• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.6
• /
• pp.666-671
• /
• 2000

Objectives: This study evaluated the availability of mandibular symphysis corticocancellous block grafts in patients treated for reconstruction of intraoral jaw defects. Materials & Methods: 8 patients with mandibular and maxillary bony defects were treated with corticocancellous block of symphysis. The types of defects included 4 pathologic jaw defects and 4 vertical and/or horizontal alveolar deficiencies. The age ranged from 13 to 45 years. Additional treatments such as plate fixation, alloplastic bony substitutes, and/or barrier membrane application were perfomred. They were evaluated for complications and healing of defects. Follow-up period ranged from 6 to 15 months. Results: 2 patients experienced complications such as wound dehiscence and mild resorption of exposed bone. None of the patients needed secondary operation. Paresthesia of lip, chin, and teeth were recovered completely by 6 months postoperatively. Reconstructed wound showed favorable healing and bony consolidation. Conclusion: Corticocancellous block of mandibular symphysis can be used for the reconstruction of a variety of intraoral local jaw defects selectively. Advantages were easy fixation of graft, possibility of restoration of original alveolar contour, and decreased donor site morbidity.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.6
• /
• pp.620-627
• /
• 2000

The purpose of this study is to investigate the clinical and histologic changes in distraction osteogenesis according to different distraction rates in the rat's tibia. Eighteen adult rats underwent open osteotomy and attachment of an external unilateral distraction device in the middle of left tibia. Latency was allowed for 7 days before distracton began. The distraction device was activated with varying distraction rates of 0.5mm, 1mm, 2mm and same rhythm of twice a day until 5mm length gain was achieved. The animals were sacrificed at post-distraction 4, 8 weeks to observe the bony healing states. At each group, clinical, radiographic and histologic studies were done. The results obtained from this study were as follows: 1. The 0.5mm group showed excellent osteogenesis than other groups. The new bone was formed by intramembranous bone formation mostly and endochondral bone formation partly. 2. The 1mm group showed delayed osteogenesis and incomplete bony healing at 8 weeks. 3. The 2mm group showed weak osteogenesis and fibrous union or nonunion at 8 weeks. From these results, it could be stated that distraction rate of 0.5mm per day was most useful in rat's tibia. The rate of 1mm showed delayed bony healing and needed more consolidation period. Distraction osteogenesis is a excellent clinical method for regenerating local bone deficiencies in limbs and craniofacial area. The more studies needed for the higher animals and human about distraction rates and other biomechanical factors on the basis of this study.

• Imaging Science in Dentistry
• /
• v.32 no.4
• /
• pp.201-206
• /
• 2002

Purpose : To evaluate the radiographic change of operation sites after orthognathic surgery using the digital image processing and fractal analysis. Materials and Methods : A series of panoramic radiographs of thirty-five randomly selected patients who had undergone mandibular orthognathic surgery (bilateral sagittal split ramus osteotomy) without clinical complication for osseous healing, were taken. The panoramic radiographs of each selected patient were taken at pre-operation (stage 0), 1 or 2 days after operation (stage 1), 1 month after operation (stage 2), 6 months after operation (stage 3), and 12 months after operation (stage 4). The radiographs were digitized at 600 dpi, 8 bit, and 256 gray levels. The region of interest, centered on the bony gap area of the operation site, was selected and the fractal dimension was calculated by using the tile-counting method. The mean values and standard deviations of fractal dimension for each stage were calculated and the differences among stage 0, 1, 2, 3, and 4 were evaluated through repeated measures of the ANOVA and paired t-test. Results : The mean values and standard deviations of the fractal dimensions obtained from stage 0, 1, 2, 3, and 4 were 1.658±0.048, 1.580±0.050, 1.607±0.046, 1.624±0.049, and 1.641 ±0.061, respectively. The fractal dimensions from stage 1 to stage 4 were shown to have a tendency to increase (p < 0.05). Conclusion: The tendency of the fractal dimesion to increase relative to healing time may be a useful means of evaluating post-operative bony healing of the osteotomy site.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.18 no.4
• /
• pp.746-757
• /
• 1996

Bony defects may be found as a result of congenital anomalies, traumatic injury, automobile collisions and industrial accidents in the maxillofacial area. Such conditions are often associated with severs functional and esthetic problem. Various surgical procedure has been utilized in attempts to repair and reconstruct bony defects. Bone is a complex, living, constantly changing tissue. The architecture and composition of cancellous and cortical bone allow the skeleton to perform its essential mechanical functions. Periosteum covers the external surface of bone and consists of two layers : an outer fibrous layer and an inner more cellular and vascular layer. The inner osteogenic layer or cambium layer can form new bone while the outer layer firms part of the insertions of tendons, ligaments and muscles. This study was under taken to evaluate bone healing process on partial defect of calvarial bone with or without periosteum in rat. We made calvarial defects of different size(4mm, 6mm, 8mm) with periosteum or without periosteum in rat to study the effect of defect size on healing process. Control and experimental groups sacrified at 1, 2, 4, 6, 8 weeks, postoperatively. We examed the specimens by gloss findings, light microscophy, and fluorescent microscophy. The results were as follows. 1. Gloss findings: Control groups are larger bony defects than experimental groups after 2 weeks, and than control groups advanced healing of defected bone but experimental groups are lesser after 4, 6 weeks. After 8 weeks, bone defect has not been identified in control and experimental groups. 2. Light microscope: All defects of control groups are larger bony defects than experimental groups after 2 weeks. And than control groups show smaller defect after 4 weeks. After 8 weeks, the control group reveal pin-point sized, hardly identifiable defect space and the experimental group reveal small, but definite defect space. 3. Fluorescent microscope : Each week, new bone formation of control group is very similar to the experimental group. In this study, Osteogenesis of calvarial bone defects with periosteum or without periosteum was examined for 8 weeks in rats. The replaced periosteum had batter new bone formation than the removed periosteum.

