• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권2호
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• pp.130-136
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• 2005

Bone grafts are widely used in the reconstruction of osseous defects in the oral and maxillofacial region. Autogenous bone grafts are considered the gold standard in grafting of the oral and maxillofacial region, because of its osteoconductive and osteoinductive properties. Mandibular symphysis & ascending ramus bone graft have been used more frequently because of easy surgical access, reduced operative time, and following minimal morbidity. However, even though the frequent use of the anterior part of ascending ramus and the different regions of mandible, rare of the reports provide information about the quantity of bone available in this donor site. So this study was taken to evaluate & quantify the amount of bone graft material in the anterior ascending ramus regions. This study was made on 36 samples of CT image. In 3D volume image, imaginary osteotomy & segmentation were done and the dimensions and volume of the bone grafts were measured and evaluated. the average volume of the graft materials obtained from the ascending ramus was $3656.83{\pm}108.19mm^3$, and the average dimensions of graft materials were $(33.68{\pm}0.48){\times}(34.92{\pm}0.51){\times}(15.96{\pm}0.27){\times}(9.05{\pm}0.27)mm$.

• Imaging Science in Dentistry
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• 제46권3호
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• pp.223-227
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• 2016

A static, unilateral, and focal bone depression located lingually within the ascending ramus, identical to the Stafne's bone cavity of the angle of the mandible, is being reported. During development of the mandible, submandibular gland inclusion may lead to the formation of a lingual concavity, which could contain fatty tissue, blood vessels, or soft tissue. However, similar occurrences in the ascending ramus at the level of the parotid gland are extremely rare. Similar cases were previously reported in dry, excavated mandibles, and 3 cases were reported in living patients. A 52-year-old African American male patient was seen for pain in the mandibular teeth. Panoramic radiography showed an unusual concavity within the left ascending ramus. Cone-beam computed tomography confirmed this incidental finding. The patient was cleared for the extraction of non-restorable teeth and scheduled for annual follow-up.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권6호
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• pp.539-544
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• 2011

Maxillary canting and vertical shortening of the unilateral mandibular ramus height is common in cases of severe facial asymmetry. Normally, mandibular distraction osteogenesis (DO) with horizontal osteotomy at the ascending ramus is used for vertical lengthening of the mandibular ramus to correct facial asymmetry with an absolute shortened ascending ramus. In this case report, vertical lengthening of the ascending ramus was performed successfully with unilateral DO and sagittal split ramus osteotomy (SSRO), where the posterior part of the distal segment can be distracted simultaneously in an inferior direction with maxillary DO, resulting in a lengthening of the medial pterygoid muscle. This case describes the acquired unilateral mandibular hypoplasia caused by a condylar fracture at an early age, which resulted in abnormal mandibular development that ultimately caused severe facial trismus. The treatment of this case included two-stage surgery consisting of bimaxillary distraction osteogenesis for gradual lengthening of the unilateral facial height followed by secondary orthognathic surgery to correct the transverse asymmetry. At the one year follow-up after SSRO, the vertical length was maintained without complications.

• 대한치과교정학회지
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• 제14권1호
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• pp.75-92
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• 1984

