• 대한치과의사협회지
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• 제13권6호
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• pp.533-538
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• 1975

• 대한치과교정학회지
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• 제20권2호
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• pp.217-226
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• 1990

The purposes of this study were to clarify the effect of tooth size and arch size upon the crowding. 175 upper casts were measured and following conclusions were made. 1. Tooth size, intermolar width, 2nd premolar width of crowded group were not significantly different from those of noncrowded groups. 2. Intercanine width, arch length of noncrowded group were significantly larger than crowded group. 3. Multiple regression equations were derived by using tooth size, arch perimeter, arch length, intermolar width.

• 제어로봇시스템학회논문지
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• 제16권3호
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• pp.300-304
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• 2010

This study was performed to development a dental three-dimensional laser scanning system and measure the accuracy of new adjustable upper dental impression tray. The metal stock, individual, and new adjustable stock trays were used for 30 stone casts(10 casts each) duplicated a resin master model of maxilla. The dental stone was poured in a vinyl polysiloxane impressions and allowed to set for on hour. The master model and the duplicated casts were digitized using an dental scanning system. The distance between the reference points were measured and analyzed on the graphic image of 3D graphic software of CATIA. The statistical significance of the differences between the groups was determined by a two-way ANOVA. There were no significant differences between the accuracies of the adjustable stock tray and the master model except only anterior arch width on the upper arch. The adjustable upper stock tray showed clinically acceptable accuracies of the study cast produced by them.

• 대한치과보철학회지
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• 제37권4호
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• pp.506-515
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• 1999

Dental practice can produce and spread some infectious diseases from patients to dentist, dental assistant, and dental labors. One possible method for preventing these cross-contamination is to immerse dental impression in chemical disinfectants. So for many investigators studied on the dimensional changes of dental impressions and on the surface qualities of stone casts made from impression following immersion in disinfectants. This study was proposed to evaluate some popular impression disinfectant combination from the point of dimensional stability. Impression was taken from dental arch-shaped metal model. Irreversible hydrocolloid and 3 elastomers(polyvinyl siloxane, polysulfide, polyether) were immersed in 3 disinfectants (2% glutaraldehyde, 1% povidone-iodine, 0.5% sodium hypochlorite) for 10 minutes and measured both cross-arch and anterior-posterior distance under stereo microscope to evaluate dimensional change. The results obtained were as follows: 1. Dimensional changes of irreversible hydrocolloid impression was statistically different in cross-arch and anterior-posterior distance when immersed in 2% glutaraldehyde solution and in anterior-posterior distance when immersed in 0.5% sodium hypochlorite solution from control group (p<0.05). 2. Dimensional changes of polyvinyl siloxane and polysulfide impression were not statistically different from control group (p>0.05). 3. Dimensional changes of polyether impression was statistically different in cross-arch distance when immersed in 0.5% sodium hypochlorite solution and in anterior-posterior distance when immersed in 1% povidone-iodine solution from control group (p<0.05). 4. In all cases, dimensional changes were less than 0.1% from the original dimension and concluded clinically acceptable.

• 대한치과교정학회지
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• 제27권3호
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• pp.457-471
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• 1997

본 연구는 치열궁 길이 부조화(Arch length discrepancy : 이하 ALD)의 원인요소간의 상대적 중요성과 혼합치열기에서의 예측가능성을 알아보고자 시행되었다. Angle씨 I급 대구치관계이며 근기능 이상이나 골격형태의 이상이 없다고 판단되는 142명의 진단모형을 이용하여 성별과 ALD의 양에 따라 여섯군으로 나누어 각 치아의 크기와 치열궁 각 부위의 크기를 계측하였다. SPSS통계처리 프로그램을 이용하여 각군의 평균, 표준편차를 구하고 Student t-test, 상관관계 분석, 요인분석, 다중회귀분석을 실시하였으며 혼합치열기에서 얻을 수 있는 자료들을 이용한 ALD의 예측가능성을 평가하여 다음과 같은 결과를 얻었다. 1. 성별에 따른 차이는 정상군에서는 거의 보이지 않았으며 spacing군은 대부분의 계측치에서, crowding군은 몇가지 치열궁의 크기에 관한 계측치에서 유의한 차이를 보였다. 2. 남자crowding군과 여자 spacing군은 해당 정상군에 비해 주로 치아크기에 관한 계측치에서 유의한 차이를 보였다. 3. 남자 spacing군과 여자crowding군은 해당 정상군에 비해 치열궁의 크기에 관한 계측치에서 유의한 차이를 보였다. 4. 상관관계분석과 요인분석결과에서는 주로 치열궁의 크기에 관한 계측치들이 ALD와 큰 연관성을 나타내었다. 5. 혼합치열기에서 얻을 수 있는 정보인 중절치, 측절치, 제1대구치의 폭경과 제1대구치간 폭경, 치열궁 장경 을 이용한 ALD의 다중회귀분석은 최소 $63\%$에서 최대 $80\%$의 예측도(R square)를 보였다.

• 대한치과교정학회지
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• 제24권3호
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• pp.721-733
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• 1994

Orthodontic tooth movement is closely related to the stress on the periodontal tissue. In this research the finite element method was used to observe the stress distribution and to find the best condition for effective tooth movement in the case of unilateral molar expansion. The author constructed the model of lower dental arch of average Korean adult and used $.032'\times.032'\times60mm$ TMA wire. The wire was deflected in the horizontal and vertical direction to give the 16 conditions. The following results were obtained ; 1. When the moment and force were controlled properly the movement of anchor tooth was minimized and the movement of moving tooth was maximized. 2. As the initial horizontal deflection increased the buccal displacement of both teeth was also increased. As the initial horizontal deflection increased the lingual movement of anchor tooth and the buccal movement of moving tooth increased. 3. When the initial horizontal and vertical deflection rate was 1.5 the effective movement of moving tooth was observed with minimal displacement of anchor tooth.

