• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.3
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• pp.93-102
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• 1990

The main objectives of this study was to observe the effects of Hyperbaric oxygen therapy on the healing processes of mandibuar fracture of normal rats & streptozotocin - induced diabetic rats. Author used 120 rats (Sprague - Dawley Strain) dividing into controf (60) & experimental group (60) of normal & diabetic rats. Complete fracture was produced on the left mandibular body of 120 rats, rendered hyperbaric oxygen therapy (2 hrs, daily at 2.5 atm) on experimental group and observed effects of hyperbaric oxygen therapy microscopically. The obtained results were as follows : 1. The experimental group of HBO in normal rats had the good effect until 6th week, especially the better effect at 3rd week, because of decrease of inflammatory cell infiltration, heavy proliferation of fibroblast & capillary and active callus formation. 2. The hyperbaric oxygen therapy in mandibular fracture of diabetic rats influenced especially on the healing process at 5th week, because there were much decrease of inflammatory cell infiltrations, heavy proliferation of fibroblast, capillary, osteoblasts, moderate fibrous callus formation, osteocastic activity and mild bony callus formation.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.406-417
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• 2020

Purpose: This study investigated whether the placement of ribose cross-linked collagen (RCLC) membranes without primary soft tissue closure predictably resulted in sufficient alveolar ridge preservation in contained and non-contained extraction sockets. Methods: Membranes were positioned across extraction sockets, undermining full-thickness flaps, and the gingival margins were fixed by double-interrupted sutures without crossed horizontal mattress sutures for 1 week. In non-contained sockets, a bone substitute was used to support the membrane within the bony envelope. Radiographs and clinical images obtained 4 months later were analyzed by ImageJ software using non-parametric tests. Results: In 18 patients, 20 extraction sockets healed uneventfully and all sites received standard-diameter implants (4.1, 4.8, or 5.0 mm) without additional bone augmentation. Soft tissues and the muco-gingival border were well maintained. A retrospective analysis of X-rays and clinical photographs showed non-significant shrinkage in the vertical and horizontal dimensions (P=0.575 and P=0.444, respectively). The new bone contained vital bone cells embedded in mineralized tissues. Conclusions: Within the limitations of this pilot study, open healing of RCLC membranes may result in sufficient bone volume for implant placement without additional bone augmentation in contained and non-contained extraction sockets.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.257-265
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• 1999

To investigate the sequential changes in microvascular architecture and osseous regeneration during the bony healing after an application of the guided tissue regeneration method, we made artificial defects measuring $0.7cm{\times}0.3cm$ in size on femoral bones of rats measuring about 200gm and applied non-absorbable TEFE membrane at experimental sites but not at control sites. Then we observed the sequential changes and correlations between new vacuolation and bony regeneration using microvascular corrosion cast method and routine light microscopic observation at 1, 2 and 3 weeks after operation, respectively. The results showed that there were close relationships between regeneration of microvasculature and bone. In early phase, the invasion of granulation tissue at control sites delayed bony regeneration, however, in later phase, there was no remarkable differences in bony regeneration between control and experimental sites. The placement of barrier also affected in revascularization of regenerating bony defects. This is, the experimental sites showed parallel arranged nutritional vessels along long axis with well developed retiform plexus whereas the control revealed vertical invasion of microvasculature from outside of marrow space through bony defects which was also rearrange with time into parallel pattern with a vertical plexus but lesser organized than that of experimental sites. These findings suggest that the reconstruction of regenerating vasculature within the marrow cavity only may be sufficient and/or more be efficient in regeneration of bony defects.

• Imaging Science in Dentistry
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• v.39 no.1
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• pp.19-25
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• 2009

Purpose: To longitudinally observe the healing process of extracted socket and the alterations of the residual ridge in healthy adult dogs using cone beam CT (CBCT). Materials and Methods: The mandibular premolars of two beagle dogs were removed and the extraction sites were covered with the gingival tissue. CBCTs (3D X-ray CT scanner, Alphard vega, Asahi Co.) were taken at baseline and at 1 week interval for 12 weeks. Radiographic density of extracted wounds was measured on normalized images with a custom-made image analysis program. The amount of alveolar crestal resorption after the teeth extraction was measured with a reformatted three-dimensional image using CBCT. Bony healing pattern of extracted wound of each group was also longitudinally observed and analyzed. Results: Dimensional changes occurred during the first 6 weeks following the extraction of dogs' mandibular premolars. The reduction of the height of residual ridge was more pronounced at the buccal than at the lingual aspect of the extraction socket. Radiographic density of extracted wounds increased by week 4, but the change in density stabilized after week 6. New bone formation was observed at the floor and the peripheral side of extracted socket from week 1. The entrance of extracted socket was sealed by a hard-tissue bridge at week 5. Conclusion: The healing process of extracted wound involved a series of events including new bone formation and residual ridge resorption.

