• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.30.1-30.7
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• 2017

Background: The positions of the mandibular lingula and foramen have been set as indexes for inferior alveolar nerve (IAN) block and ramus osteotomies in orthognathic surgery. This study aimed to evaluate the anatomical structures of mandibular ramus, especially the mandibular lingula and foramen, by analyzing the cone-beam computed tomography (CBCT) data of young adults. Methods: We evaluated 121 sides of hemi-mandibular CBCT model of 106 patients (51 male and 55 female patients; 18 to 36 years old). All the measurements were performed using the 2- and 3-dimensional rulers of $OnDemand3D^{(R)}$ software. Results: Statistical analysis of the data revealed that there was no significant difference in the mandibular angle between the genders. The mandibular lingula was found to be located at the center of ramus in males, but a little posterior in relation to the center in females. The mandibular lingula was rarely located below the occlusal plane; however, the position of the mandibular foramen was more variable (84.3% below, 12.4% above, and 3.3% at the level of the occlusal plane). Conclusions: The results of this study provide a valuable guideline for IAN block anesthesia and orthognathic surgery. CBCT can be considered effective and accurate in evaluating the fine structures of the mandible.

• 대한치과의사협회지
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• 제5권1호
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• pp.71-74
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• 1964

The authors have observed a case of eosinophilic granuloma which occurred in 10 years old girl 1.The lesion which occurred swelling and facial disfigurement , was located in the right side of ramus mandible, but toothache and loosening of tooth was absent. 2. Roentgenograph showed bean-sized monocystic radiolucent shadow in mandible border.3. Microscopically,few hemorrhagic araas were existed, and numerous eosinophilic leukocytes eosinophilic myelocyteswith inflammatory cells were infiltrated.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권4호
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• pp.279-283
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• 1998

The osteoporosis is a disease that represents a reduction in the volume of bony tissue relative to whole bone volume. And mandible also may be affected. Such porotic mandible may influence the result of the surgery like dental implant surgery relating mandible. So, the author examed the panoramic view of 89 persons for finding the possibility of useful diagnostic parameters of osteoporosis. To know the correlationship between the condition of vertebra and mandible, bone marrow density of lumbar spine from 2nd to 4th, and the number of residual tooth, panoramic mandibular index (PMI), angular cortical bone thickness (ACT) and ramus cortical bone thickness (RCT) were compared. The result is that PMI and ACT have similar relative weak linear correlationship, RCT have very weak linear correlationship, the number of residual tooth have not linear correlationship.

• 대한수의학회지
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• 제33권3호
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• pp.351-359
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• 1993

This study was carried out to identify metric and non-metric characteristics of the mandible of the Korean native goat. The results were summarized as follows : The length of the mandible was more correlated with the width of the base of the ramus mandibulae than the margo alveolaris(p<0.01). The height between incisura vasorum facialium and processus condylaris had very high correlation with the height between incisura vasorum facialium and incisura mandibulae(p<0.01). The former was also more correlated to the height of the mandible in front of the first molar tooth than the height of the mandible behind the last molar tooth(p<0.01). The symphysis was formed between both mandibles and it was not able to observe ossification in all case. The number of alveoli for incisor teeth were four each mandible, however three alveoli were observed in two cases. There was usually one or occasionally, two foramina mentalia on the lateral surface of the corpus mandibulae below the margo interalveolaris near the symphysis. The incisura vasorum facialium was poorly developed. A distinct groove was observed rostroventral to the foramen mandibulae. The processus condylaris was shown hammer shape, and the caput mandibulae was flat rectangular form. The processus coronoideus was formed a rectangle and curved laterally. The incisura mandibulae was well developed.

• 대한치과의사협회지
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• 제52권10호
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• pp.623-632
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• 2014

안면비대칭의 주원인은 하악골이며, 하악골의 비대칭 성장에 대한 상악골의 보상성장에 따라 교합면 경사 등이 초래된다. 디지털 사진과 삼차원 CT 등 다양한 방법으로 정확한 진단을 하고 수술을 포함한 치료계획을 세운다. 술전 교정 치료는 상악골과 하악골 치열의 치성 보상(dental compensation)을 제거하면서 상악 치열의 중심은 상악골의 정중선에, 하악 치열의 중심은 하악골 정중선에 맞게 이동하여 술후 상하악 치열궁이 일치하면서 동시에 안모 정중선에 일치하게 맞추어야 한다. 악교정 수술은 일반적으로 상하악 동시 수술을 하게 되며 우각부 풍융도 교정과 이부 성형술(genioplasty) 등을 부가적으로 할 수 있으며, 교합면 경사 교정과 수평 회전 등의 이동이 상하악 위치에 서로 영향을 주면서 수술 후 안모 변화에 대한 예측을 어렵게 만들기 때문에, 다양한 분석을 통해 정확한 예측으로 최선의 결과를 얻는 것이 가장 중요하다.

