• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.7-14
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• 2008

Purpose: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. Materials and Methods: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. Results: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. Conclusion: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.756-765
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• 1997

Background : To study the prognosis of patients with lung cancer, many investigators have reported the methods to detect cell proliferation in tissues including PCNA, thymidine autoradiography, flow cytometry and Ki-67. PCNA, also known as cyclin, is a cell related nuclear protein with 36KD intranuclear polypeptide that is maximally elevated in S phase of proliferating cells. In this study, PCNA was identified by paraffin-embedding tissue using immunohistochemistry which has an advantage of simplicity and maintenance of tissue architecture. The variation of PCNA expression is known to be related with proliferating fraction, histologic type, anatomic(TNM) stage, degree of cell differentiation, S-phase fraction and survival rate. We analyzed the correlation between PCNA expression and S-phase fraction, survival. Method : To investigate expression of PCNA in primary lung cancer, we used immunohistochemical stain to paraffin-embedded sections of 57 resected primary non-small cell lung cancer specimen and the results were analyzed according to the cell type, cell differentiation, TNM stage, S-phase fraction and survival. Results : PCNA expression was divided into five group according to degree of staging(-, +, ++, +++, ++++). Squamous cell type showed high positivity than in adenocarcinoma. Nonsignificant difference related to TNM stage was noticed. Nonsignificant difference related to degree of cell differentiation was noticed. S-phase fraction was increased with advance of PCNA positivity, but it could not reach the statistic significance. The 2 year survival rate and median survival time were -50% 13 months, +75% 41.3 months, ++73% 33.6 months, +++67% 29.0 months, ++++25% 9 months with statistic significance (P<0.05, Kaplan-Meier, generalized Wilcox). Conclusion : From this study, PCNA expression was high positive in squamous cell cancer. And, there was no relationship between PCNA positivity and TNM stage, cellular differentiation or S-phase fraction. But, the patients with high positive PCNA staining showed poor survival rate than the patients with lower positive PCNA staining (p<0.05). It was concluded that PCNA immunostaining is a simple and useful method for survival prediction in paraffin embedded tissue of non-small cell lung cancer.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.6
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• pp.469-477
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• 2009

Purpose: This study was performed to evaluate the effect of various graft materials used with a titanium cap on the ability of new bone formation in the rabbit calvarium. Materials and Methods: A total of 32 sites of artificial bony defects were prepared on the calvaria of sixteen rabbits by using a trephine bur 8 mm in diameter. Each rabbit had two defect sites. 0.2 mm deep grooves were formed on the calvaria of sixteen rabbits by using a trephine bur 8 mm in diameter for the fixation of a titanium cap. The treatments were performed respectively as follows: without any graft for the control group (n=8), autogenous iliac bone graft for experimental group 1 (n=8), alloplastic bone graft ($SynthoGraft^{(R)}$, USA) for experimental group 2 (n=8), and xenogenic bone graft ($NuOss^{(R)}$, USA) for experimental group 3 (n=8). After the treatments, a titanium cap (8 mm in diameter, 4 mm high, and 0.2 mm thick) was fixed into the groove. At the third and sixth postoperative weeks, rabbits in each group were sacrificed for histological analysis. Results: 1. In gross examination, the surgical sites showed no signs of inflammation or wound dehiscence, and semicircular-shaped bone remodeling was shown both in the experimental and control groups. 2. In histological analysis, the control group at the third week showed bone remodeling along the inner surface of the cap and at the contact region of the calvarium without any specific infiltration of inflammation tissue. Also, there was no soft tissue infiltration. Bone remodeling was observed around the grafted bone and along the inner surface of the titanium cap in experimental group 1, 2, and 3. 3. Histologically, all groups at the sixth week showed the increased area of bone remodeling and maturation compared to those at the third week. In experimental group 2, the grafted bone was partially absorbed by multi nucleated giant cells and new bone was formed by osteoblasts. In group 3, however, resorption of the grafted bone was not observed. 4. Autogenous bone at the third and sixth week showed the most powerful ability of new bone formation. The size of newly formed bone was in decreasing order by autogenous, alloplastic, and heterogenous bone graft. There was no statistically significant difference among autogenous, alloplastic, and heterogenous bones(p>0.05). Summary: This result suggests that autogenous bone is the best choice for new bone formation, but when autogenous bone graft is in limited availability, alloplastic and xenogenic bone graft also can be an alternative bone graft material to use with a suitably guided membrane.

