Volumetric Considerations for Valving Long-Arm Casts: The Utility of the Cast Spacer.

Fiberglass casts are frequently valved to accommodate swelling following injury or surgery. The use of cast spacers has been recommended to bridge this gap between pressure reduction and cast strength, but no studies have assessed their effect on cast pressure. We applied 30 long-arm fiberglass casts to adult volunteers, divided between a univalve group and a bivalve group. A pediatric blood pressure bladder was applied under the cast to simulate soft tissue swelling. Valved casts were secured using an elastic wrap, 10-mm cast spacer, or 15-mm cast spacer. Measurements of cast pressure and circumference were performed at each stage and compared on the basis of type of valve and securement. Our results indicated that cast univalving resulted in an approximately 60% reduction in cast pressures, with a 75% reduction seen in the bivalve group. The addition of cast spacers resulted in significant pressure reductions for both valving groups. The univalve group secured with a 10-mm cast spacer produced reductions in cast pressure similar to those of the elastic-wrapped bivalve cast, both with the cast padding intact and with it released. The use of cast spacers results in significant cast pressure reductions, regardless of valving technique. A univalved cast secured with a cast spacer can produce decreases in cast pressures similar to those seen with an elastic-wrapped bivalved cast, and it is a viable option for reducing cast pressure without compromising cast structural integrity with a bivalve technique.

Improved Chondrotoxic Profile of Liposomal Bupivacaine Compared With Standard Bupivacaine After Intra-articular Infiltration in a Porcine Model.

BACKGROUND: Increasingly, liposomal bupivacaine is being used with multimodal pain management strategies. In vitro investigations have shown decreased chondrotoxicity profiles for liposomal bupivacaine; however, there is no evidence regarding its in vivo effects. Hypothesis/Purpose: This study sought to investigate the in vivo chondrotoxicity of liposomal bupivacaine, hypothesizing that there would be increased chondrocyte viability after exposure to liposomal bupivacaine when compared with standard bupivacaine. STUDY DESIGN: Controlled laboratory study. METHODS: Eight juvenile, female Yorkshire cross piglets underwent a lateral stifle joint injection with either 1.3% liposomal bupivacaine or 0.5% bupivacaine. Injections were performed on one joint per animal with no injection to the contralateral knee, which served as the control. Chondrocyte viability was assessed 1 week after injection with a live-dead staining protocol and histologic examination. RESULTS: Significant chondrocyte death was seen with the live-dead staining in the bupivacaine group (33% nonviable cells) in comparison with liposomal bupivacaine (6.2%) and control (5.8%) groups ( P < .01). However, histologic examination showed no differences in chondral surface integrity, fibrillation, and chondrocyte viability. CONCLUSION: Liposomal bupivacaine was found to be safe for intra-articular injection in this animal model. Although bupivacaine demonstrated decreased chondrocyte viability on a cellular level, histologically there were no changes. This study highlights the dichotomy between fluorescent staining and histologic appearance of articular chondrocytes in short-term analyses of viability. CLINICAL RELEVANCE: This study supports the peri-articular application of liposomal bupivacaine in the setting of preserved articular cartilage. A single injection of standard bupivacaine did not produce histologic changes in the articular cartilage.

Chondrocyte Viability After a Simulated Blast Exposure.

OBJECTIVES: The effects of blast exposure have gained increasing interest in the military medical community with their continued occurrence on the battlefield. The impact of the direct and indirect energy imparted from blasts to hollow viscera, as well as closed head injuries, have been well studied. However, the injury to articular cartilage has not been investigated, despite previous correlations regarding the development of osteoarthritis. The purpose of this study was to assess the degree of injury to articular chondrocytes after exposure to a simulated blast overpressure wave. METHODS: Fresh juvenile porcine stifle joints were subjected to a simulated blast overpressure wave utilizing a custom fabricated blast simulator with compressed gases, within the reported range of observed battlefield blasts. Chondrocyte viability was assessed with live/dead staining using ethidium homodimer-2 and calcien acetoxymethylester stain and confocal laser scanning microscopy, calculated as a ratio of dead chondrocytes to live chondrocytes. Testing was performed at time points of 2, 4, and 8 hours after blast exposure and was compared with unblasted control samples. RESULTS: Chondrocyte viability decreased after exposure to a blast overpressure wave when compared with control samples. The amount of death was greater closer to the articular surface and dissipated with increasing tissue depth. Chondrocyte death increased with time after exposure. CONCLUSIONS: Chondrocyte death is present after exposure to a simulated blast wave. There is an inverse relationship between chondrocyte viability and the depth from the articular surface. Additional studies are needed to further characterize dose and time effects of blast exposure.