This study attempted to analyze the distribution of stress, to examine the bending effect in the mandible according to the pulling directions and determine on which pulling directions are adequate when an orthopedic force was applied to the mandible. An orthopedic force, 500gm, was applied to the gnathion, one point of the chin area, in three directions. The three directions were ; high puli' from gnathion to the center of condyle head, and vertical pull, from gnathion to a parallel line with the posterior border of the ramus, and medium pull, from the gnathion to a parallel line with the lower border of mandible. The distribution of principal stress, bending moment and amount of displacement within the mandible was analyzed by a 3-dimensional finite element method and that of the various portions of mandible were computed and compared according to the pulling directions. The results were as follows : 1. The bending moment of each part of a mandible has been found to be markedly larger in case of vertical pull than in case of either high pull or medium pull. In vertical pull the bending moment turned out to largest at the condyle head and neck portion, the gonial angle portion, the coronoid portion and the ascending ramus portion, respectively, while comparatively large at the cuspid and bicuspid portion and the first molar portion. In case of high pull it was largest at the gonial angle portion and becoming smaller at the coronoid portion, the ascending ramus portion, the condyle head and neck portion, and the cuspid and bicuspid portion, in that order. In case of medium pull, however, the bending moment was largest at the condyle head and neck portion, becoming smaller at the first molar portion, the ascending ramus portion, the coronoid portion, the cuspid and bicuspid portion, and gonial angle portion, in that order. 2. As for the bending effect it was calculated to be mostly oriented downward at the mandibular body and backward at the mandibular ramus in both high pull and vertical pull. In case of medium pull it was oriented upward at the mandibular body and forward at the mandibular ramus. 3. The bending effect also turned out to be mostly oriented outward in case of high pull and medium pull, and inward in vertical pull. 4. At the mandibular body and ramus, the bending effect in the upward-downward direction and that in the forward-backward direction were found to be larger than in the inward-outward direction. 5. If and when we expect any correcting effect on the mandibular protrusion by means of the chin cup appliance, we can say sure as conclusion that high pull and vertical pull are more effective than medium pull.

• 대한치과의사협회지
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• 제17권1호통권116호
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• pp.29-34
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• 1979

• Imaging Science in Dentistry
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• 제46권2호
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• pp.77-85
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• 2016

Purpose: To analyze the relative position of the mandibular foramina (MnFs) in patients diagnosed with skeletal class III malocclusion. Materials and Methods: Computed tomography (CT) images were collected from 85 patients. The vertical lengths of each anatomic point from the five horizontal planes passing through the MnF were measured at the coronoid process, sigmoid notch, condyle, and the gonion. The distance from the anterior ramus point to the posterior ramus point on the five horizontal planes was designated the anteroposterior horizontal distance of the ramus for each plane. The perpendicular distance from each anterior ramus point to each vertical plane through the MnF was designated the horizontal distance from the anterior ramus to the MnF. The horizontal and vertical positions were examined by regression analysis. Results: Regression analysis showed the heights of the coronoid process, sigmoid notch, and condyle for the five horizontal planes were significantly related to the height of the MnF, with the highest significance associated with the MnF-mandibular plane (coefficients of determination ($R^2$): 0.424, 0.597, and 0.604, respectively). The horizontal anteroposterior length of the ramus and the distance from the anterior ramus point to the MnF were significant by regression analysis. Conclusion: The relative position of the MnF was significantly related to the vertical heights of the sigmoid notch, coronoid process, and condyle as well as to the horizontal anteroposterior length of the ascending ramus. These findings should be clinically useful for patients with skeletal class III mandibular prognathism.

• 대한치과의사협회지
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• 제14권7호
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• pp.575-579
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• 1976

• Imaging Science in Dentistry
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• 제35권4호
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• pp.215-219
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• 2005

Hepatocellular carcinoma is one of the most common cancer worldwide, primarily affecting those in regions with a high prevalence of viral hepatitis. However, the metastasis of hepatocellular carcinoma to the oral cavity is a rare phenomenon. This report presents a case of metastatic hepatocellular carcinoma in the left mandibular angle and ramus region of a 62-year-old man. Panoramic radiograph revealed an ill-defined radiolucent lesion extending from the retained root of the mandibular left second molar into the ascending ramus. The lesion had irregular and ill-defined margins.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권4호
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• pp.253-256
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• 2009

Schwannoma(neurilemmoma) is a benign neoplasm that originates from the Schwann cells. Schwannoma most commonly arises in the soft tissue of the head and neck. Intraoral lesions are uncommon, however, and intraosseous schwannoma are even rare. The most common site of occurrence for these unusual lesions is the mandible. This article documents a case of an intraosseous schwannoma located in the mandibular ascending ramus. The lesion was surgically removed and no radiographic evidence of recurrence was observed after 1 year.

• 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.