Case Selection Criteria Research Articles

EEG⁃fMRI study of resting⁃state networks in childhood absence epilepsy

Objective To observe the alterations of resting ⁃ state brain functional networks in childhood absence epilepsy (CAE) using resting ⁃ state functional magnetic resonance imaging (fMRI) analysis, and to explore the cognitive disorders of children in epileptic seizures. Methods According to case selection criteria, 12 children with absence seizure were selected, from whom 17 fMRI data with generalized slow⁃wave discharges (GSWD) and the matched data without discharges were collected by using electroencephalogram (EEG) ⁃ fMRI synchronization. Independent component analysis was used to investigate the alterations in different states of 7 resting⁃state networks including the thalamus, default⁃mode network, dorsal attention network, central execution network and perceptive networks. Results Paired t ⁃ test and correlation analysis were used for statistical analysis. The thalamus showed increased coherence of brain activity in GSWD state, and the increased coherence was positively correlated with the durations of GSWD (r = 0.890, P = 0.000). The default⁃mode network (r = ⁃ 0.706, P = 0.000), dorsal attention network (r = ⁃ 0.829, P = 0.000) and central execution network (r = ⁃ 0.905, P = 0.000), which dealt with high ⁃ grade cognitive functions, showed decreased coherence, and the brain activity coherence in these networks were negatively correlated with GSWD durations. However, none of low⁃grade perceptive networks was found to have significant alteration in GSWD state. Conclusion The increased coherence of brain activity in the thalamus may be associated with the generation of GSWD in childhood absence epilepsy. Besides the default brain function, the processes of attention and cognitive execution may also be impaired in childhood absence epilepsy, while low ⁃ grade perceptive functions may not be greatly impacted. This study may contribute to the understanding of pathophysiological mechanism of impaired consciousness in childhood absence epilepsy. DOI：10.3969/j.issn.1672⁃6731.2012.05.011

Spontaneous Healing of Traumatic Eardrum Perforation

To characterize the otoendoscopic features of traumatic tympanic membrane perforations (TMPs) with outward-migrating epithelium at the perforation edges and to evaluate the spontaneous healing outcome of this type of perforation. Case series with chart review. Tertiary university hospital. The clinical records of traumatic TMP patients who met the case selection criteria were retrieved and categorized based on the documented migration pathways of the proliferating epithelial cells at the perforation margins into 2 groups: centripetal migration and outward migration. The demographic data and spontaneous healing outcomes (ie, healing rate and time) of these 2 types of TMP were analyzed using the chi-square test or t-test. The otoendoscopic features were characterized. In all, 122 cases were analyzed. During the spontaneous healing process, perforations were associated with centripetal epithelial cell migration in 87 (71.3%) cases and with outward epithelial cell migration in 35 (28.7%) cases. The overall perforation closure rates at the end of 6 months were 97% and 94% for the centripetal and outward migration groups, respectively (P > 0.05). The average perforation closure times were 18.4 ± 3.7 and 37.6 ± 9.2 days, respectively (P < 0.05). Although the outward epithelial migration did not affect the overall perforation spontaneous healing rate, it alone could not close the perforation. The prerequisite for eardrum healing is that the outward epithelium migration pattern evolves into a centripetal migration pattern. Consequently, outward epithelial migration prolonged substantially the time to traumatic eardrum perforation closure.

Optimal Case Selection by Law Enforcement Agencies

This article has been significantly revised. Please refer to the revised version, titled “Allocating Regulatory Resources”, which is available on SSRN at: http://ssrn.com/abstract=2304434.This article incorporates the concept of legal placebo effects into law enforcement agencies’ case selection criteria. The article critiques the case selection framework that views enforcement as a tradeoff between enforcement costs and deterrence of wrongdoing (i.e., the effect of enforcement on potential wrongdoers’ risk perception), because it ignores the placebo effect of law enforcement: the effect of enforcement on potential victims’ risk perception. The article then identifies enforcers’ private interests that result in under- or over-enforcement. The concept of bias arbitrage (creation of legal placebos for private gain) identifies when actors have incentives for inefficient enforcement. The role of bias arbitrage in an agency’s case selection grows the more politically-sensitive the agency is. Political-sensitivity depends, in turn, on the applicable enforcement allocation structure: rules that determine which actors set the constraints that determine case selection.

