• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.236-248
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• 2013

In this study, 37 subjects with normal facial shape and normal occlusion are classified and reference value for such classification was investigated. Difference in position of maxillary incisor was studied according to the cl assification. Moreover, by investigating correlation between factors affecting forehead morphology and positio n of maxillary incisor, following results have been obtained. 1. Morphology of forehead can be classified as angular type, round type, straight type, and concave type. 2. There were no specific reference value for evaluation of forehead morphology but possibilities of evaluating forehead morphology using S value and forehead length (Tri-Gla) still remain. 3. There were no correlation between forehead morphology and position of maxillary incisor. 4. Forehead inclination and Andrew analysis show statistically significant negative correlation. That is, as forehead inclination increases, maxillary incisor is positioned posteriorly and this relationship can be shown as following equation, Andrew analysis = -0.39*Forehead inclination.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.13 no.1
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• pp.19-24
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• 2004

This study is intended to provide a referable information of exposed amount of maxillary central incisor of Korean by ages and gender under rest position. The result of this study will give guidelines for making prothesis. The subjects of this study are patients of Charmgoun Dental Hospital in Busan, Korea. A statistical analysis was conducted after taking digital photos of patients' teeth with a ruler and measuring the length of teeth on the computer program. The results of this study were as follows : 1. The length of maxillary central incisor that exposed under upper lip is decreased by increasing age in rest position.; the average length is 3.455mm in 20s, 2.525mm in 30s, and 1.543mm in 40s. 2. The exposal length in females is more than males, average length is 2.796mm in female and 2.342mm in male. However, there is not significant difference between the genders. 3. The exposed average length of maxiallry central incisor under upper lip is 2.618mm at rest. 4. The clinical crown average length of maxillary central incisor is 10.195mm, but incresing age, there is no significant defference. 5. There is significant difference between the genders in the clinical crown length of maxillary central incisor.; the length is 10.637mm in men, 9.90mm in women.

• The korean journal of orthodontics
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• v.45 no.3
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• pp.130-135
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• 2015

Objective: In our previous study, glass-fiber-reinforced plastics (GFRPs) made from polycarbonate and glass fibers were prepared for esthetic orthodontic wires using pultrusion. These laboratory GFRP wires are more transparent than the commercially available nickel-titanium wire; however, an investigation of the color stability of GFRP during orthodontic treatment is needed. Accordingly, in the present study, the color stability of GFRP was assessed using colorimetry. Methods: Preparation of GFRP esthetic round wires (diameter: 0.45 mm [0.018 inch]) using pultrusion was described previously. Here, to investigate how the diameter of fiber reinforcement affects color stability, GFRPs were prepared by incorporating either $13-{\mu}m$ (GFRP-13) or $7-{\mu}m$ glass (GFRP-7) fibers. The color changes of GFRPs after 24 h, and following 1, 2, and 4 weeks of coffee immersion at $37^{\circ}C$, were measured by colorimetry. We evaluated the color stability of GFRPs by two evaluating units: the color difference (${\Delta}E^*$) and National Bureau of Standards (NBS). Results: After immersion, both GFRPs showed almost no visible color change. According to the colorimetry measurements, the ${\Delta}E^*$ values of GFRP-13 and GFRP-7 were 0.73-1.16, and 0.62-1.10, respectively. In accordance with NBS units, both GFRPs showed "slight" color changes. As a result, there were no significant differences in the ${\Delta}E^*$ values or NBS units for GFRP-13 or GFRP-7. Moreover, for both GFRPs, no significant differences were observed in any of the immersion periods. Conclusions: Our findings suggest that the GFRPs will maintain high color stability during orthodontic treatment, and are an attractive prospect as esthetic orthodontic wires.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.253-263
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• 2006

Purpose: Recently, dental implant systems have been widely used for the treatment of the extraction site, but we have been confronted with many limitations in esthetics, phonetics and function. Transitional implants(TI) were developed as a method of providing fixed provisional restorations during conventional implant healing. Until now, little data have been provided on korean transitional implants. The purpose of this study is to evaluate the implant placement site histologically after 4 weeks and 8 weeks. Materials and Methods : Test group( IntermetzzoTM MEGAGEN, KOREA) and control group(Mini Drive Lock, Intra Rock, U.S.A.) were immediately placed in interseptal or interproximal bone of beagle dog after mandibular premolars extraction, and had a healing period with non-submerged state but without loading, Both TI surfaces were composed of rough surfaces. Results: In the test group, the average percentage of BIC were respectively 39.40%(SD7.35) after 4 weeks and 44.05%(16.76) after 8 weeks, and In the control group were 50.75%(1.48) and 59.40%(0.00). Discussion: We evaluated the initial ability of the osseointegration of TI through this study. Because TI is placed with a conventional implant simultaneously and loaded immediately, the ability of osseointegration is a very important factor for the success of TI during the initial healing phase. Conclusion: The results of the histological evaluation of these two groups were similar to those mentioned in other studies for osseointegration of implant.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.438-445
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• 2000

