• Imaging Science in Dentistry
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• v.40 no.2
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• pp.89-91
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• 2010

Impaction of tooth is a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise located so that it cannot erupt normally. The supernumerary tooth is also called as hyperdontia and defined as the condition of having additional tooth to the regular number of teeth. The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary incisors. The supernumerary tooth is commonly impacted but they are frequently impacted on maxilla. Ectopic impaction of supernumerary tooth on mandibular condyle, coronoid process, ascending ramus, and pterygomandibular space is very rare condition. In this case, we report a case of impacted supernumerary tooth on mandibular sigmoid notch without definite pathologic change.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.2
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• pp.533-547
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• 1999

Malignant fibrous histiocytoma is one of the most common soft tissue sarcomas in late adult life. but its incidence in oral and maxillofacial region is extremely rare. We report a case of malignant fibrous histiocytoma which occurred in the infratemporal fossa. Conventional radiograph of this case showed an ill-defined radiolucent lesion in the alveolar bone of the right maxillary first molar area. the lateral wall of the maxillary sinus. and the ascending ramus of mandible. MRI demonstrated a well defined mass of intermediate signal intensitiy in Tl weighted images but T2 weighted images showed two distinctive regions of different characteristics. Upper portion of the lesion was of hyperintense signal but (at) lower portion, the signal intensity decreased clearly, which might mean that this lesion(mass) is composed of two different subtypes though it couldn't be confirmed by histopathological examination. Biopsy was taken the lesion as only in the soft tissue of the maxillary posterior alveolar region and confirmed the storiform-pleomorphic type of malignant fibrous histiocytoma. Histopathological subtype was well consistent with the relatively aggressive imaging findings of that region. We expect more detailed analysis of the nature of malignant fibrous histiocytoma with improvement of the imaging modality and the identification of the relationship between diagnostic imaging and histopathologic findings.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.3
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• pp.247-253
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• 2006

Pleomorphic adenoma of the parotid gland typically presents as painless, mobile mass of long duration, and originate in the superficial lobe but, more rarely these tumors may involve the deep lobe of the parotid gland. The average size of a parotid neoplasm is 2 to 4 cm. The effective treatment of parotid pleomorphic adenoma is surgical excision. The simple excision or enucleation resulted in recurrence rate of 45% in benign tumor. Therefore, the superficial parotidectomy with identification and preservation of the facial nerve is now the most widely accepted surgery. We report a case of the huge pleomorphic adenoma of the left parotid gland in a 67-year-old man who complained the large mass, measured about $10\times7\times5$cm-sized, in front of the left ear and on the mandibular ascending ramus. The diagnosis was confirmed by the clinical examination, computed tomographic scan, fine needle aspiration, and incisional biopsy. Superficial parotidectomy including the tumor and preservation of the facial nerve using the modified Blair approach was performed. And satisfactory results have been obtained cosmetically and functionally.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.431-436
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• 2010

Purpose: It is estimated that the odontogenic keratocyst (OKC) makes up 10% to 12% of all developmen-tal odontogenic cysts. The lesion has been of particular interest because of its specific histopathologic fea-ture, high recurrence rate, and aggressive behavior. Materials and Methods: We investigated 266 OKCs of Korean patients for the sex of patient, the age of the patient, the location of OKC, the recurrence rate related to radiographic impression. Results: The male-to-female ratio was 1.47:1, showing a slight male predilection. Odontogenic keratocysts had a peak of occurrence in the third decade of life. The mandibular angle and ascending ramus area (49.6%) is the most frequent site of OKCs in the jaws. Fourteen cases of unilocular (12%) and 5 cases of multilocular (20%) OKCs recurred. Thirteen cases of smooth (12.9%) and 6 cases of lobulated (14.6%) OKCs recurred. Seventeen cases of OKCs without perforation of cortical bone (12.5%) and 2 cases of OKCs with perforation of cortical bone (33.3%) recurred. Fifteen people of patients with single lesion (12.2%) and 4 people of patients with multiple lesions (66.7%) recurred. Conclusion: In this resul, we consider multiple odontogenic keratocysts can recur more easily. So we have to treat them more carefully and need long-time follow-ups.

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.45-59
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• 1989

This study was undertaken to analyze the displacement and stress distribution in the mandible according to the pulling directions during mandibular first molar cervical traction after mandibular second molar extraction. The 3-dimensional finite element method(FEM) was used for a mathematical model composed of 594 elements and 1019 nodes. An orthodontic force, 450 gm, was applied to the each mandibular first molar in parallel, and below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$ and meet the midsagittal plane by $40^{\circ}$ toward posterior direction. The results were as follows: 1. Mandibular teeth were displaced in more downward, posterior and lateral direction. Especially high stress was noted in case of parallel pull than in case of below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$. 2. Mandibular first molar was moved bodily. 3. Generally, alveolar bone, mandibular body, ascending ramus and mandibular angle portion were displaced in downward, posterior and lateral direction. But coronoid process was displaced in downward, forward and lateral direction, and anterior and inner middle portion of condyle head and neck were displaced in downward, forward and medial direction, and posterior and outer middle portion of condyle head and neck were displaced in upward, forward and medial direction. 4. Maximum stress was observed at the condyle head and neck portion. With steeper direction of force, condyle head and neck showed more stress than parallel relation to the occlusal plane.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.5
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• pp.298-300
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• 2003

Ameloblastomas are generally considered to be benign tumors of odontogenic epithelial origin with high local recurrence. Rarely ameloblastomas exhibit malignant behavior with development of metastases. In this report, we present a 19-year-old woman with ameloblastoma in the right ascending ramus and multiple recurrences. Eleven years after first therapy, ameloblastoma metastasized to ipsilateral submandibular lymph node. We also review literature about cause, treatment and work-up of malignant ameloblastoma.

