• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.1_2
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• pp.135-142
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• 1992

This study was performed to define the anatomical position of the mandibular canal and the findings during the sagittal split ramus osteotomy of the mandible. The mandibles of 20 adult Korean were used. The dimension of mandibular canal from the mandibular foramen to the 1st molar was measured at 4 specific coronal-sectional location by CT scan. The results were as follows ; 1. The distance from the mandibular canal to the medial aspect of the buccal cortical plate was greatest($4.5{\pm}1.1mm$) at 2nd molar area and was not significantly greater than at any other section. 2. Buccal cortex was thickest($3.8{\pm}0.9mm$) at 2nd molar and thinnest ($2.5{\pm}0.3mm$) mandibular foramen um 3. The distance from the mandibular canal to the medial aspect of the lingual cortical plate was not significant at any sections. 4. The distance from the mandible canal to the inferior border of mandible was greatest at the mandibular foramen($20.7{\pm}3.9mm$). The canal was located more closely to the inferior border at 1st, 2nd molar area 5. The diameter of the mandibular canal was between $2.5{\pm}0.3mm$ and $2.8{\pm}0.6mm$. 6. The total mandibular thickness was greatest($21.1{\pm}2.6mm$) at 2nd molar area and narrowest($17.2{\pm}3.2mm$) at mandibular foramen area.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.350-359
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• 2005

Sagittal split ramus osteotomy(SSRO) has been commonly performed in the mandibular prognathism. The previous studies of the mandibular anatomy for SSRO have mostly been used in dry skull without consideration of age, sex or jaw relationship of patients. This study was performed to evaluate the location of mandibular canal and the anatomy of ramus, such as the location of mandibular lingula and the ramal bone marrow, which were associated with SSRO procedures, in the patients with mandibular prognathism and normal young adults by using computerized tomographs(CT) and 3D images. The young adults at their twenties, who were considered to complete their skeletal growth, and seen in the Department of Orthodontics and Oral and Maxillofacial Surgery in Chonnam National University Hospital between March 2000 and May 2003, were selected. This study was performed in 30 patients (15men, 15women) who were diagnosed as skeletal class I normal relationship, and another 30 patients (15men, 15women) who were diagnosed as skeletal class III relationship upon clinical examination and lateral cephalometric radiographs. The patients were divided into 2 groups : Class I group, the patients who had skeletal class Ⅰ normal relationship(n=30, 15men, 15women), and Class III group, the patients who had skeletal class III relationship(n=30, 15men, 15women). Facial CT was taken in all patients, and pure 3D mandibular model was constructed by V-works version 4.0. The occlusal plane was designed by three points, such as the mesiobuccal cusp of both mandibular 1st molar and the incisal edge of the right mandibular central incisor, and used as a reference plane. Distances between the tip of mandibular lingula and the occlusal plane, the sigmoid notch, the anterior and the posterior borders of ramus were measured. The height of ramal bone marrow from the occlusal plane and the distance between mid-point of mandibular canal and the buccal or lingual cortex of the mandible in the 1st and 2nd molars were measured by V-works version 4.0. Distance(Li-OP) between the occlusal plane and the tip of mandibular lingula of Class III Group was longer than that of Class I Group in men(p<0.01), but there was no significant difference in women between both groups. Distance(Li-SN) between the sigmoid notch and the tip of mandibular ligula of Class III group was longer than that of Class I Group in men(p<0.05), but there was no significant difference in women between both groups. Distance(Li-RA) between the anterior border of ramus and the tip of mandibular lingula of Class III Group was shorter than that of Class I Group in men and women(p<0.01). Distance(Li-RP) between the posterior border of ramus and the tip of mandibular lingula of Class III Group was slightly shorter than that of Class I Group in men(p<0.05), but there was no significant difference in women between both groups. Distance(RA-RP) between the anterior and the posterior borders of ramus of Class III Group was shorter than that of Class I Group in men and women(p<0.01). Longer the distance(SN-AN) between the sigmoid notch and the antegonial notch was, longer the vertical ramal length above occlusal plane, higher the location of mandibular lingula, and shorter the antero-posterior ramal length were observed(p<0.01). Height of ramal bone marrow of Class III Group was higher than that of Class I Group in men and women(p<0.01). Distance between mandibular canal and buccal cortex of Class III Group in 1st and 2nd lower molars was shorter than that of Class I Group in men and women (p<0.05 in 1st lower molar in men, p<0.01 in others). These results indicate that there are some anatomical differences between the normal occlusal patients and the mandibular prognathic patients, such as the anterior-posterior length of ramus, the height of ramal bone marrow, and the location of mandibular canal.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.3
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• pp.196-204
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• 2002

