• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.34 no.6
• /
• pp.377-383
• /
• 2012

Purpose: The aim of this study was to evaluate the effect of 4-hexylresorcinol and hydroxyapatite combination graft on bone regeneration in the rabbit calvarial defect model. Methods: Ten New Zealand white rabbits were used for this study. Bilateral round shaped defects (diameter: 8.0 mm) were created on the parietal bone. 4-hexylresorcinol and hydroxyapatite combination graft material was grafted into the right parietal bone defect area (experimental). The left bone defect area was not filled with anything (control). The animals were sacrificed at 4 weeks and 8 weeks after grafting. A micro-computerized tomography of each specimen was taken, and the specimens were stained for histological analysis. Results: The average value of bone mineral density (BMD) and Bone volume (BV) was higher in the experimental group than in the control group at 4 weeks and 8 weeks after surgery. However, the difference was not statistically significant (P>0.05) at 8 weeks after grafting. The BMD and BV in the experimental group at 4 weeks after surgery was significantly higher than those in the control group (P<0.05). Conclusion: 4-hexylresorcinol and hydroxyapatite combination graft material showed higher initial bone formation than the control, however, there was no difference at 8weeks after operation.

• Imaging Science in Dentistry
• /
• v.37 no.2
• /
• pp.69-77
• /
• 2007

Purpose: To evaluate the accuracy of the imaging reformation of cone beam computed tomography for the assessment of bone defect healing in rat model. Materials and Methods: Sprague-Dawley strain rats weighing about 350 gms were selected. Then critical size bone defects were done at parietal bone with implantation of collagen sponge. The rats were divided into seven groups of 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, and 8 weeks. The healing of surgical defect was assessed by multi planar reconstruction (MPR) images and three-dimensional (3-D) images of cone beam computed tomography, compared with soft X-ray radiograph and histopathologic examination. Results: MPR images and 3-D images showed similar reformation of the healing amount at 3 days, 1 week, 2 weeks, and 8 weeks, however, lower reformation at 3 weeks, 4 weeks, and 6 weeks. According to imaging-based methodologies, MPR image revealed similar reformation of the healing amount than 3-D images compare with soft X-ray image. Among the four threshold values for 3-D images, 400-500 HU revealed similar reformation of the healing amount. Histopathologic examination confirmed the newly formed trabeculation correspond with imaging-based methologies. Conclusion: MPR images revealed higher accuracy of the imaging reformation of cone beam computed tomography and cone beam computed tomography is a clinically useful diagnostic tool for the assessment of bone defect healing.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.4
• /
• pp.250-254
• /
• 2010

Introduction: This study evaluated the bone regenerative effect of silk fibroin mixed with platelet-rich fibrin (PRF) of a bone defect in rabbits. Materials and Methods: Ten New Zealand white rabbits were used for this study and bilateral round shaped defects were formed in the parietal bone (diameter: 8.0 mm). The silk fibroin mixed with PRF was grafted into the right parietal bone (experimental group). The left side (control group) was grafted only PRF. The animals were sacrificed at 4 weeks and 8 weeks. A micro-computerized tomography (${\mu}$CT) of each specimen was taken. Subsequently, the specimens were decalcified and stained for histological analysis. Results: The average value of plane film analysis was higher in the experimental group than in the control group at 4 weeks and 8weeks after surgery. However, the difference was not statistically significant.(P>0.05) The tissue mineral density (TMD) in the experimental group at 4 weeks after surgery was significantly higher than the control group.(P<0.05) Conclusion: Silk fibroin can be used as a scaffold of PRF for rabbit calvarial defect repair.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.29 no.3
• /
• pp.345-353
• /
• 2002

Bone morphogenetic proteins(BMPs) are secretory signal molecules which have a variety of regulatory functions during morphogenesis and cell differentiation. To evaluate roles of BMPs and their receptors on mouse sagittal suture development, we have examined their expression patterns in serial sections of sagittal sutures by in situ hybridization during embryonic stages(E15-E18). BMP-2 and BMP-3 were expressed in the osteogenic front and parietal bone on embryonic 15day, from E16 in hair follicle. BMP-4 was strongly expressed in the osteogenic front and weakly expressed in the mesenchyme and parietal bone. BMP-S was expressed in the hair follicles. BMP-6 was not expressed in this study. BMP-7 was expressed in parietal bone during embryonic stage. BMPR-IB was expressed in the osteogenic front, but BMPR-IA was not. From these datas, we suggest that the BMP-4 regulates the early commitment of mesenchymal cells to the osteogenic lineages, the BMP-2 and BMP-3 may be involved in regulating the differentiation of osteoblast precursor cells. BMP-7 was involved in maintenance of differentiated osteoblasts. BMPs were key signaling molecules that regulate early calvarial bone morphogenesis, mediated by BMPR-IB.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.28 no.2
• /
• pp.118-126
• /
• 2006

