• 대한치과보철학회지
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• 제29권2호
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• pp.177-194
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• 1991

The purpose of this study was to analyze the magnitude and distribution of stress using a photoelastic model from a distal extension removable partial dentures with three kinds of mandibular major connectors, that is, lingual bar, linguoplate, and swing-lock attachment. A photoelastic model was made of the epoxy resin(PC-1) and hardener(PCH-1) and coated with plastic cement-1 (PC-1) at the lingual surface of the epoxy model and set with three kinds of chrome-cobalt removable partial dentures. A bilateral vertical load of 15kg to the middle portion of the metal bar crossing both the first molars of the right and the left, and a unilateral vertical load of 12.5kg to the right first molar were applied with the use of specially designed loading device and the reflective circular polariscope was used to analyze the photoelastic model under each condition. The following results were obtained : 1. When the bilateral vertical load was applied, the magnitude and distribution of the stress concentration of the edentulous area and the terminal abutment or adjacent teeth was in the order of lingual bar, linguoplate, swing-lock attachment. 2. When the unilateral vertical load was applied, the magnitude and distribution of the stress concentration of the edentulous area and the terminal abutment or adjacent teeth was in the order of lingual bar, linguoplate, swing-lock attachment. 3. When the unilateral vertical load was applied, the magnitude and distribution of the stress concentration of the termial abutment or adjacent teeth on the non-loaded side showed the least stress distribution in case of swing-lock attachment. 4. When the bilateral vertical load and the unilateral vertical load were applied the swing-lock attachment showed the mildest uniform stress distribution on the edentulous area and the alveolar bone around the abutment teeth.

• Journal of Periodontal and Implant Science
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• 제46권6호
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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.

• 대한소아치과학회지
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• 제35권2호
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• pp.376-381
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• 2008

성장기 아동의 치열은 대부분 혼합 치열로, 이 시기에는 유치 탈락 또는 계승치 미맹출로 인해 치열에 빈 공간이 많아지고, 계승치가 맹출되었다 하더라도 고정성 장치를 부착시키고 강한 호선을 적용시키기는 매우 어렵다. 이런 치료 진행의 문제점을 해결하기 위해 horseshoe 장치가 유용하게 사용될 수 있다. 이 장치는 치열에 빈 공간이 있는지의 여부에 관계없이 장치 제작이 가능하며, 치열 상태와 무관하게 전 치열을 하나로 묶어준다. 그리고 구강내에 이미 맹출된 치아의 모든 치면을 피개하므로 치아의 정출과 회전이 발생하지 않으면서 악간 고무줄의 힘에 의해 치조골의 골개조가 상악과 하악 치궁에서 서로 반대 방향으로 유도된다. 경희대학교 치대병원 소아치과에 내원한 환아에서, Horseshoe Appliance를 이용하여 III급 부정교합에서 양호한 결과를 얻었기에 보고하는 바이다.

• 구강회복응용과학지
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• 제25권4호
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• pp.431-436
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• 2009

심한 치조골 흡수를 동반한 III급 악골 관계 환자의 총의치 제작의 경우 안정적이고 지속적인 교합을 제공하는 치료계획을 세워야 한다. 불리한 치관 대 치근 비와 임상적 동요도가 관찰되는 하악 잔존치를 고정하여 사용함으로써 환자의 불편감을 줄이고 시간적, 경제적으로 효율적인 치료를 제공할 수 있다. 본 증례에서는 상악 편악 무치악 환자의 기능적인 하악 운동과 조화로운 총의치 균형 교합을 이루기 위해 T-Scan System을 이용하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권2호
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• pp.150-157
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• 2008

This study evaluated the influence of smooth and brushite-coated implant surfaces in dogs. The first through fourth mandibular premolars were extracted from eight young adult dogs. Twelve weeks after extraction. implantation was performed at the extraction sites. In total, 40 implant fixtures were implanted in the dog mandibles. Twenty machined implants served as controls and twenty brushite-coated surfaces served as tests. Dogs were sacrificed 2 and 4 weeks after implantation. The hemi-mandibles were obtained and processed histologically to obtain non-decalcified sections. Longitudinal sections of each implant were made and analyzed using light microscopy. The overall implant success rate was 83.3%. Histomorphometrically. the experimental group had a better percentage of bone-implant contact than the control group (p<0.05) and there was a significant difference between the 2- and 4-week groups after implantation (p<0.05) Our results suggest that the implant surface morphology influences the increase in peri-implant osteogenesis in the early period of peri-implant healing.

• Restorative Dentistry and Endodontics
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• 제14권2호
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• pp.49-64
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• 1989

The purpose of this study was to evaluate the effect of several materials on the healing process of apical wound. Sixteen mandibular premolars obtained from 4 healthy dogs were used for this study. Under general anesthesia, the pulpal chamber of each tooth was opened and the pulps were extirpated. The root canals were then instrumented with H-file and irrigated with physiologic saline solution ; the apices were purposely perforated and enlarged with the engine K-reamer. In the experimental groups, apical wounds were filled with one of calcium hydroxide, hydroxylapatite, and tricalcium phosphate materials, mixture of each materials and physiologic saline solution, with a lentulo spiral. In the control group, apical wounds were not filled with any material. All the root canals were filled by the lateral condensation technique with gutta-percha cone and ZOE sealer. The access opening of all the teeth were closed with amalgam. On the 10, 20, 40 and 60th day after experiment, experimental animals were sacrificed. Segments of jaws, each containing one tooth, were fixed in 10% formalin solution and decalcified in Plank-Rychlo solution. The specimens were embedded in paraffin and serially sectioned to an average thickness of $6{\mu}m$. The sections were stained by hematoxylin-eosin and Masson's trichrome stain method and examined under light microscope. The results were as follows : 1. In the experimental groups, the new bone formations were observed in apical wounds. 2. Fourty days later, apical wounds were healed by granulation tissue in the experimental groups, but were not healed by granulation tissue in the control group, and the healing process of experimental groups were more rapid than that of control group. 3. Sixty days later, chronic inflammation disappeared in the experimental groups, and the materials used showed biologic affinity to the periapical tissue. 4. In all the groups, the resorption of cementum appeared on the 10th and 20th day after experiment, and the deposition of cementum appeared on the 40th and 60th day after experiment, especially showing narrowness of apical foramen due to newly formed cementum in calcium hydroxide group. 5. Calcum hydroxide and tricalcium phosphate particles were gradually resolved, but hydroxylapatite particles were not resolved through the experimental period.

