• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.6
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• pp.570-575
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• 2001

This study evaluated the short-term outcome of treating fractures of the mandible with bioabsorbable plates. Thirty-four fractures of the mandible in 27 patients were treated by open reduction and internal fixation using bioabsorbable plates and 2.4-mm, 2.0-mm, and 1.5-mm pre-tapped screws. The duration of intermaxillary fixation ranged from 0 to 23 days, with a mean of 5.3 days. Patients were evaluated for complications during the follow-up period, which ranged from 2 to 18 months. Five patients(18.5%) experienced complications. These included infection (four patients), and premature occlusal contact(one patient). Except for one case, all complications were minor and adequately managed with incision and drainage, elastic traction, and medication. Delayed infection (osteomyelitis) developed in a symphysis fracture and was treated by saucerization and antibiotics. The fracture line subsequently showed complete consolidation. Bioabsorbable plates can be selectively used for internal fixation in mandibular fractures with the advantage that they do not need to be removed.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.1
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• pp.159-170
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• 1995

Few cases of florid osseous dysplasia has been described as a condition that characteristically affects the jaws. It usually manifests as multiple radiopaque masses distributed throughout the jaws. Confusion exists about the relationship of florid osseous dysplasia, gigantiform cementoma, chronic sclersing osteomyelitis, sclerosing osteitis or multiple enostosis. Authors experienced a case of florid osseous dysplasia of the jaws in 52-year-old female on the basis of clinical, radiographic and histopathologic findings. The characteristic features are as follows : 1. In clinical examination, there was no clinical sign and symptoms except extracted area. And there was no facial asymmetry. 2. Radiograms show round or lobular dense radiopaque masses surrounded by radiolucent bands in lower molar teeth area bilaterally. And slight increased radiopacities in maxillary molar teeth area bilaterally. There was no expansion or thinning of buccal and lingual cortical bones. There is no displacement or resorption of involved teeth. In right side of mandible, mandibular canal is displaced inferiorly due to mass. 3. Photomicrograms show densely mineralized sclerotic acellular masses with empty lacunae. Pattern is suggestive of cementum, although it could be considered sclerotic bone. In the periphery, lesion consisting of moderately cellular fibrous tissue in which globular calcified products are deposited.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.359-365
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• 2014

Successful results of treatments using double crown prostheses for the partially edentulous patients who have a few remaining teeth have been reported in several journals. A double crown removable partial denture can be an alternative treatment for the patients with a poor periodontal condition of remaining teeth. Since a double crown removable partial denture can be applied without the risk of surgical operation to the medically compromised patients with a poor periodontal condition which is inadequate for dental implants, it has psychological and economical advantages. In this case, there were sufficient remaining teeth to be restored with fixed prostheses in maxilla, while there were a few remaining teeth with a very poor periodontal condition so that it was almost impossible to restore with a clasp removable partial denture using these remaining teeth in mandible. In addition, the patient had the medical history of surgical operation due to osteomyelitis in the mandibular anterior areas a year ago, thus difficult to conduct an implant placement. The main objective of this report is to introduce our case because a double crown partial denture using a few mandibular remaining teeth showed satisfactory results in functional and esthetical aspects during more than two years follow-up period in this unfavorable condition.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.27.1-27.8
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• 2018

Purpose: Various complications occur when a maxillofacial fracture is malunionized or improperly resolved. Malocclusion is the most common complication, followed by facial deformity, temporomandibular joint disorder (TMD), and neurological symptoms. The purpose of this study was to evaluate the dental treatment of postoperative complications after maxillofacial fracture. Materials and methods: In this study, nine patients with a postoperative complication after maxillofacial fracture who had been performed the initial operation from other units and were referred to the authors' department had been included. Of the nine patients, six had mandibular fractures, one had maxillary fractures, one had maxillary and mandibular complex fractures, and one had multiple facial fractures. All the patients had tooth fractures, dislocations, displacements, and alveolar bone fractures at the time of trauma, but complications occurred because none of the patients underwent preoperative and postoperative dental treatment. Malocclusion and TMD are the most common complications, followed by dental problems (pulp necrosis, tooth extrusion, osteomyelitis, etc.) due to improper treatment of teeth and alveolar bone injuries. The patients were referred to the department of dentistry to undergo treatment for the complications. One of the nine patients underwent orthognathic surgery for a severe open bite. Another patient underwent bone reconstruction using an iliac bone graft and vestibuloplasty with extensive bone loss. The other patients, who complained of moderate occlusal abnormalities and TMDs such as mouth-opening limitation, underwent occlusal treatment by prosthodontic repair and temporomandibular joint treatment instead of surgery. Results: One patient who underwent orthognathic surgery had complete loss of open bite and TMD after surgery. One patient who underwent reconstruction using an iliac bone graft had a good healing process. Other patients were treated with splint, injection, and physical therapy for mouth-opening limitation and temporomandibular joint pain. After treatment, the TMDs were resolved, but the remaining occlusal abnormalities were resolved with prosthetic restoration. Conclusions: Considering the severity of malocclusion and TMJ symptom and the feasibillity of reoperation, nonsurgical methods such as orthodontic and prosthodontic treatments and splint therapy can be used to manage the dental and TMD complication after the trauma surgery. However, reoperation needs to be strongly considered for severe malocclusion and TMD problem.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.4
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• pp.240-249
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• 2020