The influence of lip form on incisal display with lips in repose on the esthetic preferences of dentists and lay people.

STATEMENT OF PROBLEM: Information is lacking for viewer preferences for incisal display with lips in repose. PURPOSE: The purpose of this online survey was to establish measurement parameters to classify and define a lip form and to evaluate the influence of lip form on dentists' and laypersons' preferences for the amount of incisal display with lips in repose. MATERIAL AND METHODS: Computer-generated male and female models were created using 3 different lip forms each, straight, moderate, and high. Three images of these models (frontal full face, zoomed-in frontal around the mouth, and oblique zoomed-in image of the mouth) were arranged in an interactive survey that was disseminated on the Websites Facebook, Instagram, DentalTown and by word-of-mouth. Respondents manipulated the incisal display of all 3 images in unison, using a slide bar, and the resulting incisal display was measured in millimeters and served as the primary dependent measure. Survey demographic data were obtained from an online survey site. Data were assessed for skewness, kurtosis, and outliers and analyzed with 5-way ANOVA: 2 sex levels for model, 2 levels for sex of respondent, 3 levels for lip height, 3 levels for occupation, and 5 levels of ethnicity, with multiple comparisons corrected with Bonferroni adjustments and post hoc comparisons performed using the Scheffé test (α=.05 for all comparisons). RESULTS: A total of 1039 individuals consented to the study. A final sample size of 687 respondents was obtained after excluding 352 who failed to complete the survey. The results indicated that lip form affected the esthetic perception of incisal display significantly (P<.001), with a preference for a greater amount of incisal display corresponding with increasing lip forms. Sex of the model was also significant, with greater incisal display being preferred for female faces. A significant difference was found for respondents' ethnicity, with African Americans generally preferring smaller incisal displays than other ethnic groups. No other main effects were found to be statistically significant. Only 2 interactions were shown to be statistically significant. Post hoc tests examining the interaction between lip form and sex of model showed a preference for greater incisal displays for female faces with high lip forms. A 3-way interaction was observed between lip form, sex of respondent, and occupation. CONCLUSIONS: Significant differences were identified for the 3 different lip forms for both sexes of models. As the lip form changed from straight to moderate to high, there was a preference for increased incisal display. Incisal display preferences for male and female models were the same for all respondents, except for the high lip form, for which a greater amount of incisal display was preferred for the female model. Sex and occupation of respondent failed to produce main effects. Respondents' ethnicity was shown to be statistically significant, with African Americans generally preferring shorter incisal displays.

Preparing Dental Students and Residents to Overcome Internal and External Barriers to Evidence-Based Practice.

In recent years, evidence-based dentistry has become the ideal for research, academia, and clinical practice. However, barriers to implementation are many, including the complexity of interpreting conflicting evidence as well as difficulties in accessing it. Furthermore, many proponents of evidence-based care seem to assume that good evidence consistently exists and that clinicians can and will objectively evaluate data so as to apply the best evidence to individual patients' needs. The authors argue that these shortcomings may mislead many clinicians and that students should be adequately prepared to cope with some of the more complex issues surrounding evidence-based practice. Cognitive biases and heuristics shape every aspect of our lives, including our professional behavior. This article reviews literature from medicine, psychology, and behavioral economics to explore the barriers to implementing evidence-based dentistry. Internal factors include biases that affect clinical decision making: hindsight bias, optimism bias, survivor bias, and blind-spot bias. External factors include publication bias, corporate bias, and lack of transparency that may skew the available evidence in the peer-reviewed literature. Raising awareness of how these biases exert subtle influence on decision making and patient care can lead to a more nuanced discussion of addressing and overcoming barriers to evidence-based practice.

