• 대한치과교정학회지
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• 제32권5호
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• pp.343-353
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• 2002

제1소구치 발치를 동반한 설측교정치료시 lingual K-loop archwire로 전치부 후방견인을 시 행한 경우 전치부 및 구치부에서 치조골에 발생하는 초기응력을 알아보기 위하여, K-loop의 vortical leg 길이는 15mm로 하고 편측당 350gm의 힘으로 활성화시 킨 후 상악궁 광탄성 모형의 응력동결을 시행하고 각 치아별로 절단하여 3차원 광탄성법으로 분석한 바 다음과 같은 결론을 얻었다. 1. 중절치의 근심면은 치관측일수록 더 큰 인장응력을 보였으며 원심면은 치관측일수록 더 큰 압축응력을 보였다. 순면에서는 치관측일수록 더 큰 인장응력을 보였으며 설면에서는 치근측일수록 더 큰 압축응력을 보였다 치근첨에서는 압축응력이 나타났다. 2. 측절치의 근심면에서는 치관측만 인장응력이 관찰되었고 원심면에서는 고른 압축응력을 보였다. 순면에서는 치관측일수록 더 큰 인장응력이 관찰되었고 설면에서는 치관측에서는 인장응력을, 치근측에서는 압축응력을 보였다. 치근첨에서는 압축응력이 관찰되었다. 3. 견치의 근심면은 치관측에서는 인장응력을, 치근측에서는 압축응력을 보였고 원심면은 인장응력을 보였다. 순면과 설면은 치관측일수록 큰 인장응력을 보였다. 순면보다 설면에서 더 큰 인장응력을 보였다. 치근첨에서는 압축응력이 관찰되었다. 4. 제2소구치는 근심면은 인장응력을 보이며 원심면은 치관측에서는 압축응력을, 치근측에서는 인장응력을 보였다. 협면은 치관측에서 압축응력을 보였으며, 설면은 치관측일수록 더 큰 인장응력이 관찰되었다. 치근첨에서는 인장응력을 보였다. 5. 제1대구치는 근원심면 모두에서 치관측일수록 더 큰 인장응력을 보였다. 협면에서는 응력이 나타나지 않았고, 설면은 치관측일수록 더 큰 인장응력이 관찰되었다. 협측치근들의 치근첨에서는 압축응력을, 구개측치근의 치근첨에서는 무응력을 보였다. 6. 제2대구치는 모든 치근의 치근첨에서 압축응력이 관찰되었다. 근심면은 치관측일수록 더 큰 압축응력을, 원심면은 치관측일수록 더 큰 인장응력을 보였다 협면은 치관측일수록 더 큰 인장응력을, 설면은 치관측일수록 더 큰 압축응력을 나타내었다. 따라서 전치부 후방견인시 transverse bowing effect는 뚜렷이 나타났으나, vertical bowing effect는 나타나지 않고 오히려 전치부가 함입되려는 응력이 발생하였다.

• 대한치과교정학회:학술대회논문집
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• 대한치과교정학회 2001년도 제34회 학술대회
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• pp.31.2-32
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• 2001

• 대한치과교정학회:학술대회논문집
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• 대한치과교정학회 2001년도 제34회 학술대회
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• pp.78.3-79
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• 2001

• 대한치과교정학회:학술대회논문집
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• 대한치과교정학회 1999년도 제32회 학술대회
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• pp.63-63
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• 1999

• 대한치과의사협회지
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• 제37권11호통권366호
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• pp.813-817
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• 1999

• 대한치과교정학회지
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• 제23권4호
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• pp.485-492
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• 1993

Multiloop Edgewise Archwire(MEAW) is effective in relief the Curve of Spee in mandibular arch but up Sl down orthodontic elastics must be used with it. The purpose of this study was to analyse the effect of orthodontic elastics, like as up & down elastics, Class II elastics, and Class III elastics, and the effect of L loop in Multioop Edgewise Archwire. 1. Intrusive force of MEAW in anterior teeth was reduced and uprighting force in premolars was increased by up & down elastics. 2. Uprighting force was significintly increased with Class III elastics in multiple L loop arch wire. 3. The force of Class II elastics made molars tip mesially and Curve of Spee deep.

