• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.4
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• pp.208-212
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• 2015

Keratocystic odontogenic tumor (KCOT) is a common benign tumor of osseous lesions in dental and maxillofacial practice. We describe three cases of large KCOT located in the posterior part of the mandible extending to the angle and ramus region, which were enucleated via sagittal split osteotomy (SSO) of the mandible. There are cases in which a conventional enucleation procedure does not ensure complete excision of the entire lesion without damage to vital structures like the inferior alveolar nerve. In such cases, a SSO approach could be a better choice than conventional methods. The purpose of this article is to describe our experience using unilateral mandibular SSO for removal of a KCOT from the mandible.

• The Journal of the Korean dental association
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• v.9 no.12
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• pp.791-795
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• 1971

Thirty-four children who were patients at the Pedodontic Department of Infirmary of Dental College, S.N.U., aged from 3 years 1 month to 6 years 10 months. One quadrant jaw was measured for each child, Each of the 5 teeth was measured in 6 specific areas, therefore, a total of 1,020 measurements were observed. The results were as follows: 1. Facial surface was the shallowest of all. It was 0.14 mm. shallower than lingual, 0.62mm. shallower than mesial, 0.98mm. shallower than distal. 2. The sulcus generally increased in depth from anterior to posterior. 3. The anterior segment in the maxilla was the shallowest of all. It was 0.68mm. shallower than posterior of maxilla, 0.08 mm. shallower than anterior of mandible, 0.63 mm. shallower than posterior of mandible. 4. The most frequent measurement observed in the both jws was 1.4mm. 5. The mean for the complete anterior segment in the maxilla was 1.3±0.50 mm. In the posterior segment of the maxilla, the mean was 2.0v0.74mm. In the mandible, the mean for the anterior segment was 1.4±0.46 mm. In the posterior segment of the mandible, the mean was 2.0±0.56 mm. 6. The mean gingival sulcus depth for the entire Primary Dentition was 1.7±0.59 mm.

• Korean Journal of Veterinary Research
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• v.9 no.2
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• pp.49-53
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• 1969

The distribution of radiophosphorus ($^{32}P$) was observed in three groups of female Albino tat consisted of early pregnancy group (10 days of pregnancy), late pregnancy group (18 days of pregnancy) and nonpregnanted control group. The results obtained were as follows: 1. The various sites arranged in the descending of absorption rate of $^{32}P$ were femur, mandible, liver, spleen, ovary, fetus (only from early pregnancy group) and kidney in both groups of non-pregnanted and early pregnancy and femur, mandible, fetus, liver, ovary, spleen and kidney in the late pregnancy group. 2. The significant difference (P<0.05) in the absorption rate was found between femur and mandible in the early pregnancy group. 3. The absorption rate of fetus from late pregnancy group was significantly (P<0.01) higher than that of fetus from the early pregnancy group. 4. The high absorption rate was observed with femur and mandible in both groups of non-pregnanted and early pregnancy. 5. The significantly (P<0.01) high absorption rate was observed with ovary and fetus from the late pregnancy group.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.515-520
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• 2017

Sexual dimorphism of the mouthpart, antenna and mandible of the Cyllorhynchites ursulus in South Korea was studied with linear measurements. The mouthpart and antenna measurements were conducted with a stereoscopic microscope using 122 specimens (72 males and 50 females). Microscopic observation of the mandible were conducted with a Field Emission Scanning Electron Microscope (FE-SEM) using 103 specimens (73 males and 30 females). Results showed that the size difference between males and females was significant in the size of the mouthpart and antenna. On the other hand, we could not detect sexual size dimorphism in the microstructure of the mandible. The bivariate plots made by the result of Principal Component Analysis (PCA) and Discriminant Analysis (DA) showed a size dimorphism in the size of the mouthpart and the antenna between males and females. Based on our study, sexual dimorphism in the mouthpart and antenna exists in C. ursulus from the South Korean population, and this difference seems to be related to the behavioral differences between males and females.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.4
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• pp.321-326
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• 2021

