• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.518-528
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• 2008

Purpose: The long-term experience of using osseointegrated implants for prosthetic rehabilitation of the edentulous patients shows that high success rates can be predictably achieved. Primary implant stability has been identified to be a prerequisite to achieve osseointegration. In this study, we set up the amount of removed bone so that it differed on implant installation site for each group. The influence of each initial stability on secondary stability and osseointegration was compared with time lapse using resonance frequency analysis and histomorphometric analysis. Materials and methods: A total 27 US $II^{(R)}$ (Osstem, Korea) implants were placed in the mandibular edentulous area of 3 beagle dogs. The implant site was prepared by the conventional technique with drills, and three experimental groups were divided into under-drilling group, normal-drilling group and over-drilling group. The Implant Stability Quotient (ISQ) was measured at intervals of immediately, 4, 8, 12 weeks after placement using $Osstell^{(R)}$ mentor RFA. After the animals were sacrificed, histomorphometric evaluation was executed for measuring BIC and BD. Results: 1) The under-drilled group showed most high ISQ value for whole experiment period. 2) Bone-to-implant-contact(BIC) showed the tendency to be increased gradually as the experiment period passed except the 8 weeks of the normal group. 3) The under-drilled group showed most high bone density(BD) level for whole experiment period, and it was expressed the aspect to be increased gradually according to an experiment period passage in the average of all group. 4) Resonance frequency analysis and histomorphometric analysis are presumed by generally proportional. Conclusions: As this research result, it seems that there are some correlation between resonance frequency analysis and histomorphometric analysis. As are accomplished osseointegration stably so that more superior at the region which the overpressure comes to add, it will be applicable method in clinical field.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.5
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• pp.419-424
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• 2009

Odontogenic myxoma, a rare tumour that occurs in the jaws, locally invasive, destructive tumors that do not metastasize to lymph nodes. Large odontogenic myxoma on mandible is treated by mandibulectomy, defected mandible is reconstructed by bone graft. Reconstructed mandible is difficult to reconstruct dentition using implant because of deficiency of bone amount. So it is necessary to additional bone graft. But a poor aspect of soft tissue lead to unsatisfactory result. Because of distraction osteogenesis is possible to reconstruction of an amount of bone and soft tissue, that is advantage to reconstruction of alveolar bone on reconstructed mandible. We report with review of literatures the 25 years old male patient who had odontogenic myxoma in left mandible, was undergone mandibulectomy and successfully implant installation and prosthetic restoration after distraction osteogenesis(Track $Plus^{(R)}$, KLS Martin, Germany) on the reconstructed mandible with a free iliac bone graft, and we have conservative and successful result.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.67-70
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• 2009

Purpose: This study presents the use of mini implants for fixed restoration and implant supported overdenture to enable the practitioner to overcome the anatomic obstacles of ridge width and narrow interdental space. Patients and methods: This study consisted of 9 patients who required single implants for one or two teeth replacement and 1 patient who required implant supported overdenture after mandiblectomy, iliac bone graft due to ghost cell tumor. The ages ranged from 29 to 70 years (mean 51). All patients were in good health. Clinical and radiographs were taken pretreatment, postoperatively, during rehabilitation, and at follow ups. Results: Total implant survival rate was 94.7%. One implant was removed due to its mobility as a result of bad bone quality (Type IV) and patient's carelessness (Heavy smoker). All patients except one reported complete satisfaction regarding to function, aesthetics, and phonetics. Radiographic follow up every 3months postoperatively showed success in achieving function and maintaining marginal bone level. Conclusion: Clinician can overcome both severe ridge deficiency and small interdental space with mini implant.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.5
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• pp.348-352
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• 2002

