• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.2
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• pp.180-186
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• 2014

One or two mesiodens are mostly common to the clinician. However, three mesiodens is rarely found and can cause complications such as orthodontic problems or interruptions of the adjacent teeth with more than 1 or 2 mesiodens. Many factors cause irregularities in the permanent dentition. Mesiodens, especially in the anterior maxilla, can disturb the eruption of adjacent permanent teeth and cause diastemas, ectopic eruptions, root resorption, or the formation of dentigerous cysts. The early diagnosis of mesiodens is important for preventing such complications, and the timing of intervention should be based on their location and number. Periodic checkups and improved diagnostic devices make it easy to find mesiodens and associated complications. In this case, 3 supernumerary teeth in the maxillary anterior region were affecting the eruption of the adjacent permanent incisors. To minimize complications and preserve the deciduous teeth, the three supernumerary teeth were extracted in 2 steps. Since cone-beam computed tomography was not available, a brace wire was used to measure the depth of the mesiodens.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.135-139
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• 2003

A dentigerous cyst is an epithelium-lined sac that surrounds the crown of an unerupted tooth or odontoma. And the most common sites of this cyst are the mandibular and maxillary third molar and maxillary cuspid a areas. Clinically, expansion of bone with subsequent facial asymmetry, extreme displacement of teeth, severe root resorption of adjacent teeth and pain are all possible sequelae of this cyst. The standard treatment for a dentigerous cyst is enucleation and extraction of the involved tooth. But in large cysts, this can lead to functional, cosmetic and psychologic consequences to the patients. So recently, more conservative methods are used. We report 5 cases of dentigerous cysts in pediatric patient which were treated by a conservative approach, By this methods, we can preserve teeth and guide eruption of the teeth which are involved in cystic area.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.479-486
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• 1998

Bimaxillary Protrusion can be treated effectively in growing patients and in adults with conventional orthodontic therapy. However, In the adult patient, combined surgical and orthodontic treatment modalities may offer distinct advantages over such conventional therapy. In those cases complicate by vertical jaw dysplasia, sagittal dysplasia, or transverse skeletal discrepancy in addition to bimaxillary protrusion, the possibilities of obtaining successful results through orthodontic treatment alone greatly diminish. Surgical retraction of both maxillary and mandibular anterior segments with subapical osteotomies and ostectomies in the extraction site may be a good treatment alternative. Treatment time and possible adverse effects of lengthy orthodontic therapy may be reduced and optimum esthetic improvement may be facilitated. On the following cases, patient who had bimaxillary protrusion with Angle class III malocclusion was treated with combined orthodontic - surgical therapy by anterior subapical segmental osteotomies.

• Journal of Periodontal and Implant Science
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• v.37 no.1
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• pp.45-51
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• 2007

This study evaluated the possibility of the 3-dimensional attachment of human periodontal ligament fibroblasts to a periodntally involved root surface after an EDTA treatment in vitro. The human PDL fibroblasts were isolated from the middle third of the root of periodontally healthy teeth extracted for orthodontic reasons. The cells were cultured in a medium containing Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at $37^{\circ}C$ in humidified air containing 5% $CO_2$. Eight single-rooted teeth were obtained from patients diagnosed with periodotitis. After scaling and root planing, four teeth were etched with 24% ethylenediaminetetracetic acid (EDTA) for two minutes (Experimental group). The other four teeth were not treated with EDTA and were used as the control group. The human PDL fibroblasts were placed in the total root surface and cultured for 4 weeks. The teeth were fixed in 2.5% glutaraldehyde in PBS before preparation for the scanning electron microscopy (SEM) examination. The human PDL fibroblasts showed a healthy morphology on the root surfaces treated with EDTA (Experimental group) and a relatively unhealthy appearance on the treated root surfaces (Control group). This suggests that EDTA favorably affects the 3-dimensional attachment of human PDL fibroblasts cultured on the root surfaces. which may play an important role in periodontal healing and regeneration.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.435-440
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• 2011

Maxillary canine impaction is a common eruption problem in children. Impaction frequently involves further complications such as root resorption of adjacent teeth, cyst formation and migration of the neighboring teeth, etc. Various treatment modalities include extraction of preceding deciduous canine, orthodontic traction, and surgical extraction followed by immediate replantation of the extracted tooth at the proper position(autotransplantation). Autotransplantation is considered as the treatment of choice when surgical exposure and subsequent orthodontic traction are difficult or impossible due to unfavorable impacted position. The prognosis of autotransplantation is affected by the degree of apex formation, surgical procedures performed, timing of root canal treatment, and length of stabilization period. In these two cases presented, the patients with unerupted maxillary canine were treated with autotransplantation. One case was thought that guidance of eruption by orthodontic traction was difficult because of its unfavorable impacted position. In the other case, parents didn't agree to treat by orthodontic traction, therefore autotransplantation was done. In both cases, autotransplantation was carried out following root canal treatment and orthodontic treatment, and both cases have demonstrated to be successful to this day.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.536-545
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• 1997

The purposes of this study were to evaluate the degree of cavity cleanliness and to observe cavity wall morphology when root-end retrograde cavity preparation was done with ultrasonics. Root resections were done on 20 extracted human maxillary central incisors after canal filling with gutta-percha, and retrocavities were prepared using a slow-speed round bur as a control, and stainless steel ultrasonic tips of power settings of 2 and 6 ($Miniendo^{TM}$, EIE, SA, USA) as experimentals. The degree of the remaining cavity debris and smear layer, and wall morphology were evaluated under the scanning electron microscope. The results were as follows : Cavity prepared with ultrasonics of either power setting showed significantly less smear layer than did slow-speed preparations (p<0.01). However, there was no significant difference in canal debris (p<0.05). Cavity prepared with ultrasonics showed hatcheted appearance of wall, while slow-speed preparation showed relatively plain one.

