• Journal of Periodontal and Implant Science
• /
• v.50 no.2
• /
• pp.106-120
• /
• 2020

Purpose: A new form of porous polyethylene, characterized by higher porosity and pore interconnectivity, was developed for use as a tissue-integrated implant. This study evaluated the effectiveness of porous polyethylene blocks used as an onlay bone graft in rabbit mandible in terms of tissue reaction, bone ingrowth, fibrovascularization, and graft-bone interfacial integrity. Methods: Twelve New Zealand white rabbits were randomized into 3 treatment groups according to the study period (4, 12, or 24 weeks). Cylindrical specimens measuring 5 mm in diameter and 4.5 mm in thickness were placed directly on the body of the mandible without bone bed decortication, fixed in place with a titanium screw, and covered with a collagen membrane. Histologic and histomorphometric analyses were done using hematoxylin and eosin-stained bone slices. Interfacial shear strength was tested to quantify graft-bone interfacial integrity. Results: The porous polyethylene graft was observed to integrate with the mandibular bone and exhibited tissue-bridge connections. At all postoperative time points, it was noted that the host tissues had grown deep into the pores of the porous polyethylene in the direction from the interface to the center of the graft. Both fibrovascular tissue and bone were found within the pores, but most bone ingrowth was observed at the graft-mandibular bone interface. Bone ingrowth depth and interfacial shear strength were in the range of 2.76-3.89 mm and 1.11-1.43 MPa, respectively. No significant differences among post-implantation time points were found for tissue ingrowth percentage and interfacial shear strength (P>0.05). Conclusions: Within the limits of the study, the present study revealed that the new porous polyethylene did not provoke any adverse systemic reactions. The material promoted fibrovascularization and displayed osteoconductive and osteogenic properties within and outside the contact interface. Stable interfacial integration between the graft and bone also took place.

• Journal of Yeungnam Medical Science
• /
• v.13 no.1
• /
• pp.116-133
• /
• 1996

The biocompatibility of the titanium has been estabilished through various experimental studies such as cell culture toxicity test, pyrogen test, mutagen test and others. In order to confirm biocompatibility after fabrication of titanium and to clarify the difference between the bone reaction after insertion of the lathed titanium rods and the bone reaction after insertion of the finished and polished rods, both rods were implanted into the proximal femur of a rabbit. Histologic reactions in the bone were observed according to the ASTM standards at the intervals of 6 weeks, 12 weeks and 26 weeks after implantation. The result were as follows : In 6 weeks after implantation of lathed titanium rods, inflammatory reactions, such as minimal degree infiltration of polymorphonuclear leukocytes and lymphocytes were observed in all cases. This was thought to he caused by surgical trauma. However, inflammatory cell infiltration was not seen after implantation of polished and finished rods in all cases. The cellular infiltration and the histologic reaction of the hone after implantation of lathed group were significantly more pronounced than those after implantation of the finished group. In 12 weeks after implantation of lathed rods, two of four cases revealed a minimal degree of cellular infiltration. No inflammatory cell infiltration was demonstrated after implantation of the finished group. The cellular infiltration and histologic reaction seemed to be more pronounced in the lathed group, but they were not significant statistically. At 26 weeks after implantation of the lathed and finished group, there was no cellular infiltration in both groups. New bone formation was observed up 26 weeks, and no difference between lathed titanium rods and finished titanium rods were apparent. Mild bone necrosis was observed in 1 case out of 11 cases in which lathed titanium rods were implanted. Bone necrosis was not observed in the finished titanium rod group. Fibrosis was observed in both groups, but differences were not significant between the experimental groups. In the lathed titanium rods group and the shorter interval group, inflammatory cell infiltration was significantly higher. Finished titanium rods and longer interval groups had markedly decreased tendences in histologic reaction ratings. As a conclusion, although certificated titanium might be safe to use, difference of biocompatibility were observed depending on the method of surface finish. By identifying biocompatibility as a long-term standardized animal study, we can develop progressed internal fixation device that is safe for human beings.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.18 no.3
• /
• pp.448-453
• /
• 1996

This is case report of florid osseous dysplasia occurred in the entire maxilla and mandible of 47-year-old female. Florid osseous dysplasia is an expansile, exuberant asymptomatic form of benign fibro-osseous disease of the periodontal ligament, often associated with jaw cysts and to be though as an abnormal reaction of bone to irritation or stimulation. The treatment was performed with removal of the necrotic bone, bone curretage and hyperbaric oxygen therapy. The patient did not well postoperatively and has shown sign of persistant infection with pus discharge.

