• The korean journal of orthodontics
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• v.14 no.1
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• pp.65-81
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• 1984

In order to observe the responses of the periodontal tissue on the tension side following the experimental tooth movement, 35 Guinea pigs were divided into the control group (5 animals) and 6 experimental groups (3 movement groups and 3 retention groups) consisting of each 5 animals. The experimental tooth movement of Guinea pig's upper incisors installing open helical loop were carried out by rendering continuous force : 5g (1st groups) 35g (2nd groups), 100g (3rd groups), respectively for 7 days. 3 movement groups (15 animals) were sacrificed soon after the continuous force, and 3 retention groups (15 animals) were sacrificed after the retention period of another 7 days. The following results were obtained from the observation of the surrounding tissues of teeth on the tension side through light microscopy any transmission electron microscopy. 1. The vessel walls in the experimental groups were thinner than those of the control group, the number of blood vessel had the tendency to increase. The greater the strong force applied to each group, the more the destruction of cells and fibers was found and the more the number of the red blood cell of vessel outside appeared. 2. New collagen fibers were produced from fibroblasts in the 1st groups (light force), but were produced rather less in the 2nd groups (medium force) and the 3rd groups (heavy force). 3. In the forming patterns of the new alveolar bone of the 3rd groups (heavy force), the bone trabeculae were formed towards the direction of the force to be applied, but the new alveolar bone in the 1st groups (light force) was produced evenly throughout the all surfaces of the alveolar bone rather than the patterns of bone trabeculae ; therefore, the patterns of new alveolar bone were observed differently according to the magnitude of the force applied. 4. In the retention group, it was observed that the collagen fibers were produced from the osteoblasts in the marginal areas of the periodontal ligaments being widely opened and were deposited on the alveolar bone surface but the production of collagen fibers from the osteoblasts in the other area of the periodontal ligaments was almost ceased, and a rest line on the new alveolar bone surface was found.

• Journal of Nutrition and Health
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• v.27 no.5
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• pp.473-482
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• 1994

This study was to compare the bioavailability of calcium from anchovy and tofu to those of calcium from calcium carbonate(CaCO3)as the control diet and non-fat dry milk(NFDM). Rats weighing 50-60g were placed on experimental diets and deionized water at free access for 4 weeks. Diets contained 0.2% calcium from calcium-carbonate, NFDM, anchovy, tofu or 0.5% calcium as obtained were as follows : 1) No significant differences in the apparent absorption of calcium(62.5%-71.0%) were observed in the rats fed four different calcium sources at the level of 0.2% while 0.5% calcium diet group apparently absorbed calcium less efficiently(52.2%). 2) Bone length of tibia and femur was not significantly different among the groups, though 0.5% calcium of control group showed slightly longer length. 3) Tibia fat-free dry weights of 0.2% calcium of NFDM and anchovy diet groups were not significantly different from that of 0.5% calcium of control group. For femurs NFDM, anchovy and tofu groups were similar in their fat-free dry weight to that of 0.5% calcium group. 4) For calcium contents tibia contents tibia from anchovy treated group showed higher value than calcium-carbonate and tofu groups and the value was not significantly different from that of 0.5% calcium group. In femur NFDM, tofu and calcium-carbonate groups were not significantly different in their calcium content but 0.5% calcium group had higher level of calcium than 0.2% calcium groups. 5) The normalized values(NV) show that there was no significant differences in NV among 0.2% CaCO3 anchovy and tofu groups, while NV of NFDM group was significantly lower than that of calcium-carbonate group. NV of 0.5% calcium group was a little more than 50% of those in 0.2% calcium groups. Though the values obtained for the calcium bioavailability were somewhat variable among experimental products, it was demonstrated that anchovy and tofu are as good as NFDM for the dietary calcium provider when calcium intake is at marginal level.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.41-45
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• 2009