• The Journal of Korean Academy of Prosthodontics
• /
• v.30 no.3
• /
• pp.361-378
• /
• 1992

The purpose of this investigation was to evaluate the effect of the porous hydroxyapatite particles (Interpore $200^{(R)}$) and guided tissue regeneration membrane ($Gore-Tex^{TM}$ augmentation material) on amount and shape of generating new bone adjacent to implant. Implants were placed immediately after extraction in the bilateral 3rd, 4th premolars of the mandible of the adult dogs. In all experimental groups, artificial bony defects were formed at the buccal cortex area, 3.3mm in width and 3.0mm in depth. In the control group : sutured without HA particles & membranes after placing implants, the experimental group 1 : membrane was place over the artificial bony defect, the experimental group 2 : bony defect was filled with HA particles and covered with membrane. The examination of bone-implant interfaces using light microscope and fluorescent microscope concluded as follows. 1. In all three experimental groups, osseointegration was observed without epithelial migration. 2. In the healing degree of bony defect area, the experimental group 1, 2 showed more prominent healing than control group, and the experimental group 1 showed the most excellent bone formation. 3. In fluorescent microscopic finding, bone remodeling was observed in regenerated bone tissue at defect area of experimental group 1, but in experimental group 2, irregular, discontinuous linear fluorescence was observed at the lower portion of defect area and sign of bone remodeling was weak.

• Restorative Dentistry and Endodontics
• /
• v.41 no.4
• /
• pp.310-315
• /
• 2016

Two case reports describing a new technique of creating a repositionable piezoelectric bony window osteotomy during apicoectomy in order to preserve bone and act as an autologous graft for the surgical site are described. Endodontic microsurgery of anterior teeth with an intact cortical plate and large periapical lesion generally involves removal of a significant amount of healthy bone in order to enucleate the diseased tissue and manage root ends. In the reported cases, apicoectomy was performed on the lateral incisors of two patients. A piezoelectric device was used to create and elevate a bony window at the surgical site, instead of drilling and destroying bone while making an osteotomy with conventional burs. Routine microsurgical procedures - lesion enucleation, root-end resection, and filling - were carried out through this window preparation. The bony window was repositioned to the original site and the soft tissue sutured. The cases were re-evaluated clinically and radiographically after a period of 12 - 24 months. At follow-up, radiographic healing was observed. No additional grafting material was needed despite the extent of the lesions. The indication for this procedure is when teeth present with an intact or near-intact buccal cortical plate and a large apical lesion to preserve the bone and use it as an autologous graft.

• Journal of Periodontal and Implant Science
• /
• v.29 no.3
• /
• pp.553-560
• /
• 1999

The aim of the present study was to evaluate the effect of the expanded polytetrafluoroethylene (e-PTFE) membrane exposure on the initial healing of the periodontal tissue in guided tissue regeneration (GTR) procedure. 90 sites selected from 90 patients were treated with gingival flap surgery supported by an e-PTFE membrane. The material included angular bony defects with probing attachment loss of > 5mm or degree II furcation involvement. Treated sites were classified with membrane exposure group and non-exposure group at membrane removal and evaluated healing type. The results were obtained as follows. 1. e-PTFE membrane was exposed at 61 sites (67.8%) among 90 sites. 2. Thirteen sites (14.4%) depicted rapid healing type, 65 sites (72.2%) depicted typical healing type, 9 sites (10%) showed delayed healing type and 3 sites (3.3%) were categorized as adversed healing type. 3. In e-PTFE membrane exposure group, 1 site (1.6%), 51 sites (83.6%), 6 sites (9.8%) and 3 sites (4.9%) showed rapid healing type, typical healing type, delayed healing type and adverse healing type respectively. 4. In e-PTFE membrane non-exposure group, 12 sites (41.3%), 14 sites (48.3%) and 3 sites (10.3%) showed rapid healing type, typical healing type and delayed healing type respectively. Adverse healing type was not observed. 5. The rate of favourable healing between e-PTFE membrane exposure group and non-exposure group was not statistically significant(p=0.56). These results suggest that the prevention of membrane exposure may be important to obtain rapid healing type. However favourable healing could be obtained with stringent infection control program even if membrane was exposed.

