• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.5
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• pp.337-342
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• 2012

The osseous or osteocutaneous free fibula flap has become the gold standard for most mandibular reconstructions because of its favorable osseous characteristics. However, disadvantages, such as the time-consuming reconstructive step, difficulty in performing the osteotomies to precisely recreate the shape of the missing segment of mandible and poor bone-to-bone contact play a role in making the surgeons look for alternative flaps. With the advent of computerized design software, which accurately plans complex 3-dimensional reconstructions, has become a process that is more efficient and precise. However, the ability to transfer the computerized plan into the surgical field with stereolithographic models and guides has been a significant development in advancing reconstruction in the maxillofacial regions. The ability to "pre-plan" the case, mirror and superimpose natural structures into diseased and deformed areas, as well as the ability to reproduce these plans with good surgical precision has decreased overall operative time, and has helped facilitate functional and esthetic reconstruction. We describe a complex case treated with this technique, showing the power and elegance of computer assisted maxillofacial reconstruction from the University of Michigan, Oral and Maxillofacial Surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.2
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• pp.84-89
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• 2015

We report the eventually successful treatment of a huge bone defect and peri-implantitis following reconstruction of a previously failed intra-mobile cylinder implant system (IMZ) implant site using distraction osteogenesis (DO). In the anterior mandible, two IMZ implants failed and surgical debridement was performed in accordance to the patient's needs. Thereafter, mobility and suppuration were decreased and the patient visited the dental clinic on a regular basis for oral health maintenance. However, the inflammation did not resolve, and the bone destruction around the implants progressed for 4 years. Finally, the implants failed and a severe bone defect remained after implant removal. To reconstruct the bone defects, we attempted bone graft procedures. Titanium mesh was unsuccessfully used to obtain bone volume regeneration. However, DO subsequently was used to obtain sufficient bone volume for implant placement. The new implants were then installed, followed by prosthetic procedures. In conclusion, progression of peri-implantitis could not be arrested despite surgical intervention and repeated maintenance care for 3 years. Reconstruction of the peri-implantitis site was complicated due to its horizontal and vertical bone defects. Lesions caused by implant failure require an aggressive regenerative strategy, such as DO. DO was successful in reconstruction of a peri-implantitis site that was complicated due to horizontal and vertical bone defects.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.1
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• pp.104-109
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• 1991

Loss of mandibular continuity due to neoplasm, trauma, or infection results in major esthetic and biologic compromise. The use of costochondral grafts for reconstruction of temporomandibular joint, described first by Gillies in 1920, has been accepted as a suitable method for replacing the mandibular condyle, especially in growing children. Autogenous iliac bone graft has been a satisfactory source of mandibular reconstruction since Sykoffs report in 1900. Autogenous bone grafts from the posterior aspects of the ilium provide large amount of PMCB with acceptable donor site morbidity. In timing of reconstruction, initial disease, age, medical history, growth and development, esthetic and psychologic factors should be considered. We present a case of osteosarcoma in the mandible that was treated by a hemimandibulectomy and the defect was reconstructed 20 months later with composite method of costochondral and posterior iliac bone graft.

• Imaging Science in Dentistry
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• v.54 no.2
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• pp.129-137
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• 2024

Purpose: Patients with head and neck cancer (HNC) who undergo dental procedures during radiotherapy (RT) face an increased risk of developing osteoradionecrosis (ORN). Accordingly, new tools must be developed to extract critical information regarding the dose delivered to the teeth and mandible. This article proposes a novel approach for visualizing 3-dimensional planned dose distributions on panoramic reconstruction computed tomography (pCT) images. Materials and Methods: Four patients with HNC who underwent volumetric modulated arc therapy were included. One patient experienced ORN and required the extraction of teeth after RT. In the study approach, the dental arch curve (DAC) was defined using an open-source platform. Subsequently, pCT images and dose distributions were generated based on the new coordinate system. All teeth and mandibles were delineated on both the original CT and pCT images. To evaluate the consistency of dose metrics, the Mann-Whitney U test and Student t-test were employed. Results: A total of 61 teeth and 4 mandibles were evaluated. The correlation coefficient between the 2 methods was 0.999, and no statistically significant difference was observed (P>0.05). This method facilitated a straightforward and intuitive understanding of the delivered dose. In 1 patient, ORN corresponded to the region of the root and the gum receiving a high dosage (approximately 70 Gy). Conclusion: The proposed method particularly benefits dentists involved in the management of patients with HNC. It enables the visualization of a 3-dimensional dose distribution in the teeth and mandible on pCT, enhancing the understanding of the dose delivered during RT.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.5
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• pp.458-463
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• 2006