Background: Reduced bone height is one of the major problems faced in restoring tooth loss with implants. By the use of short implants, it is possible to reduce complicated and invasive treatment such as bone graft, allowing more simple surgery. But short implants are generally considered to have lower success rates than that of standard implants. Purpose: To assess the results of short Straumann implants by a retrospective study of short Straumann implants with TPS(titanium plasma-sprayed) and SLA(sandblasted, large grit, acid etched) surfaces. Materials and methods: 173 implants in 106 patients who received short Straumann implant surgery(${\le}8\;mm$) in the department of oral and maxillofacial surgery, Kyunghee Dental Hospital, from February 1996 to October 2006 were selected and studied. All of the implants were followed up after prosthetic rehabilitation. The average follow-up period was 34 months with 119 months as the longest follow up period. The average follow-up period after prosthetic rehabilitation was 31 months. 64 females(60.4%) and 42 males(39.6%) participated in the research with the age range of 19 to 85(mean age 47). 20 patients(18.9%) were under 40, 85 patients(80.2%) were over 40 and under 70, and only one patient(0.9%) was over 70 years old. Results: 27 implants(15.6%) had TPS surface while 146 implants(84.4%) had SLA surface. 9 implants(5.2%) were 3.3, 108 implans(62.4%) were 4.1mm and 56 implants(32.4%) were 4.8mm in diameter. 167 implants(96.5%) were 8mm and 6 implants(3.5%) were 6mm in length. There were 24 implants(13.9%) on the maxillas and 149 implants(68.8%) on the mandibles. 119 implants(68.8%) were rehabilitated with FPD(fixed partial denture), 47 implants(27.2%) with single crowns and 4 implants(2.3%) with overdentures. Among the fixed partial dentures, 30 of them were splinted with short implants only. After over an year of follow-up period, 139 implants(96.5%) out of 144 implants showed marginal bone loss of less than 1mm. 3 out of 173 implants failed showing 98.27% survival rate. Conclusions: The use of short Straumann implants(${\le}8mm$) can be a simple and reliable treatment method in minimal residual bone height.

• Journal of Periodontal and Implant Science
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• v.49 no.3
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• pp.171-184
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• 2019

Purpose: To evaluate the effects of intra-alveolar socket grafting, subepithelial connective tissue grafts, and individualized abutments on peri-implant hard and soft tissue outcomes following immediate implant placement. Methods: This randomized experimental study employed 5 mongrel dogs, with 4 sites per dog (total of 20 sites). The mesial roots of P3 and P4 were extracted in each hemimandible and immediate dental implants were placed. Each site was randomly assigned to 1 of 4 different treatment groups: standardized healing abutment (control group), alloplastic bone substitute material (BSS) + standardized healing abutment (SA group), BSS + individualized healing abutment (IA group), and BSS + individualized healing abutment + a subepithelial connective tissue graft (IAG group). Clinical, histological, and profilometric analyses were performed. The intergroup differences were calculated using the Bonferroni test, setting statistical significance at P<0.05. Results: Clinically, the control and SA groups demonstrated a coronal shift in the buccal height of the mucosa ($0.88{\pm}0.48mm$ and $0.37{\pm}1.1mm$, respectively). The IA and IAG groups exhibited an apical shift of the mucosa ($-0.7{\pm}1.15mm$ and $-1.1{\pm}0.96mm$, respectively). Histologically, the SA and control groups demonstrated marginal mucosa heights of $4.1{\pm}0.28mm$ and $4.0{\pm}0.53mm$ relative to the implant shoulder, respectively. The IA and IAG groups, in contrast, only showed a height of 2.6mm. In addition, the height of the mucosa in relation to the most coronal buccal bone crest or bone substitute particles was not significantly different among the groups. Volumetrically, the IA group ($-0.73{\pm}0.46mm$) lost less volume on the buccal side than the control ($-0.93{\pm}0.44mm$), SA ($-0.97{\pm}0.73mm$), and IAG ($-0.88{\pm}0.45mm$) groups. Conclusions: The control group demonstrated the most favorable change of height of the margo mucosae and the largest dimensions of the peri-implant soft tissues. However, the addition of a bone substitute material and an individualized healing abutment resulted in slightly better preservation of the peri-implant soft tissue contour.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.1
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• pp.32-44
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• 2023