In oral and maxillofacial surgery, bone graft is very important procedure for functional and esthetic reconstruction. So, many researcher studied about bone graft material like autogenous bone, allograft bone and artificial bone materials. The purpose of this study is to evaluate the quantity of bone generation induced by $Grafton^{(R)}$ graft, human allogenic demineralized bone matrix. Total 24 sites of artificial bony defects prepared using trephin bur(diameter 8 mm) on parietal bone of six adult New Zealand White rabbits. Experimental group had six defect sites which grafted $Grafton^{(R)}$(0.1 cc). Active control group had nine defect sites, into which fresh autogenous bone harvested from own parietal bone was grafted and passive control group had nine defect sites without bone graft. After six weeks postoperatively, the rabbits were sacrificed. The defects and surrounding tissue were harvested and decalcified in 10% EDTA, 10% foamic-acid. Specimens were stained with H&E. New bone area percentage in whole defect area was measured by IMT(VT) image analysis program. Quantity of bone by $Grafton^{(R)}$ graft was smaller than that of autograft and larger than that of empty defects. In histologic view $Grafton^{(R)}$ graft site and autograft site showed similar healing progress but it was observed that newly formed bone in active control group was more mature. In empty defect, quantity and thickness of new bone formation was smaller than in $Grafton^{(R)}$-grafted defect. $Grafton^{(R)}$ is supposed to be a useful bone graft material instead of autogenous bone if proper maintenance for graft material stability and enough healing time were obtained.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.2
• /
• pp.217-228
• /
• 2003

Co-ordinate growth of the brain and skull is achieved through a series of tissue interactions between the developing brain, the growing bones of the skull and the sutures that unite the bones. Craniosynostosis, the premature fusion of cranial sutures, presumably involves disturbance of these interactions. Bmp2, one of bone morphogenetic proteins (Bmps), is involved in the regulation of the shapes of individual bones and the relative proportions of the skeleton. Mutations in the homeobox gene Msx2, known as a downstream gene of Bmp, cause Boston-type human craniosynostosis. The phenotype of Dlx5 homozygote mutant mouse presents craniofacial abnormalities including a delayed ossification of calvarial bone. These facts suggest important roles of Bmp2, Msx2 and Dlx5 genes in the cranial bone growth and suture morphogenesis. To elucidate the function of these molecules in the early morphogenesis of mouse cranial sutures, we first analyzed by in situ hybridization the expression of Bmp2(E15-18), Msx2 and Dlx5 genes in the developing sagittal suture of calvaria during the embryonic stage. Bmp2 mRNA was intensely expressed in the osteogenic fronts and also at the low level in the periosteum of parietal bones during embryonic stage, Msx2 mRNA was intensely expressed in the sutural mesenchyme and mildly expressed in the dura mater during the embryonic stage. Dlx5 mRNA was intensely expressed osteogenic fronts and parietal bones. To further examine the role of Bmp signaling in cranial suture, we did in vitro experiments in E15.5 mouse calvarial explants. Interestingly, implantation of Bmp2-soaked beads onto the osteogenic fronts after 48 hours organ culture resulted in the increase of the tissue thickness and cell number around Bmp2 beads, compared to BSA control beads. In addition Bmp2 induced etopic expressions of Msx2 and Dlx5 genes. On the other hand, overexpression of FGF2 did not induce the expression of Msx2 and Dlx5. Taken together, these data indicate that Bmp2 signaling molecule has a important role in regulating the cranial bone growth and early morphogenesis of cranial suture. We also suggest that Bmp signaling is involved in all the stages of osteogenesis of cranial bones and the maintenance of cranial suture by regulating Msx2 and Dlx5 genes, and that Msx2 and Dlx5 genes are specific transcription factors of Bmp signaling pathway.