Ameloblastoma of the maxilla is an unusual epithelial tumor of odontogenic origin. According to many authors and reports, ameloblastoma account for approximately 1% of all tumors of the jaws, but when pseudotumors and cysts are excluded, the ratio rises to 11%. Of these tumors,80% originate in the mandible, while 20% originate in the maxilla. Although it is considered benign histopathologically, it can behave in a slowly growing infiltrative fashion, with multiple recurrences and eventual intracranial, or even distant, spread. We clinically analyzed common site in maxilla, radiographic findings, recurrence rate, duration between treatment and recurrence, the presence and site of distant metastasis in 15 patients who were diagnosed as ameloblastoma of the maxilla and took treatments from 1985 to 1999 in Dept. of Oral and Maxillofacial Surgery, Dental Hospital, Seoul National University. In this paper, treatment outcomes and our clinical experiences of maxillary ameloblastoma are reported with review of literatures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.327-333
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• 2006

Future cell-based therapies such as tissue engineering will benefit from a source of autogenous pluripotent stem cells. There are embryonic stem cells (ESC) and autologous adult stem cells, two general types of stem cells potentilally useful for these applications. But practical use of ESC is limited due to potential problems of cell regulation and ethical considerations. To get bone marrow stem cells is relatively burden to patients because of pain, anesthesia requirement. The ideal stem cells are required of such as the following advantages: easy to obtain, minimal patient discomfort and a capability of yielding enough cell numbers. Adipose autologus tissue taken from intraoral fatty pad or abdomen may represent such a source. Our study designed to demonstrate the ability of human adipose tissue-derived stromal cells (hATSC) from human abdominal adipose tissue diffentiating into osteocyte and adipocyte under culture in vitro conditions. As a result of experiment, we identified stromal cell derived adipose tissue has the multilineage potentiality under appropriate culture conditions. And the adipose stromal cells expressed several mesenchymal stem cell related antigen (CD29, CD44) reactions. Secondary, we compared the culture results of a group of hATSC stimulated with TGF-${\beta}$1, bFGF with a hATSC group without growth factors to confirm whether cytokines have a important role of the proliferation in osteogenic differentiation. The role of cytokines such as TGF-${\beta}$1, bFGF increased hATSC's osteogenic differentiation especially when TGF-${\beta}$1 and bFGF were used together. These results suggest that adipose stromal cells with growth factors could be efficiently available for cell-based bone regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.499-503
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• 2007

Introduction: In orthognathic surgery, internal fixation has been usually done with titanium plates and screws. Recently, Biodegradable plates and screws have been frequently used but the reports of long term results of postoperative stability are rare, especially after maxillary reposition in orthognathic surgery. Objective: In order to clarify the clinical utility of self-reinforced bioresorbable poly-70L/30DL-Lactide miniplates & screws in maxillary fixation after LeFort I osteotomy, this study examined the postsurgical changes in maxilla and complications of biodegradable plates and screws. Study design: Nineteen patients who had undergone maxillary internal fixation using biodegradable plates and screws were evaluated radiographically and clinically. A comparison study of the changes in maxilla position after surgery in all 19 patients was performed with 1-week, 1-month, 3-months, 6-months and/or 1-year postoperative lateral cephalograms by tracing. Complication of the biodegradable plates and screws was evaluated by follow-up roentgenograms and clinical observation. And one-way ANOVA test was used for statistical analysis. Results: The position of the maxillary bone was stable after surgery and was not changed significantly from 1 week to 1 year after operation. And we could not find any complication of biodegradable plates and screws. Conclusions: Internal fixation of the maxilla after LeFort I osteotomy using self-reinforced biodegradable plates and screws is a reliable method for maintaining postoperative position of the maxilla after LeFort I osteotomy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.161-171
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• 2010

