• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.170-179
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• 2000

The rh-BMP-4 is a subgroup of TGF-${\beta}$ superfamily. The application of rh-BMP in alveolar bony defect was reported to new alveolar bone and new cementum formation. For minimized complications following tooth replantation, a operator must replant a tooth fast at the pertinent position. This study was to evaluate the effect of rh-BMP-4 on periodontal regeneration and root resorption following tooth replantation in rats. The 50 Sprague-Dawley rats weighting about 130gm were used in this study. The animals were divided into three groups. Group 1 ; immediate replantation after extraction : Group 2 ; replantation stored teeth extraction of first molar, the removal of periodontal ligament with collagenase, and etching with citric acid : Group 3 ; replantation stored teeth with treated rh-BMP-4 in mesial root. Experimental animals were sacrificed 3, 7, 14 days after replantation by heart infusion. The maxillae were removed, fixed, demineralized, dehydrated, infiltrated and embedded with JB-4 mixture. For light microscopic observation, 5 micron sections were cut and stained with toluidine blue. The results of this study were as follows : 1. After experimental 3 days, all groups were observed dead space between periodontum and root. 2. After experimental 7 days, group 1 and group 3 were observed filling periodontal fibers between alveolar bone and root but group 2 were not. 3. After experimental 7 days, group 3 were observed appearance of attached cementoblast like cell on root surface. Group 1 were observed regular arrangement of fibroblasts and collagen fibers at ${\times}400$ observation. 4. After experimental 14 days, all group were observed filling periodontal fibers between alveolar bone and root. Group 1 were observed normal arrangement of periodontal fibers. Group 3 were observed less abnormal arrangement of periodontal fibers. Group 2 were not observed functional normal arrangement of periodontal fibers. 5. After experimental 14 days, group 2 and 3 were observed several root resorption and irregular root surface but group 1 were not. These results suggest that the rh-BMP-4 can stimulate cementogenesis and enhance to attach collagen fibers.

• Imaging Science in Dentistry
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• v.44 no.1
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• pp.85-88
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• 2014

Osteosarcoma is a classical malignant bone-forming neoplasm which usually presents with an aggressive clinical course. The current case is presented with the radiographic feature of widening of the periodontal ligament space of the involved teeth, which is considered to be the earliest radiographic manifestation of osteosarcoma involving the jaw bone. The main aim of this case report was to focus on the importance of early diagnosis of this tumor based on clinical and radiographic examinations, and confirmation by histopathology. Considering the rarity of the disease type and particularly taking into account the fast progression and aggressiveness of this neoplasm, it is clear that the presentation of a clinical case represents a major contribution to better understanding of osteosarcomas involving the jaw bone.

• Journal of Periodontal and Implant Science
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• v.46 no.6
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• pp.396-404
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• 2016

Purpose: The aim of this retrospective study was to determine the association between dental implants in the posterior region and traumatic occlusion in the adjacent premolars, using data collected during from 2002 to 2015. Methods: Traumatic occlusion in the adjacent premolars was assessed by examining clinical parameters (bleeding on probing, probing pocket depth, fremitus, and tooth mobility) and radiographic parameters (loss of supporting bone and widening of the periodontal ligament space) over a mean follow-up of 5 years. Clinical factors (gender, age, implant type, maxillary or mandibular position, opposing teeth, and duration of functional loading) were evaluated statistically in order to characterize the relationship between implants in the posterior region and traumatic occlusion in the adjacent premolars. Results: The study inclusion criteria were met by 283 patients, who had received 347 implants in the posterior region. The incidence of traumatic occlusion in the adjacent premolars was significantly higher for splinted implants (P=0.004), implants in the maxillary region (P<0.001), and when implants were present in the opposing teeth (P<0.001). The other clinical factors of gender, age, and duration of functional loading were not significantly associated with traumatic occlusion. Conclusions: This study found that the risk of traumatic occlusion in the adjacent premolars increased when splinted implants were placed in the maxillary molar region and when the teeth opposing an implant also contained implants.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.401-409
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• 1997

