• The korean journal of orthodontics
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• v.29 no.1 s.72
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• pp.83-94
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• 1999

The purpose of this study was to evaluate the changes of cancellous and cortical bone and the effect of estrogen in ovariectomized rats. Fifty female rats, 250gm in body weight, were divided into three groups : ovariectomized group(OVE), ovariectomized and estrogen-injected group(OVE-EST), and sham operated and estrogen-injected group(EST). Bilateral ovariectomy was performed at the onset of the experiment. In OVE-EST group and EST group, estrogen was injected $50{\mu}g/kg$ B.W. every other days from 3 weeks after surgery to sacrifice. Each five rats were sacrificed after 5, 6, 7 weeks. One side of mandibular body was radiographed with a soft x-ray apparatus(Hitex Co., Ltd., Japan). Thereafter the obtained microradiographs were used for the morphometric analysis using a Image analyzer. The morphometric analysis was perforrmed for parameters such as total bone area, cortex bone area and medullary bone area. The other side of the mandibular bone was decalcified and embedded in paraffin as using a general method. The specimens were sectioned and stained with Mallory's anilline blue and observed light microscopically. The results were as follows. 1 In all groups, the proportion of cortex to total bone area was not significantly different. 2. In ovariectomized(OVE) group, the proportion of marrow cavity to medullary bone area increased significantly from 5 to 7 weeks(p<0.05). In ovariectomized and estrogen-injected(OVE-EST) group, it decreased significantly at 7 weeks, and in estrogen-injected(EST) group, it decreased significantly from 6 weeks(p<0.05). 3. Microradiogram and histopathologic findings revealed that marrow cavity was enlarged and osteoclasts were observed around irregular bone surface in OVE group. In OVE-EST group, the size of marrow cavity at 7 weeks was similar to that of control group. In EST group, as dense trabecular bone increased from 5 to 7 weeks, marrow cavity decreased.

• Imaging Science in Dentistry
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• v.39 no.1
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• pp.41-49
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• 2009

Purpose: To detect the progression of experimentally induced periapical lesions on periapical radiograph and cone beam computed tomograph (CBCT) by quantitative analysis. Materials and Methods: After the removal of coronal pulps from premolars of two Beagle dogs, the root canals of premolars were exposed to oral environment during one week and then sealed for 70 days. Digital periapical radiographs and CBCTs were taken at baseline and every 7 days for 77 days after pulp exposure. We examined occurrence and areas of periapical bone resorption. Three comparative groups of CBCT radiographs were prepared by average projection of thin slabs with different bucco-lingual thicknesses (0.1, 3.0, and 8.0 mm) using a 3D visualization software. Radiographic densities were compensated by image normalization. Digital images were processed with mathematical morphology operations. The radiographic density and morphological features of periapical lesions were compared among three groups of CBCT in different time points. Results: In the CBCT group with 0.1 mm thickness, radiographic density (p<0.05) and trabecular bone area (p<0.01) were significantly decreased at the fifth week. However, in the CBCT groups with 3 mm and 8 mm thickness and periapical radiographs, none of densitometric and morphological features showed any significant differences in different time points. Radiographic density of periapical lesion showed increasing tendency at the eleventh week after pulp exposure. Conclusion: Radiographic detection of periapical lesions was possible at the fifth week after pulp contamination by quantitative method and was affected by buccolingual bone thickness.

• Archives of Plastic Surgery
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• v.50 no.1
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• pp.49-53
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• 2023

Juvenile ossifying fibroma (JOF) is a variant of the ossifying fibroma and includes two histopathological subtypes: trabecular and psammomatoid. Psammomatoid JOF (PJOF) in craniofacial structures should be distinguished from other fibro-osseous lesions, such as fibrous dysplasia (FD), considering the difference in the treatment protocols. Here, we present a rare case of PJOF that was initially misdiagnosed as a case of FD and emphasize the importance of considering JOF in the differential diagnosis of patients with craniofacial fibro-osseous lesions. A 4-year-old boy demonstrated progressive enlargement of the zygomaticomaxillary area on his left side for the last 6 months. The patient was diagnosed as a case of FD based on the clinical features and radiographic findings, and was operated considering the rapid progression. To achieve facial symmetry, contouring of the zygomatic bone and arch was performed. However, the patient demonstrated rapid enlargement at the 3-month postoperative follow-up. The decision was made to surgically remove the tumor due to visual field impairment. Intraoperatively, a rubbery mass, which was separated from the surrounding cortical bone, was identified and excised. The lesion was confirmed as PJOF by histopathological examination. The possibility of PJOF should not be ruled out in the differential diagnosis of patients with fibrous-osseous lesions. In the event of suspected PJOF, accurate diagnosis should be made through definitive biopsy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.1
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• pp.83-88
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• 2011

The goal of this treatment is the surgical-orthodontic eruption of impacted permanent teeth associated with a large dentigerous cyst in a preadolescent patient. Although enucleation of the entire cyst and the extraction of impacted teeth are common treatments, missing permanent teeth cause several problems in young patients. In this report, an 11-year-old female visited with the chief complaint of a large radiolucent lesion from the mandibular anterior area to the left mandibular posterior area. The permanent left canine and premolars were displaced toward the mandibular inferior border area. The extraction of infected deciduous teeth and marsupialization were performed. After 4 months, orthodontic buttons for forced eruption were applied to the impacted permanent teeth. The teeth emerged into the oral cavity 3 months after the orthodontic treatment. Although the root form was abnormal, there were no other pathogenic signs. The alveolar bone had a normal trabecular pattern and the teeth appeared to be well maintained at postoperative 24 months.

• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.153-162
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• 1996

Rapid maxillary expansion is widely used for the correction of anteroposterior discrepancies, constriction of the maxillary arch, etc. This experiment was undertaken to examine the serial changes in the osteogenesis as well as the collagen fiber bundles in the intermaxillary suture during the rapid maxillary expansion treatment. Four young female dogs aged 6 to 8 months old and not showing menarche yet were used for the experiment. The maxillary impression of dogs were taken, expansion device cast and Hyrax screw soldered at the midline in the 1st premolar area. RME device was delivered to the dogs and the activation of 0.25 mm per quarter-turn was done 2 times per day for 10 days until 5 mm separation was made. Separation of the maxilla was confirmed by X-ray. The animals were sacrificed on 0, 15, 30, 60 days from the finish of maxillary separation and preparations for light microscopy and surface electron microscopy were made. The sutures were cut into frontal serial sections for examination of the histological reactions. The following results were obtained and the conclusions made. 1. The edges of the two palatal plates bordering the midpalatal suture which at the beginning of the retention period were mainly composed of compact bone, underwent extensive resorption followed by new bone formation and gradually became spongy bone rich in bone marrow which in the 60 day retention animal became the compact bone with short intermaxillary suture space. During this transformation, newly formed trabecular bone tissues were added to the original margin. 2. Throughout the expansion period, the collagen fibers underwent successive changes such as stretching, loss of polarity, and finally fibrillogenesis. Towards the end of the expansion procedure, sharpey's fiber formation in newly formed bones were observed. 3. Bony spicules were found in the initial stage of retention on occlusal topographic X-rays, which later were confirmed to have ossified. 4. Judging from the histological changes occuring during the experimental expansion, excessive expansion will cause an excessive bleeding, and retard the remodeling of intermaxillary suture. According to the above results, the bone remodeling after rapid maxillary expansion was preceded by the migration of migratory cells into the intermaxillary suture area. The bone remodeling phenomena were on-going during the 2 months retention sample.

• Archives of Craniofacial Surgery
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• v.12 no.1
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• pp.58-62
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• 2011

Purpose: The focal ossification of auricular cartilage is an unusual clinical entity in which the ear becomes partially or totally rigid and immalleable. This condition may result from cold injury, local trauma, inflammation, or various systemic diseases. Patients may feel mild discomfort, but there are usually no other serious symptoms. We present a case of focal ossification of auricular cartilage in which the cause is unknown. Methods: A healthy 58-year-old man presented with a 2-year history of hard mass of right posterior auricular area. He denied any precipitating historical events like cold injury and inflammation. Routine testing did not demonstrate systemic abnormalities. Ultrasonographic examination revealed a $22{\times}10{\times}11mm$ sized heterogenous isoechoic mass showing an acoustic shadow. Results: Excisional biopsy was performed under local anesthesia. Histological examination revealed the ossification with deposition of trabecular bone in normal elastic cartilage. The patient was healed without any problems and satisfied with the result. Conclusion: We report clinical experience of focal ossification of auricular cartilage, which is quite a rare clinical entity. It should be considered that there is the possibility of ossification of cartilage when it meets the benign mass of the ear.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.85-97
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• 1998

The purpose of this study was to observe the effects of sodium fluoride on the bony repair and regeneration processes after the rapid palatal expansion in the growing dogs. Eighteen dogs were divided into experimental and control groups. They were in the late mixed dentition. The rapid Palatal expansion was undertaken in all the animals($180^{\circ}$ turn/day) for ten days. The animals were sacrificed on 0, 15 and 45 days after the finish of expansion. One mg NaF/kg of body weight/day were given orally to the experimental group. Blood samples were drawn before and after expansion and the se겨m calcium, phosphate and alkaline phosphatase level were measured. The undecalcified bone section of midpalatal suture area was made, and observed under the light microscopy The results were as follows ; 1. The day after expansion, the infiltration of inflammatory cells were prominent and the new bone formation started at the edges of the two palatal plates bodering the midpalatal suture in both groups. Especially, the newly formed osteoid were very extensive and the osteoblasts lining the osteoid were very active in the experimental group. 2. At fifteen days after expansion, the active osteoblasts lining the osteold at the surface of trabecular bony spicules and active new bone formation were observed in the both groups. However, the cellular activity and new bone formation were more prominent In the experimental group. 3. At forty five days after expansion, the continuous osteoid and new bone formation and active osteoblasts were observed in the experimental group. But these phenomena were not observed in the control group. In the control group, the numerous osteoclasts were adjacent midpalatal suture and the bony remodeling process was begun. The serum alkaline phosphatase level was maintained highly in the experimental group, but decreased in the control. According to the above results, the author reached the conclusion that sodium fluoride has the stimulation effects on the osteoid production of the osteoblasts during the healing process after the rapid Palatal expansion more continuously.