The osteoradionecrosis of the mandible can be a serious complication of radiotherapy for malignancies of the head and neck. The cause and pathogenesis of osteoradionecrosis are unclear and anecdotal. There are various treatment-, patient- and tumor-related risk factors on development of osteoradionecrosis. The treatment of osteoradionecrosis relies on conservative measures (antibiotics, debridement, irrigation and HBO) and surgical measures (sequestrectomy, marginal resection and segmental resection with or without reconstruction). But the indications are not defined. We present the two cases of patients who were not controlled by conservative treatment but good-resulted by surgical treatment.

• Journal of Oral Medicine and Pain
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• v.24 no.1
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• pp.69-80
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• 1999

OBJECTIVES: This study was designed to measure the minimal cross-sectional areas and volumes of the pharynx in snoring patients and normal subjects and to see if there is an increase in the minimal cross-sectional areas and volumes of the pharynx with advancement of the mandible. METHODS: The pharyngeal computed tomography and 3-dimensional reconstruction were used to measure the cross-sectional areas and volumes of the nasopharynx, oropharynx, and hypopharynx with the jaw in normal position and in protrusive position in 7 patients with snoring and 7 control subjects while they were awake. RESULTS: The oropharynx was revealed to have the most narrow site in the pharynx and there was a tendency for the snorers to have a smaller nasopharyngeal and oropharyngeal cross-sectional area than normal subjects but not statistically significant. There were no significant differences in the volumes of the nasopharynx and oropharynx between the two groups. With advancement of the jaw the minimal cross-sectional area of oropharynx was significantly increased, and the volume was also increased but not significantly. The minimal cross-sectional areas and volumes of nasopharynx as well as hypopharynx were not significantly influenced by the advancement of the mandible. CONCLUSIONS: There was a tendency for snorers to have a smaller oropharynx than normal subjects and the oropharyngeal lumen was increased with the advancement of the mandible in both snorers and normal subjects.

• Korean Journal of Head & Neck Oncology
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• v.29 no.2
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• pp.65-67
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• 2013

Osteomyelitis is an infection of bone or bone marrow, caused by pyogenic bacteria or mycobacterium. Osteomyelitis can be acute or chronic, inflammatory process of the bone and its structures. Chronic osteomyelitis will result in variable sclerosis and deformity of the affected bone. With an infection of the bone, the subsequent inflammatory response will elevate this overlying periosteum, leading to a loss of the nourishing vasculature, vascular thrombosis, and bone necrosis, resulting occasionally in formation of sequestra. These become areas that are more resistant to systemic antibiotic therapy due to lack of the normal Havesian canals that are blocked by scar tissue. At this aspect, not only systemic antibiotic therapy, but also surgical debridement maybe required to remove the affected bone and prevent disease propagation to adjacent areas. We experienced a patient who diagnosed tongue cancer and underwent wide partial glossectomy few years before, with an ulcerative lesion around right retromolar trigon. We diagnosed cancer recurrence because PET indicated hot uptake on mandible which was nearby previous tongue tumor site. The patient received hemiglossectomy via paramedian mandibulotomy, partial mandibulectomy and fibula osteocutaneous free flap reconstruction. But final diagnosis was mandible osteomyelitis on pathology report. Here, we present the case with a review of the related literatures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.1
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• pp.13-20
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• 2009

