• The korean journal of orthodontics
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• v.4 no.1
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• pp.41-48
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• 1974

The author has selected 70 non-extraction and extraction cases. The linear measurements were made in the maxillary dental cast at pre-and post-treatment. The purpose of this study was to detect out the changes occured during orthodontic treatment. On the basis of findings of this study, the following results are made: 1. In extraction cases: 1) The maxillary intercanine width increased. 2) The maxillary dental arch width decreased. 3) The maxillary inter first molar width decreased. 4) The maxillary dental arch length decreased. 5) The maxillary dental arch length (I-3) increased. 2. In non-extraction cases, the maxillary intercanine width decreased in Angle's class III.

• The korean journal of orthodontics
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• v.16 no.2
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• pp.115-122
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• 1986

This study was undertaken to determine the relapse amount in the various malocclusions and correlative coefficient with other factors. The sample were consisted of 60 orthodontic patients whose models were perfect before treatment, after treatment and after 6 months post treatment. For this study 8 liner lengths were measured in maxilla and mandible respectively. The results were as follows. 1. The change with treatment of maxillary dental arch length was most large in non extraction group of Angle's class II malocclusion. 2. The relapse compared with other treatment changes was most little in the arch perimeter. 3. The relapse was increased in proportion to the beginning age of the treatment in non extraction group. 4. The relapse of maxillary intermolar width was increased and those of overbite & molar relationship were decreased in proportion to the duration of active treatment. 5. The relapse of maxillary intercanine width was increased with a time goes after treatment.

• 대한치과교정학회:학술대회논문집
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• 1999.11a
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• pp.52.3-53
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• 1999

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.3
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• pp.217-225
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• 2001

Any fracture passing through the socket of a teeth is compounded intraorally, even if the fracture is not displaced and the tooth is firm in its socket. Before the advent of antibiotic therapy the danger of infection in a compounded fracture posed severe problems in treatment. Infection is reduced by antibiotic therapy but prolonged use of antibiotics is not justified in an attempt to save a tooth which might eventually be sacrificed. There is still controversy in the management of third molar in mandibualr angle fracture, particulary in regard to their retention or removal at the time of fracture treatment. So we surveyed the 159 patients who were treated with open reduction of mandibular angle fracture containing third molar in fracture line, and compared with the postoperative infection rate depending on time intervals between injury and operation, eruption state of third molar, non-extraction or extraction of third molar related to eruption state, non-extraction or extraction of third molar related to condiition of third molar and its surrounding periodontium and were to propose treatment guidline of third molar in mandibular angle fracture The results obtained were as follows : 1. There were no statistical significance between the time from injury to operation and postoperative infection. 2. There were no statistical significance between eruption state of third molar and postoperative infection. 3. In case of retention of the third molar, there were no statistical significance between eruption state of third molar and postoperative infection, but in case of extraction, postoperative infection was high rate in complete impacted cases. 4. There were no statistical significance between non-extraction or extraction of third molar and postoperative infection depending on condition of third molar. There are no difference in infection rate statistically according to the time from injury to operation, eruption state and condition of third molar, but retention of third molar revealed lowered infection rate in completely impacted cases. By terms of the manegement of third molar, we should extract or preserve third molar in the line of the mandibular angle fracture according to possibility of infection.

• The korean journal of orthodontics
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• v.50 no.1
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• pp.52-62
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• 2020

This case report presents the orthodontic treatment of a 25-year-old patient with skeletal Class II and severe maxillary arch crowding, moderate mandibular arch crowding, anterior crossbite, and a missing lower incisor. He was treated with molar distalization using a modified C-palatal plate and temporary anchorage devices to create sufficient space for retraction. The total treatment duration was 21 months. After treatment, his occlusion and smile esthetics showed significant improvement. The modified C-palatal plate represents a treatment modality that enhances the prospects of non-extraction treatment and reduces the need for extraction.

• The korean journal of orthodontics
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• v.44 no.3
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• pp.119-127
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• 2014

Objective: To evaluate the long-term effects of self-ligating brackets (SLBs) on transverse dimensions of arches and skeletal and soft tissues and to quantitatively evaluate the treatment outcome after non-extraction treatment with SLBs. Methods: The sample consisted of 24 (18 female and six male) subjects, with a mean age of $14.23{\pm}2.19$ years, who received treatment with the Damon$^{(R)}$3 appliances. Complete records including cephalometric radiographs and plaster models were obtained before treatment (T1), immediately after treatment (T2), six months after treatment (T3), and two years (T4) after treatment. Digital study models were generated. Twenty lateral cephalometric, six frontal cephalometric, and eight dental cast measurements were examined. The Peer Assessment Rating index was used to measure the treatment outcome. The Wilcoxon test was applied for statistical analysis of the changes. Results: There were significant increases in all transverse dental cast measurements with active treatment. There was some significant relapse in the long term, particularly in maxillary width (p < 0.05). Statistically significant increases were found in nasal (p < 0.001), maxillary base, upper molar, lower intercanine, and antigonial (p < 0.05) widths in T1-T2. Lower incisors were proclined and protruded in T1-T2. Conclusions: SLBs correct crowding by mechanisms involving incisor proclination and protrusion and expansion of the dental arches, without induction of clinically significant changes in hard and soft tissues of the face.