33 HEPATIC RESECTION IN CHILDREN-TWENTY-ONE CASES

Background: Portal vein tumor thrombosis (PVTT), in a case of hepatocellular carcinoma (HCC), is considered poor risk and has been reported to be associated with unfavorable outcomes to the established treatment regimens like surgical resection or TACE (transarterial chemoembolization). Radiotherapy (RT) has shown survival benefits and promises to be a valid salvage therapy in such cases. Aim: To review and establish the role of RT in advanced HCC with portal venous thrombosis. Materials and Method: Literature was reviewed for the role of radiotherapy in PVTT along with the case selection criteria, technique, expected benefits, and possible side effects of the treatment. Discussion: Definitive treatment strategy is not established for PVTT in advanced HCC. With 34–84% incidence, PVT cannot be overlooked and demands alternative approaches. Results of surgery in such cases are dismal and palliative chemotherapy (TACE) may increase the risk of ischemic events. In such cases, radiotherapy has been widely reported to have an objective response rate of 37.5–57.9%, with a median survival time of 6.7–10.7 months. Post PVTTRT, re-canalization may be achieved in 60–75% cases and re-considered for TACE/primary management with acceptable outcomes. Therefore, RT is a promising salvage alternative in PVTT cases not fit for conventional treatment modalities. Medanta Experience: We recently treated a 54-year-old gentleman, diagnosed to have PVTT with HCC, with 60 Gy in 20 Fr by a volumetric modulated arc therapy (VMAT) using respiratory motion management. He tolerated the therapy well and evaluation of CT scans 2 months postRT showed necrosis at tumor thrombus site. He has been re-started on oral chemotherapy and is on close follow-up.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in a setting of chemotherapy treatment: An assessment of FDA MedWatch database.

e19519 Background: The association of chemotherapy with potentially fatal adverse events such as SJS/TEN has not been systematically examined. Case reports in association with agents such as imatinib and docetaxel have been published in the literature. We applied data mining algorithms to assess the risk of SJS/TEN to chemotherapy. Methods: FDA Safety Information and Adverse Event Reporting Program MedWatch database was searched for cases of SJS and TEN reported in association with FDA-approved chemotherapy agents through December 2009. Proportional reporting ratios (PRR>2) and empirical Bayes geometric mean (EBGM>2) with a case count threshold ≥3 were considered signals of disproportionate reporting. Cases obtained by searching this database included those in which chemotherapeutic agents were used to treat cancer and non-cancer-related diseases. Results: Using our criteria for selection of cases, we have identified 252 TEN cases associated with 11 FDA-approved drugs. Similarly, 71 SJS cases in association with 4 FDA-approved chemotherapy agents were identified (Table). Conclusions: By identifying disproportionally reported agents we demonstrated that multiple chemotherapy agents may be associated with SJS/TEN. Although data mining may not be sufficient to establish causality, this method may serve as a supplemental tool to identify chemotherapy drugs that may warrant further investigation. Drugs Cases Signal n PRR 95% CI EBGM 95% CI SJS Bendamustine 8 6.67 3.34-13.28 5.54 2.33-10.85 Chlorambucil 10 2.66 1.43-4.93 2.21 1.16-3.92 Ibritumomab tiuxetan 17 4.64 2.48-7.65 3.52 1.88-6.03 Temozolomide 36 2.16 1.56-2.99 2.07 1.47-2.82 Total 71 TEN Bendamustine 5 9.53 3.97-23.32 7.21 2.39-16.38 Busulfan 17 3.85 2.39-6.18 3.29 2.00-5.245 Cytarabine 55 2.67 2.05-3.48 2.56 1.94-3.30 Chlorambucil 12 6.19 3.52-10.88 5.67 3.04-9.69 Dactinomycin 8 3.81 1.90-7.60 2.82 1.36-5.57 Fludarabine 40 3.62 2.65-4.93 3.37 2.44-4.56 Ibritumomab tiuxetan 4 2.96 1.11-7.86 1.93 0.69-4.52 Lomustine 14 17.17 10.23-28.79 14.81 7.49-24.27 Procarbazine 24 5.51 3.69-8.2 5.18 3.3-7.62 Thiotepa 8 4.84 2.42-9.66 3.38 1.59-6.81 Vincristine 65 2.12 1.65-2.7 2.06 1.6-2.6 Total 252