The ideal restorative material should mimic the properties of the tissues it replaces. Dental composite resins have been used widely as restorative materials due to its advantages such as excellent esthetics and ease of manipulation. But inadequate wear resistance has been a major factor limiting the use of composite restorative materials. Improved manufacturing techniques have allowed the development of hybrid composites, with a greater percentage volume filler loading, which have improved physical and mechanical properties. However they are lacking in the study of wear resistance. The purpose of this study was to evaluate the wear of human enamel against ceromer by the use of a pin-on-disk type wear testers. Discs of ceromer(Targis ; lvoclar Vivadent, Amherst. NY) and discs of type III gold alloy as a control were used f9r test specimens. Intact cusp of premolar and molar were used for enamel specimens. The wear of enamel was determined by weigh-ing the cusp before and after each test, and the weight converted to volumes by average densi-ty of enamel. Surface profilometer was used to quantify wear of the ceromer and gold specimens. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces The results were as follows; 1. Ceromer produced less enamel wear than gold(p<0.05) 2. The wear volume of ceromer was greater than that of gold(p<0.01) 3. The hardess of ceromer was lower than that of gold, but there was no correlation between the hardness and wear of the ceromer and gold. 4. SEM analysis revealed that there were many voids and microcracks in the wear tract of ceromer In gold group, many minute V-shaped grooves were examined.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.166-173
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• 2012

Dilaceration is a developmental disturbance in shape of teeth. It refers to an angulation, or a sharp bend or curve, in the root or crown of a formed tooth. Dilacerations are estimated to occur in 3% of all permanent dentitions. However, the etiology of dilaceration is not yet fully understood. Traumatic injury to the deciduous predecessors and ectopic development of the tooth germ are the two commonly cited causes of this anomaly. The involved tooth is usually the maxillary central incisor and it also shows high prevalence of impaction. At first, We tried to do surgical exposure with orthodontic traction but to no avail. After then surgical repositioning of the dilacerated tooth was performed. Finally, Satisfactory results were obtained at the end of treatment, with improvement in dental esthetics and functional aspects.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.426-433
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• 2013

When restoring edentulous patients with lower complete denture, the smaller supportive and retentive area of mandible can lead to poor support and stability, denture dislodgement and pain resulting discomfort. In this situation, implant prosthesis can improve esthetics, stability and occlusal force. Whereas, patients with a upper complete denture can adjust more easier because of palate. Therefore, it is suggested to rehabilitate fully edentulous patients with lower implant-supported, upper complete denture as one of the treatment options. So, we are going to report the case and literature review about how the lower implant prosthesis opposing to upper complete denture affects the bone resorption of maxillary residual ridge.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.307-313
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• 2016

Overdenture is one of the methods of patients with severely worn dentition. Remaining natural teeth help preserve alveolar bone and proprioception and provide rigid support. Also, overdenture distributes the concentrated stress applied to the abutment tooth and denture supporting tissues. There is an advantage that it can provide long-term stability to denture. In this case, the patient with only a few teeth due to severe wear and caries was satisfied with good function and favorable esthetics by using overdenture.

• Journal of the Korea Convergence Society
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• v.10 no.6
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• pp.287-297
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• 2019

The purpose of this study was to examine the relationship of body-shape perception and periodontal diseases in female adolescents based on the sixth 3rd-year(2015) data of the National Health and Nutrition Examination Survey. The subjects in this study were 211 female teenagers who were at the western ages of 12 to 18. As a result of analyzing, it's found that the body-shape perception of the female teens were linked to age, sleep hours, BMI, weight control and toothbrushing frequency, and whether they had periodontal diseases or not was found to be under the influence of age, smoking, sleep hours, stress, BMI and toothbrushing frequency. When the relationship between their body-shape perception and peridontal diseases was analyzed by controlling the confounders, the adolescents who considered their own bodies to be obese suffered from 3.18-fold more periodontal diseases(OR=3.18, 95% CI: 1.21, 8.38) than the teenagers who considered their body shape to be average. In the future, oral health care should be provided in consideration of the mental health of female adolescents to prevent periodontal diseases.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.170-179
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• 2019

The prosthodontic treatments in maxillary anterior teeth focus on achieving esthetic appearances. It is possible to improve the esthetic appearance by adjusting the shape, arrangement, and color of the maxillary anterior teeth. For anterior teeth restoration, it is necessary to evaluate the relationship of teeth, lip and gingival architecture with the facial profile of patient. Also, clinician needs to fully understand what the patient wants to. DSD (digital smile design) concept can be applied as a tool to improve communication with the clinician, technician and patient. In addition, DSD can help to meet the needs of the patient. In this case, it was impossible to achieve symmetry due to congenital missing of maxillary central incisor. The definitive treatment goal was to get the harmony of maxillary anterior teeth, lip and the patient's face. This case report describes that the patient and clinician got the satisfying esthetic outcome by using DSD.