• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권5호
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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.

• Imaging Science in Dentistry
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• 제33권4호
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• pp.239-244
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• 2003

Malignant fibrous histiocytoma (MFH) is a pleomorphic soft tissue sarcoma. Three cases of MFH were reported in our study. The first case involved in the right infratemporal fossa of a 32-year-old female was presented. MR imaging revealed a 5.0 × 3.3 cm soft tissue mass of inhomogeneous high signal intensity. The second case was found in the right hard palate of a 66-year-old male. CT demonstrated bone destruction and MR imaging showed a 4 × 4 cm sized soft tissue mass of heterogeneous high signal intensity. The final case was found in the left masticator space of a 37-year-old male. The CT image showed a large mass with massive bone destruction of the left mandibular ramus, while the MRI displayed a soft tissue mass, 8 cm diameter. Our cases exhibited the general features of MFH. MRI is essential in the imaging of MFH, namely to depict tumor borders and demonstrate relationships with adjacent structures.

• 대한치과교정학회지
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• 제17권1호
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• pp.135-148
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• 1987

To investigate the relationship between craniofacial growth and bone maturity of the hand wrist in normal occlusion, the author took cephalogram and handwrist radiogram of 391 students (male 192, female 199) and assessed the measurements of cephalogram according to skeletal maturity stages of the hand and wrist. In this study, four skeketal stages and 36 linear, angular measurements of the cephalometrics were selected. In hand-wrist X-ray the bones used to determine skeletal maturity were the middle phalanges of the third finger, and distal epiphysis of the radius. In cephalogram, the landmark used to measure the angle and length were N, S, Po., Ar., Go., Me., Gn., Pog., Point B, Point A, ANS, PNS, Or., U1, L1, U6, L6 etc.. The results were as follows, 1. The table of mean, standard deviation, p-value from measurements were made in each group and both sex. 2. The increased measurements according to skeletal maturity were anterior cranial bese length, posterior cranial base length, ramus height, anterior facial height, posterior facial height, L1 to mandibular plane (mm), facial plane angle. In contrast to, decreased measurements were genial angle, facial cnvexity and facial plane angle. 3. Denture pattern measurements (IMPA, FMIA, occlusal plane to Go-Gn, interincisal angle, U1 to SN plane, U1 to SN plane, U1 to facial plane, L1 to facial plane etc.) .had nothing to do with skeletal maturity. 4. Skeletal maturity had close relationship with craniofacial growth, but had little to do with tooth development.

• 대한치과교정학회지
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• 제20권2호
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• pp.293-304
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• 1990

The purpose of this study was to describe the morphologic differences between long-face adults and normal-face adults on the lateral and P-A cephalograms. Long-face and normal-face subifects were selected clinically, and then each of them was taken the lateral cephalogram. According to SN-MP angle and ATFH on the lateral cephalogram, long-face group and normal-face group were classified. 2 long-face adults and 18 normal-face adults were collected, and each of them was taken the P-A cephalogram. The results were as follows: 1. The morphologic differences between long-face adults and normal-face adults were closely related to mandibular morphology. 2. Long-face adults, compared with normal-face adults, demonstrated significant increase in ALFH, and significant decrease in ramus height. 3. Long-face adults, compared with normal-face adults, demonstrated significant increase in AUDH and, ALDH, especially in ALDH. 4. On the P-A cephalogram, no measures of transverse dimension demonstrated significant differences between two groups. 5. On the P-A cephalogram, facial height/facial width ratio was significantly larger than normal in the long-face adults, and in the normal-face adults, facial height/facial width ratio was approximately 90%. 6. In the correlation analysis of SN-MP angle and ATFH with all the other variables, the correlation coefficients of SN-MP angle and PTFH/ATFH that of ATFH and ALFH on the lateral cephalogram demonstrated the highest value, and on the P-A cephalogram, SN-MP angle and Cg-GA-Me (Lt.), ATFH and lower facial height demonstrated the highest value of correlation coefficients.

