• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.17 no.1
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• pp.233-248
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• 1987

The author studied the effect of periapical bone loss on radiographic interpretation by using a dry adult human mandible. Artificial bony lesions were created at the apices of two mandibular second molars and four mandibular bicuspids. The jaw was stabilized and various artificial lesions were radiographed under ideal circumstances. Radiographic pictures were recorded and compared with the size of the actual lesions. The obtained results were as follows: 1. The size of actual lesions were always larger than their radiographic pictures. 2. The size of actual lesion had a greater discrepancy in the molar area where the cortical plates were havier, but the lesions in the bicuspid areas were only slightely larger than their radiographic pictures, and in these areas the cortical plates were quite thin. 3 Periapical lesions located in cancellous bone did not appear on a radiograph, regardless of the size of the created lesion, but when the junctional bone was involved or the cortical plate was perforated, the definite bone destructive change was observed on the roentenogram. 4. Removal of the entire buccal or lingual plate did not affect the trabecular pattern of bone on the roentgenogram. 5. When the cancellous bone and junctional bone were removed simultaneously, altered trabecular patterns were observed on the roentgenogram.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.161-168
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• 1981

This study was undertaken to observe the histologic changes of surrounding maxillary sutures to the widening of midpalatal suture, using two adult dogs, weighing about 10 kg, for experimental, and one for control group. After widening of the midpalatal suture with expansion screw for ten days was performed, and followed by sacrifice of experimental animals. Tissues were excised from 5 surrounding maxillary suture portions such as, internasal, interfrontal, midsagittal, zygomatrco-temporal, and midpalatal sutures. After that, the specimens were fixed and decalcified in $10\%$ formalin sol. and $5\%$ nitric acid. Embedding in paraffin and serial sections at a thickness of 5 micron was done, After Hematoxylin-Eosin staining and light microscopic examination, Following results were obtained: 1. In midpalatal suture area, which showed most prominent histologic change, High degree of fibronlastic and osteoblastic proliferation lining the bony trabeculae with osteoid tissue projection into the fibrous connective tissue were observed. 2. In interfrontal suture area, moderate degree of fibroblastic and osteoblastic proliferation was observed. 3. In internasal suture area, active osteoblastic and osteoclastic proliferation lining the bony trabeculae was observed, and separation of fibrous connective tissue was also observed. 4. In midsagittal and zygomatico-temporal suture areas, no histologic changes can be observed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.563-569
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• 1996

Skeletal and dental changes were examined in 38 patients of mandibular prognathism who been treated by a bilateral sagittal split osteotomy(SSRO) and internal fixation using titanium mini-screws. All patients were followed up for over 8 months after the surgeries, and postoperative cephalometric measurements were compared at 2 months and at 8 months. Linear measurements of the "Pog-most posterior screws" and angular measurementsts of "SN-Pog'were compared to figure out the change of bony fragments. The significancy of data were tested by unpaired T-test. The results were as follows : 1. The fixation screws were changed in cephalometric position as little as $0.32{\pm}2.51mm$ in SSRO and $0.15{\pm}1.00mm$ in SSRO & Le Fort I Osteotomy.(P<0.05) 2. Mandibular set-back over 5mm resulted in less stability of the fixation screws and higher relapse tendency. 3. The internal fixation using two screws along the inferior border and one on the superior ridge is considered to be very resistant to postoperative relapse of the repositioned bony segments.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.3
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• pp.163-168
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• 2003

Three-dimensional solid model has not been widely used in surgical prediction of orthognathic surgery because frequent artifacts from occlusal restorations or prosthesis limited the usefulness of simulated surgery involving occlusion. We prepared three-dimensional(3D) solid model from CT data and integrated the 3D solid model with dental cast using a face-bow transfer technique combined with skeletal reference measurement and confirmation with cephalometric radiographs. With this simple and easy method, it was possible to predict bony interference between the proximal and distal segment of the mandible so that we can prevent condylar displacement after sagittal split ramus osteotomy of the mandible with prominent asymmetry. The method error was within 2mm and it seemed to be useful in preoperative planning for maxillofacial surgery with maxillo-mandibular occlusal change.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.493-500
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• 2001

