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Objective:To investigate the changes of occlusal plane in the process of retracting maxillary anterior teeth with different vertical traction force.Methods:The three dimensional finite element model of maxillary anterior teeth en-masse retraction by micro-implant was constructed with cone beam CT scanning and MIMICS and ANSYS software.Then the movement tendency of tooth and the changes of the maxillary occlusal plane was calculated when the vertical traction force was 0,0.5,0.75 and 1 N in the process of en-mass retraction,respectively.Results:Lingual tipping of anterior teeth,distal tipping of the first molar and the maxillary occlusal plane clockwise rotation by the retraction forces were observed.With the vertical traction force increasing,lingual tipping of anterior teeth and distal tipping of the first molar were decreased,and the occlusal plane clockwise rotation was prevented.Conclusion:The upper dentition movement and occlusal plane rotation can be changed effectively by the vertical traction with different force.When retract anterior teeth,0.5-0.75 N vertical traction force is beneficial to prevent clockwise rotation of the maxillary occlusal plane.
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OBJECTIVE:To establish the method for the determination of 9 illegal dyes in Carthamus tinctorius.METHODS:HPLC-MS/MS was adopted.The determination was performed on SB-C18 column with mobile phase consisted of 10 mmol/L ammonium formate-acetonitrile (gradient elution) at the flow rate of 0.2 mL/min.The column temperature was 30 ℃,and the sample size was 10 μL.Mass spectrometry condition:electrospray ion source,negative ion multi-ion reaction monitoring mode,ion spray voltage of 3 500 V,drying gas temperature of 350 ℃,drying gas flow rate of 10 L/min,colliding gas of high pure nitrogen gas,scanning range of m/z 50～ 1 000.RESULTS:The linear ranges of ponceau,acid red 73,lemon yellow,azorubin,allura red,gold orange Ⅱ,sunset yellow,pyrosine and golden orange G were 5.313 5～531.35 ng/mL(r=0.987 0),1.312 0～1 312.00 ng/mL(r=0.994 8),124.480 0～2 824.00 ng/mL(r=0.983 2),6.300 0～630.00 ng/mL(r=0.964 8),1.035 8～517.92 ng/mL(r=0.996 4),0.552 0～1 104.00 ng/mL(r=0.909 0),5.046 3～2 018.52 ng/mL(r=0.996 2),5.046 3～2 018.52 ng/mL(r=0.997 6),1.079 5～2 159.00 ng/mL(r=0.990 0),respectively.The limits of quantitation were 10.418 7,1.131 0,68.401 0,13.695 7,1.670 7,0.238 0,3.973 3,1.064 7,1.285 0 ng/kg.The limits of detection were 3.125 6,0.339 3,20.520 3,4.108 7,0.501 2,0.071 4,1.192 0,0.319 4,0.385 5 ng/kg,respectively.RSDs of precision,stability and reproducibility tests were all lower than 3.0％.The recoveries were 91.2％-99.1％ (RSD=0.7％-2.2％,n=6).CONCLUSIONS:The established method is specific,sensitive,simple and rapid,and can be used for the detection of 9 illegal dyes in C.tinctorius.
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OBJECTIVE:To establish the method for the determination of 9 illegal dyes in Carthamus tinctorius.METHODS:HPLC-MS/MS was adopted.The determination was performed on SB-C18 column with mobile phase consisted of 10 mmol/L ammonium formate-acetonitrile (gradient elution) at the flow rate of 0.2 mL/min.The column temperature was 30 ℃,and the sample size was 10 μL.Mass spectrometry condition:electrospray ion source,negative ion multi-ion reaction monitoring mode,ion spray voltage of 3 500 V,drying gas temperature of 350 ℃,drying gas flow rate of 10 L/min,colliding gas of high pure nitrogen gas,scanning range of m/z 50～ 1 000.RESULTS:The linear ranges of ponceau,acid red 73,lemon yellow,azorubin,allura red,gold orange Ⅱ,sunset yellow,pyrosine and golden orange G were 5.313 5～531.35 ng/mL(r=0.987 0),1.312 0～1 312.00 ng/mL(r=0.994 8),124.480 0～2 824.00 ng/mL(r=0.983 2),6.300 0～630.00 ng/mL(r=0.964 8),1.035 8～517.92 ng/mL(r=0.996 4),0.552 0～1 104.00 ng/mL(r=0.909 0),5.046 3～2 018.52 ng/mL(r=0.996 2),5.046 3～2 018.52 ng/mL(r=0.997 6),1.079 5～2 159.00 ng/mL(r=0.990 0),respectively.The limits of quantitation were 10.418 7,1.131 0,68.401 0,13.695 7,1.670 7,0.238 0,3.973 3,1.064 7,1.285 0 ng/kg.The limits of detection were 3.125 6,0.339 3,20.520 3,4.108 7,0.501 2,0.071 4,1.192 0,0.319 4,0.385 5 ng/kg,respectively.RSDs of precision,stability and reproducibility tests were all lower than 3.0％.The recoveries were 91.2％-99.1％ (RSD=0.7％-2.2％,n=6).CONCLUSIONS:The established method is specific,sensitive,simple and rapid,and can be used for the detection of 9 illegal dyes in C.tinctorius.