• The korean journal of orthodontics
• /
• v.18 no.2
• /
• pp.367-385
• /
• 1988

In case of skeletal Class III malocclusion with underdeveloped maxilla, the extraoral orthopedic force for the stimulation of maxillary growth or anterior reposition of the maxilla has been used clinically for the improvement of facial skeletal relationship. The purpose of this investigation was to examine the initial reaction of maxillofacial complex to the maxillary protraction by using extraoral orthopedic force. The dried human skull was used and this investigation was done by means of double exposure holographic interferometry. The protraction forces placed on the canine or the first molar were parallel, $10^{\circ}$ downward, $20^{\circ}$ downward to the occlusal plane. Fringe pattern of each protraction condition was compared and analized. The results were as follows: 1. Each maxillofacial bone displaced saparately. 2. More displacement was shown at the area of the teeth and the alveolar bone. 3. A counterclockwise rotation of the maxilla wa decreased by downward protraction and especially 20 degree downward protraction from the canine showed least rotation. 4. On the zygomatic arch, outward bend was observed and this effect was decreased by downward protraction. 5. On the zygomatic bone, the counter clockwise rotation was increased by the downward protraction. 6. When maxillary expansion was applied at the same time, outward and upward displacement with counterclockwise rotation was observed on the maxilla. 7. The lateral pterygoid plate of sphenoid bone was affected by maxillary protraction.

• The Journal of the Korean dental association
• /
• v.37 no.2 s.357
• /
• pp.137-145
• /
• 1999

More and more, esthetic and functional reconstruction of intra oral bone defect by trauma, pathologic disease is increasing in these days. the study about this field is going. Autogenous bone graft has advantage in biocompatyibility, but loss of donor material was relatively large. Allogenic graft has disadvantage in immunologic refusal reaction. We reconstructed several cases of periodontal, alveolar bone defects and pathologic bone defects, In all cases, we used resorbable membrane Biomesh and autogenous bone graft from retromolar triangle area, chin, torus, maxillary tuberosity, and extraction socket. From these cases, we obtained good prognosis, so we report clinical cases of Guided Tissue Regeneration with autogenous bone graft.

• The Journal of Korean Medicine
• /
• v.23 no.2
• /
• pp.190-197
• /
• 2002

Objectives : This study was performed to examine the effect of Yukmigiwhang-tang kamibang, a mixture of oriental herbal extracts, on the transcription of bone fonnation genes, BMP4 (bone morphogenetic protein 4) and TG2 (transglutaminase-2). Methods : Bone-related cells, MG-63 (human male osteosarcoma), HOS-TE85 (human female osteosarcoma), and KG-l (bone marrow) were cultured with portions of Yukmigiwhang-tang kamibang and the transcription activities of bone-related genes, BMP4 (bone morphogenetic protein 4) and TG2 (transglutaminase-2), were determined by Reverse-Transcription Polymerase Chain Reaction (RT-PCR). Results : Transcription of BMP4 gene in HOS-TE85 cell increased up to 40% at 0.3% (v/v) of Yukmigiwhang- tang kamibang extract and that of TG2 gene in MG-63 cells also increased up to 40% at 0.3-0.4% of the same extract. Although it was less significant when compared to those in other cells, the transcription of BMP4 gene in KG-l cells also increased up to 10 to 25%. Conclusions : These results clearly demonstrated that Yukmigiwhang-tang kamibang have an effect on transcription activity of bone-related genes, TG2 and BMP4, suggesting that it may play an important role in bone formation.