Objective : Anterior cervical locking plates are the devices for achieving anterior cervical spinal fusion. This study was conducted to evaluate the locking plate system regarding its long-term advantages and disadvantages in the view of interbody fusion rate, hardware-related failures, vertebral change close to the fusion segment and postoperative complications. Method : Eight-six patients, operated from Jan., 1996 to Jun. 1998, were followed-up for more than two years. All of the cases were fused with iliac bone graft and ORION locking plate(Sofamor Danek USA, Inc., Memphis, TN) fixation. The patients were discharged or transferred to rehabilitation department 2-7 days after operation. A comprehensive evaluation of the interbody fusion state, instrument failure, vertebral change and postoperative complications were made by direct interview and cervical flexion-extension lateral plain films. Results : There were 55 male and 31 female with a mean age of 45 years(18-75 years). The mean follow-up period was 29 months(24-43 months). Various disorders that were operated were 40 cervical discs, 6 cervical stenosis including OPLL, 2 infections, and 38 traumas. Fusion level was single in 59 cases, two levels of each disc space in 15 cases, and two levels after one corpectomy in 12 cases. There was no instrument failure. Pseudoarthrosis was observed in two cases(2%) without radiological instability. The other patients(98%) showed complete cervical fusion with stable instrument. Mild settling of interbody graft with upward migration of screws was found in 12 cases(14%). Anterior bony growth at the upper segment was found in 5 cases(6%). Postoperative foreign body sensation or dysphagia was observed in 12 cases(4%), and disappeared within one month in 7 cases and within six months in 4 cases. One patient complained for more than six months and required reoperation to remove paraesophageal granulation tissue. Conclusion : The results show that Orion cervical locking plate has some disadvantages of upward migration of screws, anterior bony growth at the upper segment, or possibility of esophageal compression even though it has advantages of high interbody fusion rate or low instrument failure. Author believe that anterior cervical locking plate in the future should be thinner, and should have short end from the screw hole, and movable screw with adequate stability.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.4
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• pp.412-420
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• 1991

Seventeen rigid screw fixation and sixteen nonrigid wire fixation cases of mandibular sagittal slit ramus osteotomy were selected to compare postoperative dental and skeletal changes. A constructed horizontal plane was drawn seven degrees under sella-nasion plane and detailed cephalometirc assessment was applied to serial radiographic films taken before surgery($T_0$), immediately after surgery($T_1$), and at least six months after surgery($T_2$). Linear and angular positional changes were measured and analyzed statistically using paired t-test method and percent of positional changes(amount of post-op change/amount of intra-op change)${\times}100$. The results were as follows; 1. It was 29.4% in rigid fixation cases and 37.5% in nonrigid fixation cases comparing the postoperative positional change of more than 2mm at point B. So rigid fixation method was slightly more stable. 2. In nonrigid fixation cases, the positional change might be caused by incomplete bony union at the osteotomy site and soft tissue tension acting on this site. 3. In rigid fixation cases, the positional change might be caused by interaction between relapse tendency of protracted condyle-proximal segment and neighboring soft tissue tension.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.2
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• pp.265-276
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• 1990

The purpose of this experiment was to evaluate radiographic interpretation, of various sized 60 periapical and 60 cancellous lesions in 10 mandibular sections of 5 dogs according to kVp (65, 70, 75, 80 and 85 kVp). The results were as follows; The change of kilovoltage within 65kVp-85kVp range did not have influence on the radiographic interpretation of the same-sized bony defects at the constant radiographic density (p> 0.05). When the bony defects were less than the size of No.2 round bur, radiographic interpretation of bony defects prepared with No.2 round bur was easier than those prepared with No. 1 round bur at 80-85kVp in periapical region (p<0.05). However, in cancellous bone, this radiographic interpretation was easier at 65-75kVp (p<0.05). There were significant differences in the radiographic interpretation between the defects confined only to the cancellous, bone and the defects involved in the compact bone (p<0.05). However there were no significant differences between the defects confined only to the cancellous bone and the defects involved in junctional area of cancellous and compact bone (p>0.05). From the results of densitometric analysis, there was a difference in densitometric measurements at the same radiographic interpretation scores, and aluminum equivalent differences of 0.15-1.66㎜ thickness were needed for radiographic interpretation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.3
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• pp.157-170
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• 1993