Objectives: Although the side effects of radiation therapy vary from mucositis to osteomyelitis depending on the dose of radiation therapy, to date, an experimental animal model has not yet been proposed. The aim of this study was to develop an animal model for assessing complications of irradiated bone, especially to quantify the dose of radiation needed to develop a rat model. Materials and Methods: Sixteen Sprague-Dawley rats aged seven weeks with a mean weight of 267.59 g were used. Atraumatic extraction of a right mandibular first molar was performed. At one week after the extraction, the rats were randomized into four groups and received a single dose of external radiation administered to the right lower jaw at a level of 14, 16, 18, or 20 Gy, respectively. Clinical alopecia with body weight changes were compared and bony volumetric analysis with micro-computed tomography (CT), histologic analysis with H&E were performed. Results: The progression of the skin alopecia was different depending on the irradiation dose. Micro-CT parameters including bone volume, bone volume/tissue volume, bone mineral density, and trabecular spaces, showed no significant differences. The progression of osteoradionecrosis (ORN) along with that of inflammation, fibrosis, and bone resorption, was found with increased osteoclast or fibrosis in the radiated group. As the radiation dose increases, osteoclast numbers begin to decrease and osteoclast tends to increase. Osteoclasts respond more sensitively to the radiation dose, and osteoblasts are degraded at doses above 18 Gy. Conclusion: A standardized animal model clinically comparable to ORN of the jaw is a valuable tool that can be used to examine the pathophysiology of the disease and trial any potential treatment modalities. We present a methodology for the use of an experimental rat model that incorporates a guideline regarding radiation dose.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.3
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• pp.191-196
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• 2020

Objectives: Beyond the original application approved by the U.S. Food and Drug Administration, recombinant human bone morphogenetic protein-2 (rhBMP-2) is used for medication-related osteonecrosis of the jaw (MRONJ) treatment because of its bone remodeling enhancement properties. The purpose of the study was to investigate the bone formation effect of rhBMP-2/absorbable collagen sponge (ACS) in patients with MRONJ. Materials and Methods: In this retrospective cohort study, 26 female patients diagnosed with MRONJ and who underwent mandibular sequestrectomy at Ajou University Dental Hospital from 2010 to 2018 were included. The experimental group was composed of 18 patients who received rhBMP-2/ACS after sequestrectomy, while the control group was composed of 8 patients who did not receive rhBMP-2/ACS after sequestrectomy. A total dose of 0.5 mg of rhBMP-2 was used in the experimental group at a concentration of 0.5 mg/mL. Follow-up panoramic X-rays were taken immediately after the surgery and more than 6 months after the surgery. Using those X-rays, a radiographic index of bone defect area was calculated using the modified Ihan Hren method, which measures radiographic density of the normal bone and the defect site. Results: This study suggests that rhBMP-2 contributes to new bone formation. The mean radiographic index immediately after surgery and more than 6 months after the surgery for the experimental group was 68.4% and 79.8%, respectively. The mean radiographic index immediately after surgery and more than 6 months after the surgery for the control group was 73.4% and 76.7%, respectively (Wilcoxon signed rank test, P>0.05). The mean radiographic index increased 11.4% in the experimental group and 3.27% in the control group (Mann-Whitney U-test, P<0.05). Conclusion: Based on the results, use of rhBMP-2/ACS on bone defect sites after sequestrectomy could be a successful strategy for treatment of MRONJ patients.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.5
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• pp.403-414
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• 2005

The purpose of this study was to identify the effectiveness of the modified distraction osteogenesis (DO) method with the concept of overdistraction and compression stimulation which have been previously suggested by the authors in 2002 and to explore the optimal distraction-compression ratio and appropriate latency period for the compression force application during consolidation. The experimental specimens were assessed with radiography, histologic findings, and dual energy x-ray absorptiometry (DEXA) after the conventional DO method and the modified DO technique had been applied on rat mandibles. Total 60 rats were used for the study. In experimental group of 54 adult rats, mandibular osteotomies between the first and second molar areas were performed and customized external distractors were applied. The surgeries on 6 rats of control group also were done with same osteotomy technique and DO device application. Final amount of distraction was set-up as 2 mm on both groups. But, in a experimental group of 54 rats, distraction osteogenesis with a compression force were performed with the different distraction-compression ratio and variant latency periods for compression. The three ratio-subgroups were made as distraction 4 mm group with compression 2 mm, distraction 3 mm group with compression 1 mm, and distraction 2.5 mm group with compression 0.5 mm. In addition, The three subgroups with 3, 7, 11 days latency period prior compression were allocated on each ratio-subgroups. Total 9 subgroups consisted of 6 rats on each subgroup. In control group of 6 rats, conventional distraction technique were routinely performed. The rats of control groups were sacrificed on postoperative 3, 6 weeks after 2 mm distraction. The rats in the experimental groups also were sacrificed on the same euthanasia days of control groups to compare the wound healing. Final available specimens were 55 rats except 5 due to osteomyelitis, device dislodgement. Distraction-compression combined group on 6 weeks generally had showed increased bone mineral density than the same period group of conventional distraction technique on the DEXA study. More matured lamellar bone state and extended trabecular pattern in the combined group than those of control group were also observed in the histologic findings on 6 weeks. In the distraction-compression combined groups, the bone density of 2.5 mm distraction subgroups with 0.5 mm compression showed the highest value on the DEXA study among various force ratio groups. In the distraction-compression combined groups, the bone density of 3 day latency period subgroups showed the highest value on the DEXA study among various latency period groups for the compression application. From this study, we could deduce that 1/5 force ratio for the compression versus distraction, 3 day latency period prior compression application would be the most effective condition if modified distraction osteogenesis technique might be applicable. The modified DO method with a compression force may improve the quality of bone regenerate and shorten total treatment period in comparison with conventional DO technique clinically.