• The korean journal of orthodontics
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• v.24 no.3 s.46
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• pp.547-554
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• 1994

This study was carried out in order to find out the soft tissue profile changes associated with maxillary incisor retraction in Angle's class I malocclusion patients. For this study fifty two female adult patients (Maximum Retraction Group 23, Minimum Retraction Group 29) who received orthodontic treatment were chosen. Following conclusions were obtained by analysing the changes of soft tissue and hard tissue before and after treatment. 1. When considering the mean changes of soft tissue and hard tissue, UP, LIP, Ls, Li (p<0.001), Point B, Si (p<0.01), Point A, Ss (p<0.05) were significant posterior movement in Maximum Retraction Group and UIP (p<0.001), LIP, Ls, Li (p<0.01), Point B, Si (p<0.05) were significant posterior movement in Minimum Retraction Group. 2. When considering the correlations between hard tissue and soft tissue changes, greater correlations were found in Minimum Retraction Group between UIP and Ls (p<0.01), Point A and Ss, UIP and Li, Point B and Si (p<0.05) than Minimum Retraction Group. 3. Correlations (p<0.01) were found between upper incisor retraction and posterior movement of the upper and lower lip in Thin Lip-Thickness Group, whereas no significant correlations were found in Thick Lip-Thickness Group. 4. Mean changes of the soft tissue thickness subsequent to incisor retraction were increased (p<0.01) in upper lip (Ls-Ls'), whereas no changes were found in lower lip.

• The korean journal of orthodontics
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• v.13 no.2
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• pp.177-183
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• 1983

The soft tissue covering of the face plays an important role in facial esthetics, speech and other physiologic functions. Thus, it is recognised by all clinical orthodontists that success of orthodontic treatment is closely related to the changes in soft tissues of the face. The purpose of this study was to evaluate the changes of bony and soft tissues in prepost treatment of Angle's Class III malocclusion. The sample consisted of 18 males and 37 females, pretreatment age of 9 years to 11 years. For this study 11 landmarks were plotted, 14 linear length, 4 soft tissue thickness and 2 angles were measured. The obtained results were as follows; 1. In the linear measurements of bony and soft tissue changes, A, Is, Ss, Ls and Li were located more anteriorly in both sexes. However Si and B showed more remarkable anterior movement in female. 2. In the comparison of the changes of the soft tissue thickness, Ss and Li in male subjects and Ss in female subjects increased. 3. In the degree of correlation between changes in the soft tissue profile and changes in the skeletal profile, Is: Ls, Il: Li and B: Si in both sexes had significant correlations. However A:Ss had remarkable significant correlation in female. 4. There were significant correlations between change in ${\angle}A$ and change in ${\angle}B$ in all sexes. 5. There were little correlation between changes in distance difference of Is and Ii and Change in distance difference of Ls and Li in all sexes.

• The korean journal of orthodontics
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• v.13 no.2
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• pp.193-199
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• 1983

The purpose of orthodontic treatment is to produce functional occlusion and to create or maintain facial esthetic harmony. The soft-tissue covering of the face also plays an important role in facial esthetics, speech and other physiologic functions. The study of the soft-tissue profile is important for the planning of orthodontic treatment. The author studied cephalometric X-ray films on 49 patients (23boys, 26 girls) with Angle's class II division 1 malocclusion, ranged from 9 to 13 years of age. Roentgenocephalmetric X-ray films were taken pre and post orthodontic care. Tracings were made in usual manner. The obtained results were as follow. 1. There was no significant sexual difference on mean changes. 2. In the comparison of the soft-tissue thickness changes, Ls-Ls' and Si-Si' in male subjects were remarkable. 9. There were significant correlations between osseous (Ss') change and soft-tissue (Ss) chang, of maxilla in male and female subjects subsequent to orthodontic treatment. 4. The ratios between the protraction of the Ss' and that of the Ss were 1:1.5 in all sexes, the ratios between the Si' and that of the Si were 1:1.4 in male and 1:1.2 in female. 5. There were significant correlations between maxillary central incise. angulation change $({\angle}A)$ and upper lip inclination change $({\angle}B)$ in all sexes. 6. There were little correlations between change in distance difference of Is and Ii and change in distance difference of Ls and Li in all sexes in all sexes.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.299-308
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• 2002

The purpose of this morphometric study was to obtain detailed quantitative information on all cell types in the testis interstitium of Korean ring-necked pheasants combined with data on changes in the steroidogenic function of the testis during the breeding and nonbreeding seasons. Animals collected during the breeding season, testis weights, sperm production, serum testosterone levels, leuteinizing hormone-stimulated testosterone secretion, and the length of the seminiferous tubules were significantly (p < 0.05) increased as compared to the nonbreeding season. Seminiferous tubules occupied 93.25% of testis volume in the breeding season. Leydig cells constituted 0.82% of the testicular volume. The mean volume of an Leydig cell was $1039{\mu}m^3$, and each testis contained about 24.53 million Leydig cells. Testes of the pheasants during the nonbreeding season displayed a 98% reduction in testis volume that was associated with a decrease in the absolute volume of seminiferous tubules (98% reduction), tubular lumen(100%), interstitium(90%), blood vessels(84%), lymphatic spaces(97%), Leydig cells(79%), mesenchymal cells(51%), and myoid cells(61%). The number of Leydig cells, mesenchymal cells, myoid cells per testis in the breeding season was higher (p < 0.05) than in the nonbreeding season. Although the average volume of a Leydig cell was 74% lower in the nonbreeding season, the average volume of a myoid and mesenchymal cell remained unchanged. These results demonstrate that there are a striking differences in the testicular structure of the Korean ring-necked pheasant in the breeding and nonbreeding seasons. Every structural parameter of the Leydig cell was pasitively correlated with both serum and LH-stimulated secretion concentrations of testosterone. Correlation of changes in hormonal status with morphometric alterations of all Leydig cell suggests that the Korean-ring necked pheasant may be used as a model to study structure-function relations in the avian testis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.3
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• pp.250-261
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• 2006