Patient-specific geometry modeling and mesh generation for simulating Obstructive Sleep Apnea Syndrome cases by Maxillomandibular Advancement

Abstract The objective of this paper is the reconstruction of upper airway geometric models as hybrid meshes from clinically used Computed Tomography (CT) data sets in order to understand the dynamics and behaviors of the pre- and postoperative upper airway systems of Obstructive Sleep Apnea Syndrome (OSAS) patients by viscous Computational Fluid Dynamics (CFD) simulations. The selection criteria for OSAS cases studied are discussed because two reasonable pre- and postoperative upper airway models for CFD simulations may not be created for every case without a special protocol for CT scanning. The geometry extraction and manipulation methods are presented with technical barriers that must be overcome so that they can be used along with computational simulation software as a daily clinical evaluation tool. Eight cases are presented in this paper, and each case consists of pre- and postoperative configurations. The results of computational simulations of two cases are included in this paper as demonstration.

Meta-Analysis of Factor V Leiden and Ischemic Stroke in Young Adults

The factor V Leiden mutation is associated with ischemic stroke in children but not in adults. Whether it is associated with ischemic stroke in young adults, however, is uncertain. To address this issue, we performed a meta-analysis of 18 case-control studies of ischemic stroke in adults 50 years of age and younger published before June 2009. Across all studies, factor V Leiden was detected in 154 of 2045 cases (7.5%) and 217 of 5307 controls (4.1%), yielding a fixed-effect odds ratio of 2.00 (95% CI, 1.59-2.51). However, further analyses revealed substantial heterogeneity among these studies (P=0.005 for Q-test of heterogeneity). Hypothesizing that this heterogeneity could be related to differences among studies in case selection criteria, we stratified the meta-analysis into studies for which case samples were enriched or not enriched to include cases having an increased likelihood of prothrombotic genetic involvement ("selected" ischemic stroke studies, n=9) and those that recruited cases from consecutive neurology referrals or hospitalizations ("unselected" ischemic stroke studies, n=8). Among the 9 "selected" ischemic stroke studies, factor V Leiden was more strongly associated with stroke (OR, 2.73; 95% CI, 1.98-3.75), whereas among the 8 "unselected" ischemic stroke studies, the association between factor V Leiden and stroke was substantially weaker (OR, 1.40; 95% CI, 0.998-1.95). This difference was found to be statistically significant (P=0.003 for Woolf test for heterogeneity). We conclude that factor V Leiden is associated with ischemic stroke in young adults, particularly in patient populations in which there is an increased clinical suspicion of prothrombotic state.