• 대한치과교정학회지
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• 제50권2호
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• pp.136-144
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• 2020

Hemifacial microsomia (HFM) patients may experience emotional withdrawal during their growth period due to their abnormal facial appearance. Distraction osteogenesis at an early age to improve their appearance can encourage these patients. Some abnormalities of the affected side can be overcome by distraction osteogenesis at an early age. However, differences in the growth rate between the affected and unaffected sides during the rest of the growth period are inevitable due to the characteristics of HFM. Therefore, re-evaluation should be performed after completion of growth in order to achieve stable occlusion through either orthognathic surgery or camouflage orthodontic treatment. An eight-year-old patient visited the clinic exhibiting features of HFM with slight mandibular involvement. He received phase I treatment with distraction osteogenesis and a functional appliance. Distraction osteogenesis was performed at the right ramus, which resulted in an open bite at the right posterior dentition. After distraction osteogenesis, a functional appliance and partial fixed appliance were used to achieve extrusion of the affected posterior dentition and settlement of the occlusion adjustment on the unaffected posterior dentition. The patient visited the clinic regularly for follow-up assessments, and at the age of 20 years, he showed facial asymmetry of the mandible, which had deviated to the right side. He received orthodontic treatment to improve the occlusion of his posterior dentition after the growth period. Without orthognathic surgery, stable occlusion and a satisfactory facial appearance were obtained through camouflage orthodontic treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권2호
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• pp.89-93
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• 2009

Purpose: The purpose of this study is to investigate the clinical and histological features of odontogenic keratocyst Patients and Methods: A retrosective review of 100 patients who were diagnosed as odontogenic keratocyst by hitological findings during the period of January 2000 and December 2005 in the Dept. of Oral and Maxillofacial surgery Pusan National University was consecuted. For each patient, age, sex, location of lesion, initial diagnosis by radiographic features, treatment procedure, hitologic findings and recurrance rate were evaluated. Results: In this study, OKC has male prevalance to female by 1.38:1, and most likely occurs during third decade. The most common site of lesion was mandibular ramus region(34.6%) and the most common symptom was swelling(50%). The most common initial diagnosis by radiographic findings was OKC and cyst enucleation was the most common treatment method. The recurrance rate was 28% and existence of daugther cyst is thought to be most convincing factor for prediction of recurrence. Conclusion: In this study, total recurrence rate was 28% and existence of daugther cyst is thought to be most convincing factor for prediction of recurrence. But, since 97% of patients were treated by enucleation and adjuntive excision, further styudy is need about concordance of recurrence rate with surgical method.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권1호
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• pp.11-16
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• 2014

Objectives: The aim of this study was to evaluate the pattern of lingual split line when performing a bilateral sagittal split osteotomy (BSSO) for asymmetric prognathism. This was accomplished with the use of cone-beam computed tomography (CBCT) and three-dimensional (3D) software program. Materials and Methods: The study group was comprised of 40 patients (20 males and 20 females) with asymmetric prognathism, who underwent BSSO (80 splits; n=80) from January 2012 through June 2013. We observed the pattern of lingual split line using CBCT data and image analysis program. The deviated side was compared to the contralateral side in each patient. To analyze the contributing factors to the split pattern, we observed the position of the lateral cortical bone cut end and measured the thickness of the ramus that surrounds the mandibular lingula. Results: The lingual split patterns were classified into five types. The true "Hunsuck" line was 60.00% (n=48), and the bad split was 7.50% (n=6). Ramal thickness surrounding the lingual was $5.55{\pm}1.07$ mm (deviated) and $5.66{\pm}1.34$ mm (contralateral) (P =0.409). The position of the lateral cortical bone cut end was classified into three types: A, lingual; B, inferior; C, buccal. Type A comprised 66.25% (n=53), Type B comprised 22.50% (n=18), and Type C comprised 11.25% (n=9). Conclusion: In asymmetric prognathism patients, there were no differences in the ramal thickness between the deviated side and the contralateral side. Furthermore, no differences were found in the lingual split pattern. The lingual split pattern correlated with the position of the lateral cortical bone cut end. In addition, the 3D-CT reformation was a useful tool for evaluating the surgical results of BSSO of the mandible.