• Biomaterials and Biomechanics in Bioengineering
• /
• v.3 no.2
• /
• pp.71-84
• /
• 2016

The finite element method is wide used in simulation in the biomechanical structures, but a lack of studies concerning finite element mesh quality in biomechanics is a reality. The present study intends to analyze the importance of the mesh quality in the finite element model results from humeral structure. A sensitivity analysis of finite element models (FEM) is presented for the humeral bone and cartilage structures. The geometry of bone and cartilage was acquired from CT scan and geometry reconstructed. The study includes 54 models from same bone geometry, with different mesh densities, constructed with tetrahedral linear elements. A finite element simulation representing the glenohumeral-joint reaction force applied on the humerus during $90^{\circ}$ abduction, with external load as the critical condition. Results from the finite element models suggest a mesh with 1.5 mm, 0.8 mm and 0.6 mm as suitable mesh sizes for cortical bone, trabecular bone and humeral cartilage, respectively. Relatively to the higher minimum principal strains are located at the proximal humerus diaphysis, and its highest value is found at the trabecular bone neck. The present study indicates the minimum mesh size in the finite element analyses in humeral structure. The cortical and trabecular bone, as well as cartilage, may not be correctly represented by meshes of the same size. The strain results presented the critical regions during the $90^{\circ}$ abduction.

• Journal of Periodontal and Implant Science
• /
• v.39 no.1
• /
• pp.1-8
• /
• 2009

Purpose: Bisphosphonates are drugs used to suppress osteoclastic activity and to treat osteoporosis, Paget's disease of bone and bone metastasis. The purpose of this report is to review the literatures on bisphosphonates use that could affect bone healing and cause osteonecrosis of the jaws. Materials and methods: Medline research was carried out to find relevant articles on bisphosphonates and osteonecrosis of the jaw. Results: Oral administration of bisphosphonates is reported to decrease the risk of adverse bone outcomes. On the contrary, IV bisphosphonates is known to significantly increase the risk. Prevention of the osteonecrosis of the jaw is primary concern before usage. If the adverse bone reaction takes place, proper management and treatments are required to alleviate pain of patients and prevent further progression of necrosis. Conclusion: Case reports of bisphosphonates induced osteonecrosis of the jaw are increasing. Dentists and physicians should be aware of the higher frequency of osteonecrosis of the jaw in patients receiving IV bisphosphonates and be prepared to prevent and cope with adverse bone reaction.

• Journal of the Korean Ceramic Society
• /
• v.43 no.3 s.286
• /
• pp.156-161
• /
• 2006

Impedance spectroscopy was applied to the initial hydration of calcium phosphate bone cements in order to investigate the electrical/dielectric properties. Hydration or equivalently setting was monitored as a function of the amount of water and initial powder characteristics. Higher amounts of water produced more open microstructures, leading to higher conductivity and enhanced dielectric constant. The effects of the initial characteristics in the powder were investigated using bone cement powder prepared with and without granulation. Granulated powder exhibited a significant change in resistance and produced a higher dielectric constant than those of conventional powder. Through a simplified modeling, the effects of thickness in reaction products and pore sizes were estimated by the frequency-dependent impedance measurements. Furthermore, impedance spectroscopy was proven to be a highly reliable tool for evaluating the continuous change in pore structure occurring in calcium phosphate bone cements.

• The korean journal of orthodontics
• /
• v.10 no.1
• /
• pp.37-43
• /
• 1980

This study was undertaken to assess the effects of demethylchlortetracycline on bone growth of mandibular symphyseal region in rats. Demethylchlortetracycline at 30mg/kg body weight, respectively, were daily administered by mouth to the sewen female rats from 10th day of pregnancy to 13th day. Thirty six new-born rats from these experimental animals were used for histological examination at 1, 5, 10, 15, 20, 25 and 30 days. All these new-born rats were killed by an overdose of ether. Mandibular bodies were removed and fixed in $10\%$ neutral formalin,. Carney and aceton. Specimens were embedded, sectioned and stained with H-E, Van Gieson, PAS and prepared for alkaline phosphatase. The results were as follows; 1. Until erupting of incisors, hyaline cartilage was located in relatively large symphyseal space, but bone trabeculae of ossifying area at incisal side were arranged irregularly in experimental group. 2. During this period, PAS reaction was moderately positive, but alkaline phosphatase reaction was slightly positive. 3. By erupting or incisors, symphyseal space appeared narrower like control group, but alkaline phosphatase reaction tended to slow down. 4. By erupting of molars, symphyseal space appeared muck narrower, and cartilane plate was reduced and aealed off like control group. Alkaline phosphatase reaction tended to slow down severely.