Introduction: This study was to assess the effectiveness of new bone formation and regeneration by using a rhBMP-2 and $\beta-TCP$ as a carrier in rabbits’mandible. Materials and Methods: The mandibles of 36 rabbits were exposed and cortical bone was penetrated for this study. The experimental subjects were divided into 3 groups each 12 rabbits ; control group, experimental group 1, and experimental group 2. Control group had the defect itself without any treatment, in the experimental group 1, $\beta-TCP$P only was grafted, and in the experimental group 2, rhBMP-2 soaked in $\beta-TCP$ was grafted. The rabbits were sacrificed after 1, 2, 3, 4, 6, and 8weeks, and new bone formation area was examined and measured for bone quantitative and qualitative analysis with light, fluorescent and polarized microscopy. Results: In the experimental group 1, new bone formation from the adjacent host bone was made by osteoconduction, and in the experimental group 2, direct new bone formation by osteoinduction of rhBMP-2 as well as new bone formation by osteoconduction of $\beta-TCP$ were observed. Conclusion: rhBMP-2 of experimental group 2 is very effective in the bone formation in early 2weeks and bone remodelling from 3weeks.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.4
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• pp.468-474
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• 2008

Purpose: Previous clinical investigations of sinus floor augmentation have demonstrated repneumatization of grafted sinus. The aim of this study is to evaluate and compare the height changes of sinus floor after grafting with deprotenized bovine bone mineral (DBBM) and beta tricalcium phosphate (TCP). Materials and methods: 34 sinuses in 28 patients were augmented with 100% DBBM or 100% TCP through lateral approaches. Sinusgraft height was measured before, immediately after, and 6 months after bone graft with panoramic radiography. Result: After 6 months, the decreases of graft heights were 14.53% for DBBM group and 15.15% for TCP group. There was no statistically significant difference. Discussion and Conclusion: Long-term stability of sinus-graft height represents an important factor for implant success. After the uses of DBBM and TCP for maxillary sinus floor augmentations, acceptable graft height maintenances were observed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.4
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• pp.475-479
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• 2008

Aim: The aim of this study was to investigate the arterial arcade of maxillary sinus by determining the distance between the alveolar crest and the inferior border of the vessels in Korean population. Materials and methods: 76 patients and 87 available sinuses were determined by CT scan (Implagraphy, Vatech, Seoul, Korea). The distance between alveolar crest and inferior border of the vessel was determined considering the tooth area of posterior maxilla. Results: The lowest distance was observed on first molar area and the average distance is 16.9 mm. Discussions: it is important in sinus lift surgery that the vessels not to be damaged and that the anastomosis is situated in the lateral wall of maxillary sinus, which has to be exposed to gain access to the maxillary sinus. The knowledge of arterial arcade of maxillary sinus is important to perform the sinus floor elevation procedure effectively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.4
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• pp.412-418
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• 2008

Bone morphogenetic proteins (BMPs) in combination with stem cells gain more significance for their use in bone tissue engineering. The mesenchymal stem cell can be differentiated into osteoblast by the treatment of BMP. The aim of this study is to characterize the osteogenic differentiation process of adult stem cells derived from buccal fat pad according to BMP-2 within culture media and decide the appropriate concentration of BMP-2 to facilitate osteogenesis. The authors procured the stem cell from buccal fat pad and analyzed for presence of stem cell by flow cytomety against CD-34, CD-105 and STRO-1. The buccal fat derived stem cells (BFDC) were treated by application of the different concentration with BMP-2 of 0, 10, 50, 100 and 200ng/ml, respectively. And their ability to differentiate into osteogenic pathway were checked by alkaline phosphatase(ALP) staining, Alizarin red staining and RT-PCR for osteocalcin(OC) gene expression at 7, 14 and 21day of culture. Flow cytometric analysis and biochemical assays demonstrated that BFDC might be a distinguished stem cells, and mineralization was accompanied in proportion to BMP-2 concentration. However, with 100ng/ml concentration of BMP-2, the BFDC demonstrated most efficient staining pattern of ALP and Alizarin red. The feasibility of the osteogenic differentiation in the group of both 50ng/ml and 200ng/ml of BMP-2 showed similar activity and relatively weaker than that of 100ng/ml. These results suggest that the BMP-2 stimulate osteogenesis by BFDC effectively and that bone induction might be controlled through negative regulatory feedback in higher concentration.