• 대한치과의사협회지
• /
• 제55권10호
• /
• pp.725-732
• /
• 2017

Thin labial plate will be resorbed after extraction. Immediate implantation cannot prevent soft and hard tissue loss. Bone graft can be necessary in the immediate implantation after anterior tooth extraction. Slowly-resorbed or non-resorbable bone graft material have many advantages in esthetic area because of maintenance of volume. The clinicians should select the adequate cases of immediate implantation according to the indication and contraindication.

• 대한치과의사협회지
• /
• 제36권11호통권354호
• /
• pp.794-799
• /
• 1998

Many references report that abnormal diastema except temporary diastema existing in mixed dentition period is caused by maxilary heavy labial frenum, malocclusion, progressive periodontal disease, and loss of posterior teeth. We can diagnose patient as diastema caused by periodontal disease, especially, in case of accompanying progressively destructed anterior maxillary alveolar bone defect, and interseptal bone defect. We report Multiple disciplinary approach for diastema associated with periodontal disease. Periodontal treatment(Guided Tissue -Regeneration, alveoloplasty, bone graft), or thodontic treatment (space closure, redistribution), and the final proshodontic restoration for retention were used.

• 대한치과교정학회지
• /
• 제34권3호
• /
• pp.269-277
• /
• 2004

혼합 치열기의 교정치료 증례 중에서 경도의 총생을 가진 경우 상악 대구치를 원심 이동함으로서 양호한 치료의 결과를 얻는 경우가 많다 주로 악외 견인장치를 적용하여 원심이동을 시행하지만 환자의 협조도에 따라 구치의 원심이동이 결정되는 단점을 가지고 있다. 구강내 고정원 사용시 생길 수 있는 반작용을 최소화하기 위해 정에 의해 개발된 C-space regainer는 후방이동 시키고자 하는 치아를 제외한 거의 모든 치아들을 완벽하게 묶음으로서 효과적인 후방이동을 가능케 하는 장치이다. 후속영구치의 맹출 공간 부족으로 매복 치에 의한 인접치의 치근손상이 예상되는 성장기 II급 부정교합 환자에서 악기능 교정장치에 t-space regainer의 개념을 적용한 변형된 C-space regainer, 즉 C-activator가 사용되어 양호한 치료 결과를 얻었기에 이어 보고하는 바이다.

• 대한치과보철학회지
• /
• 제43권3호
• /
• pp.322-330
• /
• 2005

Statement of problem. In distal extension removable partial denture, the preservation of health of abutment teeth is very important, but abutment teeth are subjected to unfavorable stress. Purpose. The purpose of this study was to investigate the biomechanical effects of mandibular removable partial dentures with various prosthetic designs using strain gauge analysis. Material and methods. Artificial teeth of both canines were anchored bilaterally in a mandibular edentulous model made of resin. Bilateral distal extension removable partial dentures with splinted and unsplinted abutments were fabricated. Group 1 : Clasp-retained mandibular removable partial denture with unsplinted abuhnents Group 2 : Clasp-retained mandibular removable partial denture with splinted abutments by 6-unit bridge Group 3 : Bar-retained mandibular removable partial denture Strain gauges were bonded on the labial plate of the mandibular resin model, approximately 2 mm close to the abutments. Two vertical experimental loadings (100N and 200N) were applied subsequently via two miniature load cells that were placed at mandibular first molar regions. Strain measurements were performed and simultaneously monitored from a computer connected to data acquisition system. For within-group evaluations, t-test was used to compare the strain values and for between-group comparisons, a one-way analysis of variance (ANOVA) was used and Duncan test was used as post hoc comparisons. Results. Strain values increased as the applied load increased from 100N to 200N for all groups (p<.05). The strain values of group 1 and 2 were tensile under loadings. In contrast, strain values of group 3 were compressive in nature. Under 100N loading, group 1 showed higher strain values than group 3 in absolute quantity (p<.05). Under 200N loading, group 3 showed higher strain values than group 1 and 2 in absolute quantity (p<.05). Group 1 showed higher strain values than group 2 (p<.05). Conclusion. Splinting of two isolated abutments by bridge reduced the peri-abutment strain in comparison with unsplinted abutments. Strain of bar-retained removable partial denture increased much more as applied load increased, but was compressive in nature.

• Journal of Periodontal and Implant Science
• /
• 제29권3호
• /
• pp.715-724
• /
• 1999

The purpose of this study was to approve the possibility of clinical application of selftesting technique to confirm the cleanness status of the tooth surface after mechanical toothbrushing. Thirty-two periodontal patients who did not compromise any other systemic diseases were divided into two groups. Control group was instructed only the Bass method for toothbrushing, and then experimental group was demonstrated the Bass method and self-testing technique respectively for plaque control during this experiment. Selftesting technique is composed the comparison of roughness of the labial surface of maxillary central incisor and other toothsurface with touch sense using the tip of tongue. Plaque score and Gingival index were measured as clinical parameters at baseline and 1, 2 and 4 weeks after scaling and root planing. The results were as follows ; 1. Plaque scores and gingival index of 1, 2, and 4 weeks of two groups were statistically significant differences when compared with baseline value (p<0.05). 2. Plaque scores and gingival index of baseline and 1 week between two groups were not significant differences (p<0.05). 3. Plaque scores and gingival index of 2 and 4 weeks of test group were statistically significant difference when compared with control group (p<0.05). From the above results, self-testing technique which decides necessity of additional toothbrushing when tongue tip of subjects touch the maxillary molar buccal surfaces and mandibular molar lingual surfaces nd compares with maxillary anterior labial surfaces after toothbrushing appeared to effect the motivation of subjects. This study suggests that self-testing technique for cleanness after toothbrushing should be effect on the maintenance of oral hygiene when it is applied to clinical practice.

