• 대한치과교정학회지
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• 제30권1호
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• pp.115-126
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• 2000

치열궁의 확장은 치아의 총생 부정교합을 비발치로 치료하기 위한 방법중 하나이며, 치열궁 확장의 진단과 치료를 위하여 상악절치의 근원심 폭경으로부터 이상적인 제1소구치간 치열궁 폭경과 제1대구치간 치열궁 폭경을 예측하는 공식이 제시되어 있다. 이 연구의 목적은 제시된 공식중에서 Pont의 예측식, Schmuth의 예측식 및 Cha들의 예측식을 정상교합의 계측과 비교하고, 이들 예측식의 임상적 신뢰성을 평가하는 것이다. 13세에서 23세사이의 한국인 태생 정상교합자의 석고모형을 대상으로 상악 절치 근원심 폭경,제1소구치간 치열궁 폭경 및 제1대구치간 치열궁 폭경사이의 상관관계를 평가하였으며, 정상교합의 절치폭경의 합을 Pont의 예측식, Schmuth의 예측식 및 Cha 들의 예측식에 대입하여 이상적 제1소구치간 및 제1대구치간 치열궁 폭경의 예측치를 산출하고, 이를 정상교합자의 그것과 비교하여 다음의 결과와 결론을 얻었다. 1. 정상교합에서 상악 절치 근원심 폭경의 합 (SI)으로부터 산출된 제1소구치간 치열궁 폭경 지수는 81.96이었고, 제1대구치간 치열궁 폭경 지수는 62.55이었다. 2. 정상교합에서 상악 절치 근원심 폭경의 합 (SI)과 제1소구치간 치열궁 폭경 (PmW)사이의 상관계수는 0.50이었고, 제1대구치간 치열궁 폭경(MW)사이의 상관계수는 0.39로 모두 통계적 유의성이 있는 저도의 상관관계를 나타냈다. 3. 정상교합에서 상악 절치 근원심 폭경의 합으로부터 제1소구치간 폭경과 제1대구치간 폭경의 예측을 위한 상관식은 신뢰성이 매우 낮았다 ($r^2\;=\;0.25,\;r^2\;=\;0.15$). 4. 이상적 제1소구치간 치열궁 폭경의 예측에 있어서 Pont와 Schmuth의 예측식은 실제보다 크게 예측되는 경향을 보였으며, Cha 들의 예측식은 보다 크거나 작게 예측되는 비율이 같았다. 5. 이상적 제1소구치간 치열궁 폭경의 예측이 1 mm의 오차한계 이내로 예측된 경우는 Cha들의 예측식이 가장 높으며 ($45\%$), Pont의 예측식과 Schmuth의 예측식은 각각 $40\%$와$39\%$ 이었다. 5. 이상적 제1대구치간 치열궁 폭경의 예측에 있어서 모든 예측식은 작게 예측되는 경향을 보였으며, 그 중에서도 Cha 들의 예측식은 예측성이 가장 양호하였다. 7 이상적 제1대구치간 치열궁 폭경의 예측이 1 mm의 오차한계 이내로 예측된 경우는 Cha 들의 예측식이 $40\%$ 로 가장 높으며, Pont와 Schmuth의 예측식은 각각 $29\%$와 $13\%$ 이었다. 이상의 결과는 상악 절치의 근원심 폭경의 합으로부터 이상적 제1소구치간 치열궁 폭경 및 제1대구치간 치열궁 폭경을 예측하는 것은 임상적 신뢰성이 낮을 것임을 시사한다.

• Imaging Science in Dentistry
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• 제43권2호
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• pp.85-90
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• 2013

Purpose: This study was performed to determine the buccal alveolar bone thickness following rapid maxillary expansion (RME) using cone-beam computed tomography (CBCT). Materials and Methods: Twenty-four individuals (15 females, 9 males; 13.9 years) that underwent RME therapy were included. Each patient had CBCT images available before (T1), after (T2), and 2 to 3 years after (T3) maxillary expansion therapy. Coronal multiplanar reconstruction images were used to measure the linear transverse dimensions, inclinations of teeth, and thickness of the buccal alveolar bone. One-way ANOVA analysis was used to compare the changes between the three times of imaging. Pairwise comparisons were made with the Bonferroni method. The level of significance was established at p<0.05. Results: The mean changes between the points in time yielded significant differences for both molar and premolar transverse measurements between T1 and T2 (p<0.05) and between T1 and T3 (p<0.05). When evaluating the effect of maxillary expansion on the amount of buccal alveolar bone, a decrease between T1 and T2 and an increase between T2 and T3 were found in the buccal bone thickness of both the maxillary first premolars and maxillary first molars. However, these changes were not significant. Similar changes were observed for the angular measurements. Conclusion: RME resulted in non-significant reduction of buccal bone between T1 and T2. These changes were reversible in the long-term with no evident deleterious effects on the alveolar buccal bone.

