• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.2
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• pp.149-165
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• 1999

The pathomechanism of obstructive sleep apnea(OSA) is not clearly elucidated. The possible mechanisms are pathologic reduction of pharyngeal muscular tonus during sleep, abnormal anatomical stenosis of nasopharyx or a combination of the above two mechanisms. It is very important to find the cause(anatomical location or pathologic dynamic change) of OSA in order to treat it. Cephalometric analysis in patients with obstructive sleep apnea is a good method for evaluating anatomical morphologic change but it cannot give any information about the dynamic changes occurring during sleep. On the contrary, nasopharyngeal endoscopy offer 3 dimensional image and information about the dynamic changes. Accordingly, these two diagnostic tools can be utilize in the diagnosis and treatment planning of OSA Cephalometric analysis of craniofacial skeletal and soft tissue morphology in 53 patients with OSA and 43 controls was performed and cephalometric analysis and nasopharygeal endoscopy were performed in 9 patients with OSA in order to come up with individualized therapy plans. Following results were obtained ; Patients with OSA showed 1. body weight gain 2. clockwise mandibular rotation 3. increased anterior lower facial height 4. inferiorly positioned hyoid bone 5. increased length of soft palate 6. decreased sagittal dimension of nasopharyx 7. increased vertical length of inferior collapsable nasopharyx 8. increased length of tongue Through cephalometric analysis and nasopharygeal endoscopy(mutually cooperative in diagnosis), 9. one can find the possible origin of OSA and make a adequate individualized therapy plan and predict accurate prognosis. Cephalometric analysis and nasopharygeal endoscopy are highly recommended as a diagnostic aid in OSA patients

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.4
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• pp.309-315
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• 2016

Recently, finite element analysis technique has been widely used for structural and mechanical understandings of human body in the dentistry field. This research proposed an effective finite element modeling method based on CT images, and parametric studies were performed for the occlusal simulation. The analyses were performed considering linear material behaviors and nonlinear geometrical effect, and validated with the experimental results. In addition, the skull models with two different molar relations such as Class I and full-CUSP Class II were generated and the analyses were performed using the proposed analytical method. As results, the relationships between the mandibular movement and occlusal force of both two models showed similar tendency in human occlusal force. However, stress was evenly distributed from teeth to facial bone in the skull model with Class I, while stress concentration was appeared in the model with full-CUSP Class II due to the changes of occlusal surfaces of the model.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.61-68
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• 1996

In Fibrous dysplasia(FD) of the jaws, the majority of cases can await the cessation of growth before surgical intervention, and it seems prudent to delay surgery whenever possible until growth has ceased. In craniofacial FD, however, the dangers of dystopia, dystopia and loss of vision may require early surgery to prevent or control cranio-orbital complications. Delaying surgery in those circumstances may be significantly detrimental to such patients. Conservative surgical management of FD is widely practised and we advocate an extension to this conservative treatment by combining surgical recontouring with appropriate osteotomies if indicated, to achieve an optimal esthetic and functional results in craniofacial FD. One case will be presented to illustrate the feasiblility of such combined treatment, to report the uneventful healing of osteotomies in the FD of the jaws, and to demonstrate the use of titanium miniplate fixation in dysplastic bone. The other case had expansile disease of the left facial and fronto-temporal bones and osteolytic change left mandible. This patient complained of severe spontaneous bleeding of left mandibular premolar area and it was suspected as central hemangioma of the left mandible and craniofacial FD. Angiogram disclosed generalized dilation of the external carotid artery and its branches, especially terminal branches of the left facial and inferior alveolar arteries. But no specific abnormalities, such as A-V shunt, venous lake, or early venous drainage, was seen. So it was diagnosed craniofacial FD with hypercellularity and generalized bony recontouring was performed via coronal and transoral approaches.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.577-583
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• 2008