• Journal of Periodontal and Implant Science
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• v.51 no.2
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• pp.135-143
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• 2021

Purpose: To investigate factors affecting the antagonistic and adjacent teeth in patients after implant restoration and prosthetic rehabilitation. Methods: In total, 160 patients who visited Kyungpook National University Dental Hospital for implant surgery, prosthesis placement, and supportive periodontal therapy (SPT) were included in this study. The average follow-up period was 88.06 months, and the maximum was 175 months. Patients' history of smoking, diabetes, hypertension, and osteoporosis was investigated, and panoramic radiographs were taken after surgery and prosthetic treatment. During the follow-up period, extraction and prosthetic/endodontic treatments of the antagonistic and adjacent teeth were analyzed. The statistical analyses were performed using descriptive statistics, the chi-square test, the Fisher exact test, and multiple logistic regression analyses. Results: Treatment was performed on 29.4% of the studied antagonistic teeth with extraction performed in 20.0% and prosthetic treatment in 10.0%. Furthermore, 19.4% of the studied adjacent teeth underwent treatment, of which extraction was performed in 12.5% and prosthetic treatment in 7.5%. The treatment rate for adjacent teeth was 25.3% in smokers, which was higher than that of non-smokers (12.3%) (P=0.039). Patients who were non-adherent to SPT showed a significantly higher rate (19.6%) of antagonistic prosthetic treatment than did those who were adherent (5.5%) (P=0.006). Conclusions: Implant restoration can affect the adjacent and antagonistic teeth. Smoking, osteoporosis history, and absence of SPT may be risk factors for the treatment of the adjacent and antagonistic teeth.

• The korean journal of orthodontics
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• v.32 no.3 s.92
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• pp.185-194
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• 2002

When treating borderline cases which have mild crowding, non-extraction treatment may be considered firstly. But crowding may be reappeared by relapse and it may have problems in esthetics and stability. Secondarily four first premolar extraction treatment may be considered. But this may cause dish-in face by overretracting anterior teeth. In this cases, extraction of four second premolar is preferred because this resolves crowding without aggravating profile and has good stability after treatment. So we review cases treated by four second premolar extraction which show good treatment results and stability. The patients had good profile, Class I molar relationship, mild crowding and skeletal discrepancy and their growth had almost completed.

• Fashion & Textile Research Journal
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• v.3 no.5
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• pp.466-472
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• 2001

To find a suitable condition in this process examined, we investigated the main control factors, such as, the NaOH concentrations, such as, the NaOH concentrations, the heat treating times, and the heating temperatures. The resulting mechanical properties of the fabrics also studied. The samples used were Nylon/Co-PET sea-island type composite microfiber (Co-PET content: 35%) non-woven fabric. The conclusions obtained were as follows. 1. For the complete extraction of Co-PET from the sample non-woven fabric in the dry hot air process, $160^{\circ}C$ of air temperature, 15 min. of treatment time, and around 30% of NaOH concentration were required. On the other hand, in the wet hot air process, $140^{\circ}C$ of air temperature, 3.5 min. of treatment time, and around 30% of NaOH concentration were required. 2. The mechanical properties of the continuous processed samples showed that the WT, B, and WC increased with increasing the weight reduction ratio. However, the G, decreased with increasing the weight loss ratio. Note that, particularly in B, it increased drastically when the weight deduction ratios exceeded 30%. 3. As increasing the wet hot air temperature from 130 to $140^{\circ}C$, B appeared to increase, however, WT, G, and WC appeared to decrease. 4. The best condition found in this continuous process to extract Co-PET is the wet hot air temperature of 140, NaOH concentration of 28% or above, and the treatment time 2-4 min.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.399-409
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• 2012

Effects of pretreatment and extraction conditions on total polyphenol yield from licorice root were investigated using statistical method. For pretreatment, heat treatment at $121^{\circ}C$ for 10 min was applied. Licorice root content in solvent (10, 20, and 30%) ethanol concentration (20, 40, and 60%) and reaction time (1, 2, and 3 h) were used as variables for extraction conditions. Two experiments, with heat treated and no treated licorice, were prepared with same experimental design. Box behnken design was employed and produced a total of 15 trials. Total polyphenol yield from licorice root was not affected by heat treatment. Among variables, licorice content in solvent showed most significant effect regardless of other variables (p<0.05). Finally, optimum conditions for the extraction of total polyphenol from licorice root was detected as following: 10% of licorice in solvent, 52% ethanol as solvent, 2 h of reaction time and non-heat treatment and the extraction yield from optimized condition was 17.6 mg/g licorice root.