• 대한치과교정학회지
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• 제44권1호
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• pp.36-43
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• 2014

Objective: The purpose of this study was to quantitatively evaluate the cortical bone densities of the maxillary and mandibular alveolar processes in adults with different vertical facial types using cone-beam computed tomography (CBCT) images. Methods: CBCT images (n = 142) of adult patients (20-45 years) were classified into hypodivergent, normodivergent, and hyperdivergent groups on the basis of linear and angular S-N/Go-Me measurements. The cortical bone densities (in Hounsfield units) at maxillary and mandibular interdental sites from the distal aspect of the canine to the mesial aspect of the second molar were measured on the images. Results: On the maxillary buccal side, female subjects in the hyperdivergent group showed significantly decreased bone density, while in the posterior region, male subjects in the hyperdivergent group displayed significantly decreased bone density when compared with corresponding subjects in the other groups (p<0.001). Furthermore, the subjects in the hyperdivergent group had significantly lower bone densities on the mandibular buccal side than hypodivergent subjects. The maxillary palatal bone density did not differ significantly among groups, but female subjects showed significantly denser palatal cortical bone. No significant difference in bone density was found between the palatal and buccal sides in the maxillary premolar region. Overall, the palatal cortical bone was denser anteriorly and buccal cortical bone was denser posteriorly. Conclusion: Adults with the hyperdivergent facial type tend to have less-dense buccal cortical bone in the maxillary and mandibular alveolar processes. Clinicians should be aware of the variability of cortical bone densities at mini-implant placement sites.

• 대한치과교정학회지
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• 제45권5호
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• pp.236-244
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• 2015

Objective: The aim of this study was to investigate three-dimensional molar displacement after distalization via miniscrews and a horizontal modification of the trans-palatal-arch (TPA). Methods: The subjects in this clinical trial were 26 Class II patients. After the preparation of a complete set of diagnostic records, miniscrews were inserted between the maxillary 2nd premolar and 1st molar on the palatal side. Elastic modules connected to the TPA exerting an average force of 150-200 g/side parallel to the occlusal plane were applied. Cone-beam computed tomography was utilized to evaluate the position of the miniscrews relative to the adjacent teeth and maxillary sinus, and the direction of force relative to molar furcation. The distances from the central point of the incisive papilla to the mesiopalatal cusps of the 1st maxillary molars and the distances between the mesiopalatal cusps of the left and right molars were measured to evaluate displacement of the maxillary molars on the horizontal plane. Interocclusal space was used to evaluate vertical changes. Results: Mean maxillary 1st molar distalization was $2.3{\pm}1.1mm$, at a rate of $0.4{\pm}0.2mm/month$, and rotation was not significant. Intermolar width increased by $2.9{\pm}1.8mm$. Molars were intruded relative to the neighboring teeth, from 0.1 to 0.8 mm. Conclusions: Distalization of molars was possible without extrusion, using the appliance investigated. The intrusive component of force reduced the rate of distal movement.

• 대한소아치과학회지
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• 제26권4호
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• pp.630-635
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• 1999

치아의 전위는 매우 드문 치아 기형의 하나로서 발생 또는 맹출중 인접한 2개의 영구치의 위치가 서로 바뀐것을 말한다. 전위는 상악과 하악 모두에서 발생 가능한데 그중에서 상악에서의 발생이 더 흔하며 상악견치는 가장 호발하는 치아이다. 상악에서는 상악 견치와 제 1 소구치와의 전위가 가장 빈도가 높고 그 다음으로 상악 견치와 측절치와의 전위가 많다. 전위는 완전 전위와 불완전 전위로 나눌수 있는데 완전 전위는 치관뿐 아니라 치근의 위치까지 전위된 경우를 말하고 불완전 전위는 치근의 위치는 정상이고 치관만 전위된 경우이다. 전위의 원인에 대하여 명확하게 밝혀진 것은 없으나 유치의 만기잔존이나 조기상실, 발생중의 전위나 정상 맹출 경로로부터의 이탈, 유치열시기의 안면외상 등이 제기되고 있고 이밖에 과잉치, odontoma 또는 odontogenic cyst, 염증성 병소 등을 그 원인으로 생각해 볼 수 있다. 본 증례는 유치열시기의 안면외상으로 인하여 상악 영구 견치와 측절치의 전위가 발생한 경우로서 치료후 전위된 위치로의 양호한 배열을 이루었다.