The purpose of this study was to analize the initial stress distribution around apex and the alveolar bone of the upper anterior teeth when applying intrusive force by the use of utility arthwire, Burstono 3-piece infusion archwire, and 'J' hook headgear which is usually used in clinital practice. By the use of the polarization plate, initial stresses were analized when 80g and 150g forte applied. The results were as follows. 1. With the utility archwire, moderate levels of stress were evenly distributed on the apical areas of the anterior teeth and concentrated on the apical areas of the first molars. 2. With the Burstone's 3-piece intrusion archwire, moderate levels of stress were evenly distributed on the apical areas of the anterior and posterior teeth. 3. With the 'J' hook headgear, severe levels oi stress were widely distributed on the alveolar bone and apical areas of the upper anterior teeth, and concentrated on the apical area between the central and the lateral incisors. Especially, weak levels of stress appeared along the periodontal ligament space of all teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.448-452
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• 2004

Trauma from occlusion(TFO) is injury to the periodontal tissue as a result of occlusal forces. Mobility is a common clinical sign of occlusal trauma. In acute occlusal trauma, this may be accomanied by pain, tenderness to percussion, thermal sensitivity, and pathologic tooth migration. Chronic occlusal trauma may be marked by excessive wear and gingival recession. Radiographic finding include a widened periodontal ligament space, radiolucence and condensation of the alveolar bone and root resorption. TFO is related to the pathogenesis of periodontal disease. It can cause increased tooth mobility TFO itself does not initate or aggravate marginal gingivitis or initiate periodontal pockets. Active trauma can accelerate bone loss, pocket formation and gingival recession depending on the presence of local irritants and inflammation. Gingival recession associated with occlusal forces includes traumatic crescent, McCall's festoon and Stillman's cleft. TFO plays a minor role in the pathogenesis of early to moderate periodontitis. A 5-year-old male visited Yonsei University Pedodontics clinic with a chief complaint about gingival recession. Mobility, excessive wear, gingival recession were detected by clinical exam on the both mandibular deciduous ca nine. On the radiographic view, vertical alveolar bone loss was observed on both mandibular deciduous canine.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.2
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• pp.144-153
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• 2018

The aim of this study was to understand the roles of Sonic Hedgehog (SHH) signaling during tooth root and periodontium formation. In this study, we generated the dental mesenchyme-specific Smoothened (Smo) activated/inactivated mice with the activity of Cre recombinase under the control of osteocalcin promoter. In the Smo activated mutant molar sections at the postnatal 28 days, we found extremely thin root dentin and widened pulp chamber. Picrosirius red staining showed loosely arranged fibers in the periodontal space and decreased cellular cementum with some root resorption. Immunohistochemical staining showed less localization of matrix proteins such as Bsp, Dmp1, Pstn, and Ank in the cementum, periodontal ligament, and/or cementoblast. In the Smo inactivated mutant mouse, there was not any remarkable differences in the localization of these matrix proteins compared with the wild type. These findings suggest that adequate suppressing regulation of SHH signaling is required in the development of tooth root and periodontium.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.443-457
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• 1997

The purpose of this study was to evaluate the effects of ethanolic extracts of Scutellaria Radix on the alveolar bone formation in the extract socket of rat. Thirty-six Sprague-dawley rats were used in this study. Mean body weight of rat was $130{\pm}5g$. Experimental animal were administered 0.4% ,${\beta}-aminopropionitril$(Sigma, USA) with the solid commercial food for 5 days. All the maxillary 1st molar of the rats were extracted by using of the tissue forcep under the general anesthesia with Pentobarbital sodium(Tokyo Chemical Co, Japan) injection into intraperitoneal space. All the extracted rats were divided into two group, experimental group which were feeded the solid food mixed ethanolic extracts of Scutellaria Radix, and control group which were feeded same food without reagent. At 1, 3, 5, 7, 9 and 14th days after tooth extraction, rats in both groups were serially sacrificed respectively. All the specimen were treated as usual method and prepared Hematoxylin-eosin stain for the light microscopic observation. The results were as follows : 1. Bone formation of extracted socket starts from the area on remained periodontal ligament than other area. 2. In the case of administration of the extracted Scutellaria Radix showed rapid healing process of connective tissue than non-administrated group. 3. In the case of administration of the extracted Scutellaria Radixshowed rapid osteogenesis than non-administrated With above results, it was concluded that ethanolic extracts of Scutellaria Radix may play a favorable role on the healing process of exatraction socket after extraction in rats. It was suggested that further study to evaluate the different concentration and administration method of ethanolic extracts of the Scutellaria Radix into same experimental model.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.481-489
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• 2007