• 대한치과교정학회:학술대회논문집
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• 대한치과교정학회 1997년도 제30회 학술대회
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• pp.51.1-51.1
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• 1997

• 대한치과교정학회지
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• 제45권1호
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• pp.20-28
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• 2015

Objective: The purpose of this study was to observe stress distribution and displacement patterns of the entire maxillary arch with regard to distalizing force vectors applied from interdental miniscrews. Methods: A standard three-dimensional finite element model was constructed to simulate the maxillary teeth, periodontal ligament, and alveolar process. The displacement of each tooth was calculated on x, y, and z axes, and the von Mises stress distribution was visualized using color-coded scales. Results: A single distalizing force at the archwire level induced lingual inclination of the anterior segment, and slight intrusive distal tipping of the posterior segment. In contrast, force at the high level of the retraction hook resulted in lingual root movement of the anterior segment, and extrusive distal translation of the posterior segment. As the force application point was located posteriorly along the archwire, the likelihood of extrusive lingual inclination of the anterior segment increased, and the vertical component of the force led to intrusion and buccal tipping of the posterior segment. Rotation of the occlusal plane was dependent on the relationship between the line of force and the possible center of resistance of the entire arch. Conclusions: Displacement of the entire arch may be dictated by a direct relationship between the center of resistance of the whole arch and the line of action generated between the miniscrews and force application points at the archwire, which makes the total arch movement highly predictable.

• 대한치과교정학회지
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• 제49권1호
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• pp.21-31
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• 2019

Objective: This study was performed to explore the effect of different bracket, archwire, and ligature combinations on resistance to sliding (RS) and rotational control in first-order angulation. Methods: Three types of brackets (multi-level low friction [MLF], self-ligating, and conventional brackets) coupled with four nickel-titanium archwires (0.012, 0.014, 0.016, and 0.018-inch diameter) and two stainless steel ligatures (0.20 and 0.25 mm) were tested in different first-order angulations ($0^{\circ}$, $2^{\circ}$, $4^{\circ}$, $6^{\circ}$, $8^{\circ}$, $10^{\circ}$, $15^{\circ}$, $20^{\circ}$) by using an Instron universal mechanical machine in the dry state at room temperature. RS value was evaluated and compared by one-way ANOVA. Results: Under the same angulation, the RS values showed the following order: conventional brackets > MLF brackets > self-ligating brackets. The RS was the highest for conventional brackets and showed a tendency to increase. The RS for MLF brackets coupled with thinner archwires and ligatures showed a similar tendency as the RS for the self-ligating bracket. In contrast, the RS for MLF brackets coupled with thicker archwires and ligatures increased like that for conventional brackets. MLF brackets showed the greatest range of critical contact angles in first-order angulation. Conclusions: The RS in first-order angulation is influenced by bracket design, archwire, and ligature dimension. In comparison with self-ligating and conventional brackets, MLF brackets could express low friction and rotational control with their greater range of critical contact angles.

• 대한치과교정학회지
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• 제53권2호
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• pp.89-98
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• 2023

Objective: This study aimed to compare the mechanical and thermal properties in the anterior and posterior segments of new and retrieved specimens of a commercially available multizone superelastic nickel-titanium (NiTi) archwire. Methods: The following groups of 0.016 × 0.022-inch Bioforce NiTi archwires were compared: a) anterior and b) posterior segments of new specimens and c) anterior and d) posterior segments of retrieved specimens. Six specimens were evaluated in each group, by three-point bending and bend and free recovery tests. Bending moduli (Eb) were calculated. Furthermore, the new specimens were evaluated with scanning electron microscopy/energy-dispersive X-ray spectrometry. A multiple linear regression model with a random intercept at the wire level was applied for data analysis. Results: The forces in the posterior segments or new specimens were higher than those recorded in the anterior segments or retrieved specimens, respectively. Accordingly, Eb also varied. Higher austenite start and austenite finish (Af) temperatures were recorded in the anterior segments. No statistically significant differences were found for these temperatures between retrieved and new wires. The mean elemental composition was (weight percentage): Ni, 52.6 ± 0.5; Ti, 47.4 ± 0.5. Conclusions: The existence of multiple force zones was confirmed in new and retrieved Bioforce archwires. The retrieved archwires demonstrated lower forces during the initial stages of deactivation in three-point bending tests, compared with new specimens. The Af temperature of these archwires may lie higher than the regular intraoral temperature. Even at 2 mm deflections, the forces recorded from these archwires may lie beyond biologically safe limits.