• Journal of Korean Dental Science
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• v.7 no.1
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• pp.16-24
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• 2014

Purpose: This study was planned to clarify a negative view of chewing gum due to the concern that continuous gum chewing might cause a change in the gonial angle and make the lower facial appearance look square. Materials and Methods: We had 25 adults (13 males and 12 females, with an average of 27.3 years) chew 6 g of gum (spearmint) evenly with both right and left posterior teeth for one hour per day for three months. We then measured their gonial angle, the inclination of occlusal plane, facial height, bone marrow density, and masticatory force before chewing, 1, 2, and 3 month after chewing to verify its significance statistically. Result: The results showed that the gonial angle increased from $122.7^{\circ}$ to $123.3^{\circ}$ (P>0.05), and thus the jaws became slightly slimmer. There was no change in the occlusal plane inclination and facial height. Meanwhile bone marrow density in the mandibular angle and ascending ramus increased from $0.285g/cm^2$ to $0.290g/cm^2$ (P<0.05), and masticatory force also increased by 0.5 kg on the right side and 0.8 kg on the left side (P<0.05). Conclusion: Continuous chewing of gum gives an appropriate exercise effect to the stomatognathic system. As chewing gum has effect on increase bone marrow density without changing the mandibular angle and facial appearance the claim that jaw bone changes to a square jaw through chewing gum is regarded to be groundless.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.4
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• pp.275-282
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• 1992

Maxillofacial war injures is specific representative of severe hard and soft tissue defect. This type of injuries were different from the trauma because it may be fatal. The purpose of this study was to evaluate the injury type base on the retrograde medical record in the 104 patients from Feb. 1991 to Aug. 1992 in Korea Veterans Hospital. The obtained results were as follows. 1. Among 104 cases, 51 cases(49.0%) were classified as mandibular defects only, and 53 cases (51.0%) were classified as maxillary with mandibular defect (combined). 2. The etiologic factors of injury were gunshot, artillery and grenade or shell: 33 cases, 14cases, and 10 cases respectively in Korea War, 19 cases, 5 cases, and 8 cases respectively in Vietnam War. 3. In 57 cases of mandibular partial defect, the angle area showed the highest frequencies, 18 cases(31.6%). 4. In 42 cases of mandibular segmental defect, the area between the 1st molar and the ascending ramus showed the highest frequencies. 17 cases(40.4%), and almost all cases were unilateral defect (40 cases, 95.0%) 5. Reconstruction method performed for segmental mandibular defect were wire or plate(15 cases, 35.7%) and soft tissue closure only(12 cases, 28.7%), respectively.

• Korean Journal of Head & Neck Oncology
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• v.21 no.2
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• pp.190-195
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• 2005

Background and Objectives: Fibula is the flap of choice for reconstruction of wide mandible defects after tumor ablation surgery. In mandible reconstruction, restoring the mandible frame to provide mandibular contour and dental arch while restoring masticatory function are important. Even though vascularized fibula can be osteotomized freely, proper design and flap insetting is not easy because of its three dimensional structure and difference in design according to the defect sites. We reviewed patients who underwent mandible reconstruction with fibular flaps according to the defect sites and suggest proper modification methods of fibular flap according to the various defects sites after tumor ablation surgery. Materials and Methods: Twelve consecutive mandible reconstruction with fibular free flaps were performed for defects after tumor ablation surgery. Patients were classified into 4 groups according to the type of mandibular defect(Group 1 : defect on central segment including symphysis, Group 2 : defect on lateral segment(with or without central segment) confined to body, Group 3 : defect on body and ascending ramus that does not include the condyle, Group 4 : defect including the condyle). Results: We suggest different modification methods of fibular free flap for each patient group. Group 1, 3 ; contour by using multiple closing wedge osteotomy. Group 2 ; single or double barrel reconstruction without wedge osteotomy. Group 4 ; contour using single or multiple wedge osteotomy and condylar reconstruction with costochondral graft. Conclusion: Fibular free flaps can be contoured to any desired shape after multiple osteotomies to restore various mandibular defects. It is a reliable and versatile method for reconstruction of mandibular defects after tumor ablation surgery.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.341-355
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• 1999

Squamous cell carcinoma is the most common type of oral cancer and odontogenic myxoma is relatively uncommon benign tumor of mesenchymal origin. There are, to our knowledge, no prior reports of simultaneously occurring squamous cell carcinoma and odontogenic myxoma of the jaw bones. In this case, at first, the plain films and computed tomograms revealed a large expansile multilocular radiolucent lesion on left mandible and marked expansion of cortical plate. In addition this radiograms revealed also infiltrative bony destruction of anterior and medial border of ascending ramus of left mandible and alveolar bone of left maxilla, floating teeth on left lower molar area and metastatic enlargement of left submandibular, jugular digastric and spinal accessory lymphnodes. Magnetic resonance imaging of this patient revealed infiltrative growth of tumor on alveolar bone of left maxilla, left retromolar fat pad. left masseter and left medial pterygoid muscle. Intraoral presurgical biopsy presented typical features of squamous cell carcinoma. After chemotherapy with radiation therapy during 6 months. this central lesion was diagnosed as odontogenic myxoma by the postsurgical biopsy. After 3 months, this patient presented multiple metastatic signs at lumbar spines, rib and liver. Consequently, our case is simultaneous occurrence of squamous cell carcinoma and odontogenic myxoma.