• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.32 no.1
• /
• pp.23-26
• /
• 2010

The vascular changes in periodontal tissues cause local hypoxia which seems to affect the periodontal tissue cells. Abrupt changes in oxygen availability within the periodontium have been suggested to have a regulatory role in alveolar bone remodeling during tooth movement, bone growth or fracture healing. The purpose of this study was to study the effects of hypoxia on formation of osteoclast responsible for bone resorption, in vitro. Primary mouse bone marrow cells were cultured in normoxic (20% $O_2$) and hypoxic (1% $O_2$) conditions and assayed for cellular proliferation. The results obtained were as follows : 1. Reducing oxygen tension increased the formation of multinucleated osteoclasts. 2. Hypoxic stimulus increased the size of mature osteoclasts.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.27 no.2
• /
• pp.103-110
• /
• 2001

This study was performed to observe the effect of ultrasound(1.0MHz, $0.75W/cm^2\;and\;1.0W/cm^2$) irradiation on cultured MC3T3-E1 cell, osteoblastic like cell with respect to the proliferation, protein synthesis, and alkaline phosphatase activity of the cells. The results were as follows: 1. The proliferation of MC3T3-E1 cells was increased on ultrasound irradiated group compared with control group. 2. The protein synthesis was not apparently increased on ultrasound irradiated group compared with control group. 3. The alkaline phosphatase activity level was not apparently increased on ultrasound irradiated group compared with control group. From the above results and other literatures, we could suggest that the ultrasound with the appropriate intensity and frequency may have important roles in stimulation of cell proliferation. Therefore the ultrasound may be used in the acceleration of the bone regeneration and bone fracture healing.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.17 no.1
• /
• pp.46-54
• /
• 1995

Postoperative infection following orthognatic surgery is rare. When postoperative infections occur, the initial treatment consists of incision and drainage of the affected area, culturing to identify bacterial stains and verify antibiotic sensitivity, and the institution of the appropriate antibiotic regimen. Some plates and screws may eventually require removal, the initial therapy should be attempted to retain the plates and screws until adequete healing has taken place. In orthoganthic surgery, intra-operative complications as a lesion of inferior alveolar nerve, fracture of osteomised segments, incomplete sectioning, malposition of segments, haemorrhage may occur. The surgeon should be familiar with possible complications to be caused and how to manage them. Prevention of postoperative infection following the orthognathic surgery consists of minimal periosteal reflection, aseptic management of operation field, proper surgical technique, rigid fixation, prophylactic antibiotics.

• Journal of Korean Foot and Ankle Society
• /
• v.12 no.2
• /
• pp.128-134
• /
• 2008

Purpose: We evaluated the complications and failures after total ankle arthroplasty during at least 2 years short term follow up. Materials and Methods: There were 45 cases of 42 patients of HINTEGRA$^{{R}}$ (Newdeal SA, Lyon, France) model from November 2004 to August 2006. Follow up averaged at least 2 year. We evaluated the complications and analyzed the cause of the failures. Results: There were totally 15 cases of complication, 5 cases of medial impingement syndrome, 3 cases of varus malposition, 2 cases of delayed healing of wounds, and each one case of deep peroneal nerve problem, medial malleolus fracture, post-operative deep infection, gouty arthritis pain, and Achilles tendinitis. Conclusion: Total ankle arthroplasty had higher complication rate than any other joint arthroplasty, so we need a more meticulous preoperative and peri-operative care.

• The Journal of Advanced Prosthodontics
• /
• v.7 no.4
• /
• pp.329-337
• /
• 2015

PURPOSE. This retrospective study aims at the evaluation of implant-supported overdentures (IODs) supported by ceramo-galvanic double crowns (CGDCs: zirconia primary crowns + galvano-formed secondary crown). MATERIALS AND METHODS. In a private practice, 14 patients were restored with 18 IODs (mandible: 11, maxilla: 7) retained by CGDCs on 4 - 8 implants and annually evaluated for technical and/or biological failures/complications. RESULTS. One of the 86 inserted implants failed during the healing period (cumulative survival rate (CSR) implants: 98.8%). During the prosthetic functional period (mean: $5.9{\pm}2.2years$), 1 implant demonstrated an abutment fracture (CSR-abutments: 98.2%), and one case of peri-implantitis was detected. All IODs remained in function (CSR-denture: 100%). A total of 15 technical complications required interventions to maintain function (technical complication rate: 0.178 treatments/patients/year). CONCLUSION. Considering the small sample size, the use of CGDCs for the attachment of IODs is possible without an increased risk of technical complications. However, for a final evaluation, results from a larger cohort are required.