Langerhans cell histiocytosis (LCH) is characterized by proliferation of pathological Langerhans cells within different organs. It mainly affects children, but adult cases also occur, with an incidence rate of one to two per million. LCH results from the clonal proliferation of Langerhans cells. And its etiopathogenesis is still unknown. The hypothesis that it is a neoplastic or inflammatory disease, as well as the existence or not of immunological, viral or genetic predisposing factors, has been widely discussed in the literature, but no conclusive proof has ever been provided. Although lesions may appear in tissues of various origins such as skin, hypothalamus, liver, lung, or lymphoid tissue, bone is the most common site of the disease. The head and neck are affected in almost 90% of cases. The maxillary and mandibular bones are affected in 5 to 10% of cases. In our report, we present four cases of LCH in patients aged 3, 4, 7 and 9 years respectively, with primary manifestation in maxillofacial area.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.584-588
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• 2008

Facial asymmetry is particularly associated with mandible among other facial bones and it could be either congenital or acquired. Congenital factors are related to Treacher Collin syndrome, Pierre Robin syndrome, hemifacial microsomia and other various syndromes. Acquired factors are such as damaged or diseased growing condyles, hormonal disorder, oral mal-habit, muscular force, tumor, infection and so on. Diagnosis and treatment of facial asymmetry are complicated due to differences in sizes and positions of mandibles. The aspects of facial asymmetry is various and complicated upon each individual. Depending on causes of the facial asymmetry, there also are morphological differences. For such reasons, precise anatomical analysis and diagnosis of the facial asymmetry are essential before any surgical procedure followed by the appropriate treatment plan. This case is regarding a 21-year old patient diagnosed as the facial asymmetry due to an infantile maxillofacial surgery. Employing various morphological evaluations, potential problems during the procedure are predicted beforehand. This case reports a favorable result of sagittal split ramus osteotomy performing the oblique vertical bone cutting in posterior-superior of the mandibular second molar.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.127-135
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• 2009

Objectives : The titanium fixation system has been used in orthognathic surgery for fixation of bone segments usually, but the biodegradable fixation system was developed and also being used. The strongest point in the biodegradable system is that no extra operation should be needed to remove fixation materials. In spite of this merit, oral & maxillofacial surgeons hesitate to use this system in fracture or orthognathic surgery. In this study, as we got some clinical experiences, we'd like to report the result of clinical study using the biodegradable fixation system in orthognathic surgery. Patients and Methods : A total of 35 patients composed of 17 males and 18 females with 25 osteotomies in maxilla and 34 osteotomies in mandible were fixated with the biodegradable fixation system(Inion $CPS^{(R)}$). We investigated methods of stabilization, fixation time, and complications on the basis of the method as above. Results : Four 2mm thick L shaped plates with 7 holes of which 1 hole was removed were fixed in maxilla with six $2.0{\times}7mm$ screws. Three $2.5{\times}16{\sim}18mm$ screws were used to fix superior ramus area and one mandibular angle area in mandible. It took about 27.4 minutes in maxilla, 25.3 minutes in mandible to perform the fixation which took longer time than the titanium system(9.5 minutes in maxilla, 8 minutes in mandible). Generally, there was no problem except 9 cases in which there were some complications. Conclusions : In most cases, the biodegradable fixation system can be used without problem in usual orthognathic surgery. But, this system is inferior to the titanium fixation one in some respects such as fixation time, size, and physical property. Some supplementations for such weak points as aforementioned should be needed for the universal use of biodegradable materials.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.22.1-22.9
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• 2017