• Journal of Veterinary Science
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• v.21 no.1
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• pp.10.1-10.12
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• 2020

Blood perfusion of skeletal muscle and callus was evaluated using contrast-enhanced ultrasonography (CEUS) in a canine osteotomy model to determine the applicability of CEUS in the assessment of neovascularization during fracture healing and to compare the vascular signals on CEUS between external skeletal fixation and cast-applied dogs. In 6 Beagle dogs, a simple transverse osteotomy was performed at the left tibial shaft and external skeletal fixation (n = 3) or a cast (n = 3) was applied. Radiography, power Doppler ultrasonography (power Doppler), and CEUS were performed until complete union was achieved. On CEUS, vascular changes were quantitatively evaluated by measuring peak intensity (PI) and time to PI in the soft tissue and callus and by counting the vascular signals. Vascular signals from the soft tissue were detected on power Doppler and CEUS on day 2. Significantly more vascular signals were detected by CEUS than by power Doppler. On CEUS, PI in the surrounding soft tissue was markedly increased after the fracture line appeared indistinctively changed on radiography in all dogs. In the cast-applied dogs, vascular signals from the periosteal and endosteal callus were detected on CEUS before mineralized callus was observed on radiography. CEUS was useful in assessing the vascularity of soft tissue and callus, particularly in indirect fracture healing, and provided indications of a normally healing fracture.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.207-215
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• 2009

Purpose: The aim of the present study is to evaluate the long term bone healing after horizontal ridge augmentation using auto block bone graft for implant installation timing. Materials and Methods: Five Beagle dogs(which were 14 months old and weighted approximately 10kg). In surgery 1(extraction & bone defect), premolars(P2, P3,P4) were extracted and the buccal bone plate was removed to create a horizontally defected ridge. After three months healing, in surgery 2(ridge augmentation). Auto block bone grafts from the mandibular ramus were used in filling the bone defects were fixed with stabilizing screws. The following fluorochrome labels were given intravenously to the beagle dogs: oxytetracycline 1week after the surgery, alizarin red 4 weeks after the surgery, calcein blue 8 weeks after the surgery. The tissue samples were obtained from the sacrificed dogs of 1, 4, 8, 12, 16 weeks after the surgery. Non-decalcified sections were prepared by resin embedding and microsection to find thickness of $10{\mu}m$ for the histologic examination and analysis. Results: 1. We could achieve the successful reconstruction of the horizontal bone defect by auto block bone graft. The grafted bone block remained stable morohologically after 16 weeks of the surgery. 2. In the histologic view. We observed osteoid tissue from the sample $4^{th}$ week sample and active capillary reconstruction in the grafted bone from the $12^{th}$ week sample. Healing procedures of auto bone grafts were compared to that of the host bone. 3. Bone mineralization could be detected from the $8^{th}$ week sample. 4. Fluorochrome labeling showed active bony changes and formation at the interface of the host bone and the block graft mainly. Bony activation in the grafted bone could be seen from the $4^{th}$ week samples. Conclusions: Active bone formation and remodeling between the grafted bone and host bone can be seen through the revascularization. After the perfect adhesion to host bone, Timing of successful implant installation can be detected through the ideal ridge formation by horizontal ridge augmentation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.5
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• pp.276-283
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• 2012

Objectives: Curettage and enucleation are two of the most common procedures performed in oral and maxillofacial surgery units. To access a cystic lesion, the buccal cortical plate is removed. The no reposition (NR) group underwent surgery without repositioning the buccal cortical plate. The reposition (R) group underwent surgery with a repositioning of the buccal cortical plate. This study compared the two surgical procedures in terms of bone healing and complications. Materials and Methods: Patients who underwent curettage and enucleation surgery were enrolled in this study. Panoramic radiographs of the patients in both the NR group (n=26) and R group (n=34) were taken at the baseline and at 6, 12 and 24 months after surgery. The radiolucent area was calculated to evaluate bony healing in each radiograph. The complications were analyzed through a review of the medical records. Results: The correlation between bony healing and surgical approach was not significant in the 6th, 12th, and 24th month (P<0.05). The complication rate was not associated with gender, graft material, bone graft and drain insertion (P<0.05). On the other hand, the R group had a higher complication rate (35.3%) than the NR group (0%). The difference in the mean lesion size between the NR group ($37,024{\pm}3,617$ pixel) and R group ($92,863{\pm}15,931$ pixel) was significant (independent t test, P=0.004). Conclusion: Although the reposition method is chosen when the lesion size is large, it is associated with more complications. Indeed, infection, discomfort and recurrence of the lesion were the most common complications in the R group. Furthermore, the R method does not have a strong point in terms of bone healing compared to the NR method. Therefore, the R method cannot be considered an ideal approach and should be used in limited cases.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.1
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• pp.1-13
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• 1990

