• 대한장애인치과학회지
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• 제8권2호
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• pp.113-117
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• 2012

저자는 ARS를 가진 15세 여자 환아에 대한 임상적, 방사선학적 관찰을 통해 다음과 같은 지견을 얻었다. 1. 환아는 Axenfeld-Rieger Syndrome의 안과적 증상인 전안부 형성부전을 나타낸다. 2. 환아의 구강 및 구개악안면 소견으로 다수의 영구치 결손 및 왜소치, 상악 형성 부전, 구치부의 반대교합이 관찰되었다. 3. 환아의 성장에 따른 주기적인 치과적 검진과 추가적인 치료가 필요할 것으로 생각된다.

• 대한치과교정학회지
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• 제21권2호
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• pp.353-366
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• 1991

This study was performed to analyze the effects of forces to the alveolar bone by various molar uprighting spring such as helical uprighting spring. T-loop spring, Modified T-loop spring and open coil spring. The simplified two-dimensional photoelastic model was constructed with a lower left posterior quadrant containing the second molar, the first and second premolars and the canine, with the first molar missing. Several molar uprighting springs were fabricated from 0.017 by 0.022 inch blue Elgiloy and applied to the photoelastic model. Two-dimensional photoelastic stress analysis was performed, and the stress distribution was recorded by photography The results obtained were as follows; 1. In all the kinds of the springs, the center of rotation of the mandibular second molar was oserved at the apical 1/5-1/6 between the alveolar crest and the root apex. 2. In all the kinds of the spring, the stress induced in the mesial root surface of the mandibular second molar was relatively homogeneous but there was some difference in the magnitude of the stress. 3. In the kinds of the springs, the distal crown tipping moment of the second molar was increased in turn as open coil spring, helical uprighting spring, T-loop spring, and modified T-loop spring. 4. The largest extrusive force was occured in the T-loop spring, intrusive force was occured in Modified T-loop spring only, and the largest distal tipping force was occured in open coil spring. 5. In the T-loop spring with activation, the stress induced in the mesial root surface of the second molar was increased gradually from the root apex to the alveolar crest and highly concentrated in the alveolar crest.

• 대한치과교정학회지
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• 제35권6호
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• pp.485-494
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• 2005

상악 측절치와 견치의 치근 사이에 식립한 microimplant를 이용하여 상악 전치의 합임과 설측으로의 치근 이동을 얻을 수가 있었으며, 상악 견치와 제1소구치의 치근 사이에 식립한 microimplant를 이용하여 과맹출된 상악 견치를 함입시켰다. 또한 상악 제1, 2대구치의 치근 사이에 식립한 microplant를 이용하여 상악 견치 및 구치의 후방 이동 및 상악 전치의 후방 견인을 시행하였다. Anterior bite plane과 intrusion arch, 그리고 II급 고무 등과 같은 전통적인 방법을 사용하여 하악 전치의 합입 및 구치부의 정출을 얻을 수가 있었으며, 과개 교합 및 상악 전치의 설측 경사가 해소 되면서 하악골이 전방으로 약간 이동하였다. 이와 같이, MIA는 II급 2류 부정교합환자에 있어서 II급 견치 및 구치 관계 그리고 과개 교합을 동시에 해소 하는데 절대적인 고정원을 제공하였다.

• 대한소아치과학회지
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• 제27권1호
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• pp.122-134
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• 2000

