• 대한장애인치과학회지
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• 제12권2호
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• pp.72-76
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• 2016

저자는 뇌병변 장애와 보행장애로 반복적인 외상성 치아손상을 받은 환아의 치료를 시행하였다. 최근 실활된 미성숙 영구치의 계속된 치근 형성을 위해 재생적 근관치료 술식이 많이 시도되어 성공적인 결과를 보이고 있다. 하지만 장애로 인해 반복적인 외상의 위험을 가진 환아에서 치수조직의 재생 보다는 치근단형성술을 통한 치근단의 폐쇄와 근관 충전이 비용과 장기적인 예후의 측면에서 유리한 치료방법이 될 수 있음을 확인하였다.

• The Journal of Advanced Prosthodontics
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• 제12권4호
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• pp.218-224
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• 2020

PURPOSE. The objectives of this study were to evaluate the fracture strength and fracture patterns of provisional crowns fabricated from different materials and techniques after receiving stress from a simulated oral condition. MATERIALS AND METHODS. A monomethacrylate-based resin (Unifast Trad) and a bis-acryl-based (Protemp 4) resin were used to fabricate provisional crowns using conventional direct technique. A milled monomethacrylate resin (Brylic Solid) and a 3D-printed bis-acrylate resin (Freeprint Temp) were chosen to fabricate provisional crowns using the CAD/CAM process. All cemented provisional crowns (n=10/group) were subjected to thermal cycling (5,000 cycles at 5°-55℃) and cyclic occlusal load (100 N at 4 Hz for 100,000 cycles). Maximum force at fracture was tested using a universal testing machine. RESULTS. Maximum force at fracture (mean ± SD, N) of each group was 657.87 ± 82.84 for Unifast Trad, 1125.94 ± 168.07 for Protemp4, 953.60 ± 58.88 for Brylic Solid, and 1004.19 ± 122.18 for Freeprint Temp. One-way ANOVA with Tamhane post hoc test showed that the fracture strength of Unifast Trad was statistically significantly lower than others (P<.01). No statistically significant difference was noted among other groups. For failure pattern analysis, Unifast Trad and Brylic Solid showed less damage than Protemp 4 and Freeprint Temp groups. CONCLUSION. Provisional crowns fabricated using the CAD/CAM process and the conventionally fabricated bis-acryl resins exhibited significant higher fracture strength compared to conventionally fabricated monomethacrylate resins after the aging regimen. Therefore, CAD/CAM milling and 3D printing of provisional restorations may be good alternatives for long term provisionalization.

• Korean Journal of Radiology
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• 제23권3호
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• pp.343-354
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• 2022

Objective: To develop and evaluate a deep learning-based artificial intelligence (AI) model for detecting skull fractures on plain radiographs in children. Materials and Methods: This retrospective multi-center study consisted of a development dataset acquired from two hospitals (n = 149 and 264) and an external test set (n = 95) from a third hospital. Datasets included children with head trauma who underwent both skull radiography and cranial computed tomography (CT). The development dataset was split into training, tuning, and internal test sets in a ratio of 7:1:2. The reference standard for skull fracture was cranial CT. Two radiology residents, a pediatric radiologist, and two emergency physicians participated in a two-session observer study on an external test set with and without AI assistance. We obtained the area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity along with their 95% confidence intervals (CIs). Results: The AI model showed an AUROC of 0.922 (95% CI, 0.842-0.969) in the internal test set and 0.870 (95% CI, 0.785-0.930) in the external test set. The model had a sensitivity of 81.1% (95% CI, 64.8%-92.0%) and specificity of 91.3% (95% CI, 79.2%-97.6%) for the internal test set and 78.9% (95% CI, 54.4%-93.9%) and 88.2% (95% CI, 78.7%-94.4%), respectively, for the external test set. With the model's assistance, significant AUROC improvement was observed in radiology residents (pooled results) and emergency physicians (pooled results) with the difference from reading without AI assistance of 0.094 (95% CI, 0.020-0.168; p = 0.012) and 0.069 (95% CI, 0.002-0.136; p = 0.043), respectively, but not in the pediatric radiologist with the difference of 0.008 (95% CI, -0.074-0.090; p = 0.850). Conclusion: A deep learning-based AI model improved the performance of inexperienced radiologists and emergency physicians in diagnosing pediatric skull fractures on plain radiographs.