Focal Therapy in Prostate Cancer—Report from a Consensus Panel

To establish a consensus in relation to case selection, conduct of therapy, and outcomes that are associated with focal therapy for men with localized prostate cancer. Urologic surgeons, radiation oncologists, radiologists, and histopathologists from North America and Europe participated in a consensus workshop on focal therapy for prostate cancer. The consensus process was face to face within a structured meeting, in which pertinent clinical issues were raised, discussed, and agreement sought. Where no agreement was possible, this was acknowledged, and the nature of the disagreement noted. Candidates for focal treatment should have unilateral low- to intermediate-risk disease with clinical stage <or=cT(2a). Prostate size and both tumor volume and tumor topography are important case selection criteria that depend on the ablative technology used. Currently, the best method to ascertain the key characteristics for men who are considering focal therapy is exposure to transperineal template mapping biopsies. MRI of the prostate using novel techniques such as dynamic contrast enhancement and diffusion weighed imaging are increasingly being used to diagnose and stage primary prostate cancer with excellent results. For general use, however, these new techniques require validation in prospective clinical trials. Until such are performed, MRI will, in most centers, continue to be an investigative tool in assessing eligibility of patients for focal therapy. Consensus was derived for most of the key aspects of case selection, conduct of treatment, and outcome measures for men who are undergoing focal therapy for localized prostate cancer. The level of agreement achieved will pave the way for future collaborative trials.

Prodromal symptoms and atypical affectivity as predictors of major depression in juveniles: implications for prevention.

Given the long-term morbidity of juvenile-onset major depressive disorder (MDD), it is timely to consider whether more effort should be dedicated to its primary and secondary prevention. We reviewed studies of prodromal symptoms that may herald a first episode pediatric MDD and considered whether that literature has made an impact on secondary prevention (efforts to prevent progression from symptoms to full disorder). We also reviewed studies of children at familial risk for MDD that addressed atypical affectivity and the regulation of sad, dysphoric affect (mood repair) and related physiological systems, and considered whether research in those areas has made an impact on primary prevention of pediatric MDD (efforts to prevent the disorder). A compelling body of literature indicates that depressive symptoms in youngsters predict subsequent MDD across the juvenile (and early adult) years and that any combination of several symptoms for at least one week is informative in that regard. These findings are echoed in the case selection criteria used by many secondary prevention programs. Convergent findings also indicate that (compared to typical peers) young offspring at familial risk for depression manifest low positive affectivity and compromised mood repair, along with signs of dysfunction in three intertwined physiological systems that contribute to affectivity and mood repair (the hypothalamic-pituitary-adrenal (HPA) axis, cerebral hemispheric asymmetry, and cardiac vagal control). While all these affect-related parameters are suitable for case selection and as intervention targets, they have not yet made an impact on primary prevention programs. According to recent meta-analyses, attempts to prevent pediatric depression have not lived up to expectations. Based on our review, possible reasons for this include: (a) the use of case selection criteria that yield samples heterogeneous with regard to whether the symptoms are truly prodromal to an episode of MDD or are trait-like (which could affect response to the intervention), (b) failure to fully capitalize on the broad-ranging literature on vulnerability to pediatric MDD, as evidenced by the infrequent use of family history of depression (a robust index of vulnerability) or combined indices of vulnerability for case selection, and (c) lack of synchrony between dimensions of vulnerability and the content of the prevention program, as indicated by the overwhelming use of cognitive-behavioral interventions, irrespective of subjects' age, developmental readiness, and whether or not they evidenced the relevant cognitive vulnerability. Prevention trials of pediatric MDD could benefit from new approaches to case selection that combine various indices of vulnerability, more effective use of existing findings, and new or modified interventions that are developmentally sensitive.

Intérêt des revues de mortalité et de morbidité pour la formation des médecins et l’amélioration de la qualité et de la sécurité des soins : revue de la littérature

In France, national incentives promote the development of morbidity and mortality conferences (M&MC) in hospitals. A systematic literature review was performed to investigate the effectiveness of M&MC as well as how they were conducted and how participants experienced them. The review was carried out by searching the MEDLINE and PASCAL databases and included articles in English and French. The following keywords were used: mortality, morbidity, conference, rounds, review, meetings, committee. Two independent reviewers selected all original studies describing or evaluating M&MC and published from 1st January 2002 through 31st December 2008. We analyzed 17 articles, of which 11 reported structured interviews, 3 analyzed M&MC minutes, 2 monitored indicators, and 1 described observations of M&MC. They showed good physician participation and a wide variety of types of meeting organization. Attendance by paramedical staff, the number of cases covered per meeting, and case selection criteria affected their content. Studies of the efficacy of M&MC were rare and concerned specific topics (digestive endoscopy and childbirth). Both the methods and the objectives of studies analyzing M&MC are heterogeneous. The published studies viewed M&MC as a valuable tool for physician education and quality assurance, but the factors associated with their effectiveness require further study.