• Journal of Korean Foot and Ankle Society
• /
• v.15 no.4
• /
• pp.187-194
• /
• 2011

Ankle injuries may involve the distal tibiofibular syndesmosis and can be associated with a variable degree of trauma to the soft tissue and osseous structures that play an important role in ankle joint stability. Ankle syndesmotic injury may occur solely as a soft tissue injury or in association with variable ankle fractures. Ankle syndesmotic injury does not necessarily lead to ankle instability; however, the coexistence of deltoid ligament injury critically destabilizes the ankle joint. The prevalence of these injuries may be higher than previously reported. The diagnosis of syndesmotic injury as not always easy because isolated ankle sprains may be missed in the absence of a frank diastasis and syndesmotic instability may be unnoticed in the presence of bimalleolar ankle fractures. Controversies arise at almost every phase of treatment includings : type of fixation(screw size, type of implant), number of cortices required for fixation and of need for hardware removal. Regardless of controversies, the most important goal should be restore and maintain the normal tibiofibular relationship to allow for healing of the ligamentous structures of the syndesmosis.

• Journal of Trauma and Injury
• /
• v.26 no.3
• /
• pp.81-88
• /
• 2013

Purpose: Among patients with multiple traumatic fractures, a tendency to form more callus exists in groups with multiple fractures combined with traumatic brain injury. This retrospective study evaluated the hematologic factors that might be useful to predict callus formation by comparing serologic tests and clinical and radiologic results in two groups. Methods: From January 2000 to December 2010, patients with femur shaft fractures were divided in two groups: one without traumatic brain injury (control group: 32 cases), and the other with traumatic brain injury (study group: 44 cases). We evaluated routine serologic exams and the amount of callus formation during the follow-up period. Results: Only the alkaline phosphatase level was statistically different between the two groups, not the White blood cell count, C-reactive protein, total calcium, and lactate dehydrogenase level. The amount of callus formation on the antero-posterior radiograph at the last follow up period was 74.9% in the study group and 42.1% in the control group. Then lateral radiograph showed 73.2% callus formation rate in the study group and 31.8% in the control group. Conclusion: In routine serologic exams, the two groups had no significant differences, except for the alkaline phosphatase level. The group with traumatic brain injury had much more callus formation, but there was no reliable factor to predict callus formation on the routine serologic exam.

• Biomaterials and Biomechanics in Bioengineering
• /
• v.5 no.1
• /
• pp.37-50
• /
• 2020

Development of lightweight implant plates are important to reduce the stress shielding effect for a prosthesis of femur bone fractures. Stainless steel (SS-316L) is a widely used material for making implants. Stress shielding effect and other issues arise due to the difference in mechanical properties of stainless steel when compared with bone. To overcome these issues, composite materials seem to be a better alternative solution. The comparison is made between two biocompatible composite materials, namely Ti-hydroxyapatite and Ti-polypropylene. "Titanium (Ti)" is fiber material while "hydroxyapatite" and "polypropylene" are matrix materials. These two composites have Young's modulus closer to the bone than stainless steel. Besides the variety of bones, present paper constrained to femur bone analysis only. Being heaviest and longest, the femur is the most likely to fail among all bone failures in human. Modelling of the femur bone, screws, implant and assembly was carried out using CATIA and static analysis was carried out using ANSYS. The femur bone assembly was analyzed for forces during daily activities. Ti-hydroxyapatite and Ti-polypropylene composite implants induced more stress in composite implant plate, results less stress induced in bone leading to a reduction in shielding effect than stainless steel implant plate thus ensuring safety and quick healing for the patient.

• The Journal of the Korean bone and joint tumor society
• /
• v.13 no.2
• /
• pp.180-184
• /
• 2007

The etiology of post-traumatic, and presumably post-fracture, osteolysis of the pubic bone is unknown, although the pathological process is similar to bony destruction related to bone tumor or osteomyelitis. We have seen and wish to report one patient in whom destruction of the pubic bone was a prominent feature of the healing process following trauma.

• Journal of Veterinary Science
• /
• v.24 no.6
• /
• pp.79.1-79.16
• /
• 2023

Background: The need for a storage method capable of preserving the intrinsic properties of bones without using toxic substances has always been raised. Supercooling is a relatively recently introduced preservation method that meets this need. Supercooling refers to the phenomenon of liquid in which the temperature drops below its freezing point without solidifying or crystallizing. Objectives: The purpose of this study was to identify the preservation efficiency and applicability of the supercooling technique as a cortical bone allograft storage modality. Methods: The biomechanical effects of various storage methods, including deep freezing, cryopreservation, lyophilization, glycerol preservation, and supercooling, were evaluated with the three-point banding test, axial compression test, and electron microscopy. Additionally, cortical bone allografts were applied to the radial bone defect in New Zealand White rabbits to determine the biological effects. The degree of bone union was assessed with postoperative clinical signs, radiography, micro-computed tomography, and biomechanical analysis. Results: The biomechanical properties of cortical bone grafts preserved using glycerol and supercooling method were found to be comparable to those of normal bone while also significantly stronger than deep-frozen, cryopreserved, and lyophilized bone grafts. Preclinical research performed in rabbit radial defect models revealed that supercooled and glycerol-preserved bone allografts exhibited significantly better bone union than other groups. Conclusions: Considering the biomechanical and biological superiority, the supercooling technique could be one of the optimal preservation methods for cortical bone allografts. This study will form the basis for a novel application of supercooling as a bone material preservation technique.