For the study of its stability when the screw has been fixed after sagittal split ramus osteotomy(SSRO) of the mandible, the methods of screw arrangement are classified into two types, triangular and straight. The angles of screws to the bone surface are classified as perpendicular arrangements, the $60^{\circ}$ anterioinferior screw, known as triangular, and the most posterior screw, called straight arrangement, thus there are four types. The finite element method model has been made by using a three dimensional calculator and a supercomputer. The load directions are to the anterior teeth, premolar region, and molar region, and the bite force is 1 Kgf to each region. The distribution of stress, the von-Mises yield strength, and safety of margin refer to the total sum of transformed energy have been studied by comparison with each other. The following conclusion has been researched : 1. When shear stress is compared, in the triangular arrangement in the form of "ㄱ", the anterosuperior screw is seen at contributing to the support of the bone fragment. In the straight arrangement, substantial stress is seen to be concentrated on the most posterior angled screw. 2. When the von-Mises yield strength is compared, it seemed that the stress concentration on the angled anteroinferior screw is higher, it shows a higher possibility of fracture than any other screw. In the straight arrangement, stress appeared to be concentrated on the most posteriorly angled screw. 3. When the safety margins of the transfomed energy are compared, the energy conduction is much greater in the case of the angled screw than in the case of the perpendicular screw. The triangular arrangement in the form of "ㄱ" shows a superior clinical sign to that of the straight arrangement. Judging from the above results, when the screw fixation is made after SSRO in practical clinical cases, two screws should be inserted in the superior border of mandibular ramus and a third screw of mandibular inferior border should be inserted in the form of triangular. All screws on the bony surface should be placed perpendicularly-$90^{\circ}$ angles apparently best promote bony support and stability.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.197-208
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• 1997

The purpose of this study was to evaluate the amount and interrelationship of the soft and hard tissue change after mandibular setback surgery in skeletal Class III malocclusion. The sample consisted of 25 adult patient (12 male and 13 female) who had severe anteropostrior skeletal discepancy. These patient had received presurgical orthodontic treatment and surgical treatment which is bilateral sagittal split ramus osteotomy. The presurgical and postsurgical lateral cephalograms were evaluated. The computerized statistical analysis was carried out with SPSS/PC program. The result were as follows: 1. After mandibular bilateral sagittal split ramus osteotomy, lower facial soft. tissue horizontal posterior changes were high significance value. but vertical soft tissue changes were low significance value. 2. After mandibular bilateral sagittal split ramus osteotomy, relative upper lip protrusion increased(p<0.01) and relative lower lip protrusion decreased(p<0.01) and lower facial soft tissue thickness increased(p<0.01).

• The korean journal of orthodontics
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• v.15 no.1
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• pp.23-42
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• 1985

The morphology and growth changes of the Craniofacial Complex are important in orthodontics and cephalometrics for analysis and evaluation of facial bone growth are widely used. The author analyzed the data using lateral cephalometric roentgenogram of 75 Korean male and 50 Korean females age of 6 to 10 with normal occlusion to provide informations-relative rates of facial bone growth of Korean which is to be contributed in Korean standard. The results were as follows: 1. Means, standard deviation and coefficient of variation of Korean children were obtained. 2. The item which showed significent difference between male and female was craniofacial height in absolute dimension. 9. No difference of sex was showed in increment of craniofacial height and depth. 4. Among the craniofacial depth increments, the lower facial depth dimension increased most, midfacial depth dimension increased less, and cranial depth dimension increased the least. 5. The horizontal body of mandible showed rapid growing tendency more than did the ascending ramus.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.2
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• pp.521-537
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• 1998

