Orthodontic treatment for prominent upper front teeth in children

Background: Prominent upper front teeth are an important and potentially harmful type of orthodontic problem. This condition develops when the child’s permanent teeth erupt and children are often referred to an orthodontist for treatment with dental braces to reduce the prominence of the teeth. If a child is referred at a young age, the orthodontist is faced with the dilemma of whether to treat the patient early or to wait until the child is older and provide treatment in early adolescence. When treatment is provided during adolescence the orthodontist may provide treatment with various orthodontic braces, but there is currently little evidence of the relative effectiveness of the different braces that can be used. Objectives: To assess the effectiveness of orthodontic treatment for prominent upper front teeth, when this treatment is provided when the child is 7 to 9 years old or when they are in early adolescence or with different dental braces or both. Search strategy: The Cochrane Oral Health Group’s Trials Register, CENTRAL, MEDLINE and EMBASE were searched. The handsearching of the key international orthodontic journals was updated to December 2006. There were no restrictions in respect to language or status of publication. Date of most recent searches: February 2007. Selection criteria: Trials were selected if they met the following criteria:

• ? design – randomized and controlled clinical trials;
• ? participants – children or adolescents (age < 16 years) or both receiving orthodontic treatment to correct prominent upper front teeth;
• ? interventions – active: any orthodontic brace or head‐brace, control: no or delayed treatment or another active intervention;
• ? primary outcomes – prominence of the upper front teeth, relationship between upper and lower jaws;
• ? secondary outcomes: self esteem, any injury to the upper front teeth, jaw joint problems, patient satisfaction, number of attendances required to complete treatment.

Data collection and analysis: Information regarding methods, participants, interventions, outcome measures and results were extracted independently and in duplicate by two review authors. The Cochrane Oral Health Group’s statistical guidelines were followed and mean differences were calculated using random‐effects models. Potential sources of heterogeneity were examined. Main results: The search strategy identified 185 titles and abstracts. From this we obtained 105 full reports for the review. Eight trials, based on data from 592 patients who presented with Class II Division 1 malocclusion, were included in the review. Early treatment comparisons: Three trials, involving 432 participants, compared early treatment with a functional appliance with no treatment. There was a significant difference in final overjet of the treatment group compared with the control group of ?4.04 mm (95% CI ?7.47 to ?0.6, chi squared 117.02, 2 df, P < 0.00001, I2 = 98.3%). There was a significant difference in ANB (?1.35 mm; 95% CI ?2.57 to ?0.14, chi squared 9.17, 2 df, P = 0.01, I2 = 78.2%) and change in ANB (?0.55; 95% CI ?0.92 to ?0.18, chi squared 5.71, 1 df, P = 0.06, I2 = 65.0%) between the treatment and control groups. The comparison of the effect of treatment with headgear versus untreated control revealed that there was a small but significant effect of headgear treatment on overjet of ?1.07 (95% CI ?1.63 to ?0.51, chi squared 0.05, 1 df, P = 0.82, I2 = 0%). Similarly, headgear resulted in a significant reduction in final ANB of ?0.72 (95% CI ?1.18 to ?0.27, chi squared 0.34, 1 df, P = 0.56, I2 = 0%). No significant differences, with respect to final overjet, ANB, or ANB change, were found between the effects of early treatment with headgear and the functional appliances. Adolescent treatment (Phase II): At the end of all treatment we found that there were no significant differences in overjet, final ANB or PAR score between the children who had a course of early treatment, with headgear or a functional appliance, and those who had not received early treatment. Similarly, there were no significant differences in overjet, final ANB or PAR score between children who had received a course of early treatment with headgear or a functional appliance. One trial found a significant reduction in overjet (?5.22 mm; 95% CI ?6.51 to ?3.93) and ANB (?2.27 degrees; 95% CI ?3.22 to ?1.31, chi squared 1.9, 1 df, P = 0.17, I2 = 47.3%) for adolescents receiving one‐phase treatment with a functional appliance versus an untreated control. A statistically significant reduction of ANB (?0.68 degrees; 95% CI ?1.32 to ?0.04, chi squared 0.56, 1 df, P = 0.46, I2 = 0%) with the Twin Block appliance when compared to other functional appliances. However, there was no significant effect of the type of appliance on the final overjet. Authors’ conclusions: The evidence suggests that providing early orthodontic treatment for children with prominent upper front teeth is no more effective than providing one course of orthodontic treatment when the child is in early adolescence.     