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<p><b>OBJECTIVES</b>To investigate the correlation of bone mineral density (BMD) of mandibular angle, hand and total body in healthy individuals aged from 5 to 18 years.</p><p><b>METHODS</b>Eight hundred and thirty-nine healthy individuals from 5 to 18 years old (422 males, 417 females) in 5 primary and secondary schools in Guangzhou were divided into 14 age groups. Dual energy X-ray absorptiometry (DXA) was used to measure the BMD of mandibular angle, hand and total body. The data were statistically analyzed using Pearson correlation analysis.</p><p><b>RESULTS</b>The BMD of mandibular angle increased with age. In females, the BMD of mandibular angle increased quickly from 12 to 16 years old, and its increasing rate gradually slowed down after 16 years old. In males, the BMD of mandibular angle increased quickly after 14 years old, and its increase had not been stopped until 18 years old. Females in 12, 13, 14, 15, 16, 17-year-old group had significantly higher mandibular angle BMD [(0.95 ± 0.19), (1.01 ± 0.17), (1.11 ± 0.17), (1.25 ± 0.13), (1.28 ± 0.14), (1.30 ± 0.13) g/cm(2)] than males in the age-matched group (P < 0.05). There was no significant difference between mandibular angle BMD in males and in females at the age of 18, and from 5 to 11 years old (P > 0.05). For males, the mandibular angle BMD was highly correlated with age (r = 0.696, P < 0.001), hand BMD (r = 0.779, P < 0.001) and total body BMD (r = 0.831, P < 0.001). For females, the mandibular angle BMD was highly correlated with age (r = 0.795, P < 0.001), hand BMD (r = 0.839, P < 0.001) and total body BMD (r = 0.872, P < 0.001).</p><p><b>CONCLUSIONS</b>The mandibular angle BMD in healthy individuals from 5 to 18 years old increased with age. The mandibular angle BMD was closely related to hand BMD and total body BMD.</p>
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Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Absorciometria de Fóton , Fatores Etários , Densidade Óssea , Osso e Ossos , Fisiologia , Ossos da Mão , Fisiologia , Mandíbula , Fisiologia , Fatores SexuaisRESUMO
According to the problems and requirements in the management of emergency materials , a new approach to estab-lish the information management module of emergency medical rescue materials has been put forward to deal with the difficulties in the aspects of emergency medical rescue materials involving regular preparation , daily management , storage and transportation , emergency mobilization, sample grouping and portable maneuvering , and optimizing support.
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BACKGROUND: Miniscrew plant attachment to maxillary sinus is an important factor for implant safety and bone density can influence implant stability. Studies have explored implantation location of implant anchorage, such as bone thickness or bone density. However, the idea on implantation angle remains controversial. OBJECTIVE: To investigate the relationship between miniscrew implant in the interradicular space between the second premolars and the first molars in the maxilla and the maxillary sinus as well as bone density in the surroundings. DESIGN, TIME AND SETTING: Observation experiment was performed at dinan University from October 2007 to May 2008. PARTICIPANTS: A total of 38 patients with cone beam CT data were selected from Uni-Care Dental Center, Macao, including 11 males and 27 females, aged 18-35 (24.8±3.8) years. METHODS: Three dimensional images were reconstructed from cone beam CT images. For each subject, the buccolingual bone thickness was measured by postulating that the miniscrews would be inserted at 16 positions (10, 12, 14 and 16 mm above the median sagittal planes of the interradicular spaces between the first molars and the second premolars in the maxilla, and 30°, 45°, 60°, 90° from the cortical bone surface). The danger rate representing for implantation sites where buccolingual bone thickness was less than 6 mm was calculated. The density of the bone around the entire circumference of each miniscrew was also measured. MAIN OUTCOME MEASURES: Height of maxillary sinus, buccolingual bone thickness at implantation sites and bone density. The implantation sites could be divided into three groups. Group 2 exhibited the greatest danger rate and bone density and group 1 had the lowest danger rate and bone density.