Maxillary canine impaction is a frequently encountered clinical problem, and it may cause the resorption of adjacent tooth or cystic change. Treatment plan for maxillary canine impaction should be decided among extraction, orthodontic traction and autotransplantation according to several factors such as direction and position of unerupted tooth, degree of developing root apex, eruption space, exsitance of supernumerary tooth, odontoma, or cyst. Autotransplantation is a valuable alternative to extraction of impacted teeth, where surgical exposure and subsequent orthodontic realignment are difficult or impossible due to unfavorable impaction position. And its prognosis is dependent on a number of factors such as preservation of periodontal ligament, degree of root development, surgical technique, patient's age, endodontic treatment, time and type of splinting and storage medium, etc. The patients in these cases visited our dental clinic in the late permanent dentition with the chief complaint of unerupted maxillary canines. And it was thought that the spontaneous eruption guidance or orthodontic traction and alignment were difficult because of its unfavorable impacted position. Therefore, autotransplantaion and endodontic treatment were done and have been checked periodically until now.

• Imaging Science in Dentistry
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• v.46 no.4
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• pp.245-249
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• 2016

Purpose: This study was designed to evaluate differences in the required visibility of anatomic structures according to the diagnostic tasks of implant planning and periapical diagnosis. Materials and Methods: Images of a real skull phantom were acquired under 24 combinations of different exposure conditions in a cone-beam computed tomography scanner (60, 70, 80, 90, 100, and 110 kV and 4, 6, 8, and 10 mA). Five radiologists evaluated the visibility of anatomic structures and the image quality for diagnostic tasks using a 6-point scale. results: The visibility of the periodontal ligament space showed the closest association with the ability to use an image for periapical diagnosis in both jaws. The visibility of the sinus floor and canal wall showed the closest association with the ability to use an image for implant planning. Variations in tube voltage were associated with significant differences in image quality for all diagnostic tasks. However, tube current did not show significant associations with the ability to use an image for implant planning. conclusion: The required visibility of anatomic structures varied depending on the diagnostic task. Tube voltage was a more important exposure parameter for image quality than tube current. Different settings should be used for optimization and image quality evaluation depending on the diagnostic task.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.15 no.1
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• pp.41-49
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• 1985

The purpose of this study was to evaluate the initial and postoperative radiographic features of the endodontic treated teeth. The author examined the radiographs which comprise 114 teeth with 155 canals of 64 persons. The following factors were considered; Age, sex, tooth location, number of root canals, postoperative periods, initial diagnosis, and radiographic findings, postoperative radiographic findings. The apical levels of the root fillings were 76.8% to apex, 19.0% underfilling, 3.9% overfilling. The following results were obtained. 1. Of the 93 teeth which revealed initial periapical rarefaction, 66 teeth (71.0%) had showed complete bone healing, 19 teeth (20.4%) decreased rarefaction, 6 teeth (6.5%) no change, 2 teeth (2.2%) increased rarefaction after 20.0 months mean healing time. 2. 21 teeth which had no initial periapical rarefaction showed no occurrence of new periapical rarefaction. 3. Of the 66 teeth completely healed, 53 teeth (80.3%) had showed reappearance of lamina dura, 64 teeth (97.0%) reappearance of periodontal ligament space after 23.4 months mean healing time.