• Journal of Periodontal and Implant Science
• /
• v.32 no.1
• /
• pp.161-172
• /
• 2002

The present study evaluated the effects of guided tissue regeneration using xenograft material(deproteinated bovine bone powder), with and without biodegradable membrane in beagle dogs. Contralateral fenestration defects (6 ${\times}$ 4mm) were created 4 mm apical to the buccal alveolar crest of maxillary premolar teeth in 5 beagle dogs. Deproteinated bovine bone powders were implanted into fenestration defect and one randomly covered biodegradable membrane (experimental group). Biodegradable membrane was used to provide GTR. Tissue blocks including defects with soft tissues which were harvested following four & eight weeks healing interval, prepared for histo-phathologic analysis. The results of this study were as follows. 1. In control group, at 4 weeks after surgery, new bony trabecular contacted with interstitial tissue and osteocytes like cell were arranged in new bony trabecule. Bony lamellation was not observed. 2. In control gruop, at 8 weeks after surgery, scar-like interstitial tissue was filled defect and bony trabecule form lamellation. New bony trabecular was contacted with interstitial tissue but defect was not filled yet. 3. In experimental group, at 4 weeks after surgery, new bony trabecular partially recovered around damaged bone. But new bony trabecular was observed as irregularity and lower density. 4. In experimental group, at 8 weeks after surgery, lamella bone trabecular developed around bone cavity and damaged tissue was replaced with dense interstitial tissue. In conclusion, new bone formation regenerated more in experimental than control groups and there was seen observe more regular bony trabecular in experimental than control groups at 4 weeks after surgery. In control group, at 8 weeks after surgery, the defects was filled with scar-like interstitial tissue but, in experimental group, the defects was connected with new bone. Therefore xenograft material had osteoconduction but could not fill the defects. We thought that the effective regeneration of periodontal tissue, could be achieved using GTR with biodegradable membrane.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.35 no.3
• /
• pp.158-163
• /
• 2009

Objective : Recently, we are interested in bisphosphonate related osteonecrosis of the jaw (BRONJ). Most of patients with osteonecrosis have taken medicine bisphosphonate for a long time. But the mechanism of osteonecrosis in BRONJ was not clarified yet. The aim of this study is to evaluate the difference of bone healing effect after bone graft from ilium to maxillary sinus in rabbits between zoledronate-treated and zoledronate-not treated groups. Method : The subjects was divided into two groups. The experimental group was 9 rabbits, treated with intraperitoneal administration of zoledronate(0.06mg/kg) once per week for 3 weeks. In control group, same procedure was applied but administerd saline instead of zoledronate. After 4 weeks, surgical operation under local anesthesia (ketamine 3.0cc, xylazine 1.0cc) was done. At postoperative 1, 2, 4, 8 weeks later, each rabbits were sacrificed and removed the bone grafted area. Gross, radiologic and histopathologic exminations of bone grafted area were performed. Result : There were no conspicuous differences of radiological findings between experimental and control groups in any experimental weeks. In experimental group, new bone formation appeared earlier than control group at 1 week after operation, and maturation of bony tissue were more conspicuous at 2 and 4 weeks after operation, compared with control group. In 8 weeks after operation, similar microscopic findings were noted in both groups. Conclusion : In the bisphosphonate-treated rabbits, new bone formation in the bone grafted area appeared earlier and bony maturation was more concpicuous, even though there were no significant differences of gross and radiological findings. These findings suggest that bisphosphonate might be promotive effect in the healing process in early stage after administration.

• Archives of Hand and Microsurgery
• /
• v.23 no.4
• /
• pp.248-253
• /
• 2018

Purpose: The purpose of this study was to evaluate the clinical results of anatomic reduction of bony mallet finger using modified-intrafocal pinning technique. Methods: From March 2014 to October 2017, 18 patients with bony mallet finger were treated with modified-intrafocal pinning technique. Kirschner-wire was used to directly reduction the bony fragment, and extension block pinning and distal interphalangeal joint fixation were additionally performed to minimize the loss of reduction. Postoperative pain, range of motion, and radiological evaluation were performed. Duration of bone healing, functional recovery and complication rate were evaluated and Crawford's criteria was used to determine functional outcome after surgery. Results: Bone union was achieved in all cases after a postoperative mean of 6 weeks (5-7 weeks). An average of $2.8^{\circ}$ ($0^{\circ}-10^{\circ}$) extension loss occurred in all patients. All patients showed satisfactory joint congruency and reformation of the joint surface, the mean flexion angle of the distal interphalangeal joint at the final follow-up was $72.2^{\circ}$ ($70^{\circ}-75^{\circ}$). According to Crawford's classification, 12 patients (66.7%) were excellent and 6 patients (33.3%) were good. Conclusion: Modified-intrafocal pinning technique is a method of obtaining anatomical bone healing by directly reduction and fixation of the bony fragment. Combined with other conventional percutaneous pinning procedures, it is expected that good results can be obtained if applied to appropriate indications.