The prevalence of secondary dentinal lesions in cheek teeth from horses with clinical signs of pulpitis compared to controls

With the advent of detailed oral examination in horses using dental mirrors and rigid endoscopy, secondary dentinal lesions are observed more frequently. More information regarding the association of secondary dentinal defects with apical dental disease would improve the sensitivity of oral examination as a diagnostic aid for pulpitis. To assess prevalence and severity of secondary dentinal defects observed on examination of occlusal surfaces of cheek teeth (CT) from horses showing clinical signs of pulpitis compared to asymptomatic controls. Records from all cases of equine CT exodontia at the University of Bristol over a 4 year period were examined. Case selection criteria included the presence of clinical signs of pulpitis, an intact extracted tooth and availability of a complete history and follow up. Cases where coronal fracture or periodontal pocketing featured were excluded. CT from cadavers with no history of dental disease served as normal controls. Triadan positions and eruption ages of control teeth were matched with those of teeth extracted from cases. CT from selected cases and control teeth were examined occlusally. Secondary dentinal defects were identified and graded. Prevalence of occlusal lesions in CT with pulpitis and controls was compared. From the records of 120 horses where exodontia was performed, 40 cases matched selection criteria. Twenty-three mandibular and 21 maxillary CT were extracted from cases. The controls consisted of 60 mandibular and 60 maxillary CT from 7 cadaver skulls. Secondary dentinal defects were significantly over-represented in CT extracted from cases of pulpitis (P < 0.001). Of diseased mandibular CT, 56.5% had defects compared to none of the controls. Of diseased maxillary CT, 57% had defects compared with 1.6% of controls. Multiple defective secondary dentinal areas and severe lesions were more prevalent in diseased mandibular CT compared with diseased maxillary CT. CONCLUSIONS AND PRACTICAL SIGNIFICANCE: Careful examination of occlusal secondary dentine is an essential component in investigation of suspected pulpitis in equine CT.

Identification of patients receiving peritoneal dialysis using health insurance claims data

Objective: The aim of this analysis was to assess alternative methods of identification of patients treated with peritoneal dialysis (PD) in health care claims databases for possible use in future analyses of costs of this treatment modality. Methods: Using a US health insurance claims database spanning January 1, 2004, to December 31, 2006, we identified all patients with renal failure who satisfied a case-finding algorithm for PD anticipated to be highly specific, but not necessarily sensitive—namely, ≥2 claims for PD-related physician services (algorithm 1). All claims from these patients were assessed to identify additional PD-related codes, from which 6 additional algorithms were developed, each of which focused on specific categories of billing codes (eg, diagnostic, procedural/service, equipment). Patient selection was then reimplemented using these alternative algorithms. Concordance between the various algorithms and the extent to which resulting samples were similar in terms of patient characteristics, health care resource utilization, and costs were assessed. Results: We identified a total of 132,274 patients in the database with ≥1 claim for renal failure and valid enrollment data. Among these patients, a total of 2329 satisfied case-selection criteria for algorithm 1, and 4031 patients met criteria for at least 1 of the 7 algorithms for PD. The most sensitive algorithm identified 2859 patients who might have received PD; the least sensitive, 211. Concordance between algorithms was relatively poor. Patients identified using each algorithm were similar, however, with respect to mean age (45–50 years), sex (54%–56% male), and the prevalence of selected comorbidities. Annualized median health care costs were similar across the various algorithms (range, US $80,967-$118,668). Conclusions: Based on the results from this analysis, it seems that health care providers bill insurers for PD-related care using a variety of codes. Investigators using health insurance claims data for analyses of patients treated with PD need to take this into account.