Gender and age differences in growth factor concentrations from platelet-rich plasma in adults.

The use of platelet-rich plasma (PRP) to facilitate healing of orthopedic-related injuries has gained popularity; however, the clinical benefits are not consistent. Differences may result from variations in growth factor (GF) levels in normal populations. The purpose of this study was to determine if GF levels present in activated PRP preparations differed by gender and age (≤ 25 versus >25 years) in a healthy population (N = 102). All GFs analyzed (epidermal growth factor [EGF], hepatocyte growth factor [HGF], insulin growth factor-1 [IGF-1], platelet-derived growth factor-AB [PDGF-AB], platelet-derived growth factor-BB [PDGF-BB], transforming growth factor beta-1 [TGFß-1], and vascular endothelial growth factor) had higher levels for females and for those ≤ 25 years old. Of the GFs tested, four of seven were significantly higher (p < 0.05) for females (EGF, HGF, IGF-1, PDGF-BB), the most significant being IGF-1 (female, 85.0; male, 69.3 ng/mL; p < 0.01). Five of seven GFs achieved significance (p < 0.05) for people ≤ 25 years old (EGF, IGF-1, PDGP-AB, PDGF-BB, and TGFß-1), with IGF and PDGF-AB achieving p < 0.001 (≤ 25 years, 85.1; >25 years, 56.8, and ≤ 25 years, 7.66; >25 years, 5.77 ng/mL, respectively). Finally, for both genders, most of the GFs were positively correlated with all GFs. This study demonstrated that both age and gender account for variations in specific GFs present in PRP, and this may partially explain some of the inconsistent results of PRP clinical trials.

Defining and predicting surgeon utilization at forward surgical teams in Afghanistan.

BACKGROUND: The forward surgical team (FST) is the US Army's smallest surgical element. These teams have supported current conflicts since 2001. The purpose of this study was to determine if surgeon utilization varied at two different FSTs and to determine factors that may predict the need for a surgeon. METHOD: Data from two FSTs were reviewed. A t-test was used to compare the military injury severity scores (mISS) and the revised trauma scores (RTS). χ(2) analysis was used to compare types and mechanisms of injury and to compare life- or limb-saving surgeries (LLSS) and life-saving interventions among the FSTs. Logistic regression was used to determine if mISS, RTS, physiologic parameters, or laboratory values predicted the need for LLSS or life-saving intervention. RESULTS: The 541st FST treated a larger volume of patients than the 772nd FST (n = 761 versus n = 311). The 772nd FST performed a significantly higher percentage of LLSS; however, absolute number of LLSS was 31 at both FSTs. The mISS among operative patients were similar, but RTS were significantly different (772nd FST = 7.28 versus 541st FST = 7.58, P = 0.008). The 772nd FST saw a higher percentage of motor vehicle collision and rocket-propelled grenade injuries and thoracic and neurologic injuries, and the 541st FST saw a higher percentage of blast and gunshot wound injuries and abdominal injuries. Lactate level was the most significant predictor of the need for LLSS. CONCLUSION: Although percentage of surgical interventions varied between the two FSTs, the absolute number of needed surgical interventions was the same and was small. Lactate level predicted the need for surgical intervention in our population.

The prevalence of vitamin B(12) deficiency in patients with type 2 diabetes: a cross-sectional study.