• 대한소아치과학회지
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• 제29권2호
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• pp.237-242
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• 2002

Lowe 증후군 또는 안뇌신증후군(oculocerebrorenal syndrome)은 X-염색체와 관련된 유전성 질환으로 반성열성유전양상을 나타낸다. 선천성 백내장과 녹내장 등의 안 증상, 근긴장 저하 건반사감소 등의 근신경계 증상, 신장 기능이상이 가장 특징적인 임상 증상이며, 이외에도 정신 지체, 성장지연, 전두부 융기, 가늘고 성긴 모발, 돌출된 귀, 골질환 등이 발생할 수 있다. Lowe 증후군 환자는 정신지체로 인해 치과치료시 전신마취하에서의 처치가 요구되나, 대사성 산증, 악성고열의 발생위험과 사용약제에 의한 부작용 등이 위험요소로 작용할 수 있으므로, 필요한 경우 내과 또는 소아과 의료진이 참여된 협진체제 하에서 가능한 짧은 시간 진행되어야 한다. 이러한 치과적 처치의 어려움으로 Lowe 증후군 환자에서 치과질환의 예방이 좀더 강조되어야 하면, 이를 위해 보호자의 주위의 적극적 관리가 요구된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권4호
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• pp.407-413
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• 1999

구강악안면부위의 선천성 기형은 복잡한 발생학적 과정과 연관이 있으며 비정상적인 기형을 적절한 시기에 치료하지 못할 경우 이로 인한 이차적인 기형을 유발하여 치료를 더욱 어렵게 할 수 있다. 저자 등은 우측 상악돌기 후외하방에 중복 발생된 상악돌기와 과잉치로 인하여 저작장애를 보이며, 안와, 관골 및 상하악골의 심한 안모 비대칭 소견을 보이는 악안면기형환자를 골절제와 발치, 교정치료, 관골과 안와재건술, 악교정수술 및 반흔교정술 등의 4회에 걸친 수술을 통해 심미적, 기능적으로 만족스러운 결과를 얻었다. 악안면영역의 선천성 기형의 치료는 매우 난이하며 수차례의 수술을 요하고 수술 결과가 만족스럽지 못한 경우가 많으므로 사전 철저한 분석이 요구되며, 환자의 심리적 부담을 덜어주기 위한 특별한 배려가 요구된다.

• 대한치과교정학회지
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• 제34권2호
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• pp.153-163
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• 2004

II급 부정교합 치료 후 일어나는 재발에 영향을 미치는 요소를 알아보기 위하여 치료 후 결과가 안정하게 유지된 군과 재발이 일어난 군으로 구분하여 골격 및 치성요소를 비교하였다. 치료 전과 치료 후 측모 두부방사선사진을 이용하여 t-test와 상관분석을 시행한 결과 다음과 같은 결론을 얻었다. 1. 안정군과 재발군 간에 치료 전 골격 및 치성 관계는 대체로 차이가 없었다. 2. 안정군에서 하악골의 전방성장이 더 많이 일어났다. 3. 안정군에서의 하악 전치는 더 직립되었으며 상악전치는 설측 경사가 적은 경향을 보였다. 4. 재발군에서 교합평면이 전하방으로 경사되는 경향을 보였다.

• Imaging Science in Dentistry
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• 제32권4호
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• pp.201-206
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• 2002

Purpose : To evaluate the radiographic change of operation sites after orthognathic surgery using the digital image processing and fractal analysis. Materials and Methods : A series of panoramic radiographs of thirty-five randomly selected patients who had undergone mandibular orthognathic surgery (bilateral sagittal split ramus osteotomy) without clinical complication for osseous healing, were taken. The panoramic radiographs of each selected patient were taken at pre-operation (stage 0), 1 or 2 days after operation (stage 1), 1 month after operation (stage 2), 6 months after operation (stage 3), and 12 months after operation (stage 4). The radiographs were digitized at 600 dpi, 8 bit, and 256 gray levels. The region of interest, centered on the bony gap area of the operation site, was selected and the fractal dimension was calculated by using the tile-counting method. The mean values and standard deviations of fractal dimension for each stage were calculated and the differences among stage 0, 1, 2, 3, and 4 were evaluated through repeated measures of the ANOVA and paired t-test. Results : The mean values and standard deviations of the fractal dimensions obtained from stage 0, 1, 2, 3, and 4 were 1.658±0.048, 1.580±0.050, 1.607±0.046, 1.624±0.049, and 1.641 ±0.061, respectively. The fractal dimensions from stage 1 to stage 4 were shown to have a tendency to increase (p < 0.05). Conclusion: The tendency of the fractal dimesion to increase relative to healing time may be a useful means of evaluating post-operative bony healing of the osteotomy site.