• Restorative Dentistry and Endodontics
• /
• v.22 no.2
• /
• pp.546-559
• /
• 1997

The purposes of this study were to evaluate the efficiency of cavity preparation and to determine the incidence of tooth crack when root-end retrograde cavity preparation was done with ultrasonics. 91 distobuccal root-ends of extracted human maxillary first molars were cut by 3 mm perpendicularly to the long axis of tooth using a slow speed diamond saw, retrocavities were prepared using a slow-speed no. 2 round bur as controls, and stainless steel ultrasonic tips of power settings of 1 through 10 as experimentals. Time consumed and the number of strokes used for the cavity preparation were measured and evaluated, and the incidence of tooth cracks was observed under a stereomicroscope. The results were as follows : For the retrograde cavity preparation, time and number of strokes used were decreased as the ultrasonic power setting increased (p<0.001). High power setting of ultrasonics induced significantly more tooth cracks than did the slow-speed bur or low- and medium power setting of ultrasonics (p<0.05). Teeth with previous crack induced significantly more tooth cracks than those without previous one when high power setting of ultrasonics were used for the retrograde cavity preparation (p<0.001). Teeth with initial apical canal size of no. 10 induced significantly more crack than did those with size of no. 15 when low power setting of ultrasonics were used for the retrograde cavity preparation (p<0.05).

• Journal of the Korean Orthopaedic Association
• /
• v.56 no.4
• /
• pp.326-333
• /
• 2021

Purpose: A retrograde intramedullary nail is commonly used to treat femoral shaft and distal femur fractures. The authors analyzed the treatment results and the factors affecting the period of bone union for thirty-five patients treated with a retrograde intramedullary nail. Materials and Methods: Thirty-five patients who could be followed up for more than twelve months after the treatment with retrograde intramedullary nailing were analyzed retrospectively. The treatment results and the relationship between the period of bone union and the patient's age, sex, comminution of fracture, presence of open fracture, location of the fracture, and accompanying fractures were evaluated. Results: The average bone union time was 4.50 months. The period of bone union was unaffected by the age, sex, location, and presence of open fractures but was affected by the presence of comminution and accompanying fractures. Conclusion: Retrograde intramedullary nailing is effective for distal and shaft of fractures of the femur. The period of bone union is affected by the presence of comminution and accompanying fractures.

• The Korean Journal of Pain
• /
• v.25 no.3
• /
• pp.195-197
• /
• 2012

Sacral nerve stimulation through the retrograde approach has been used for peroneal or irritable bowel syndrome through the retrograde approach. However, several reasons, lead could not be advanced down ward. In this case, anterograde sacral nerve stimulation through the sacral hiatus could be used. The aim of this report is to present of technique of sacral nerve root stimulation through the sacral hiatus approach.

• Journal of Korean Dental Science
• /
• v.5 no.2
• /
• pp.60-67
• /
• 2012

Purpose: To test the apical leakage prevention performance of three different materials through protein leakage procedures using bovine serum albumin (BSA) and Bradford protein reagent. Materials and Methods: A total of 60 human single-rooted teeth were divided into 4 groups, and conventional root canal filling was done. The root was cut 3 mm from the apex, and a cavity was formed. Proroot MTA (MTA), Fuji II LC (GI), Fuji II LC with XP bond (GIA), and Caviton (CA) were used as experimental materials to fill the cavity in a retrograde filling manner. The extent of BSA leakage was then measured with a ultraviolet visible spectrophotometer 24, 48, and 72 hours after filling. Result: After 24 hours, among the 15 teeth of each group, 2 in MTA, 4 in GI, 3 in GIA, and 7 in CA showed leakage. After 48 hours, 3 in MTA, 5 in GI, 5 in GIA, and 10 in CA had leakage and discoloration. After 72 hours, among the 15 teeth of each group, 3 in MTA, 6 in GI, 5 in GIA, and 10 in CA showed leakage. The leakage in the CA group was greater than that in the MTA group at 48 and 72 hours based on Fisher's exact test (P=0.025), and the difference was statistically significant. Similarly, the leakage in the CA group was greater than that in the MTA group over time based on the Kaplan-Meier survival estimate (P=0.011), and the difference was statistically significant. Conclusion: Glass ionomer, glass ionomer after adhesive application, and MTA all showed leakage. Caviton showed greater leakage compared to MTA 48 and 72 hours after filling, and the difference was statistically significant; thus suggesting that Caviton is not appropriate as retrograde filling material considering its sealing ability.

