• 대한치과교정학회지
• /
• 제20권1호
• /
• pp.183-195
• /
• 1990

The purposes of present study were to identify possible relationships between post-treatment changes and post-retention changes. The patient's models were composed of 58 samples, and were classified non-extraction group (30 samples) and extraction group (28 samples). For each sample the first models were taken prior to the start of treatment, the second models just after the end of treatment, and the third models two years after. The results were as follows: 1. In the cases of non-extraction group, increases were in intermolar width of maxilla, interbicuspid width of maxilla and arch perimeter of mandible during treatment period, but decreases were in the same measurements during post-retention period. 2. In the cases of extraction group, decreases were in intermolar width of mandible, interbicuspid widths of maxilla and mandible, arch length of mandible, arch perimeters of maxilla and mandible during treatment period. 3. Significant decreases were in the irregularity index of both extraction and non-extraction group during treatment period. 4. There were significant differences of arch dimensional changes in intermolar widths of maxilla and mandible, interbicuspid widths of maxilla and mandible, arch lengths of maxilla and mandible, arch perimeters of maxilla and mandible between non-extraction and extraction group.

• 대한치과교정학회지
• /
• 제17권2호
• /
• pp.235-246
• /
• 1987

The purpose of this study was to detect out the changes occured during orthodontic treatment. The sample was consisted of 77 orthodontic patients. For this study 13 linear lengths and arch area were measured in maxilla, mandible respectively and were analyzed statistically. The results were as follows 1 The sequence of changes in the form and dimensions of dental arches following orthodontic treatment was as follows Class I malocclusion, Class III malocclusion, Class II malocclusion. 2 Changes in the form and dimensions of dental arches were greater in extraction cases than those of non-extraction cases 3 In comparison with maxilla and mandible on the amount of changes following orthodontic treatment in each malocclusion group, significant differences were greatest in class III malocclusion 4 In comparison with maxilla and mandible on the amount of changes following orthodontic treatment in extraction and non-extraction cases, significant differences were greater in extraction cases than those of non-extraction cases 5. The amount of changes during orthodontic treatment in extraction and non-extraction cases in male was not different from female's.

• 대한치과교정학회지
• /
• 제28권3호
• /
• pp.343-351
• /
• 1998

본 연구는 비발치로 치료된 I급 부정교합 환자의 형태적 특성을 알아보고자 시행하였다. 비발치로 치료된 I급 부정교합 환자의 치료전과 치료후 안면형태를 평가하고 이를 교정치료를 받지 않은 정상군과 4개의 제 1소구치를 발거하고 치료한 I 급 부정교합 환자군과 비교하였다. Edgewise appliance와 MEAW를 사용하여 비발치로 치료한 환자로 치료후 비교적 양호한 안모와 교합을 갖는 환자 22명을 대상으로 하였다. 이들의 평균 연령은 14.7세 였고 평균 치료기간은 2.6년이었다 치료전과 치료후의 두부계측방사선 사진에서 32개의 계측점을 사용하여 24항목의 각도와 거리를 측정하였다. Student t-test를 시행하여 비발치군의 치료전과 치료후의 변화, 비발치군과 정상군의 차이, 그리고 비발치군과 발치군의 차이를 비교한 결과($p{\leq}0.05$), 다음의 결론을 얻었다. 1. 비발치로 치료한 I 급 부정교합 환자의 치료전 ODI는 $69.9^{\circ}$, APDI는 $82.1^{\circ}$, CF는$152^{\circ}$, EI는 $152^{\circ}$ 였다. 2. 비발치군의 골격형태는 정상군과 유사하였으나 정상군보다 큰 절치간각을 보였다. 3. 발치군은 비발치군보다 돌출된 안모와 작은 절치간각, 그리고 낮은 EI를 가지고 있었다. 4. 비발치군의 치료전,후 골격형태에는 큰 변화가 없었으나 치료후 상,하악 구치의 직립과 절치간각의 감소를 나타내었다.