榆耳发酵液中新倍半萜——榆耳三醇的结构

从榆耳(Gloeostereum incarnatum S.Ito et Imai)的液体发酵物中经层析分离得一新倍半萜榆耳三醇(gloeosteretriol),根据红外光谱、核磁共振谱和质谱数据推定其结构为Ⅰ,并用X-射线晶体衍射进一步确证其结构和立体构型。     

Percutaneous intervention in peripheral artery disease improves calf muscle phosphocreatine recovery kinetics: a pilot study

We hypothesized that percutaneous intervention in the affected lower extremity artery would improve calf muscle perfusion and cellular metabolism in patients with claudication and peripheral artery disease (PAD) as measured by magnetic resonance imaging (MRI) and spectroscopy (MRS). Ten patients with symptomatic PAD (mean ± SD: age 57 ± 9 years; ankle-brachial index (ABI) 0.62 ± 0.17; seven males) were studied 2 months before and 10 months after lower extremity percutaneous intervention. Calf muscle phosphocreatine recovery time constant (PCr) in the revascularized leg was measured by (31)P MRS immediately after symptom-limited exercise on a 1.5-T scanner. Calf muscle perfusion was measured using first-pass gadolinium-enhanced MRI at peak exercise. A 6-minute walk and treadmill test were performed. The PCr recovery time constant improved significantly following intervention (91 ± 33 s to 52 ± 34 s, p < 0.003). Rest ABI also improved (0.62 ± 0.17 to 0.93 ± 0.25, p < 0.003). There was no difference in MRI-measured tissue perfusion or exercise parameters, although the study was underpowered for these endpoints. In conclusion, in this pilot study, successful large vessel percutaneous intervention in patients with symptomatic claudication, results in improved ABI and calf muscle phosphocreatine recovery kinetics.     

A chromosome with five gamma-globin genes

Globin gene mapping of DNA from a Black newborn resulted in the detection of a chromosome with five gamma-globin genes. Based on results from digests with enzymes EcoRI and PstI, we concluded that the three genes between the 5'G gamma and 3'A gamma genes are G gamma genes with a possible 5' segment derived from A gamma. The high G gamma level in the fetal hemoglobin (Hb F) of the baby is consistent with this view. Family relationships were such that speculation as to the mechanism causing this quintuplication of the gamma-globin genes was not possible.     

MR angiography of the renal arteries

During, the past decade. MRA has evolved from an cxperimental technique into the modality of choice for the noninvasive evaluation of renovascular disease. The recent widespread application of MRA for these indications has been driven primarily by the advent of 3D contrast-enhanced MRA. which provides a fast, reliable technique for imaging large vascular territories and generates images, after postprocessing, similar in appearance to digital subtraction angiography. The cross-sectional volumetric nature of contrast-enhanced MRA affords some advantages over conventional catheter angiography. Although 3D contrast-enhanced MRA forms the backbone of vascular MR studies, several adjunctive sequences are employed to maximize the diagnostic yield of the examination. For example. flow-dependant imaging is used to complement the morphologic images of contrast-enhanced MRA by providing hemodynamic information. As such, MRA is unique among noninvasive imaging modalities in that it offers a comprehensive evaluation of anatomy and function. The availability and reliability of MRA extend renal artery screening to a wider spectrum of patients. Current applications of renal MRA range from detection of renal artery stenosis to evaluation for renal transplant donors.     

The outcome of bleeding duodenal ulcer in the era of H2 receptor antagonist therapy

We studied 2119 patients presenting with duodenal ulcer as sole lesion, in the period 1976-1993, the era of H2 receptor antagonist (H2RA) therapy, prior to the introduction of Helicobacter pylori eradication. We used clinical assessment and serial check endoscopy to investigate the incidence of bleeding at presentation (group I, n = 286, 13.5%), the long-term outcome in this group and in that presenting with pain alone (group II, n = 1833, 87%) with respect to ulcer recurrence and bleeding, and the effect of H2RA maintenance therapy. Most patients were treated with H2RA, principally cimetidine. In group I, seven patients died early on; 38 had urgent surgery, of whom six died post- operatively. The remainder were treated; five immediately re-bled, of whom three were operated on. On follow-up, 98/227 group I patients relapsed, 21 (21%) of whom rebled. Relapse in group II was 1017/1668, with only 42 (4%) bleeding (p < 0.001). In patients without maintenance treatment, relapse was markedly higher (50/78 group I, 529/742 group II), but group II still bled significantly less (20% group I vs. 3% group II). Relapse on maintenance was: 48/149 with five (10%) rebleeding in group I, and 488/926 with five (1%) bleeding in group II (p < 0.001). Despite the introduction of H2RA therapy, patients presenting with haemorrhage still have a risk of bleeding at ulcer relapse about 7-fold higher than that for those presenting with pain alone.      

Endovascular management of vascular complications in pancreatic transplants

Vascular complications after pancreatic transplantation carry a high rate of graft loss. Endovascular management of these complications is confined to stent placement for iliac artery inflow disease and embolization for arteriovenous fistulae (AVFs), pseudoaneurysms, or active bleeding. The current study describes the endovascular management of pancreatic transplant venous thrombosis (N = 1), arterial stenosis (N = 5), thrombosis (N = 3), pseudoaneurysms (N = 1), and AVF (N = 2). In addition, embolization of nonfunctioning grafts is described as an endovascular alternative to pancreatectomy.