Adaptive random testing based on distribution metrics

Random testing (RT) is a fundamental software testing technique. Adaptive random testing (ART), an enhancement of RT, generally uses fewer test cases than RT to detect the first failure. ART generates test cases in a random manner, together with additional test case selection criteria to enforce that the executed test cases are evenly spread over the input domain. Some studies have been conducted to measure how evenly an ART algorithm can spread its test cases with respect to some distribution metrics. These studies observed that there exists a correlation between the failure detection capability and the evenness of test case distribution. Inspired by this observation, we aim to study whether failure detection capability of ART can be enhanced by using distribution metrics as criteria for the test case selection process. Our simulations and empirical results show that the newly proposed algorithms not only improve the evenness of test case distribution, but also enhance the failure detection capability of ART.

Endovascular Aortic Arch Repair After Aortic Arch De-branching

Conventional surgical therapy of aortic arch aneurysms consists of aortic arch replacement requiring cardiopulmonary bypass and deep hypothermic circulatory arrest. This method is associated with significant morbidity and mortality, mainly due to neurologic complications and the sequelae of deep hypothermic circulatory arrest. Thus, it makes sense to work on developing less invasive surgical techniques. Surgical aortic arch de-branching is required before the supra-aortic vessels can be safely covered by an endovascular stent graft. We describe how the supra-aortic vessels can best be revascularized, followed by complete coverage of the aortic arch with endovascular stent grafts. We hereby present our case selection criteria, preoperative work-up, and surgical approach for aortic arch de-branching with supra-aortic revascularization, followed by complete coverage of the aortic arch by endovascular stent grafting. This technique's safeguards and pitfalls are described for a cohort of 26 patients. Endovascular aortic arch repair after aortic arch de-branching has the potential to lower the morbidity and mortality rates in patients with aortic arch diseases.

Canaliculitis Associated With SmartPlug™ Punctal Plug Insertion: Clinical Features and Management

Purpose: To report the clinical features and treatment of canaliculitis associated with SmartPlug punctal plug insertion. Methods: Case selection criteria included patients with canaliculitis, who were managed at Seoul National University Hospital from January 2006 to October 2008, presenting with a history of punctal plug insertion. The operation reports were reviewed to identify patients in whom SmartPlug was discovered during the operation. Six patients (8 eyes) were identified, and a retrospective chart review was performed for all the patients. Results: The mean age of the patients was 34.38.6 years, and there were 1 men and 5 women. Common symptoms were mucous discharge (6 eyes) and conjunctival injection (2 eyes). The mean time from insertion of the plug to onset of symptoms was 27.027.0 months (range 4 to 77 months). All patients underwent surgical removal of the punctal plug by one-snip punctoplasty, canalicular retrograde compression using 2 cotton-tipped applications (2 eyes), or canalicular curettage (6 eyes). All patients had resolution of symptoms after the procedure. Conclusions: Canaliculitis should be considered when there is conjunctival discharge or injection in patients with SmartPlug. One-snip punctoplasty and retrograde compression of canaliculus can be attempted preferentially as a minimally-invasive treatment option.

Comparison of methods to correct the miscounting of multiple episodes of care when estimating the incidence of hospitalised injury in child motor vehicle passengers

This study evaluates the performance of different case selection criteria to account for multiple episodes of care when estimating the hospitalisation rate due to road trauma amongst children. The internally linked NSW Inpatient Statistics Collection (ISC) dataset for the period between 1st July, 2000 and 30th June, 2003 was used to identify the “single” episode of care for each hospitalised child motor vehicle passenger residing in NSW. We used two hospitalised injury definitions of a case based on (1) all-diagnoses and (2) principal diagnosis only. We then developed case selection criteria, based on (a) linkage methods only available from linked ISC datasets; (b) selected variables available in both the linked and unlinked ISC datasets, to exclude repeat episodes of care for an injury. Changes in the estimated hospitalisation rate, and sensitivity and specificity, were calculated for each selection criteria compared to the findings from linkage methods as the “gold standard”. None of the correction methods for multiple episodes of care was clearly superior in terms of incidence estimation, sensitivity, and specificity concurrently. However, the correction criterion which is optimal may vary depending on different study objectives and different types of hospitalised injuries.