• 대한치과교정학회지
• /
• 제49권4호
• /
• pp.222-234
• /
• 2019

Objective: To investigate the three-dimensional lip vermilion changes after extraction and non-extraction orthodontic treatment in female adult patients and explore the correlation between lip vermilion changes and incisor changes. Methods: Forty-seven young female adult patients were enrolled in this study (skeletal Class III patients were excluded), including 34 lip-protruding patients treated by extraction of four first premolars (18 patients requiring mini-implants for maximum anchorage control and 16 patients without mini-implants) and 13 patients requiring non-extraction treatment. Nine angles, seven distances, and the surface area of the lip vermilion were measured by using pre- and post-treatment three-dimensional facial scans. Linear and angular measurements of incisors were performed on lateral cephalograms. Results: There were no significant changes in the vermilion measurements in the non-extraction group. The vermilion angle, vermilion height, central bow angle, height/width ratio, and vermilion surface area decreased significantly after the orthodontic treatment in the extraction groups, but the upper/lower vermilion proportion remained unchanged. Significant correlations were found between the changes in incisor position and those in vermilion angles, vermilion height, and surface area. Conclusions: Extraction of the four first premolars probably produced an aesthetic improvement in lip vermilion morphology. However, the upper/lower vermilion proportion remained unchanged. The variations in the vermilion were closely related to incisor changes, especially the upper incisor inclination changes.

• 농업과학연구
• /
• 제39권3호
• /
• pp.387-393
• /
• 2012

In the present study, ${\beta}$-glucanase-assisted extraction of starch from glutinous barley(Hinchal ssalbory) was investigated. ${\beta}$-glucanase was added to a coarse starch suspension obtained after wet milling in the starch extraction process. It was found that in the isolated starch with enzyme treatment, protein content was lower by 0.03%, compared to that with non-enzyme treatment. More importantly it was observed that the extraction yield of starch from enzyme treatment was found to be about 12% higher than the one from non-enzyme treatment (enzyme treated: 90.56%, non-enzyme treated: 78.46%). In order to elucidate this finding, the mass-balance determination of starch in each extraction step was carried out and found that the enzyme treatment might influence on the insoluble residues(R3 and R4 fractions) to hydrolyze ${\beta}$-glucan and other materials (e.g., mucilages etc.), thereby facilitated the separation of starch from it and a next filtration process. With a phase-contrast microscope it was observed that the isolated starch with enzyme treatment contained small starch granules more than the one with non-enzyme treatment and this might result in higher extraction yield observed with the former. In order to confirm this hypothesis, further experiments would be necessary.

• 대한치과교정학회지
• /
• 제21권1호
• /
• pp.223-238
• /
• 1991

This study was carried out in order to findout the amount of tooth movement, the changes arch size and the changes in arch morphology following orthodontic treatment and to provide a guideline for to predict post-treatment arch morphology. The sample group for this study consists of 15 males and 22 females, totalling in 37 persons, who received orthodontic treatment at Orthodontic Department of Dankook Univ. Dental Hospital. They are classified into Extraction Class I treatment group (E I), Non-extraction Class I treatment group (N I), and Non-extraction Class III treatment group (N III), according to their pre-treatment malocclusion state and methods of treatment. Following conclusions and averaged dental arch form for each group were obtained by cephalometric linear measurements and dental arch measurements using pre- and post-treatment lateral cephalograms and plaster study models. 1. Intercanine width were reduced in max. of both EI and NI during the period of treatment, 2. Intermolar width were reduced in max. of EI and increased in max. of NI. Therefore although there was no difference between these two groups before the treatment, intermolar width of the max, of NI was wider than that of E1 after the treatment. 3. PMV-incisor distance and PMV-canine distance were decreased in both max. and mand. of EI and that of NI, during the period of treatment. PMV-molar distance was decreased in both max. and mand. of NI and in mand. of NIII. 4. Items that showed stability during the treatment were: max. & mand. PMV-molar distance, mand. intercanine and intermolar width in EI; mand. intercanine and intermolar width in NI; mand. & max. PMV-incisor distance, PMV-canine distance, max. PMV-molar distance and max. & mand. intercanine and intermolar width in NIII. 5. The differences in averaged canine and molar variances to post-treatment dental arch form were present only in EI and in NI. There was no variance between maxilla and mandible in each group.

• 대한치과교정학회지
• /
• 제23권1호
• /
• pp.47-55
• /
• 1993

This study was designed to recognize the factors which can affect the normal eruption of the lower third molar and the eruption rate of the lower third molar in the cases of non-extraction and the extraction of first premolar. The sample consisted of 214 cases of extraction of first premolar and 119 cases of non-extraction, and all of these cases were divided into erupted and impacted lower third molar groups and were analized according to the pantomogram. The results of the study were as follows : 1. The eruption rate of the touter third molar was $54.67\%$ in the group of extraction of the first premolar and $35.29\%$ in the non-extraction group. 2. The early inclination of the erupting lower third molar has significant effect in the eruption of it. 3. In the orthodontic treatment, the extraction of first premolar is one of the factors infuencing the nomal eruption of lower third molar. 4. The available space for the normal enruption of lower third molar was greater in first premolar extraction case than in non-extraction case.

