rt: 75.78 mm, Lt:76.41 mm), C (Rt: 69.43 mm, Lt: 69.92 mm), D (Rt: 76.92 mm, Lt:77.46 mm), E (Rt: 64.16 mm, Lt: 64.73 mm), F (4.09 mm). Those in their 30s are as follows: A (76.13 mm), B (Rt: 76.114 mm, Lt: 76.02 mm), C (Rt: 69.87 mm, Lt: 70.37 mm), D (Rt: 77.37 mm, Lt: 77.58 mm), E (Rt: 69.63 mm, Lt: 69.85 mm), F (6.14 mm). Conclusion: The knowledge about human body measurement is indispensable to plastic surgeons. In this study, inverted U shape is the most common type of hairline in 30s, and similar distribution is found in 20s. The percentage of M shape in their 30s is elevated more than 10% compared to that in their 20s. The study of hairline shapes and 11 indexes of hairlines can be useful for planning of the hair transplantation and postoperative evaluation. This study being based on photogrammetry, there may be differences between actual distance of curved face and projected distance on flat photographs.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.8 no.2
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• pp.118-121
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• 2012

Down syndrome (DS) is a genetic disease known as trisomy 21. Congenital cardiac anomalies are present in about 40% of DS patients. Dental anomalies are also common among DS patients. In DS patients, canine impaction is 10 times more frequent and transposition of maxillary canine and first premolar is 50 times more common than in general population. A female DS patient with congenital heart disease was diagnosed as having a transposed impacted maxillary canine. Sectional fixed appliance with Nance holding arch was used for the orthodontic treatment. After space was regained for the eruption of the canine, orthodontic button was attached using flap operation with closed technique. Traction and alignment of the tooth followed. To prevent endocarditis, prophylactic antibiotics were prescribed for the recommended dental procedures. Total treatment time was 25 months and no complication was found.

• Journal of Periodontal and Implant Science
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• v.47 no.6
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• pp.352-362
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• 2017

Purpose: Furcation involvement in the molars is difficult to treat, and has been recognized as a risk factor for tooth loss. Although periodontal regenerative therapies, including guided tissue regeneration and various types of bone grafts, have been applied to furcation defects, the effects of these treatments are limited, especially in large class III furcation defects. The purpose of this pilot study was to investigate the effect of reciprocal autologous root transplantation on periodontal wound healing and regeneration in class III furcation defects in dogs. Methods: Furcation defects (7 mm wide and 6 mm high) were surgically created after root separation of the unilateral third and fourth premolars in 4 dogs. Eight furcation defects were randomized to receive either reciprocal autologous root transplantation (test) or no further treatment (control). In the test group, the mesial and distal roots were transplanted into the distal and mesial extraction sockets, respectively. The animals were sacrificed 10 weeks after surgery for histologic evaluation. Results: The healing pattern in the control group was characterized by extensive collapse of the flap and limited periodontal regeneration. New bone formation in the test group ($3.56{\pm}0.57mm$) was significantly greater than in the control group ($0.62{\pm}0.21mm$). Dense collagen fibers inserting into the residual cementum on the transplanted root surfaces were observed in the test group. Slight ankylosis was observed in 2 of the 4 specimens in the test group on the mesiodistal sides where the root-planed surfaces faced the existing bone. Root resorption (RR) was detected in both the control and test groups. Conclusions: Within the limits of this study, it can be concluded that reciprocal autologous root transplantation was effective for bone regeneration in class III furcation defects in dogs. However, further studies are required to standardize the approach in order to prevent unwanted RR prior to clinical application.