• 대한치과교정학회지
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• 제42권4호
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• pp.169-181
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• 2012

Objective: The purpose of this study was to develop superimposition method on the lower arch using 3-dimensional (3D) cone beam computed tomography (CBCT) images and orthodontic 3D digital modeling. Methods: Integrated 3D CBCT images were acquired by substituting the dental portion of 3D CBCT images with precise dental images of an orthodontic 3D digital model. Images were acquired before and after treatment. For the superimposition, 2 superimposition methods were designed. Surface superimposition was based on the basal bone structure of the mandible by surface-to-surface matching (best-fit method). Plane superimposition was based on anatomical structures (mental and lingual foramen). For the evaluation, 10 landmarks including teeth and anatomic structures were assigned, and 30 times of superimpositions and measurements were performed to determine the more reproducible and reliable method. Results: All landmarks demonstrated that the surface superimposition method produced relatively more consistent coordinate values. The mean distances of measured landmarks values from the means were statistically significantly lower with the surface superimpositions method. Conclusions: Between the 2 superimposition methods designed for the evaluation of 3D changes in the lower arch, surface superimposition was the simpler, more reproducible, reliable method.

• The Journal of Advanced Prosthodontics
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• 제11권2호
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• pp.138-146
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• 2019

PURPOSE. Comparing the accuracy of casts produced from digital workflow to that of casts produced from conventional techniques. MATERIALS AND METHODS. Whole arch alginate (ALG) and polyvinyl siloxane (PVS) impressions were taken with stock trays and custom trays, respectively. The ALG impressions were poured with type III dental stone, while the PVS impressions were poured with type IV dental stone. For the digital workflow, IOS impressions were taken and physical casts were produced by 3D printing. In addition, 3D printed casts were produced from images obtained from a laboratory scanner (LS). For each technique, a total of 10 casts were produced. The accuracies of the whole arch and separated teeth were virtually quantified. RESULTS. Whole arch cast accuracy was more superior for PVS followed by LS, ALG, and IOS. The PVS and ALG groups were inferior in the areas more susceptible to impression material distortion, such as fossae and undercut regions. The LS casts appeared to have generalized errors of minor magnitude influencing primarily the posterior teeth. The IOS casts were considerably more affected at the posterior region. On the contrary, the IOS and LS casts were more superior for single tooth accuracy followed by PVS and ALG. CONCLUSION. For whole arch accuracy, casts produced from IOS were inferior to those produced from PVS and ALG. The inferior outcome of IOS appears to be related to the span of scanning. For single tooth accuracy, IOS showed superior accuracy compared to conventional impressions.

• 대한치과교정학회지
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• 제32권1호통권90호
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• pp.43-49
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• 2002

치아의 형태 이상, 선천결손 등에 의해 손상된 상하악 전치부 치열에서는 교정치료만으로는 적절한 기능 교합관계를 설정하지 못하는 경우가 많다. 치료후 상하악 전치부 치열에서 어떠한 치료가 필요할지를 미리 예측할 수 있다면 치료효율을 높일 수 있을 뿐 아니라, 타 분야와의 협진에도 보다 유리할 것이다. 이를 위해 이전의 연구에서는 한국인 정상 교합자를 이용한 견치간 폭경(intercanine width), 치열궁 장경(segment depth)과 치열궁 둘레(arch perimeter)간의 상관관계를 구했으며, 이번에는 이러한 관계를 이용한 컴퓨터 프로그램을 제작한 후 손상된 상하악 전치부 치열을 보이는 두 환자에게 이 프로그램을 치료 계획시 적용하여 보았다. 프로그램 적용 결과, 치료 계획시 필요한 변화량에 대한 정보와 각 변수간 변화(견치간 폭경, 치열궁 장경, 치열궁 둘레)에 따른 전치부 교합관계 변화를 보다 명확히 보여주었다. 추후 악안면 형태에 따른 전치부 치축변화와 치열궁 변화의 관계, 안정성 있는 견치간 폭경에 대한 정보를 제공한다면, 전치부에 대한 3차원 occlusogram의 제작이 가능할 것으로 기대된다.

• 대한소아치과학회지
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• 제23권2호
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• pp.365-374
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• 1996

The prupose of this study was to obtain standard measurements of the tooth size, Bolton ratio, width and length of dental arch and basal arch, overbite and overjet of the children who have normal dentition. The plaster cast of 97 children(47 boys and 50 girls) among the contestants in 1992, 1994, 1995 Healthy Dentition contest in Seoul were measured and following results were obtained. 1. Means and standard deviations of the mesio-distal maximum width of the permanent teeth, Bolton ratio, width and length of the dental arch and basal arch of the upper and lower dentition and overbite and overjet of the children were obtained. 2. Mesio-distal width of the teeth, width and length of the dental arch and basal arch of the upper and lower dentition of the boys were larger than those of the girls. 3. Bolton Overall ratio, Anterior ratio and overjet of the boys were larger than those of the girls and overbite of the boys were smaller than those of the girls, but no significant differences were noted between the boys and the girls(p>0.05). 4. In the comparision of the Healthy Dentition Contestants with Korean adults of Shur, all teeth of the Contestants were larger than those of Korean adults, especially upper and lower bicuspids(p<0.01). In the comparision of the Healthy Dentition Contestants with Caucasians, all teeth except upper and lower central incisor and upper first molar of the contestants were larger than those of Caucasians(p<0.05).