각화치은, 부착치은의 폭경, 치은열구의 깊이에 대해 성인에서는 많은 연구가 있었으나 아동에서의 연구는 드물었기 때문에, 유치열기, 혼합치열기 및 영구치열기의 모든 치아에 대하여 아동의 협측 각화치은 및 부착치은의 폭경과 치은열구 깊이에 대한 정상치를 구하고, 악골의 발육 및 치아의 맹출과의 관련성을 고찰하며, 점막치은 문제의 발현빈도를 조사하고자 하였다. 결론은 다음과 같다. 1. 유치열의 부착치은 폭경은 상악 유측절치 및 유견치에서 각각 3.50mm, 3.55mm로 최대값을, 하악 제1유구치에서 1.34mm로 최소값을 나타내었다. 영구치열의 경우에는 상악 측절치에서 3.00mm로 최대값을, 하악 제1소구치에서 0.55mm로 최소값을 나타내었다. 상하악 동명치아 비교시 상악 치아가 하악 치아보다 더 큰 값을 나타내었고, 남녀간 차이에는 특별한 규칙이 발견되지는 않았다. 2. 연령증가에 따른 부착치은 폭경의 변화 양상은 유치열의 경우 유견치, 제1유구치, 제2유구치에서 6세부터 증가하였다. 영구치의 경우 남자에서는 하악 중절치와 상악 제 1대구치의 측정값만이 연령에 따른 증가 추세를 나타냈으나(p<0.05), 여자에서는 상하악 중절치 측절치 및 상악 제1대구치에서 통계적으로 유의성 있는 각화치은 폭경의 증가 추세를 관찰할 수 있었다(p<0.05). 3. 치아교대기에서 부착치은 폭경의 차이는 남자 상악 중절치를 제외한 모든 경우에 유치에서의 측정값이 영구치에서의 측정값보다 큰 것으로 나타났다(p<0.05). 4. 6제부터 12세까지는 각화치은의 폭경과 치은열구의 깊이는 대부분 유치 초기값보다 그 계승영구치 최종값이 더 높은 값을 나타냈으나(p<0.05), 부착치은의 폭경에서는 유치 초기와 그 계승영구치 최종값사이에 통계적으로 유의성 있는 차이가 나타나지 않았다. 5. 점막치은 문제 발현 빈도는 남녀에 상관없이 유치열은 상하악 제 1유구치가, 영구치열은 상하악 모두 제 1소구치가 최고치를 나타냈으며 유치에서보다 그 대응 계승영구치에서 그 빈도가 더욱 높게 나타났다. 연령증가에 따라 점막치은 문제의 발현 빈도는 유치열, 영구치열에서 모두 감소하였으나, 하악 제1유구치, 하악 영구 견치, 제1, 제2소구치의 경우 연령의 증가와 상관없이 비슷하게 유지되거나 증가하는 경향을 보였다.

• Journal of Periodontal and Implant Science
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• 제40권1호
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• pp.3-10
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• 2010

Purpose: Periodontal regenerative therapies for defects created by severe periodontitis are mainly focused on bone regeneration. Although cementum regeneration needs to be better understood, it is believed to play an important role in periodontal regeneration. The first step toward a full understanding of cementum regeneration is to compare repaired cementum to pristine cementum. This study, which used histological techniques, was designed to focus on cementum regeneration and to compare pristine cementum to repaired cementum after surgical procedures with 8 and 24 week healing periods in a canine model. Methods: Buccal and lingual mucoperiosteal flaps of 10 beagle dogs were surgically reflected to create critical-sized defects. Intrabony one-wall defects, of which dimension is 4 mm width and 5 mm depth, were made at the distal aspect of mandibular second premolars and the mesial aspect of mandibular fourth premolars in the right and left jaw quadrants. Animals were sacrificed after 8 and 24 weeks post-surgery for histological specimen preparation and histometric analysis. Results: The repaired cementum was composed mostly of acellular cementum and cellular mixed fiber cementum and was thicker in the apical area than in the coronal area. The acellular cementum of the supracrestal area appeared to be amorphous. The newly formed cellular cementum was partially detached from the underlying circumpulpal dentin, which implied a weak attachment between new cementum and dentin, and this split was observed to a lesser extent in the 24 week group than in the 8 week group. The vertical height of the repaired cementum was greater in the 24 week group than in the 8 week group. Conclusions: Within the limitations of this study, we can conclude that repaired cementum after root planing was mainly acellular cementum and cementum tissue that matured to a shape similar to pristine cementum as the healing progressed from 8 to 24 weeks.