• Imaging Science in Dentistry
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• 제32권4호
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• pp.201-206
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• 2002

Purpose : To evaluate the radiographic change of operation sites after orthognathic surgery using the digital image processing and fractal analysis. Materials and Methods : A series of panoramic radiographs of thirty-five randomly selected patients who had undergone mandibular orthognathic surgery (bilateral sagittal split ramus osteotomy) without clinical complication for osseous healing, were taken. The panoramic radiographs of each selected patient were taken at pre-operation (stage 0), 1 or 2 days after operation (stage 1), 1 month after operation (stage 2), 6 months after operation (stage 3), and 12 months after operation (stage 4). The radiographs were digitized at 600 dpi, 8 bit, and 256 gray levels. The region of interest, centered on the bony gap area of the operation site, was selected and the fractal dimension was calculated by using the tile-counting method. The mean values and standard deviations of fractal dimension for each stage were calculated and the differences among stage 0, 1, 2, 3, and 4 were evaluated through repeated measures of the ANOVA and paired t-test. Results : The mean values and standard deviations of the fractal dimensions obtained from stage 0, 1, 2, 3, and 4 were 1.658±0.048, 1.580±0.050, 1.607±0.046, 1.624±0.049, and 1.641 ±0.061, respectively. The fractal dimensions from stage 1 to stage 4 were shown to have a tendency to increase (p < 0.05). Conclusion: The tendency of the fractal dimesion to increase relative to healing time may be a useful means of evaluating post-operative bony healing of the osteotomy site.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권6호
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• pp.584-588
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• 2008

Facial asymmetry is particularly associated with mandible among other facial bones and it could be either congenital or acquired. Congenital factors are related to Treacher Collin syndrome, Pierre Robin syndrome, hemifacial microsomia and other various syndromes. Acquired factors are such as damaged or diseased growing condyles, hormonal disorder, oral mal-habit, muscular force, tumor, infection and so on. Diagnosis and treatment of facial asymmetry are complicated due to differences in sizes and positions of mandibles. The aspects of facial asymmetry is various and complicated upon each individual. Depending on causes of the facial asymmetry, there also are morphological differences. For such reasons, precise anatomical analysis and diagnosis of the facial asymmetry are essential before any surgical procedure followed by the appropriate treatment plan. This case is regarding a 21-year old patient diagnosed as the facial asymmetry due to an infantile maxillofacial surgery. Employing various morphological evaluations, potential problems during the procedure are predicted beforehand. This case reports a favorable result of sagittal split ramus osteotomy performing the oblique vertical bone cutting in posterior-superior of the mandibular second molar.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권2호
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• pp.158-166
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• 2009

The application of CT with basis on 3 dimensional-reconstruction is getting more widely practiced. With the data obtained from cone-beam computed tomography(CBCT), not only the diagnosis of the patient with skeletal abnormality but also the virtual simulation of the orthognathic surgery were performed and its application would be popular in orthodontic field. We reported a case, a 19-year old man who was diagnosed mandibular prognathism and required orthognatic surgery. In this case, the virtual orthognathic surgery was simulated and surgical wafer was fabricated by using CBCT data. That wafer was applied the actual orthognathic surgery. After preoperative orthodontic treatment, we prepared surgery as follows. : (l)Acquisition of 3D image data, (2)Reconstruction of 3-dimensional virtual model, (3)Virtual model surgery, (4)Extraction of stere-olithographic image, (5)Check-up for occlusal interference, (6)Fabrication of surgical stent by stereolithography. Bilateral sagittal split ramus osteotomy was operated and used stereolithographic surgical stent. 1 month later, we superimposed CBCT datas of virtual surgery and that of actual surgery, and then compared the result. CT data's application for othognathic surgery yielded satisfactory outcomes.