Hemangioma is a benign tumor characterized by the proliferation of blood vessels. Although it often appears in soft tissues, its occurrence in bone tissue, particularly the mandible, is extremely rare. A 32-year-old female sought attention at the dental clinic complaining of a painless swelling in the posterior region of the left side of the mandible. A panoramic radiograph and computed axial tomography scan were taken, showing honeycomb and sunburst images, respectively, in the affected area. The patient underwent a biopsy, which led to the diagnosis of intraosseous hemangioma. Having assessed the characteristics of the lesion, it was decided to perform complete excision including safety margins, followed by an iliac crest bone graft to reconstruct the mandible. Awareness of the possible clinical and radiographic presentations of intraosseous hemangioma is considered important, as non-diagnosis could have severe consequences given its possible relation to dental structures.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.1
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• pp.7-22
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• 1992

The stress distributions on a human mandible for 18 load cases under two different boundary conditions (mouth open and closed), using the three dimensional finite element modeling were studied. Also, the expected fracture loads for each load cases were calculated by using the Von-Mises yield criterion. The model of a mandible with all teeth was composed of 2402 hexahedron elements and 3698 nodes. CAD techniques were used to analyze the 3-dimensional results. The conclusions of this study were as follows: 1. In the mouth open state, the maximum stress occured at the condyle neck; when the lateral load was exerted, the maximum stress occured at the load side condyle. 2. In the mouth closed state, when the loads were exerted on the mandibular body and chin, the maximum stress occured at the loaded area, and when the loads were exerted on the angle and ramus, the maximum stress occured at the condyle neck. 3. The expected fracture loads in each load case were calculated using the Von-Mises yield criterion, and it was confirmed that the mandible in the mouth open state was more easily fractured than that in the mouth closed state, and the expected fracture loads are lesser in the cases that load direction is parallel at mandibular plane than 45°. 4. The magnitudes of the expected fracture loads increased in the order of angle, ramus, body and chin in case of the mouth closed state, while chin, body, angle and ramus in case of the mouth open state. 5. The Von-Mises stress concentration regions analyzed by F.E.M. corresponded well with the results of clinical studies.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.173-177
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• 2010

In 1942, Stafne described 35 "bone cavities" at the angle of the mandible. They appeared as unilocular, well-circumscribed, round or elliptical radiolucencies located below the inferior dental canal and between the angle of the mandible and first molar tooth. Since 1942, these lesions have been frequently described under various terms: aberrant or ectopic salivary gland; static or latent or idiopathic defect, cavity or cyst; mandibular salivary gland inclusion; lingual mandibular cavity; and Stafne's cyst, defect or cavity. Usually they were asymptomatic, with a predilection for men between age 50 and 70 years, and almost unilateral. At surgical exploration, they appeared as concavities on the lingual cortex and contained salivary gland tissue, often in continuity with the submandibular gland. In 1957, Richard and Ziskind were the first to report the appearance of a Stafne's cyst in the premolar region. Contrary to posterior defects, the anterior defects are difficult to diagnose clinically because the mandibular canal is not present, and the unilocular radiolucency can be confused with other cysts (radicular, residual, odontogenic, lateral periodontal,etc). The purpose of the present report is to describe an unusual case of Stafne's cyst in the anterior region of the mandible in 58-years-old woman.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.32-40
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• 1989

