• Title/Summary/Keyword: closure operator

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WHIP SPRING FOR THE TREATMENT OF LOCALIZED TOOTH MALPOSITION IN MIXED DENTITION (혼합치열기의 국소적 치열부정을 위한 Whip Spring)

  • Kim, Min-Hee;Kim, Shin;Jeong, Tae-Sung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.24 no.4
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    • pp.758-762
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    • 1997
  • There are various types of localized tooth malpositions in the mixed dentition, such as abnormal tooth axis, anterior crossbite of some incisors, impaction, midline diastema, ectopic eruption, and so forth. We, Pediatric Dentists, have usually used removable appliances for these instances. But, removable orthodontic appliances, as is known, have marked limitations in some situations, for example, severe rotation, intrusion and extrusion, root torque, closure of large diastema, traction of impacted tooth, etc. In such cases, Whip spring, combined with fixed or removable appliance, can increase utilities of removable orthodontic appliances. The authors have applied whip springs to some cases showing localized positional and arrangement problems, and have witnessed the results as follows; 1. The refined and elaborate control of direction and magnitude of force by the operator, and accurate compliance of the patients were requisite for the treatment with it. 2. It showed special effectiveness for de rotation of incisors. Although it yields some benefit for root movement, the special consideration for incomplete roots in this age bracket was required. 3. In the localized malalignment cases in mixed dentition, uncurable with traditional removable appliances but practically unrealistic with fixed appliance therapy, the whip spring was thought to be a good alternative.

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Forehead Island Flap For Nasal Reconstruction (이마 섬피판을 이용한 코재건술)

  • Lee, Keun-Cheol;Kwon, Yong-Seok;Jung, Ki-Hwan;Han, Jae-Jung;Park, Jung-Min;Kim, Seok-Kwun
    • Archives of Plastic Surgery
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    • v.32 no.2
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    • pp.199-204
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    • 2005
  • The nose is the most prominent area of the face, therefore susceptible to trauma and skin cancer. When small sized defect is in nasal tip, it results in disturbance of the facial harmony even if replantation, composite graft, skin graft or median forehead flap has been used for the reconstruction. So it is needed that the best method reconstruction is performed according to the degree of defect or deformity. And at the same time the physiology and anatomy of nose were clarified and its aesthetic subunits were employed. How can we cover the about 3 cm sized nasal defect in nasal tip with cartilage exposure? At first, we can think forehead island flap is most appropriate. We performed 7 cases of the forehead island flap for reconstruction of the defect in nasal tip(4 cases: cancer, 3 cases: trauma) from March, 2001 to August, 2004. This result was satisfactory in the point of texture, color, donor scar, and there were no complication such as wound disruption, infection, flap atrophy, and hematoma. The advantages of forehead island flap are: 1) No injury of deep vessel and nerve, 2) control of shape and volume, 3) Short operation time, 4) primary closure of donor site, 5) one stage operation. Also, forehead island flap can cover the defect in nose where skin graft and local flap can not cover. But, operator always must take care for flap congestion and donor site scar. We thought forehead island flap is one of the best option of reconstruction of nasal tip defect.

CHARACTERIZATION OF FUNCTIONS VIA COMMUTATORS OF BILINEAR FRACTIONAL INTEGRALS ON MORREY SPACES

  • Mao, Suzhen;Wu, Huoxiong
    • Bulletin of the Korean Mathematical Society
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    • v.53 no.4
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    • pp.1071-1085
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    • 2016
  • For $b{\in}L^1_{loc}({\mathbb{R}}^n)$, let ${\mathcal{I}}_{\alpha}$ be the bilinear fractional integral operator, and $[b,{\mathcal{I}}_{\alpha}]_i$ be the commutator of ${\mathcal{I}}_{\alpha}$ with pointwise multiplication b (i = 1, 2). This paper shows that if the commutator $[b,{\mathcal{I}}_{\alpha}]_i$ for i = 1 or 2 is bounded from the product Morrey spaces $L^{p_1,{\lambda}_1}({\mathbb{R}}^n){\times}L^{p_2,{\lambda}_2}({\mathbb{R}}^n)$ to the Morrey space $L^{q,{\lambda}}({\mathbb{R}}^n)$ for some suitable indexes ${\lambda}$, ${\lambda}_1$, ${\lambda}_2$ and $p_1$, $p_2$, q, then $b{\in}BMO({\mathbb{R}}^n)$, as well as that the compactness of $[b,{\mathcal{I}}_{\alpha}]_i$ for i = 1 or 2 from $L^{p_1,{\lambda}_1}({\mathbb{R}}^n){\times}L^{p_2,{\lambda}_2}({\mathbb{R}}^n)$ to $L^{q,{\lambda}}({\mathbb{R}}^n)$ implies that $b{\in}CMO({\mathbb{R}}^n)$ (the closure in $BMO({\mathbb{R}}^n)$of the space of $C^{\infty}({\mathbb{R}}^n)$ functions with compact support). These results together with some previous ones give a new characterization of $BMO({\mathbb{R}}^n)$ functions or $CMO({\mathbb{R}}^n)$ functions in essential ways.