Purpose: The purpose of this study was to investigate the effect of implant connection type on marginal bone loss (MBL) and to analyze the factors that affect MBL. This study focuses on single implants planted in the upper and lower first molar area. Materials and Methods: A total of 87 implants from 68 patients were tracked for a period over 5 years. There were 57 external connection type (EC) implants and 30 internal connection type (IC) implants in 38 males and 30 females. The MBL and EA were measured from intraoral radiograph images taken after 5 years at most. Results: Significant difference in MBL between EC and IC type was observed in patients without GBR or diabetes. Patients without GBR exhibited an MBL of -0.065 ± 0.859 mm in EC type and -0.627 ± 0.639 mm in IC type (P = 0.025). Using multiple regression analysis, a statistically significant negative correlation was observed between MBL and conditions including implant-abutment connection type (β = -0.303), diabetes (β = -0.113), emergence angle > 30° (β = -0.234), and age (β = -0.776). Conclusion: Within this results, IC type implants had less MBL than EC type, and implant prosthesis with emergence angle over 30° showed greater MBL. To minimize the MBL of the implant and ensure implant stability, careful consideration should be given to the EA of implant prosthesis and its connection type.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.1
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• pp.27-33
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• 2014

Purpose: The purpose of this study was to investigate the food impaction between implant prostheses and adjacent natural teeth. Materials and methods: For this study, 51 patients with food impaction were selected and investigated mobility, tightness of contact area, gingival index, plaque index, attachment loss, alveolar bone level, proximal caries, marginal ridge distance and occlusal relationships. Results: Food impaction was found in the upper teeth (60.7%) more than the lower teeth (39.2%). Food impaction was occurred on mesial side of implant prostheses (86.2%) more than distal side (13.7%). Food impaction was mostly found in loose or open contact area (94.2%). Food impaction was frequent on stepped relationship between implant and adjacent teeth. Conclusion: Treatment plan should include proper adjacent and antagonistic occlusal plane and occlusal surface, to prevent food impaction, and the plan should include less adjacent tooth mobility with proper tightness between implant prostheses and adjacent teeth.

• Animal cells and systems
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• v.12 no.4
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• pp.305-311
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• 2008

Age and growth of the mudskipper, Scartelaos gigas were investigated using the second actinost bone of the pectoral girdle, based on an analysis of 560 individuals collected from the mud flats in south west Korea. Specimens were collected semimonthly from March to September of 2003. Actinost and ring radii of each ring group showed a direct one-to-one relationship, with ring radius increasing in tandem with actinost radius. Monthly change in the marginal indices showed that ring formation occurred between May and July(mainly June), being supported by the monthly change in the gonadosomatic(highest in June) and hepatosomatic(lowest in July) indices. Because the species has not been found since November, when air temperature was less than about $10^{\circ}C$, it is thought to enter to hibernation. Therefore, it was suggested that the two new actinost rings may appear a year: one during the spawning season(May-July) and another during hibernation(since November). Although the growth of S. gigas must be limited to short periods each year from March to April and from August to October, its growth rate was considerably fast. The von Bertalanffy growth parameters of S. gigas were $TL_{\infty}$=179.36 mm, K=0.78 $year^{-1}$, $t_0$=-0.7762, and age-length key were $TL_1$=134.3 mm, $TL_2$=158.6 mm, $TL_3$=169.1 mm, $TL_4$=175.0 mm.