• Journal of Korean Foot and Ankle Society
• /
• v.19 no.4
• /
• pp.171-175
• /
• 2015

Purpose: Tibiotalocalcaneal arthrodesis has been used as a treatment option for severe deformity including Charcot arthropathy, avascular necrosis of the talus, and severe osteoarthritis of the ankle and subtalar joint. The purpose of this study was to evaluate the result of the surgical outcome of tibiotalocalcaneal arthrodesis using a retrograde intramedullary nail. Materials and Methods: Tibiotalocalcaneal arthrodesis using a retrograde intramedullary nail was performed by one surgeon in 36 cases. Clinical and radiological finding was evaluated using assessment of fusion time, 5th metatarsal-tibial angle, possibility of postoperative complication, visual analogue scale for pain and American Orthopaedic Foot and Ankle Society (AOFAS) score. Results: Union was achieved in 33 cases at an average of 23 weeks (11~29 weeks). There were 3 cases of nonunion and 1 case of reoperation. Nail-tibial angle tended to be larger in nonunion cases. AOFAS score showed significantly poor outcome at malalignment (${\geq}5^{\circ}$), negative value of 5th metatarsal-tibial angle. Conclusion: Tibiotalocalcaneal arthrodesis using a retrograde intramedullary nail is considered a useful treatment option for severe destruction and deformity involving ankle and subtalar joint.

• Journal of Chest Surgery
• /
• v.35 no.10
• /
• pp.740-744
• /
• 2002

Retrograde cerebral perfusion under hypothermic circulatory arrest is a simple and useful adjunct to avoid cerebral ischemic injury in the treatment of aortic arch pathology. In the surgery of distal aortic arch and proximal descending aortic lesions through the left thoracotomy incision, right atrium-retrograde cerebral perfusion (RA-RCP) through a venous cannula positioned into the right atrium is simpler than retrograde cerebral perfusion through superior vena cava. The time limits for RA-RCP during aortic arch reconstruction have yet to be clarified. We, herein, present a case with uneventful recovery after RA-RCP of 94 minutes during reconstruction of aortic arch and descending aorta. These data suggest that RA-RCP, as an adjunct to hypothermic circulatory arrest, may prolong the circulatory arrest time and thus prevent ischemic injury of the brain, even when RA-RCP exceeds 90 minutes.

• Journal of radiological science and technology
• /
• v.24 no.1
• /
• pp.5-9
• /
• 2001

Over-density of pancreatic duct tail part on the endoscopic retrograde pancreatogram results from patient's position and inserted air during the study. The aim of this paper is to decide the filter angle to obtain an uniform density. Endoscopic retrograde pancreatography was performed to 234 patients, and angled wedge filter was used differently. They are $10^{\circ}$ (47), $20^{\circ}$ (45), $30^{\circ}$ (50), and $40^{\circ}$ (50). We also did not use wedge filter to 42 patients. We decided reliance degree in 95%. The statistical difference was p<0.05. The patients' sex rate was 1.8 : 1 between 18 and 87 years old(average age 58 years). Their body girth was 18.71 cm on the average. Of total 234 patients, difference of right and left average density was 0.01 by $30^{\circ}$ wedge filter, -0.08 $40^{\circ}$ wedge filter and 0.27 non-wedge filter. These average values of difference density were very significant statistically, and standard deviation also was close to regular distribution. In conclusion, there is a usefulness of angled wedge filter for increasing diagnostic value of pancreatic duct tall part on the endoscopic retrograde pancreatogram.