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Objective: To evaluate the method,efficacy and complication of fluoroscopic guided local injection of Pingyangmycin lipiodol emulsion(PLE) in the treatment of body surface venous malformations(VM).Methods:Forty cases of VM,including 22 cases in the maxillofacial region,5 cases in the trunk and 13 cases in the extremities,received PLE local injection under X-ray fluoroscopy.PLE was prepared by mixing 2-8 mg of pingyangmycin(PYM)with 2-8ml of ultra-fluid lipiodol,the dosage was determined by the size of lesions.The effects and complications of PLE treatment were observed. Results:Signs of VM were patches of abnormal venous opacification and washout delay of contrast medium.Thirty four cases received single injection of PLE and 6 cases were injected twice.Excellent and good results were obtained in 20 cases and 16 cases respectively after 6 months post-injection,the therapy was ineffective in the rest four cases.Total efficacy was 90 percent.There were no severe complications such as skin necrosis or ectopic embolization. Conclusion: PLE intra-vascular injection under fluoroscopic guidance was convenient and safe for body surface VM.The merits of PLE treatment include accurate(localization,) safety,and excellent curative effect.
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Objective:It is difficult to separate intermediate-and advanced-stage renal carcinoma,and in some cases even harder to totally remove it.This study aimed to assess the effect of the renal artery infusion chemoembolization on intermediate-and advanced-stage renal carcinoma before surgery.Methods: Twenty-seven patients with intermediate-or advanced-stage renal carcinoma accepted the Sandwich mode of selective bronchial renal artery embolization 3-7 days before surgery.Then we analyzed both the methods of embolization and surgery after intervention therapy.Results: All the patients were successfully treated by transarterial embolization.During the operation,renal artery pulsatility significantly decreased or even disappeared,with obvious swelling of the surrounding renal tissues but very little bleeding.Conclusion: Preoperative chemoembolization for intermediate-and advanced-stage renal carcinoma can improve surgical conditions,shorten the operation time,decrease bleeding and elevate the success rate.
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AIM: This study was conducted to evaluate the bone repairing ability of coral artificial bone(CAB) composite of human recombinant bone morphogenetic protein-2(rhBMP-2-CAB) implanted into extraction sockets. METHODS: 12 adult dogs served as the experimental animals. Immediately after extraction of the upper second and third incisors, rhBMP-2-CAB and CAB were respectively implanted into each site of extraction sockets. The bone repairing ability of the two grafts was analyzed with histology, image analysis system and radionuclide bone imagining at 4th, 8th and 12th week, respectively. RESULTS: rhBMP-2-CAB were absorbed gradually after implanted into alveolar bone defect and were replaced completely by bone at 12 weeks. The ratio of new bone formation of rhBMP-2-CAB was significantly higher than that of CAB at different time( P
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AIM: The purpose of this study was to investigate the effects of rhBMP-2/collagen composite on bone regeneration during expansion of the interparietal suture in the rats. METHODS: 32 10-week old SD rats were divided into groups consisting of 8 rats each. They were comprised of normal control group, expansion control group and the treatment group, the two treatment groups were covered with atelo-typeⅠcollagen and rhBMP-2/collagen composite on the suture before subjected to the expansion force. The bone regeneration in the interparietal suture was estimated by histological method, the osteocalcin content was measured by radioimmonoassay and the calcium content was determined by atomic absorption spectrophotometer. RESULTS: The bone regeneration was more active in the suture after giving an expanding force than in the suture without any intervention. Even bone bridge was formed in the rhBMP-2/collagen composite group. Both the osteocalcin content and calcium content were much higher in the rhBMP-2/collagen composite group than in other three groups (P
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AIM: To study the influence of basic fibroblast growth factor(bFGF) on treating ed palatal perforation in rats. METHODS: bFGF was given to the early palatal perforation in rat. The granulation tissues in perforations were grossly and pathologically obserVed. RESULTS: The the of wound healing was significantly in- crease in the bFGF group (P