The main objectives of this study was to observe the effects of hyperbaric oxygen therapy on the healing processes of mandibular fracture of streptozotocin-induced diabetic rats. Author used 60 rats (Sprague-Dawley Strain) deviding into control(30) and experimental groups(30). Complete fracture was produced on the left mandibular body of 60rats, rendered hyperbaric oxygen therapy (2 hrs. daily at 2.5 atm.) on experimental group and observed effects of hyperbaric oxygen therapy by microscopically. The obtained results were as follows; 1. Infiltration of inflammatory cells was no significant differences between the control and experimental group until 3rd week, but experimental group showed decreasing tendency after 4th week. 2. Severe proliferation of fibroblasts showed rather rapider in experimental group, at 2nd week, while at 3rd week in control group. 3. Osteoclasts appeared at 1st week in experimental group while at 3rd week in control group, and experimental group showed early bone resorption pattern. 4. Osteoblasts appeared at 1st week in experimental group while at 3rd week in control group, and experimental group showed prominent osteoblastic activity. 5. Moderate proliferation of capillary blood vessels showed in initial stage of experimental group while mild proliferation at 1-2nd week in control group. 6. Formation of cartilaginous callus showed at 4th week in experimental group, while at 6th week in control group. 7. Formation of bony callus showed mildly at 5th week, and moderately at 6th week in experimental group, while no appearance in control group, but complete bony union was not observed even in experimental group throughout this experiment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.316-322
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• 2004

A low molecular weight component named bone morphogenetic protein(BMP) chemically isolated from the organic matrix of bone, induce postfetal connective tissue cells surrounding small blood vessels to differentiate into cartilage and bone. The end product of BMP is a spherical ossicle of lamella bone filled with red bone marrow for the functional loading. This is a important point that the graft material is embedded the defect site during the implant surgery. Because present knowledge of the relationship between BMP and bone regeneration arises mainly from studies of induced bone formation in heterotopic sites, it would be helpful to determine whether BMP plays any part in the process of bone healing. The BMPs have been shown to play crucial roles in normal skeletal development as well as bone healing and are able to activate transcription of genes involved in cellular migration, proliferation, and differentiation. The delivery of BMP on matrices has been efficacious in the treatment of defect bone in implant surgery. The purpose of the histologic study was to evaluate the effect of DLB(demineralized lyophilized bone) coated with purified human BMP(hBMP-I) in immediate implant surgery with bony defect to obtain the functional structure of implant asap. The ability of a graft of hBMP-I to accelerate bony defect repair provides a rationale for its use in immediate implant surgery that have large bone defect in edentulous area.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.1
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• pp.15-24
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• 1997

The principle of guided tissue regeneration (GTR), as applied to bone healing, is based on the prevention of connective tissue from entering the bony defect during the healing phase. This allows the slower bone producing cells to migrate into and reproduce bone within the defect. GTR has demonstrated a level of success in regenerating bone defect. Several types of membrane barrier have been utilized to apply this principle in bone regeneration. The purpose of this study was to evaluate whether improved bone regeneration can be achieved with different membrane barriers ($Gore-Tex^{TM}$membrane, $COLLACOTE^{(R)}$). In the 10 NewZealand white rabbits, full-thickness bone defects on three sites of each rabbit calvaria were made. Experimental group 1 was covered with $COLLACOTE^{(R)}$, and group 2 was covered with $Gore-Tex^{TM}$membrane. Macroscopic, microscopic examinations were made serially on 1, 2, 3, 6, 12 weeks after operation. The results were as follows : 1. Macroscopically, both of experimental group 1, 2 were filled with bone-like mass but the defects of experimental group 1 disclosed markedly thinner than the original bone. 2. Microscopically, the defect of experimental group 1, 2 was filled with bony trabeculae without infection and adverse reaction. But multinucleated giant cell infiltration around $COLLACOTE^{(R)}$ was seen till 6th week. 3. Resorption of $COLLACOTE^{(R)}$ started from 3rd week and it was completely resorped on the 12th week.