• Imaging Science in Dentistry
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• 제37권4호
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• pp.225-230
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• 2007

Cholesterol granuloma is an unusual clinical entity described as an inflammatory granulation in response to the deposit of cholesterol crystals. It can develop in any portion of air cells within the temporal bone as a result of a lack of aeration and inadequate drainage, especially in the middle ear cavity. Here, we report very unusual three cases of cholesterol granuloma developed in mandible. In the first case a 68-year-old male with a large mass arising from the mandible was observed. Panoramic radiograph and computed tomography scans revealed a huge expanding lesion in the mandible. In the second case a 47-year-old female with a cystic lesion in the mandible was observed. And in the third case a 19-year-old male complaining atypical facial pain had a large lesion in the mandibular ramus. The histopathologic examinations of the cases showed numerous cholesterol crystals surrounded by multinucleated foreign body giant cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권1호
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• pp.89-93
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• 2005

Intraosseous neurilemmoma(Schwannoma) is an extremely rare benign neoplasm. The site most commonly involved is the mandible. This occurrence is understandable because of the length of the inferior alveolar canal through the mandible. No other bone contains a canal that transmits a neurovascular bundle of such size and length. We report on a peripheral and central neurilemmoma along pathway of inferior alveolar nerve of the lower lip and mandible in a 28-year old man. A panoramic radiograph of the mandible showed a well-defined bilocular lesion with a thin uniform sclerotic margin located in the ramus and body of the mandible. The CT scan confirmed a well-defined lesion with thinning of the cortex of the body of the left side of the mandible. Histologically, the lesion was a cellular neoplasm with distinct palisading and numerous Verocay bodies. Complete excision was achieved by removing the tumor with the inferior alveolar nerve.

• 대한치과보철학회지
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• 제36권2호
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• pp.203-244
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• 1998

The human mandible is always under the condition of loading by the various forces extorted by the attached muscles. The loading is an important condition of the stomatognathic system. This condition is composed of the direction and amount of forces of the masticatory muscles, which are controlled by the neuromuscular system, and always influenced by the movement of both opening and closing. Mandible is a strong foundation for the teeth or various prostheses, nevetheless it is a elastic body which accompanies deformation by the external forces on it. The elastic properties of the mandible is influenced by the various procedures such as conventional restorative treatments, osseointegrated implant treatments, reconstructive surgical procedures and so forth. Among the treatments the osseointegrated implant has no periodontal ligaments, which exist around the natural teeth to allow physiologic mobility in the alveolar socket. And so around the osseointegrated implant, there is almost no damping effect during the transmission of occlusal stress and displacements. If the osseointegrated implants are connected by the superstructure for the stabilization and effective distribution of occlusal stresses, the elastic properties of mandible is restricted according to the extent of 'splinting' by the superstructure and implants. To investigate the change of elastic behaviour of the mandible which has osseointegrated implant prosthesis of various numbers of implant installment and span of superstructre, a three dimensional finite element model was developed and analyzed with conditions mentioned above. The conclusions are as follows : 1. The displacements are primarily developed at the area of muscle attachment and distributed all around the mandible according to the various properties of bone. 2. The segmentation in the superstructure has few influence on the distribution of stress and displacement. 3. In the load case of ICP, the concentration of tensional stress was observed at the anterior portion of the ramus($9.22E+6N/m^2$) and at the lingual portion of the symphysis menti($8.36E+6N/m^2$). 4. In the load case of INC, the concentration of tensional stress was observed at the anterior portion of the ramus($9.90E+6N/m^2$) and the concentration of tensional stress was observed at the lingual portion of the symphysis menti($2.38E+6N/m^2$)). 5. In the load case of UTCP, the relatively high concentration of tensional stress($3.66E+7N/m^2$) was observed at the internal surface of the condylar neck.

• 치과방사선
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• 제12권1호
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• pp.57-61
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• 1982

The author has made a study on the classification of the mandibular 3rd molars of Korean youths through dental radiography by means of Pell & Gregory's classification and on the prevalence of the dental caries of distal surface of the mandibular 2nd molar adjacent to the mandibular 3rd molars turned anteriorly. The results are as follow; 1. It was found that the largest case number was class I (272 cases, 52.9%) in the relation of the tooth to the ramus of the mandible and 2nd molar. 2. The mesio-angular position was the largest number (239 cases, 46.5%) in the relation of the long axis of the impacted mandibular 3rd molar to the long axis of the 2nd molar. 3. The mesio-angular position of class I was the largest number (140 cases, 27.2 %) in the relation of the tooth to the ramus of the mandible and 2nd molar and the long axis of the impacted mandibular 3rd molar to the long axis of the 2nd molar. 4. The average angle of the long axis of mandibular 3rd molar in mesioangular position or horizontal position to the occlusal plane was 143° 5. Mandibular 3rd molar with lesion such as dental caries or pericoronitis was 73 cases (14.2). 6. The caries incidence rate of the distal surface of the 2nd molar was about 3.1%.

• Imaging Science in Dentistry
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• 제47권2호
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• pp.93-97
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• 2017

Purpose: The purpose of this study was to evaluate the accuracy of panoramic imaging in measuring the right and left gonial angles by comparing the measured angles with the angles determined using a lateral cephalogram of adult patients with class I malocclusion. Materials and Methods: The gonial angles of 50 class I malocclusion patients (25 males and 25 females; mean age: 23 years) were measured using both a lateral cephalogram and a panoramic radiograph. In the lateral cephalograms, the gonial angle was measured at the point of intersection of the ramus plane and the mandibular plane. In the panoramic radiographs, the gonial angle was measured by drawing a line tangent to the lower border of the mandible and another line tangent to the distal border of the ascending ramus and the condyle on both sides. The data obtained from both radiographs were statistically compared. Results: No statistically significant difference was observed between the gonial angle measured using the lateral cephalograms and that determined using the panoramic radiographs. Further, there was no statistically significant difference in the measured gonial angle with respect to gender. The results also showed a statistically insignificant difference in the mean of the right and the left gonial angles measured using the panoramic radiographs. Conclusion: As the gonial angle measurements using panoramic radiographs and lateral cephalograms showed no statistically significant difference, panoramic radiography can be considered in orthodontics for measuring the gonial angle without any interference due to superimposed images.