• Advances in biomechanics and applications
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• 제1권3호
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• pp.143-158
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• 2014

Forearm fractures in children are very common among all pediatric fractures. However, biomechanical investigations on the pediatric forearm are rather scarce, partially due to the complex anatomy, closely situated, interrelated structures, highly dynamic movement patterns, and lack of appropriate tools. The purpose of this study is to develop a computational tool for child forearm investigation and characterize the mechanical responses of a backward fall using the computational model. A three-dimensional 10-year-old child forearm finite element (FE) model, which includes the ulna, radius, carpal bones, metacarpals, phalanges, cartilages and ligaments, was developed. The high-quality hexahedral FE meshes were created using a multi-block approach to ensure computational accuracy. The material properties of the FE model were obtained by scaling reported adult experimental data. The design of computational experiments was performed to investigate material sensitivity and the effects of relevant parameters in backward fall. Numerical results provided a spectrum of child forearm responses with various effective masses and forearm angles. In addition, a conceptual L-shape wrist guard design was simulated and found to be able to reduce child distal radius fracture.

• 대한소아치과학회지
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• 제23권4호
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• pp.906-914
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• 1996

Due to the various reason, sealing of pit & fissure might be imperfect. One of these reason can be the fracture of sealant material because of the low hardness value of sealing material. The purpose of this in vitro study was to evaluate the microhardness of two different curing type pit and fissure sealants: Dual-cure and Light-cure. The result from the present study can be summarized as follows: 1. All pit and fissure sealants that used in this study showed statistically significant difference in their microhardness of upper and lower surface. (P <0.05) 2. Except of lower surface of teethmate, microhardness of 40-second curing sealant was statistically higher than that of 20-second curing sealant. (P <0.05) 3. In comparison of sealants, microhardness of dual-cure sealant was statistically higher than that of light-cure sealant. Above results suggest that the use of dual-cure sealant and longer curing time are recommended.

• Journal of Trauma and Injury
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• 제27권3호
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• pp.63-70
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• 2014

Purpose: In children, mild traumatic brain injuries (TBI) account for 70~90% of head injuries. Without guidelines, many of these children may be exposed to excess radiation due to unnecessary imaging. The purpose of this study was to evaluate the impact of a mild TBI guideline in imaging of pediatric patients. Methods: The medical records of all children who had head computed tomography and were admitted to our hospital with a TBI with Pediatric Glasgow Coma Scale and Glasgow Coma Scale of 14 to 15 were retrospectively reviewed and compared with PECARN Rule. Results: A total of 1260 children were included and all children checked with head computed tomography. 61 pediatrics had CT positive and presented skull fracture 40, hemorrhage 8, hemorrhagic contusion 7, and diffuse axonal injury 1. Also, 4 patients diagnosed both skull fracture and brain haemorrhage and 1 patient diagnosed both haemorrhage and haemorrhagic contusion. Conclusion: There are many pediatric traumatic patients who exposed to radiation due to CT. But, the most of results were negative. So, consider to follow the CT guideline for children and many do not require brain CT.

• Clinics in Shoulder and Elbow
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• 제5권2호
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• pp.102-109
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• 2002

Purpose: To evaluate the results of the treatment of the supracondylar fractures of the humerus according to the fixation methods in adults Materials and Methods: Seven patients, aged 55 to 52 years (average,69 years), were reviewed after a mean follow-up of 37 months (range, 11-65 months). According to AO classification all fractures were classified as type A2 (simple transverse supracondylar fracture). Six patients underwent closed reduction and one patient, open reduction after failure of closed reduction. Percutaneous fixation with cannulated screws was performed to the 4 patients, per- cuta)leous fixation with Kirschner wires in 3 patients. All except one patients have associated medical problems. The results were assessed based on the Mayo Elbow Performance Score. Results: All the patients with cannulated screw fixation had stable bony union with excellent ranges of motion (mean: 5-125 degrees). All the three patients who received percuatnaous smooth K-wire fixation had nonunion with poor results, one of them had changed into cannulated screw. and then had good result. Conclusion: Although simple supracondylar fracture is similar to the pediatric fracture in nature, it should be firmly fixed with the method such as threaded cannualted screw rather than the simple fixation with K-wires.