The calcifying epithelial odontogenic tumor is a rare benign odontogenic neoplasm which was first described by Pindborg in 1955 and accounts for less than 1％ of all odontogenic tumors. The tumor occurs primarily in the molar-premolar region of the mandible, and 52％ of cases are associated with an unerupted tooth. The clinical feature is most commonly a slow-growing painless swelling. The tumor may show considerable radiographic variation and usually characteristic histopathologic features. In this study, we report a case of the calcifying epithelial odontogenic tumor on the left mandibular body and ramus area in a 28-year-old male with a brief review of the concerned literatures.

• Imaging Science in Dentistry
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• v.30 no.3
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• pp.229-234
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• 2000

Cleidocranial dysplasia (previously known as cleidocranial dysostosis) is a well-known, rare and hereditary skeletal disorder characterized by a variety of dental abnormalities and as its name implies, striking involvement of the cranial vaults and clavicles. A 17-year-old female who presented with short stature and prolonged retention of deciduous teeth, subsequent delay in eruption of permanent teeth is described. She could touch her shoulders together at the midline anteriorly. Diagnostic procedures showed hypoplasia of the maxillary and zygomatic bones, open fontanelles and sutures, and aplasia of the clavicles. The paranasal sinuses were absent or underdeveloped. Characteristically, she had near parallel-sided borders in the ascending ramus of the mandible and abnormal-shaped, the slender pointed coronoid process. The zygomatic arches had a downward bend and discontinuity at the zygomaticotemporal suture area. Radiographic and clinical investigations of her cranial and skeletal abnormalities revealed features of cleidocranial dysplasia.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.2
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• pp.195-201
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• 1995

This is a case report of calcifying aponeurotic fibroma occurred in the right pterygopalatine fossa & ramus area accompanied by adenoid cystic carcinoma of the right sublingual gland of a 44-year-old female. Calcifying aponeurotic fibroma is benign tumor, but it is characterized by poorly marginated, infiltrated growth pattern and a stubborn tendency to local recurrence, but there is no record of malignant transformation or metastasis, and surgical management should be conservative(excision and reexcision). Most cases been reported at the hands and feet, but no reported case occuring in the head region is found in the literature. Adenoid cystic carcinoma is a slow-growing infiltrative tumor with high recurrence rate, and it's treatment requires radical excisin and radiotherapy. Wide surgical excision of tumor, RND and partial resection of mandible were done. And then, immediate mandibular reconstruction was performed by means of reimplantaion technique after autoclaving of the resected bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.3
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• pp.148-151
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• 2023

Schwannomas are benign tumors originating from myelinating cells constituting nerve sheaths but rarely contain cellular elements of the nerve. The authors encountered a 47-year-old female patient with a schwannoma on the anterior mandibular ramus arising from the buccal nerve, measuring 3 cm×4 cm. Surgical resection was performed with preservation of the buccal nerve via microsurgical dissection. After one month, the sensory function of the buccal nerve was recovered without complications.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.184-188
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• 2001

Horner's syndrome as a complication of orthognathic surgery is given little attention of head and neck surgery and is a relatively benign and transient condition. A 18-year-old male referred to our department with long and anteriorly projected chin. The cephalometric evaluation revealed a skeletal Class III relationship. A 10-mm setback of the mandible to eliminate Class III relationship and 4-mm vertical reduction genioplasty were performed. Three weeks after operation, the patient was recognized anhidrosis in left face and the head, and ptosis of left eye. The trauma to cervical sympathetic nerve during left sagittal split ramus osteotomy was thought to be the cause of Horner's syndrome. Patient was treated by dermatologic and opthalmologic care. Follow-up examination 8 months later, he was recovery of horner's symptom.