Background: Two-jaw surgery including mandibular and maxillary backward movement procedures are commonly performed to correct class III malocclusion. Bimaxillary surgery can reposition the maxillofacial bone together with soft tissue, such as the soft palate and the tongue base. We analyzed changes of pharyngeal airway narrowing to ascertain clinical correlations with the prevalence of snoring after two-jaw surgery. Methods: A prospective clinical study was designed including a survey on snoring and three-dimensional (3D) computed tomography (CT) in class III malocclusion subjects before and after bimaxillary surgery. We conducted an analysis on changes of the posterior pharyngeal space find out clinical correlations with the prevalence of snoring. Results: Among 67 subjects, 12 subjects complained about snoring 5 weeks after the surgical correction, and examining the 12 subjects after 6 months, 6 patients complained about the snoring. The current findings demonstrated the attenuation of the largest transverse width (LTW), anteroposterior length (APL), and cross-sectional area (CSA) following bimaxillary surgery given to class III malocclusion patients, particularly at the retropalatal level. The average distance of maxillary posterior movements were measured to be relatively higher (horizontal distance 3.9 mm, vertical distance 2.6 mm) in case of new snorers. Conclusions: This study found that bimaxillary surgery could lead to the narrowing of upper airway at the retropalatal or retroglossal level as well as triggering snoring in subjects with class III malocclusion. Based on the current clinical findings, we also found that upper airway narrowing at retropalatal level may contribute to increasing the probability of snoring and that polysonography may need to be performed before orthognathic surgery in subjects with class III malocclusion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.41.1-41.4
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• 2018

Background: Free fibular flap is one of the most useful methods in the hard tissue reconstruction of the maxillamandible. Free fibular flap presents some advantages in which the reconstruction of both soft and hard tissues can be done at the same time. It also provides a safe and successful bone graft for the reconstruction, along with a low rate of complications. Despite these advantages and the rarity of a postoperative complication, particularly in oral and maxillofacial surgery procedures, a prolonged operation might exhibit some complications related with rhabdomyolysis. We experienced the rare event of rhabdomyolysis after oral cancer surgery. Case presentation: In this article, we report the case of a patient who developed rhabdomyolysis after undergoing free fibular flap surgery. Conclusions: Despite the advantages of the free fibular flap operation, clinicians must be aware of the risk of complications because there are multiple factors that could result in rhabdomyolysis, such as duration of operation, position of the subject, and pre-existing conditions of diabetes and hypertension. Once the diagnosis of rhabdomyolysis is confirmed, a prompt treatment plan should be made and applied as soon as possible. This will increase the chance of a full recovery for the patient who is exhibiting symptoms of rhabdomyolysis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.1
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• pp.64-67
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• 2003

Odontogenic myxoma is a rare tumor which occurs almost exclusively in the jaws, and seems to be of odontogenic origin. Clinically this tumor tends to appear in the second and third decades of life, and most of the lesions are located in the premolar - molar region. It is characterized grossly by mucoid or gelatinous gray-whitish tissue that replaces the cancellous bone and expands the cortex. It is invasive locally and has a high recurrence rate ranging from 10% to 33%. Radiographically, the appearance of this tumor is varied, but usually appears as a unilocular or multilocualr radioluscency of varying size. We experienced a rare case of odontogenic myxoma 12 years old patient related to mandibular bilateral impacted canines in the mandible, so we report this case with literature.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.564-568
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• 2004

Odontoma, hamartomas of odontogenic orgin, are composed of all the structures that make up teeth, which may lead to interference with the eruption of its associated tooth. On the basis of gross, radiographic, and microscopic features, two types of odontoma are recognized: compound and complex. The etilogy of odontomas is unknown, although local trauma, infection, and gentic factors have been suggested. Odontomas occur central in bone between the roots of teeth and the mauority are asymptomatic. Although these tumors occur frequently and constitute 22% of all odontogenic tumors, are very rare. Erupted odontoma are defined as tumors that it occurs a calcifed mass may be defected on the ridge. The treatment of chico is the surgical removal of the lesion followed by a biopsy. This report presents a case of 8-year-old girl with the delayed eruption of the mandibular first molar by the calcified mass within the operculum covered the central fossa. And it was diagnosed as erupted complex odontoma by excisional biopsy.