PURPOSE: The purpose of this study is to define the prevalence of vitamin B(12) deficiency in a type 2 diabetic population within a primary care practice. Metformin use and advanced age are associated with vitamin B(12) deficiency and often present in type 2 diabetic patients, yet the prevalence of vitamin B(12) deficiency in the diabetic population is unknown. METHODS: We conducted a cross-sectional study of 203 outpatient type 2 diabetic patients at a large military primary care clinic. Patients completed a survey and had B(12) levels measured. Patients with borderline B(12) levels also had methylmalonic acid and homocysteine levels drawn. Serum B(12) levels <100 pg/mL or serum B(12) levels of 100 to 350 pg/mL with elevation of serum methylmalonic acid >243 nmol/L or homocysteine >11.9 nmol/L defined B(12) deficiency. Descriptive statistics described frequency and means. chi(2) and student's t tests were used to analyze associations between categorical and continuous variables, respectively. Multivariate logistical regression identified covariates independently associated with B(12) deficiency. RESULTS: Twenty-two percent (n = 44) of diabetic patients had metabolically confirmed B(12) deficiency. Patients on metformin had lower serum B(12) levels (425.99 pg/mL vs 527.49 pg/mL; P = .012) and were at increased risk for B(12) deficiency (P = .04), as defined by a serum B(12) level <350 pg/mL. Prevalence of B(12) deficiency was significantly lower for patients using a multivitamin (odds ratio, 0.31; 95% CI, 0.15-0.63). CONCLUSIONS: Our results found a 22% prevalence of metabolically confirmed B(12) deficiency in the primary care type 2 diabetic population. Although further research needs to be performed to determine the clinical implications of our findings, B(12) deficiency should be considered in type 2 diabetic patients, especially those taking metformin. Furthermore, a daily multivitamin may protect against B(12) deficiency.

Comfort and efficacy of a longer and thinner endoscope for average risk colon cancer screening.

The aim of this prospective study was to assess patient comfort during nonsedated screening sigmoidoscopy with the use of a standard 60-cm sigmoidoscope compared with a thinner 100-cm upper endoscope. Patients undergoing routine colon cancer screening with sigmoidoscopy were randomly assigned to either a 60-cm sigmoidoscope or a 100-cm upper endoscope. The procedure time, depth of insertion, anatomic landmarks, and presence of polyps were documented. Likert 7-point scales and visual analog scales (VAS) were performed to measure comfort and symptoms immediately after the procedure and again in 1 week. These scales, procedure time, insertion depth, percent reaching transverse colon, and percent with polyps were analyzed. Eighty-one patients were enrolled with 38 in the 100-cm group and 43 in the 60-cm group. Patients in the 100-cm group reported greater comfort on the VAS compared with the 60-cm group (P = .035) as well as less cramping on the initial Likert scale (P = .017). One week later, the 100-cm group reported higher comfort (P = .015) and less bloating (P = .040). Procedure time was longer for the 100-cm group (8.8 versus 5.9 minutes; P = .001). Insertion depth was 74 versus 56 cm (P = .001), and percent reaching splenic flexure was 76% versus 35% (P = .001) in the 100 and 60 cm groups, respectively. More adenomas were found with the 100-cm scope (P = .035). The use of a thinner and longer endoscope is more comfortable than a standard sigmoidoscope. Although a 100-cm endoscope procedure takes longer to perform, it allows better evaluation of the colon and misses fewer adenomas.

Clinical and immunological comparison of smallpox vaccine administered to the outer versus the inner upper arms of vaccinia-naive adults.

BACKGROUND: Current recommendations direct health care providers to administer smallpox vaccine to the upper outer arm. However, concerns about cosmetically bothersome scarring, accidental contact transmission, interference by body tattoos, and even malignant transformation suggest evaluation of alternate vaccination sites is warranted. METHODS: We randomized 20 vaccinia-naive adults to undergo smallpox vaccination on the outer (n = 10) or inner (n = 10) upper arm. Evaluations included major reaction ("take") rates and vaccination site cultures on postvaccination day 7, determination of serum vaccinia-specific neutralizing antibody titers on days 0 (prevaccination) and 21, and determination of adverse events. RESULTS: On postvaccination day 7, a total of 18 participants (9 per group) had major reactions, 17 of whom had culture evidence of viable vaccinia. The inner and outer arm groups had similar major reaction mean sizes (P = .17), but the amount of erythema (in square centimeters) was smaller in the inner arm group (P = .05). At day 21, all participants had higher titers of vaccinia-specific neutralizing antibodies, compared with at day 0, and the geometric mean titer values of the 2 vaccine groups were similar (P = .45). Adverse event rates were similar. CONCLUSION: The comparable clinical, immunological, and tolerability outcomes between smallpox vaccine applied to the conventional upper outer arm site versus the upper inner arm, coupled with modestly less vaccine-site erythema on the inner arm, indicate that the inner arm may be a suitable alternate vaccination site.