Diabetes mellitus, as a major health problem for the elderly, is associated with an extensive list of complications involving nearly every tissue in the body and has been shown to alter the properties of bone and impair fracture healing in both human and animals. The objective of this study was to examine the healing process of a mandibular fracture in the streptozotocin-induced rats histomorphometrically and histologically. A standardized fracture model was chosen and based on blood-glucose value at the time of surgery. A total of 11-weeks old 36 rats were divided into 2 groups; One is a streptozotocin-induced diabetic group and the other is a non-diabetic group. All was fractured experimentally. Three animals from each group were killed 1, 2, 4, 6, 8 and 12 weeks after fracture and specimens were processed undecalcified for quantitative bone histomorphometric and histologic studies. The diabetic group showed a significant decrease of histomorphometry-based parameter including trabecular bone volume, trabecular thickness in comparison to the non-diabetic rat. This was confirmed histologically. In conclusion, this study suggests that in streptozotocin-induced diabetics, the healing process of bone fracture was impaired and delayed about 2-3 weeks comparing to non-diabetics.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.5
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• pp.282-292
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• 2003

Several agents are in use to promote new bone formation during bone graft procedures in maxillofacial region. Among them, we have used crude BMP, PRP, and P-15 for experimentally created defects with accompanying graft materials in the rabbit model. The aim of this study is to analyze the effect of above mentioned agents on bone formation using histologic and histomorphometrical methods, thus to provide experimental support for clinical application of these agents. Six rabbits were used as experimental animals. Four surgical defects were created on the distal femoral heads of each animal using trephine drill. The defects were filled with each agents with accompaning graft materials as experimental groups and particulate corti-co-cancellous autogenous graft as control. For histomorphometric analysis, fluorescent dye was injected at 2week and 1week before sacrifice. Then, the animals were sacrificed at 2, 4 and 8weeks after surgery and histologic and histomorphometric examinations were achieved. At two weeks after bone graft, bone formation and active remodeling process were examined in all experimental groups and the control. But the intensity of such activities of the experiments were somewhat weaker than that of the control. In BMP group, the amount of newly formed osteoid was increased constantly and the amount was preserved constantly in PRP group. But in P-15 group, the amount of newly formed osteoid was decreased with time to 8week after surgery. Histologic findings showed superior bony quantity and quality in PRP group than that of P-15 group. MAR(Mineralization Apposition Rate) of all experimental groups were slower than that of control group. In P-15 group, constant foreign body reaction was observed at all periods and the graft material showed inwardly destroyed characteristics rather to mature. The data from this study provide the basis for future studies for evaluating the long-term remodeling process and foreign body reactions observed in P-15 group and clinical study for predictable use of these agents.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.707-724
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• 1993

The purpose of the study is to estimate hard and soft tissue changes after orthognathic surgery for the correction of the mandibular prognathism and to describe interrelationship and ratios of soft and hard tissue changes. The presurgical and postsurgical lateral cephalograms of 31 treated patients(17 males and 14 females) was used ; these patients had received combined orthodontic-surgical treatment by means of a bilateral sagittal split ramus osteotomy. Their ages ranged from 16 to 31 years and mean age was 21.4 years. A computerized cephalometric appraisal was developed and used to analyse linear and angular changes of skeletal and soft tissue profile. The statistical elaboration of the data was made by means of $SPSS/PC^+$. The results of the study were as follows : 1. The correlations of soft and hard tissue horizontal changes were significantly high and the ratios were $97\%$ at LI, $107\%$ at ILS, and $93\%$ at Pog'. 2. The correlations of vertical changes at Stm, LI and horizontal changes at Pog were high$(26\%)$ and at the other areas were not statistically high. 3. The correlations of soft ad hard tissue vertical changes were not significantly high in all areas except Gn' $(30\%)$ and Me' $(56\%)$. 4. The soft tissue thickness was significantly decreased in upper lip and increased in lower lip, and the amount of changes after surgery was reversely correlated with initial thickness. 5. The facial convexity was increased and relative protrusion of upper lip was increased and that of lower lip was decreased. 6. The upper to lower facial height(Gl-Sn/Sn-Me') was increased and upper to lower jaw height(Sn-Stms/Stmi-Me') was increased.