• 한국임상수의학회지
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• 제19권2호
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• pp.253-255
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• 2002

A 10-year-old, female mixed breed dog and a 3-year-old, female chihuahua which had swelling below lower eyelid were refered to Veterinary Medical Teaching Hospital, Seoul National University. The plain maxillary oblique view revealed radiolucency at periapical area in maxillary fourth premolar. The 2 cases were diagnosed as periapical abscess by clinical sign and radiographs, and apicoectomies were performed for resetting the lesions and preserving the teeth. Under general anesthesia with isoflurane, periapical abscess was resected by burs and the defect was filled with zinc phosphate cement. Radiograph was perfomed at 1 week and 1 year after apicoectomy and there was no evidence of recurrence.

• Restorative Dentistry and Endodontics
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• 제8권1호
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• pp.139-145
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• 1982

Eighty four human maxillary second premolars were injected with china. ink, decalcified, cleared and used in study, in vitro, to determine the number of root canals, the frequency and location of lateral canals, the frequency and location of transverse ansatomoses, the curvature of root canals, the location of apical foramens, and the frequency of apical deltas. The results were as follows: 1. Most of the teeth demonstrated one canals, but the only tooth was found to have two canal. 2. Of the 101 canals studied, 85.1% of the canals were found to have lateral canals and these ramifications were usually located in the apical third of the root. 3. Of the two root canals in one root, 25.4% of the canals were found to have transverse anastomoses and were usually located in the middle third of the root 4. 33.3% of apical foramens were located directly on the root apex and 66.7% of them laterally, and 46.5% of canals showed distal curvature.

• 대한치과교정학회지
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• 제15권2호
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• pp.291-301
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• 1985

Fifty subjects who were to be treated with fixed orhodontic appliances by light wire edgewise technique were selected. Bands with different marginal depth were made in first molar and direct bonding brackets were bonded in second premolar. For determining the effects of fixed orthodontic appliance on the gingival tissue, the changes of clinical crown length, periodontal pocket depth, gingival sulcus fluid were checked. The results were as follows: 1. Gingival condition was deteriorated after wearing the fixed orthodontic appliance, and the deteriorative rate was decreased gradually. 2. The greatest gingival change was occurred in the maxillary first molar among the experimental teeth. 3. The gingival change of maxillary teeth was greater than that of mandibular teeth. $(p\leq0.01)$ 4. The greater gingival change was occurred around subgingivally located band than around supragingivally located band. 5. Comparing the gingival changes of banded teeth with them of bonded teeth, the gingival tissue was more effected by oral hygiene than by type of appliances. 6. In the quantitive changes of gingival crevicular fluid, there was no exact relationship with gingival inflammation.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.139-144
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• 1981

Eighty four human maxillary first premolars were injected with china ink, decalcified, cleared and used in study, in vitro, to determine the number of root canals, the frequency and location of lateral canals, the frequency and location of transverse anastomoses, the curvature of root canals, the location of apical foramens, and the frequency of apical deltas. The results were as follows: 1. Most of the teeth demonstrated two canals, but 20.2% of the teeth were found to have one canal. 2. Of the 151 canals studied, 38.4% of the canals were found to have lateral canals and these ramifications were usually located in the apical third of the root. 3. Of the two root canals in one root, 35.7% of the canals were found to have transverse anastomoses and were usually located in the middle third of the root. 4. 15.2% of apical foramens were located directly on the root apex and 84.8% of them laterally, and 52.3% of canals showed distal curvature.

• Restorative Dentistry and Endodontics
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• 제12권2호
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• pp.11-15
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• 1987

Thirty maxillary second premolars were fixed, decalcified, washed and embedded in celloidin to observe the root canal size and morphology at apical 5mm area. The results were as follows: 1. Single canaled teeth and two canaled teeth were approximately equal numbered. 2. Single canaled teeth have round canal but two canaled teeth have long, slender buccal canal and ovoid lingual canal. 3. The canal size of single canaled teeth was $380{\pm}30{\mu}m,\;340{\pm}22{\mu}m$, but that of buccal canal of two canaled teeth was $360{\pm}32{\mu}m,\;240{\pm}28{\mu}m$, lingual canal was $330{\pm}28{\mu}m,\;280{\pm}20{\mu}m$.