• 대한치과교정학회지
• /
• 제18권1호
• /
• pp.105-112
• /
• 1988

To predict duration of orthodontic treatment of malocclusion, 304 male and female patients whose orthodontic treatment was finished in department of orthodontics, Infirmary of dental college, Chosun University were studied. The duration of treatment was studied according to types of malocclusion, beginning ages of treatment, Hellman's dental ages, the determination of tooth extraction, types of tooth extraction and types of orthodontic appliance. The following results were obtained. 1. The duration of treatment was 18 months in Class I malocclusion, 20 months in Class II malocclusion and 24 months in Class III malocclusion. 2. The more early treatment was done, the more duration of treatment was needed according to beginning age of treatment and Hellman's dental ages. 3. Treatment of tooth extraction case was needed for 78 days more than that of non-extraction case. 4. The duration of treatment with unilateral extraction of premolars was the shortest (598 days) and that with single arch extraction of premolars was the longest (685 days) according to types of tooth extraction. 5. The duration of treatment by removable appliance was the shortest (237 days) and the combination of removable appliance, headgear and full banded appliance was the longest (1425 days) according to types of orthodontic appliance. 6. The duration of treatment was 18 months in typical orthodontic treatment with 4 extraction of premolar and full banded appliance.

• Imaging Science in Dentistry
• /
• 제41권1호
• /
• pp.17-21
• /
• 2011

Purpose : The purpose of this study was to examine the patient- and treatment-related etiologic factors of external root resorption. Materials and Methods : This study consisted of 163 patients who had completed orthodontic treatments and taken the pre- and post-treatment panoramic and lateral cephalometric radiographs. The length of tooth was measured from the tooth apex to the incisal edge or cusp tip on the panoramic radiograph. Overbite and overjet were measured from the pre- and post-treatment lateral cephalometric radiographs. The root resorption of each tooth and the factors of malocclusion were analyzed with an analysis of variance. A paired t test was performed to compare the mean amount of root resorption between male and female, between extraction and non-extraction cases, and between surgery and non-surgery groups. Correlation coefficients were measured to assess the relationship between the amount of root resorption and the age in which the orthodontic treatment started, the degree of changes in overbite and overjet, and the duration of treatment. Results : Maxillary central incisor was the most resorbed tooth, followed by the maxillary lateral incisor, the mandibular central incisor, and the mandibular lateral incisor. The history of tooth extraction was significantly associated with the root resorption. The duration of orthodontic treatment was positively correlated with the amount of root resorption. Conclusion : These findings show that orthodontic treatment should be carefully performed in patients who need the treatment for a long period and with a pre-treatment extraction of teeth.

• 대한치과교정학회지
• /
• 제27권5호
• /
• pp.761-770
• /
• 1997

연세대학교 치과대학 부속병원 교정과와 영동세브란스 병원 치과 교정과에 내원하여 최근에 교정치료가 끝난 제 I 급 부정교합 환자중 소구치를 발치하고 치료한 발치군과 비발치로 치료한 비발치 치료군 71명을 선정하고 다시 연령에 따라 청소년기와 성인으로 분류하여 교정치료 전후의 두부방사선 계측분석 사진을 통하여 치아와 연조직의 수평$\cdot$수직적 변화를 비교분석하여 다음과 같은 결론을 얻었다. 1. 발치군과 비발치군간의 비교에서는 SN-MP angle, E-line에 대한 상순의 이동, 상악 제1대구치의 수직이동량, 하악 제1대구치의 수평이동량 등의 항목을 제외한 모든 치아계측항목과 연조직 계측항목에서 유의차를 나타내었다. 2. 청소년기의 발치군과 비발치군간의 비교에서는 상하악 전치의 경사도와 수직기준선으로부터의 전치부 수평 변화 항목, 상악 제1대구치의 근심이동, E-line에 대한 상,하순의 위치변화에서 유의차를 나타내었다. 3. 성인에서의 발치와 비발치군간의 비교에서는 상하악 전치의 경사도와 수직기준선으로부터의 수평적 위치 변화와, 상악 제1대구치의 수직 고경 및 하악 제1대구치의 근심이동, E-line과 수직기준선으로부터의 상,하순의 위치 변화에서 유의차를 나타내었다. 4. 청소년기와 성인 모두에서 SN-MP angle의 변화는 발치군과 비발치군간에 유의차가 없었다.