• Journal of Periodontal and Implant Science
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• 제26권3호
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• pp.735-751
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• 1996

An ultimate goal of periodontal therapy is to stop the disease process and to regenerate a functionally-oriented periodontium destroyed as a result of periodontal disease. The purpose of this study was to observe the effect of grafting granulation tissue obtained from extraction socket on the regeneration of horizontal furcation defect. Six dogs were used in this study. All mandibular first and third premolars were extracted. At 2, 3, and 5 days after extraction, tissues were obtained from extraction socket of 1 mongrel dog and examined by light microscope. Granulation tissue obtained at 5 days after extraction was chosen as the graft material. Five days later, horizontal furcation defects were created surgically at mandibular second and fourth premolars in the right and left side of the 5 beagle dogs. The entrance area of the artificially prepared "key hole" defects were about $3\;4mm^2$. By random selections, 2 exposed furcation defects were grafted with granulation tissue obtained from extraction socket as experimental group and 1 furcation defect was as control. The flaps were replaced to their original position and sutured with 4-0 chromic cat-gut. Three dogs were sacrificed 4 weeks and two dogs 8 weeks after surgery, and the prepared specimens were examined by light microscope. At 4 weeks, furcations were filled with epithelial lining and fibrous connective tissue infiltrated with chronic inflammatory cells. New bone formation was observed in all groups. Only experimental group showed new cementum formation. At 8 weeks, new cementum, functional arrangement of new PDL fiber, root resorption, and some ankylotic union of newly formed alveolar bone and root surface were observed in all groups. Experimental group showed that epithelial downgrowth was inhibited and new bone formation was more active compared to control. The success rate of the furcation defect healing was higher in experimental group than control. These results suggested that grafting of granulation tissue obtained from extraction socket which combined with reconstructive periodontal flap surgery may promote periodontal regeneration of horizontal furcation defect.

• Journal of Periodontal and Implant Science
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• 제40권5호
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• pp.232-238
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• 2010

Purpose: To prolong the degradation time of collagen membranes, various cross-linking techniques have been developed. For cross-linking, chemicals such as formaldehyde and glutaraldehyde are added to collagen membranes, but these chemicals could adversely affect surrounding tissues. The aim of this study is to evaluate the ability of porous non-chemical cross-linking porcine-derived collagen nanofibrous membrane to enhance bone and associated tissue regeneration in one-wall intrabony defects in beagle dogs. Methods: The second and third mandibular premolars and the first molars of 2 adult beagles were extracted bilaterally and the extraction sites were allowed to heal for 10 weeks. One-wall intrabony defects were prepared bilaterally on the mesial and distal side of the fourth mandibular premolars. Among eight defects, four defects were not covered with membrane as controls and the other four defects were covered with membrane as the experimental group. The animals were sacrificed 10 weeks after surgery. Results: Wound healing was generally uneventful. For all parameters evaluating bone regeneration, the experimental group showed significantly superior results compared to the control. In new bone height (NBh), the experimental group exhibited a greater mean value than the control ($3.04{\pm}0.23\;mm/1.57{\pm}0.59$, P=0.003). Also, in new bone area (NBa) and new bone volume (NBv), the experimental group showed superior results compared to the control (NBa, $34.48{\pm}10.21%$ vs. $5.09{\pm}5.76%$, P=0.014; and NBv, $28.04{\pm}12.96$ vs. $1.55{\pm}0.57$, P=0.041). On the other hand, for parameters evaluating periodontal tissue regeneration, including junctional epithelium migration and new cementum height, there were no statistically significant differences between two groups. Conclusions: Within the limitations of this study, this collagen membrane enhanced bone regeneration at one-wall intrabony defects. On the other hand, no influence of this membrane on periodontal tissue regeneration could be ascertained in this study.