Surgical refinement of the purse-string suture for skin and soft tissue defects of the head and neck

  • Park, Hyochun;Lee, Yunjae;Yeo, Hyeonjung;Park, Hannara
    • Archives of Craniofacial Surgery
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    • v.22 no.4
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    • pp.183-192
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    • 2021
  • Background: The purse-string suture (PSS) is a simple and rapid wound closure method that results in minimal scarring. It has been used to treat circular or oval skin defects caused by tumor excision or trauma. However, due to obscurity, it is not widely used, especially for the head and neck. This study aimed to modify the PSS to obtain predictable and acceptable results. Methods: A total of 45 sites in 39 patients with various types of skin and soft tissue defects in the head and neck were treated with PSS. We used PDS II (2-0 to 5-0), which is an absorbable suture. Minimal dissection of the subcutaneous layer was performed. The suture knot was hidden by placing it in the dissection layer. Depending on the characteristics of the skin and soft tissue defects, additional surgical interventions such as side-to-side advancement sutures, double PSS, or split-thickness skin graft were applied. Results: All wounds healed completely without any serious complications. Large defects up to 45 mm in diameter were successfully reconstructed using only PSS. Postoperative radiating folds were almost flattened after approximately 1-2 months. Conclusion: PSS is simple, rapid, and relatively free from surgical design. Owing to the circumferential advancement of the surrounding tissue, PSS always results in a smaller scar than the initial lesion and less distortion of the body structures around the wound in the completely healed defect. If the operator can predict the process of healing and immediate radiating folds, PSS could be a favorable option for round skin defects in the head and neck.

Effect of Fibrin Sealant in Extended Lattisimus Dorsi Flap Donor Site: Retrospective Study (확장 광배근 피판거상 시 공여부 장액종의 예방을 위한 피브린 실란트의 효과에 대한 후향적 연구)

  • Cho, Hyun Woo;Lew, Dae Hyun;Tark, Kwan Chul
    • Archives of Plastic Surgery
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    • v.35 no.3
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    • pp.267-272
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    • 2008
  • Purpose: Donor site seroma is the most common complication of extended latissimus dorsi flap for breast reconstruction. One of preventive treatments is to use the fibrin sealant in donor site before closure. Experimentally, it has been used successfully in the prevention of latissimus donor site seroma, but its clinical efficacy and results were very controversial. Thus, the purpose of this study is to evaluate the clinical efficacy and to determine the optimal dose of fibrin sealant. Methods: A retrospective study was done of patients operated under same surgical conditions by one operator with variable doses of fibrin sealant. The study group consisted of 60 consecutive patients who underwent breast reconstruction with extended latissimus flap reconstructions from January 2005 to December 2006. Patients were divided into 4 group by applied fibrin sealant amount(group 1=0 mL, group 2=1 mL, group 3=2 mL, group 4=4 mL). Retrospective data were obtained from total postoperative drainage amount, time from surgery to drain removal, and incidence and quantity of seroma formation in matched patients group. Results: Total drainage amount decreased relative to the amount of fibrin sealant. The seroma formation rate of 30% in the study group 4 was significantly less than group 1 rate of 71%(p<0.05). It was an improvement over the rates of as much as 79% described previously in the literature. Also, time from surgery to drain removal was shortened significantly in group 4 patients(p<0.05). Conclusion: The use of fibrin sealant in the extended latissimus dorsi flap donor site appears effective in preventing seroma. However, important factors to obtain lower seroma formation rates are proper techniques and proper amounts such as the authors suggested amount: $0.01mL/cm^2$ with spray type fibrin sealant.