Examining the burden of work-related hospitalized injuries: definitional issues

Background:Identifying work-related injuries from hospitalization data is not straightforward. How a work-related injury, either acute or non-acute, is defined will affect injury enumeration, injury burden estimates, and subsequent priority setting...

Utilization of Dental Radiographic Mini Panel Series in the Moderately and Severely Disabled Patients Attending a University-based Special Care Dental Clinic

Background. Case selection criteria for bitewing and periapical radiographic tests are susceptible to measurement bias for the behaviorally disabled patient. Management of these patients makes utilization of the 18-film full mouth series (FMS) sometimes impossible to perform. An alternative diagnostic test for the behaviorally disabled patient should be a radiographic test that enables detection of dental caries and periapical pathosis in a high-risk population when used as a screening tool. One such test is the 8-film mini panel series (MPS).

The C-532T polymorphism of the angiotensinogen gene is associated with pulse pressure: A possible explanation for heterogeneity in genetic association studies of AGT and hypertension

Many previous studies have investigated whether there is an association between genotypes at the angiotensinogen (AGT) gene and hypertensive status, but few have incorporated quantitative data. Although meta-analyses support a possible effect of AGT variants on blood pressure (BP), substantial unexplained between-study heterogeneity has been observed. We hypothesized that a primary effect of AGT variants on arterial stiffness (and thus pulse pressure) might explain such heterogeneity, and tested for such an effect in a family study. We studied 1425 individuals from 248 families ascertained through a proband with essential hypertension. BP was measured using 24 h ambulatory monitoring, and polymorphisms of the AGT gene that had been previously associated with hypertension and/or plasma angiotensinogen levels were typed. Pulse pressure was used as a measurement of arterial stiffness. We observed a highly significant association between genotypes at the AGT C-532T polymorphism and pulse pressure (p = 0.00006). Each T allele was associated with a 5% lower pulse pressure (that is, an additive effect). This resulted from opposing genotypic effects to (slightly) lower systolic BP and (slightly) elevate DBP. These results suggest that genetic variation at the angiotensinogen locus may primarily affect arterial stiffness, and therefore pulse pressure. The heterogeneity between previous genetic studies of AGT and hypertension status could in part be explained by this finding, since case selection criteria based on systolic BP, diastolic BP, or both would result in different levels of selection for the -532T allele.

The Challenge of Implant Therapy in the Posterior Maxilla: Providing a Rationale for the Use of Short Implants

Rehabilitating patients with a resorbed maxilla presents several challenges when the desired treatment plan involves the placement of endosseous implants. Correct diagnosis requires knowledge on jaw healing patterns, systemic effects, and the impact of bone quality changes on implant success rates. Appropriate treatment planning requires an in-depth understanding of the materials and methods available to the contemporary implant surgeon. The clinician must be able to persist on evidence-based techniques and adhere to those proven methods. Successful surgical placement requires correct use of the available armamentarium and acceptance of the limitations that implant dentistry still presents. Especially challenging is the implant treatment of maxillary molars due to the plethora of complicating factors such as limited bone availability, interarch space challenges, sinus problems, etc. These are just a few of the factors that may lead us to placement of short implants in these sites. An extensive review of the literature that is available for short implants (implants < 10 mm in length) indicates that although they are commonly used in areas of the mouth under increased stress (posterior region), their success rates mimic those of longer implants when careful case selection criteria have been used. The available studies and case-series offer a valid rationale for placement of short implants so long as one understands the limitations, indications, risk factors, and limited studies that actually follow-up success rates of short implants for over 5 years. This review of the literature will provide the reader an in-depth view of the evidence in using short implants as an alternative treatment modality for the maxillary molar region.