• Restorative Dentistry and Endodontics
• /
• v.25 no.1
• /
• pp.63-70
• /
• 2000

The properties of ideal retrograde filling materials include the ability to seal the root canal system in three dimensions and well tolerated by periradicular tissues. Biocompatibility testing has been done mainly with cytotoxicity tests using cell culture. Little attention has been paid to the potential adverse influence on the inflammatory and immune reaction in the periapical tissue. The purpose of this study was to investigate the effects of retrograde filling materials on human mononuclear cells in vitro. Freshly mixed and set specimens from six materials (Z100, Tetric Ceram, Fuji II, Fuji II LC, F2000, Compoglass Flow, and ZOE) were eluated with cell culture medium for 24 hours. Cytotoxic effects of these extracts were evaluated by determining cell viability and enzyme activity using MTT and lactate dehydrogenase (LD). The production of inflammatoy bone resorptive cytokine, TNF-${\alpha}$ was measured from human peripheral blood mononuclear cells (PBMC) exposed to the extracts by means of Endogen Human TNF-${\alpha}$ ELISA kit (Wobrun, MA, U.S.A.). Eluates and diluted (1 : 10) eluates with cell culture medium from freshly mixed Fuji IT had cytotoxic effects on mononuclear cells using MTT and LD. However, eluates from set Fuji II were not cytotoxic. Eluates form set ZOE exhibited cytotoxicity with LD test. TNF-${\alpha}$ levels were high in eluates from freshly mixed Fuji II and Z100. Diluted eluates from freshly mixed Z100 and F2000 stimulated the production of TNF-${\alpha}$. However, there were no significant difference in TNF-${\alpha}$ levels compared to controls. These results indicate that some materials could possibly stimulate bone resorption in the periapical tissue by means of the production of bone resorptive cytokine.

• Investigative Magnetic Resonance Imaging
• /
• v.5 no.1
• /
• pp.38-42
• /
• 2001

Dark band artifacts are often observed in angiograms of arteries obtained by 2D time-of-flight (TOF) angiography with saturation of veins by presaturation RF pulses. At some arteries the arterial blood velocity varies in a triphasic pattern during a cardiac cycle. The arterial blood, that is saturated by presaturation RF pulses in the saturation band, can flow back into the imaging slice during the retrograde flow phase of the triphasic variation. When such saturated retrograde flow occurs during the acquisition of the central part of the K space, a signal void can result in base images and consequently dark band artifacts can appear in angiograms. This phenomenon is experimentally demonstrated by varying the gap between the imaging slice and the saturation band. Furthermore, a new pulse sequence is proposed to eliminate the dark band artifacts by changing the profile of the saturation band front a rectangle to a ramp.

• Journal of Chest Surgery
• /
• v.30 no.1
• /
• pp.27-33
• /
• 1997

Retrograde myocardial protection is widely accepted in CABG operation because of the limitations of the antegrade method in the coronary arterial stenosis lesions. We analyzed 76 c ses of retrograde myocardial protection among 96 cases of CABG operation performed between April 1994 and August 1995, There were 48 males and 25 females, and the mean age was 58.2 $\pm$ 8.3 years. 53 patients (70%) were operated for unstable angina, 14 (18%) for stable angina, 6 (8%) for post-infarct angina, 1 (1%) for acute myocardial infarction, and 2()%) for failed PTCA. Preoperative coronary angiography revealed 3-vessel disease in 42 cases, 2-vessel disease in 11, 1-vessel disease in 10, and left main disease in 13 cases. We used SVG(63 cases), LIMA(69 cases), RIMA(11 cases), radial artery(6 cases), and gastroepiploic artery(1 case) for the grafts. Mean anastomosis was 3.2 $\pm$ 1.1. We protected the myocardium with antegrade induction and retrograde maintenance in all the cases except a case of retrograde induction and maintenance. During the aortic cross-clamping, blood cardioplegia was administered intermittently in 19 cases, and continuously in 57 In 39 cases, we used retrograde ardioplegia and antegrade perfusion of RCA graft simultaneously. We had no operative motality. Perioperative complications were arrhythmia in 15 cases, perioperatve myocardial infarction in 10, low cardiac output syndrome In 8, transient neurologic problem in 7, transient psychiatric problem in 6, ARF in 3, bleeding in 2, pneumonia in 2, wound infection in 1, and duodenal ulcer perforation in 1 . In this report, we experienced 76 cases of CABG operation with retrograde myocardial protection under the acceptable operative risk without operative mortality.