This study is based on 247 patients(348 cases) with facial bone fracture who were admitted to the department of oral and maxillofacial surgery, Kangnam sacred heart Hospital during the period of Jan. 1983 through sep. 1988. The patients with mandible fracture were analysed with the following items such as complications with treatment method undertaken : Bicortical osteosynthesis vs Monocortical osteosynthesis, advantages and Disadvantages. The results obtained are as follows : 1) The most common age groups for the facial bone fracture were 20 years 2) The ratio of Men to women was 5 : 1 3) The most frequent location of facial bone fractures was the Mandible(76.7%), Maxillae(10.6%), Zygoma(9.5%), Nasal bone(3.2%) 4) The ratio of Mandible to Maxillae was 7.2 : 1 5) In mandible fractures, the most frequent fracture site was Symphysis(48.7%) 6) In maxilla fractures, the most frequent case was Le fort III fracture(51.4%), followed by Le fort I fracture(29.7%), Le fort II fracture(18.9%) 7) The main contributing causes of facial bone fractures were Traffic Accident(37.7%), Fight(31.6%), Accident(27.5%) 8) In open reduction methods of mandible fracture, the frequency of postop, malocclusion was 15% in interosseous wiring, 7% in Bicortical osteosynthesis, 3% in Monocortical osteosynthesis. The miniplates show advantages over other forms of fixation, in that they are malleable and easy to insert, they achieve rigid fixation and stability.

• Imaging Science in Dentistry
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• v.31 no.3
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• pp.165-173
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• 2001

Objectives : To evaluate the absorbed and effective doses of spiral and computed tomography for the dental implant planning. Materials and Methods: For radiographic projection, TLD chips were placed in 22 sites of humanoid phantom to record the exposure to skin and the mean absorbed dose to bone marrow, thyroid, pituitary, parotid and submandibular glands and nesophagus. Effective dose was calculated, using the method suggested by Frederiksen et al.. Patient situations of a single tooth gap in upper and lower midline region, edentulous maxilla and mandible were simulated for spiral tomography. 35 axial slices (maxilla) and 40 axial slices (mandible) with low and standard dose setting were used for computed tomography. All the radiographic procedures were repeated three times. Results: The mean effective dose in case of maxilla was 0.865 mSv, 0.452 mSv, 0.136 mSv and 0.025 mSv, in spiral tomography of complete edentulous maxilla, computed tomography with standard mAs, computed tomography with low mAs and spiral tomography of a single tooth gap (p<0.05). That in case of mandible was 0.614 mSv, 0.448 mSv, 0.137 mSv and 0.036 mSv, in spiral tomography of complete edentulous mandible, computed tomography with standard mAs, computed tomography with low mAs and spiral tomography of a single tooth gap (p<0.05). Conclusions: Based on these results, it can be concluded that low mAs computed tomography is recommended instead of spiral tomography for the complete edentulous maxilla and mandible dental implant treatment planning.

• Imaging Science in Dentistry
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• v.33 no.3
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• pp.187-193
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• 2003

Purpose: To compare the measurements of the mandible and the detectability of the mandibular canal on reformatted images using a newly developed 3-dimensional implant simulation program with traditionally used CT multiplanar reconstruction program and true measurements. Materials and Methods: Ten dry dog mandibles were used in this study. Occlusal templates for CT examination were fabricated and marked with gutta perch a at ten sites. Axial CT scans were taken and reconstructed using DentaScan (D group) and Vimplant program (V group), and each mandible was sectioned at the previously marked sites (R group). Maximum vertical height (H) and maximum width (W) of the mandible, the distances from buccal border of the mandibular canal to the most buccal aspect of the mandible (X), and the distance from the superior border of the mandibular canal to the alveolar crest (Y) were measured, and the mandibular measurements in each group were compared. Detectability of mandibular canal was evaluated using a 3-point scale in both V and D groups by three oral radiologists and compared. Results: H in the V group was slightly greater than that in the D group, and Wand X in the V group was slightly less than those in the D group. H in the V group was less than that in the R group, and Wand X in the V group was larger than those in the R group. The detectability of the mandibular canal did not show statistically significant differences between V and D groups. Conclusion: The results of the experiment show that the newly developed, inexpensive Vimplant/TM/ simulation program can be used as an alternative to the traditionally used, and more expensive CT multiplanar reconstruction program.