To prove the effct of semi-rigid fixation which utilize wire and rigid fixation which utilizes miniplate toward cranio-facial growth and development of growing children for teenagers, 28 rabbits-6 weeks, about 1.5kg-were experimented. They were classified three groups the semi-rigid group was 12 rabbits which were fixed with 26 gauge stainless steel wire to cross a fronto-nasal suture, the rigid group was the other 12 rabbits which were fixed with miniplate and screw, the control group was 4 rabbits which were get rid of only periosteum. The sample of fronto-nasal of rabbits which were sacrified after 2 weeks, 4 weeks, 8 weeks, and 12 weeks of the operation were investigated and made a comparative study with the light microscops. 1. At the control group, the central part of bony suture was connected with colagen bundle, the osteoblastic layer was investigated at the bony ending, new bone which covered the inside and outside faces of the bone suture was formed between periosteum. 2. Two weeks later from the experiment, ran slightly irregularly the collagen bundle which connects both bony endings of the rigid group. 3. Four weeks later from the experiment, collagen bundle of bone surface were arranged parally a little and comparing to the semi-rigid group, newly formed woven bone of surface of the adjacent bone was made obviously a little. 4. Eight weeks later from the experiment, collagen bundle which is located between both bony ending become close. Both the semi-rigid group and the rigid group showed significant formation of new bone at the periosteum and the bone surface. 12 weeks later from the experiment, both the semi-rigid group and the rigid group showed the regular running in the collagen bundle and smooth, dense periosteum. Then they assumed a similar aspect of the control group. I think that it does not give the influence to the cranio-facial growth of children or teenager to utilize a rigid fixation for a short period. Because as the time goes on, the surface of the bone suture was recovered and adjacent bone surface of the miniplate fixation showed compensatory growth, although both the semi-rigid group which utilized wire and rigid group which utilized a miniplate brought about the change of the area of the bone suture at the early period.

• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.107-114
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• 2013

Purpose: This study is designed to evaluate the clinical and radiographical results for the displacement of fracture fragments after interlocking intramedullary nailing in humeral shaft fractures. Materials and Methods: We retrospectively reviewed the results of 8 cases of humeral shaft fractures that have displacements of over 10 mm and under 20 mm after interlocking intramedullary nailing between July 2004 and August 2011. The mean age was 54.1 years (range, 43 to 70 years) and there were 3 male and 5 female patients. Radiographically, the time to bony union, change of displacement and angulation of the fracture site, and degree of improvement of these two factors were measured. Clinically, the range of motion of shoulder and elbow joints, postoperative pain and complications were evaluated. Results: All cases showed complete bony union in last follow-up. The mean time to bony union was 16.1 weeks. At the last follow-up, almost all cases had normal range of motion of shoulder and elbow joints. But, one case had stiffness of shoulder joint. Therefore, arthroscopic capsular release and manipulation was performed. One case had transient shoulder pain and the other case had transient elbow pain. In the two cases, pull-out of proximal interlocking screw were noted, but they finally had bony union. Conclusion: Although considerable displacement of fracture fragments after interlocking intramedullary nailing in humeral shaft fractures was present, we had excellent radiographical and clinical outcomes. Therefore, an additional procedure, such as open reduction or another fixation for the fracture site, was not necessary.

• Imaging Science in Dentistry
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• v.35 no.2
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• pp.91-96
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• 2005

Purpose : To investigate the change of bone healing process after endodontic treatment of the tooth with an apical lesion by fractal analysis. Materials and Methods Radiographic images of 35 teeth from 33 patients taken on first diagnosis, 6 months, and 1 year after endodontic treatment were selected. Radiographic images were taken by JUPITER Computerized Dental X-ray $System^{(R)}$. Fractal dimensions were calculated three times at each area by Scion Image $PC^{(R)}$ program. Rectangular region of interest $(30\times30)$ were selected at apical lesion and normal apex of each image. Results : The fractal dimension at apical lesion of first diagnosis $(L_0)$ is $0.940{\pm}0.361$ and that of normal area $(N_0)$ is $1.186{\pm}0.727(p<0.05)$. Fractal dimension at apical lesion of 6 months after endodontic treatment $(L_1)$ is $1.076{\pm}0.069$ and that of normal area $ (N_1)$ is $1.192{\pm}0.055(p<0.05)$. Fractal dimension at apical lesion of 1 year after endodontic treatment $(L_2)$ is $1.163{\pm}0.074$ and that of normal area $(N_2)$ is $1.225{\pm}0.079(p<0.05)$. After endodontic treatment, the fractal dimensions at each apical lesions depending on time showed statistically significant difference. And there are statistically significant different between normal area and apical lesion on first diagnosis, 6 months after, 1 year after. But the differences were grow smaller as time flows. Conclusion : The evaluation of the prognosis after the endodontic treatment of the apical lesion was estimated by bone regeneration in apical region. Fractal analysis was attempted to overcome the limit of subjective reading, and as a result the change of the bone during the healing process was able to be detected objectively and quantitatively.