• 대한정형외과스포츠의학회지
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• 제11권1호
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• pp.62-65
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• 2012

소아 전방 십자인대 견열 골절은 비교적 드물게 발생하며, 주로 청소년기에 발생하고 경쟁 경기 중의 발생빈도가 증가하고 있다. 수술 후 합병증을 감소시키기 위해 최근에는 관절경적 수술방법이 많이 사용되고 있다. 나사못, K-강선, 봉합 나사못 등이 사용되고 있으며, 유관 나사못 고정술은 수술 술기가 가장 간단하나 단점으로 성장판 손상의 가능성이 있다. 저자들은 8세 여아의 전방 십자인대 견열 골절에서 관절경을 이용한 유관 나사못 고정술로 좋은 결과를 얻었기에 문헌 고찰과 함께 보고하는 바이다.

• 대한두개안면성형외과학회지
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• 제22권2호
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• pp.93-98
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• 2021

Background: Pediatric nasal fractures, unlike adult nasal fractures, are treated surgically as early as 7 days after the initial trauma. However, in some cases, a week or more elapses before surgery, and few studies have investigated the consequences of delayed surgery for pediatric nasal fractures. The purpose of this study was to evaluate the postoperative outcomes of pediatric nasal fractures according to the time interval between the initial trauma and surgery. Methods: The records of pediatric patients under 12 years old who underwent closed reduction of nasal bone fracture from March 2012 to February 2020 were reviewed. The interval between trauma and surgery was divided into within 7 days (early reduction) and more than 7 days (delayed reduction). Postoperative results were classified into five grades (excellent, good, moderate, poor, and very poor) based on the degree of reduction shown on computed tomography. Results: Ninety-eight patients were analyzed, of whom 51 underwent early reduction and 47 underwent delayed reduction. Forty-two (82.4%) of the 51 patients in the early reduction group showed excellent results, and nine (17.6%) showed good results. Thirty-nine (83.0%) of the 47 patients in the delayed reduction group showed excellent results and eight (17.0%) showed good results. No statistically significant difference in outcomes was found between the two groups (chi-square test p= 0.937). However, patients without septal injury were significantly more likely to have excellent postoperative outcomes (chi-square test p< 0.01). Conclusion: No statistically significant difference was found in the outcomes of pediatric nasal fractures between the early and delayed reduction groups. Successful surgical results were found even in patients who received delayed reduction (more than 7 days after trauma).

• 대한소아치과학회지
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• 제34권3호
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• pp.454-460
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• 2007

성장 발육중인 어린이나 청소년에서 치아에 가해지는 외상성 손상은 성인에 비하여 흔히 일어난다. 외상이 일어난 후부터 적절한 치료가 시행될 때까지 소요된 시간은 특히 예후를 결정하는데 중요한 요소이며, 외상성 치아 손상을 입은 환자를 검사하고 치료하는데 사용되는 시간이 제한되어 있기 때문에, 만약 적절한 치료가 시간 내에 시행되지 않는다면 환자에게 심각한 결과를 초래할 수 있다. 이전 연구들에 의하면, 외상의 발생율은 8-10세 아이들에게서 가장 흔하고, 가장 많이 이환된 치아는 상악 영구 중절치이며, 남자의 경우가 여자보다 2:1로 빈도가 높았다. 상악 중절치의 치근 완성시기는 평균 10세 정도로 알려져있다. 외상성 손상에 이환된 호발 연령대의 상악 영구 중절치는 대부분 발육중인 미성숙된 치아로, 혈류공급이 왕성하여 손상시 재혈관화에 의한 치유가 비교적 쉽게 일어날 수 있어 치수 생활력에 대한 긍정적인 예후가 기대될 수 있다. 본 증례는 외상성 손상을 받은 미성숙 상악 영구 중절치의 치근파절 치험례로, 통상적인 근관치료를 하지 않고 보존적인 술식을 통하여 치아의 생활력을 유지할 수 있었기에 그 치료 경과 및 결과를 보고하는 바이다.