• Journal of Periodontal and Implant Science
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• v.51 no.1
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• pp.63-74
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• 2021

Purpose: This study investigated the effects of hyaluronic acid (HA) on peri-implant clinical variables and crevicular concentrations of the proinflammatory biomarkers interleukin (IL)-1β and tumor necrosis factor (TNF)-α in patients with peri-implantitis. Methods: A randomized controlled trial was conducted in peri-implantitis patients. Patients were randomized to receive a 0.8% HA gel (test group), an excipient-based gel (control group 1), or no gel (control group 2). Clinical periodontal variables and marginal bone loss after 0, 45, and 90 days of treatment were assessed. IL-1β and TNF-α levels in crevicular fluid were measured by enzyme-linked immunosorbent assays at baseline and after 45 days of treatment. Clustering analysis was performed, considering the possibility of multiple implants in a single patient. Results: Sixty-one patients with 100 dental implants were assigned to the test group, control group 1, or control group 2. Probing pocket depth (PPD) was significantly lower in the test group than in both control groups at 45 days (control 1: 95% CI, -1.66, -0.40 mm; control 2: 95% CI, -1.07, -0.01 mm) and 90 days (control 1: 95% CI, -1.72, -0.54 mm; control 2: 95% CI, -1.13, -0.15 mm). There was a trend towards less bleeding on probing in the test group than in control group 2 at 90 days (P=0.07). Implants with a PPD ≥5 mm showed higher levels of IL-1β in the control group 2 at 45 days than in the test group (P=0.04). Conclusions: This study demonstrates for the first time that the topical application of a HA gel in the peri-implant pocket and around implants with peri-implantitis may reduce inflammation and crevicular fluid IL-1β levels.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.3
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• pp.301-311
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• 2009

Statement of problem: Flapless implant surgery using a soft tissue punch device requires a circumferential excision of the mucosa at the implant site. To date, Although there have been several reports on clinical outcomes of flapless implant surgeries, there are no published reports that address the appropriate size of the soft tissue punch for peri-implant tissue healing. Purpose: In an attempt to help produce guidelines for the use of soft tissue punches, this animal study was undertaken to examine the effect of soft tissue punch size on the healing of peri-implant tissue in a canine mandible model. Material and methods: Bilateral, edentulated, flat alveolar ridges were created in the mandibles of six mongrel dogs. After a three month healing period, three fixtures (diameter, 4.0 mm) were placed on each side of the mandible using 3 mm, 4 mm, or 5 mm soft tissue punches. During subsequent healing periods, the peri-implant mucosa was evaluated using clinical, radiological, and histometric parameters, which included Gingival Index, bleeding on probing, probing pocket depth, marginal bone loss, and vertical dimension measurements of the peri-implant tissues. Results: The results showed significant differences (P <0.05) between the 3 mm, 4 mm and 5 mm tissue punch groups for the length of the junctional epithelium, probing depth, and marginal bone loss during healing periods after implant placement. When the mucosa was punched with a 3 mm tissue punch, the length of the junctional epithelium was shorter, the probing depth was shallower, and less crestal bone loss occurred than when using a tissue punch with a diameter $\geq$ 4 mm. Conclusion: Within the limit of this study, the size of the soft tissue punch plays an important role in achieving optimal healing. Our findings support the use of tissue punch that 1 mm smaller than implant itself to obtain better peri-implant tissue healing around flapless implants.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.1
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• pp.69-74
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• 2009

Soft tissue sarcomas of popliteal fossa are rare, accounting for less than 5% of all soft tissue sarcomas of the extremities. In an extracompartmental space such as the popliteal, cubital fossa and inguinal space, where major vessels and nerves traverse, performing resections with wide margin is difficult and sometimes marginal margin is inevitable for limb salvage. For popliteal tumor resection, posterior approach would be a classic method. For tumors with small size and not adherent to surrounding structures, tumor is easily resected by this approach and dissection of nerve sheath or adventitia of vessel. On the contrary, tumors of large size and infiltrating the posterior structure of knee joint may show difficulty in en-bloc resection itself. These cases were candidates for amputation. Furthermore, tumors involving both popliteal fossa and anterior compartment usually had no choice but to have an amputation to prevent local recurrence. We regarded soft tissue sarcoma showing this kind of presentation as bone tumor having extraosseous mass. We performed wide en-bloc resection of proximal tibia and fibula along with sarcoma involving both compartment on liposarcoma of 47-year old man.