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.15-22
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• 2008

Purpose: The attachment level is strongly associated with tooth loss and provides useful information on patterns of destruction of the periodontium. The presence of horizontal attachment loss would not be detected in clinical measurement. Therefore, the purpose of the present study was to estimate the patterns of periodontal destruction based on the attachment area and horizontal attachment loss in extracted teeth due to severe periodontitis. Materials and Methods: 307 teeth satisfied the criteria for assessment. An indirect method, based on digital images obtained from a digital camera and an image analysis program, was used to calculate the area of root surface and attachment loss and the extent of horizontal attachment loss. The data were analysed using SPSS. Results: No statistically significant differences among root surfaces were observed in anterior teeth on the loss of attachment area. However, in posterior teeth statistically significant differences in palatal surfaces of maxillary and mandibular premolar and molar surfaces compared with buccal surfaces were observed. Horizontal attachment loss was observed in 21.5% of the teeth examined. Frequency of horizontal attachment loss was highest in the maxillary first premolar (34.8%), followed by the maxillary second premolar (27.3%) and maxillary canine (25%). The mean length of horizontal attachment loss was 1.5mm. Conclusion: More meticulous examination will be needed of the palatal surfaces of maxillary and mandibular premolar and molar teeth. The percentage of teeth with horizontal attachment loss greater than 2.1 mm was 5.2%. Considering the length of curette blades, about 5.2% of teeth were not properly debrided. Therefore, Additional supportive therapy such as local drug delivery has to be considered in treatment of the first maxillary, second premolar and canine due to the high prevalence of horizontal attachment loss.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.611-617
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• 2003

Impacted mandibular canines are less common than impacted maxillary canines. The proceeding studies show that impacted mandibular canines occur in approximately 0.1% of patients examined. The causes of impacted mandibular canines are inadequate space, premature loss of the primary dentition, excessive crown length, hereditary factors, functional disturbances of endocrine glands, tumors, and traumas. The basic choices for treatment of those cases are orthodontic migration or surgical removal. This is a case report about those two different treatment methods. One patient was 11 years old female who had treated with surgical approach and the other was 14 years old male who had received orthodontic treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.668-672
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• 2001

The purpose of study was to measure the interrater reliability of the caries diagnostic instrument, Diagnodent(KaVo, Germany), using a new laser fluorescence technique. Occlusal surfaces and smooth surfaces of one hundred extracted human premolars and molars were examined by four dentists. Pearson correlation coeffcients were 0703 to 0.870 for occlusal surfaces and 0.764 to 0.932 for smooth surfaces (P<0.01, all). Reliability coefficients which were calculated by intraclass correlation coefficients were 0.9450 for occlusal surfaces and 0.9605 for smooth surfaces. Therefore, the interrater reliability of caries diagnosis by Diagnodent is very high, and the rater training would be necessary more for occlusal surfaces than for smooth surfaces.

• Restorative Dentistry and Endodontics
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• v.26 no.1
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• pp.9-15
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• 2001

통상적인 근관형성 과정에서 근관형태의 직선화 경향을 발견할 수 있으며, 그 결과 만곡이 심한 근관에서 이상적인 근관형태를 얻기가 어렵다. 이를 극복하기 위한 많은 기구들과 근관 성형법들이 개선되고 소개되었다. 본 연구에서는 최근에 개발된 직사각형의 단면을 가지는 stainless steel file인 RT file과 Flex-R file, K-file을 이용하여 만곡근관 형성 후 최종 근관형태를 비교하여 각 file을 평가하고자 한다. 본 실험은 Bramante등의 방법을 변형하여 술 전의 근관형태와 술 후의 근관형태를 비교하였다. Schneider의 방법을 변형하여 3차원적 만곡을 계산하여 12도에서 36도 이내에 만곡도를 가진 근관을 선택하였다. 49개의 발거된 상악대구치 협측근관이나 하악대구치 근심근관을 3개의 군으로 나누고 레진과 플라스틱으로 제작된 mold에 투명한 교정용 레진으로 매몰하였다. 근첨에서 2.5, 5, 8mm지점에서 절단하여 각 mold에서 재조립한 후 다음과 같이 근관형성을 시행하였다. 제 1군은 SS K-file을 이용하여 step-back 방법 ; 제 2군은 Flex-R file을 이용하여 balanced force 방법 ; 제 3군은 RT file을 이용하여 step-back 방법으로 근관 형성하였다. 술 전과 술 후에 각 시편들을 체현미경으로 사진촬영하여 근관 중심 위치 이동률, 근관형성으로 삭제된 상아질양, 근관형성 후 모양을 Sigma scan/ image software program으로 계산하고 One way ANOVA로 통계적 유의성을 검증하여 다음과 같은 결론을 얻었다. 1. RT file이 치근단에서 K-file보다 유의성 있게 근관의 중심을 유지하는 것으로 보였다. 치아 중앙부에서는 RT file과 Flex-R file이 K-file에 대해 유의성 있게 우수한 것으로 나타났다. 2. 근관형성 후 삭제된 상아질양에서는 치근단에서 RT file이 적게 나왔으나 유의성은 없었다. 3. 근관형성 후 절단면 모양은 원형, 타원형, 불규칙한 형태들이 다양하게 나타났고 각 군간에 유의성 있는 차이는 없었다.