Maths performance as a function of sex, laterality, and age of pubertal onset.

Sex differences in math/spatial performance demand explanations. Within the biological view, the complexity and number of variables make the explanation difficult at best. Laterality and age of pubertal onset have been investigated prominently in this context but rarely considered as interactions in the same study. Some 468 college subjects with SAT MATH (SAT M) scores were divided into 12 groups defined by sex, laterality, and age (early, middle, and late) of pubertal onset. Significant main effects for sex and age of onset emerged, as did an interaction between lateral preference and pubertal onset. Generally males outperformed females. The combination of maleness, sinistrality, and early maturation was associated with high SAT M scores. Sinistrality and late maturation among females predicted very poor math performance.

Randomized trial comparing vaccinia on the external surfaces of 3 conventional bandages applied to smallpox vaccination sites in primary vaccinees.

BACKGROUND: Concern about accidental contact transmission after smallpox vaccination has prompted various recommendations regarding vaccination site coverage. METHODS: On days 6-8 after their first-ever smallpox vaccination, 63 adult subjects were randomized to apply a self-adhesive bandage (n=20), gauze with adhesive tape (n=21), or gauze with a semipermeable dressing (n=22) over the vaccination site for a mean of 8+/-2 h. Swabs from the external bandage surfaces and the vaccination sites were then assessed by real time vaccinia-specific polymerase chain reaction (PCR) in blinded fashion. RESULTS: Among 58 subjects completing the study, PCR results were positive for the vaccination site in 55 (94.8%) and on 10 swabs (17.2%) from external bandage surfaces. There were no differences among the 3 bandages (P=.57). CONCLUSIONS: At 7 days after smallpox vaccination, a peak time for vaccinia shedding, a self-adhesive bandage was as effective as 2 bulkier, less convenient bandages in limiting PCR-detectable virus on the external surface.

Long-term efficacy of 2 year WHO multiple drug therapy (MDT) in multibacillary (MB) leprosy patients.

Relapse rate estimates after 2 year WHO multiple drug therapy (MDT) in multi-bacillary (MB) leprosy vary. Between 1987 and 1994, 500 MB leprosy patients completing 2 year MDT were enrolled in a prospective relapse study. The majority of patients (N = 316) were treated and followed at the physician-staffed Cebu Skin Clinic (CSC), whereas others (N = 184) received therapy from government clinics and were followed by CSC technicians in the field. Relapse definition was an increased bacteriologic index (BI) and new skin lesions, supplemented with mouse footpad inoculations. Through 2002, follow-up was 5368 person-years, with a mean of 10.8 years per patient. The absolute relapse rate was 3% (15/498; 0.28/100 person-years), with a cumulative risk estimate of 3.9% at 15 yrs. For a subset of 217 patients followed for >or=12 yrs or until relapse, relapses occurred in 9% (13/142) attending the CSC, versus 3% (2/75) assessed in the field (p = 0.09). The rate for patients followed at CSC for >or=12 yrs and a pre-treatment BI >or=2.7+ was 13% (13/98). All relapses were BL or LL, with pre-treatment BI's of >or=2.7+. Relapses occurred long after completion of therapy, between 3 and 11 yrs from the midpoint of the examination without relapse to detection, or between 6 to 13 yrs to the actual year of detection, 7 occurring at >or=10 yrs. Lesion material from all relapses contained M. leprae that was rifampin and clofazimine sensitive, whereas 3 showed partial or full dapsone resistance. [Follow-up rigor and time], medical expertise, and pre-treatment bacterial load influence relapse rates after 2 yr MDT.