• Archives of Plastic Surgery
• /
• v.32 no.6
• /
• pp.744-752
• /
• 2005

Many craniofacial and neurosurgical procedures rely on cranial bone as a bone graft. In the majority of instances, the bone heals and gives good results. But we found that if either the dura or the pericranium were missing adjacent to the cranial bone, bone absorption would be increased. We studied a single animal model, investigating the contribution of the dura and the pericranium in the process of cranial bone absorption. The animals were divided into four groups of each five animals depending on the differential blockade of the dura and/or the pericranium by silastic sheet. Bilateral $100-mm^2$, parietal bone flaps were harvested from mature rabbits. Animals were humanely killed after 12 weeks, and histomorphometric analysis was performed. The volume maintenance is as follows; Group I; 89.0%, Group II; 80.0%, Group III; 63.3%, Group IV; 52.4%. The weight maintenance; Group I; 87.1%, Group II; 79.4%, Group III; 61.6%, Group IV; 51.1%. The histological contribution of living bone; Group I; 92.9%, Group II; 85.6%, Group III; 71.1%, Group IV; 56.2%. Significantly increased bone absorption occurred in Group II, III, IV compared with Group I. Conclusions are: 1. Cranial bone absorption is effected by both the dura and the pericranium. 2. The dura is more important than the pericranium in preventing cranial bone absorption. 3. The dura to be the source of central cranial bone and the pericranium to be the source of peripheral cranial bone.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.1
• /
• pp.78-80
• /
• 2001

The bone formation accompanied with other diseases in brain has been rarely reported. Furthermore, it has not been reported without any specific disease. We report a case of a 27 year old female who was referred to our hospital because of the incidentally found calcified lesion in plain X-ray of the skull. The CT and MRI of the brain showed a calcification with minimal enhancement at left parietal area. The calcified lesion was removed and biopsy was performed with stereotactic guided craniotomy. Pathologically, the lesion was confirmed as the membranous bone which was composed of bony trabeculations with osteocytes and the biopsy from adjacent area to the bone revealed a gliosis without any other disease.

• Journal of Korean Neurosurgical Society
• /
• v.63 no.6
• /
• pp.821-826
• /
• 2020

Objective : Hyperostosis in meningiomas can be present in 4.5% to 44% of cases. Radical resection should include aggressive removal of invaded bone. It is not clear however to what extent bone removal should be carried to achieve pathologically free margins, especially that in many cases, there is a T2 hyperintense signal that extends beyond the hyperostotic bone. In this study we try to investigate the perimeter of tumour cells outside the visible nidus of hyperostotic bone and to what extent they are present outside this nidus. This would serve as an initial step for setting guidelines on dealing with hyperostosis in meningioma surgery. Methods : This is a prospective case series that included 14 patients with convexity meningiomas and hyperostosis during the period from March 2017 to August 2018 in two university hospitals. Patients demographics, clinical, imaging characteristics, intraoperative and postoperative data were collected and analysed. In all cases, all visible abnormal bone was excised bearing in mind to also include the hyperintense diploe in magnetic resonance imaging (MRI) T2 weighted images after careful preoperative assessment. To examine bony tumour invasion, five marked bone biopsies were taken from the craniotomy flap for histopathological examinations. These include one from the centre of hyperostotic nidus and the other four from the corners at a 2-cm distance from the margin of the nidus. Results : Our study included five males (35.7%) and nine females (64.3%) with a mean age of 43.75 years (33-55). Tumor site was parietal in seven cases (50%), fronto-parietal in three cases (21.4%), parieto-occipital in two cases (14.2%), frontal region in one case and bicoronal (midline) in one case. Tumour pathology revealed a World Health Organization (WHO) grade I in seven cases (50%), atypical meningioma (WHO II) in five cases (35.7%) and anaplastic meningioma (WHO III) in two cases (14.2%). In all grade I and II meningiomas, bone biopsies harvested from the nidus revealed infiltration with tumour cells while all other bone biopsies from the four corners (2 cm from nidus) were free. In cases of anaplastic meningiomas, all five biopsies were positive for tumour cells. Conclusion : Removal of the gross epicentre of hyperostotic bone with the surrounding 2 cm is adequate to ensure radical excision and free bone margins in grade I and II meningiomas. Hyperintense signal change in MRI T2 weighted images, even beyond visible hypersototic areas, doesn't necessarily represent tumour invasion.

• Archives of Craniofacial Surgery
• /
• v.19 no.3
• /
• pp.200-204
• /
• 2018

Fibrous dysplasia (FD) is a rare, benign bone disease with abnormal bone maturation and fibroblastic proliferation. Optimal treatment of zone 1 craniofacial FD is radical resection and reconstruction. To achieve of structural, aesthetic, and functional goals, we use three-dimensionally designed calvarial bone graft for reconstruction of zygomatic defect after radical resection of FD. The authors used a rapid-prototyping model for simulation surgery for radical resection and immediate reconstruction. Donor site was selected from parietal bone reflect shape, contour, and size of defect. Then radical resection of lesion and immediate reconstruction was performed as planned. Outcomes were assessed using clinical photographs and computed tomography scans. Successful reconstruction after radical resection was achieved by three-dimensional calvarial bone graft without complications. After a 12-month follow-up, sufficient bone thickness and symmetric soft tissue contour was well-maintained. By considering three-dimensional configuration of zygomaticomaxillary complex, the authors achieved satisfactory structural, aesthetic and functional outcomes without complications.