Background In contrast to defects of the mandible and mouth floor region, in the defect of maxilla, the availability of firmly attached oral and nasal mucosal linings is needed. In addition to it, in consider of operation field, operating convenience, and esthetics, reconstruction using prelaminated flap is strongly recommended. Therefore we consider the prelaminated flap through the cases that is reconstructed using prelaminated forearm flap and prelaminated scapular flap. Patients and Methods From 2001 to 2008, in OMFS SNUDH, there were 6 cases that had reconstruction using prelaminated forearm free flap and other 3 cases that had reconstruction using prelaminated scapular flap of maxilla. The average age of patients that were reconstructed using prelaminated forearm free flap was 47.5 years, the average prelaminated period (after $1^{st}$ operation ${\sim}$ until $2^{nd}$ operation) was 51.8 days and the average follow-up period after $2^{nd}$ operation was 35.3 months. As well, the average age of patients that were reconstructed using prelaminated scapular free flap was 37 years, the average prelaminated period (after $1^{st}$ operation ${\sim}$ until $2^{nd}$ operation) was 57 days and the average follow-up period after $2^{nd}$ operation was 42.3 months. Results Except 1 case that were reconstructed using prelaminated scapular flap, we could get firmly attached oral and nasal stable skin(mucosal like) lining, more adequate thickness flap than any other flap and improved esthetic and functional results in the other 8 cases that were reconstructed using prelaminated flap. The complications of the prelaminated forearm flap cases were inconvenient swallowing, sputum, limitation of mouth opening and difficult mastication. It came from flap shrinkage of the flap in some aspect, as well as other combined operations such as mass resection or RND. The difficult point of the reconstruction of prelaminated scapular flap was the possibility of vascular damage at preparation of flap in $2^{nd}$ surgery. The damage could cause the failure of the prelaminated scapular flap. And the skin-lining of the prelaminated flap had limitations, so it is needed to study about the cultured oral epithelium-lining flap instead of the skin-lining flap. Conclusion We considered about advantages, complications and notable things of prelaminated flap through maxillary reconstruction cases using prelaminated forearm flap and prelaminated scapular flap so far. Furthermore, we should go on studying for functional reconstruction of prelaminated fasciomucosal flap using cultured oral epithelium.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.315-323
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• 2005

For reconstruction of the bony defect, distraction osteogenesis has many advantages in comparison with bone graft. However, it needs long consolidation period for sufficient bone maturity. This study is performed to evaluate the effect of PRP injection into the distracted mandible on bone formation in rabbits. Twelve house rabbits, weighing 2 kg, were used. All animals underwent bilateral mandibular osteotomy under general anesthesia. A internal distractor divice was positioned along a plane perpendicular to the line of osteotomy. After 5 days of latency period, distraction osteogenesis was started at a rate of 1 mm/day for 9 days which was distracted 9 mm totally. After completion of distraction, 0.5 ml of PRP which collected in rabbit blood was injected into the distracted mandible on experimental group, whereas no injection was done in control group. Macroscopical, radiographical, and histological, and histomorphometric examinations were performed 2, 4 and 8 weeks after distraction. All animals showed distracted mandible and severe anterior cross-bite. In radiographical findings 2 weeks after distraction, more radiopacity in the distracted gap was found in experimental group than that of control group. At 4 weeks after distraction, distracted bone was similar to normal bone in experimental group. In histological findings, 1) At 2 weeks after distraction, number of osteoblasts and angiogenesis in the distracted gap was found in experimental group than that of control group. 2) At 4 weeks after distraction, more active and distinct bone in the distracted gap was found in experimental group than that of control groups. 3) At 8 weeks after distraction, more dense and matured lamellated bone in the distracted gap was found in experimental group than that of control group. In histomorphometrical findings 8 weeks after distraction, more bone formation was observed in experimental group than control group (p<0.01). These results indicate that administration of PRP into the distracted mandible can promote bone formation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.1
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• pp.92-97
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• 2000

Osteosarcoma is a primary malignant tumor arising most often in the long bone, but rare in jaw bone. Especially osteogenic sarcoma of the mandible is a rare tumor, comprising less than 0.5% of all head and neck tumors. Osteosarcoma occurs chiefly in young persons, and presenting very survival rates. Histopathologically this tumor can be classified three types, osteoblastic, fibroblastic, chondroblastic and classified from low grade to high grade by anaplasia or mitosis of the tumor cells. Sometimes, the exact diagnosis of osteosarcoma is difficult especially in low grade osteosarcoma, even if clinical or radiographical findings suggest to osteosarcoma. So suspcious to malignant bone tumor in clinical or radiological findings, biopsy should be taked from deep portion and multiple area, and sharing the patient history and radiographs with pathologist will assist in the development of the diagnosis. We report a case of low grade osteosarcoma on the mandible initially difficulty in accurate diagnosis. The patient visited our hospital for routine dental treatment but radiographic findings displayed ill-defined radiolucency with osteoid formation on the mandible. Final diagnosis was difficulty in initial biopsy but subsequent biopsy taked from deep portion presented infiltrative growth and mitosis of the tumor cell in some area with small osteoid bone formation, so we could reach final diagnosis as low grade sarcoma. We treated this patient with bloc resection of the mandible and immediate reconstruction with iliac corticocancellous block.