• 대한치과교정학회지
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• 제50권2호
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• pp.120-128
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• 2020

Objective: The aims of the present study were to evaluate the changes in the maximum lip-closing force (MLF) after orthodontic treatment with or without premolar extractions and verify the correlation of these changes with dentoskeletal changes. Methods: In total, 17 women who underwent nonextraction orthodontic treatment and 15 women who underwent orthodontic treatment with extraction of all four first premolars were included in this retrospective study. For all patients, lateral cephalograms and dental models were measured before (T0) and after (T1) treatment. In addition, MLF was measured at both time points using the Lip De Cum LDC-110R^® device. Statistical analyses were performed to evaluate changes in clinical variables and MLF and their correlations. Results: Both groups showed similar skeletal patterns, although the extraction group showed greater proclination of the maxillary and mandibular incisors and lip protrusion compared to the nonextraction group at T0. MLF at T0 was comparable between the two groups. The reduction in the arch width and depth and incisor retroclination from T0 to T1 were more pronounced in the extraction group than in the nonextraction group. MLF in the extraction group significantly increased during the treatment period, and this increase was significantly greater than that in the nonextraction group. The increase in MLF was found to be correlated with the increase in the interincisal angle and decrease in the intermolar width, arch depth, and incisor-mandibular plane angle. Conclusions: This study suggests that MLF increases to a greater extent during extraction orthodontic treatment than during nonextraction orthodontic treatment.

• 대한치과교정학회지
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• 제50권4호
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• pp.229-237
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• 2020

Objective: To evaluate the construction reproducibility of a composite tooth model (CTM) composed of an intraoral-scanned crown and a cone-beam computed tomography (CBCT)-scanned root. Methods: The study assessed 240 teeth (30 central incisors, 30 canines, 30 second premolars, and 30 first molars in the maxillary and mandibular arches) from 15 young adult patients whose pre-treatment intraoral scan and CBCT were available. Examiner-Reference (3 years' experience in CTM construction) and Examiners-A and Examiner-B (no experience) constructed the individual CTMs independently by performing the following steps: image acquisition and processing into a three-dimensional model, integration of intraoral-scanned crowns and CBCT-scanned teeth, and replacement of the CBCT-scanned crown with the intraoral-scanned crown. The tooth axis angle in terms of mesiodistal angulation and buccolingual inclination of the CTMs constructed by the three examiners were measured. To assess the construction reproducibility of CTMs, intraclass correlation coefficient (ICC) assessments were performed. Results: The ICC values of mesiodistal angulation and buccolingual inclination among the 3 examiners showed excellent agreement (0.950-0.992 and 0.965-0.993; 0.976-0.994 and 0.973-0.995 in the maxillary and mandibular arches, respectively). Conclusions: The CTM showed excellent construction reproducibility in mesiodistal angulation and buccolingual inclination regardless of the construction skill and experience levels of the examiners.

• 대한치과교정학회지
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• 제49권6호
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• pp.413-426
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• 2019

This study was performed to describe the longitudinal management of recurrent temporomandibular joint (TMJ) ankylosis from infancy to adulthood in perspective of surgical and orthodontic treatment. A 2-year-old girl was referred with chief complaints of restricted mouth opening and micrognathia due to bilateral TMJ ankylosis. For stage I treatment during early childhood (6 years old), high condylectomy and interpositional arthroplasty were performed. However, TMJ ankylosis recurred and symptoms of obstructive sleep apnea (OSA) developed. For stage II treatment during early adolescence (12 years old), gap arthroplasty, coronoidectomy, bilateral mandibular distraction osteogenesis, and orthodontic treatment with extraction of the four first premolars were performed. However, TMJ ankylosis recurred. Because the OSA symptoms reappeared, she began to use a continuous positive airway pressure device. For stage III treatment after completion of growth (20 years old), low condylectomy, coronoidectomy, reconstruction of the bilateral TMJs with artificial prostheses along with counterclockwise rotational advancement of the mandible, genioglossus advancement, and orthodontic treatment were performed. After stage III treatment, the amount of mouth opening exhibited a significant increase. Mandibular advancement and ramus lengthening resulted in significant improvement in the facial profile, Class I relationships, and normal overbite/overjet. The OSA symptoms were also relieved. These outcomes were stable at the one-year follow-up visit. Since the treatment modalities for TMJ ankylosis differ according to the duration of ankylosis, patient age, and degree of deformity, the treatment flowchart suggested in this report could be used as an effective guideline for determining the appropriate timing and methods for the treatment of TMJ ankylosis.