• 대한치과보철학회지
• /
• 제36권1호
• /
• pp.120-132
• /
• 1998

This stusy was to investigate the marginal fitness of porcelain-fused-to- metal crown after succesive firing cycle. Main variables were the degree of marginal curvature of labiocervical margin and the type of alloy. The exaggerated marginal curvature(EMC) was created by additional reduction at the faciocervical wall of the normallized marginal curvature (NMC)-typed ivorine tooth by using milling machine. The difference in the shape was the mid facial margin was placed 2mm apical to cemento- enamel junction in labial surface. Three types of alloy were high noble, noble, and base metal alloy. Test specimens were divided into 8 groups and each group had 8 specimens. Sixty four ceramometal crowns were made totally. Measurement stages were following degassing, opaquing. body porcelain firing, and glazing, and measuring sites were 4. (midmesial, midfacial, middistal, and midlingual). Digital, travelling measuring microscope (0.5 um precision, Olympus. Japan) was used under ${\times}250$ magnification. Within the limitation of this investigation, it was concluded as belows: 1. The pattern of marginal distortion was varied. Degassing stage was not a specific, causative stage that induce most of total marginal distortion during whole procedure fabricating a ceramometal crown. Body firing stage induced discrepancy relatively more than other firing stages. 2. The specimens that were Ni-based alloy and had EMC were distorted persistently following successive fabricating procedures. But marginal openings were decreased after glazing. 3. The release of metal grinding-induced stress was presumed as a cause that induce marginal distortion. 4. The amount of discrepancies of the labial and lingual margins were greater than that of the mesial and distal margin in the specimen that had EMC. 5. Silver-plated die was not enough to resist abrasion during repeated seating of metal copings on the die-holding device.

• 대한치과교정학회지
• /
• 제43권3호
• /
• pp.134-140
• /
• 2013

Objective: To evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions. Methods: CBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons. Results: Labial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004). Conclusions: Mandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients.

• 대한치과보철학회지
• /
• 제33권2호
• /
• pp.198-209
• /
• 1995

In order to evaluate the fitness and the degree of rounding of porcelain margins in collarless metal cermic restorations, collarless metal ceramic restorations were fabricated with shoulder margins of 90 and 120 degress, each consisting of ten specimens, on master dies through the direct lift technique. And ten metal ceramic restorations with a shoulder 90 degrees were fabricated. All specimens were embedded in resin and sectioned longitudinally. The sections were observed under a stereomicroscope and photographed(${\times}$200). The labial marginal gap between the die and the porcelain margin were measured with a scale. The space between the porcelain margin and the die, that is formed from marginal rounding and cementation were calculated with a computer coordinating area curvimeter. The following results were obtained. 1. There was no statistical difference between the fitness of porcelain margin of collarless metal ceramic restorations and marginal fitness of metal ceramic restoration. 2. There was no statistical difference between a shoulder of 90 and 120 degrees in the fitness of porcelain margin of collarless metal ceramic resorations. 3. Collarless metal ceramic restorations with a shoulder of 90 degrees and 120 degrees showed significantly more labial marginal rounding than metal ceramic restorations. 4. There was no statistical difference between a shoulder of 90 and 120 degrees in rounding of porcelain margin of collarless metal ceramic restorations. According to the results, rounding of porcelain margins can be observed in collarless metal ceramic restorations. Thus, there is a need for improvement in dental materials and techniques to minimize this problem, Furthermore, care should be exercised during the clinical procedure.

• 대한소아치과학회지
• /
• 제37권4호
• /
• pp.473-481
• /
• 2010

상악 견치 매복은 소아 청소년기 환자들에게서 흔하게 발견되는 문제이다. 일반적으로 구개측 매복이 순측 매복 보다 더 흔한 것으로 알려져 있지만 서양에서는 오히려 순측 매복이 더 많은 것으로 보고되고 있다. 본 보고에서는 파노라마 방사선 사진상 상악 견치의 순측매복이 의심되는 8-10세의 혼합치열기 아동을 대상으로 급속 구개확장(rapid palatal expansion)을 시행하였으며, 이를 통하여 상악 측절치의 근원심 치근각도를 조절하여 매복 가능성이 있는 견치의 정상맹출을 유도할 수 있었기에 보고하는 바이다.

• 환경생물
• /
• 제18권1호
• /
• pp.145-151
• /
• 2000

본 연구는 창주둥이바구미과 갑충의 구기가 부드러운 식물조직을 섭식하는 바구미과 갑충과 거의 같은 구조를 하고 있다는 사실을 잘 나타내고 있다. 창주둥이바구미과 갑충에 대하여 주사전자현미경을 사용하여 구기를 본래의 위치에서 관찰하고, 여기에 해부에 의한 연구도 병행하여 얻은 구기구조에 대한 연구의 결과는 다음과 같다. 창주둥이바구미아과의 바구미는 두순 가장자리가 꾸불꾸불한 모양이고, 큰턱은 수축시 전후로 만나며 안쪽으로 약간 굽어있는 구조를 하고 있다. 작은턱 수염은 두마디로 큰 생수절을 가지며, 아랫입술 수염은 한 개의 마디로 되어 있다. 하순전기절은 평행면을 가지며 넓이보다 길이가 더 길다. 별창주둥이바구미아과의 바구미는 두순가장자리 중앙에 2-3개의 홈을 가지고, 큰턱은 수축시 전후로 만나며 안쪽으로 약간 만곡된 구조를 하고 있다. 작은턱 수염은 세마디로 생수절과 첩교절의 크기가 같으며, 아랫입술 수염은 두마디로 하순전기절 꼭대기의 융기에 의해 서로 분리되어 있다. 하순전기절의 넓이와 길이는 같다.