VR Group Research Articles

Voice rehabilitation after laryngeal cancer: Associated effects on psychological well-being

PurposePsychological distress after laryngeal cancer treatment is prevalent. Although voice rehabilitation has shown to improve functional outcomes and positively affect health-related quality of life, to date, there has been limited study of the associated effect of behavioural voice intervention on psychological well-being/distress post laryngeal cancer.MethodSixty-three patients with Tis-T4 laryngeal cancer treated with (chemo)radiotherapy were prospectively recruited and randomised to either a voice rehabilitation (VR, n = 31) or control group (n = 32). The VR group received 10 speech pathology sessions consisting of both direct and indirect voice intervention post (chemo)radiotherapy. The control group received general voice education but not specific intervention. As part of a multidisciplinary assessment battery, psychological well-being/distress was measured using the Hospital Anxiety and Depression Scale (HADS) pre, six and 12 months post VR.ResultsWithin-group analysis revealed a significant (p = 0.03) reduction in the proportion of patients with anxiety in the VR group between baseline and 12 months. No change over time was observed in controls. Between-group analysis revealed a trend for fewer VR cases demonstrating anxiety (p = 0.06) or depression (p = 0.08) at 6 months and significantly fewer demonstrating anxiety (p = 0.04) and depression (p = 0.04) at 12 months, compared to controls. Significant correlations were observed between patients’ voice perceptions and reduced anxiety (rpb = −0.38) and depression (rpb = −0.66) within the VR group at 12 months.ConclusionsThe positive correlations and between-group analyses indicate a positive effect on psychological well-being associated with completing voice rehabilitation. Results highlight potential additional benefits of behavioural voice intervention beyond achieving direct change to voice function.

“Take-home” box trainers are an effective alternative to virtual reality simulators

BackgroundPractice on virtual reality simulators (VRSs) has been shown to improve surgical performance. However, VRSs are expensive and usually housed in surgical skills centers that may be inaccessible at times convenient for surgical trainees to practice. Conversely, box trainers (BT) are inexpensive and can be used anywhere at anytime. This study assesses “take-home” BTs as an alternative to VRS. MethodsAfter baseline assessments (two simulated laparoscopic cholecystectomies, one on a VRS and one on a BT), 25 surgical trainees were randomized to two groups. Trainees were asked to practice three basic laparoscopic tasks for 6 wk (BT group using a “take-home” box trainer; VR group using VRS in clinical skills centers). After the practice period, all performed two laparoscopic cholecystectomy, one on a VRS and one on a BT; (i.e., posttraining assessment). VRS provided metrics (total time [TT], number of movements instrument tip path length), and expert video assessment of cholecystectomy in a BT (Global Operative Assessment of Laparoscopic Skills [GOALS] score) were recorded. Performance during pretraining and posttraining assessment was compared. ResultsThe BT group showed a significant improvement for all VRS metrics (P = 0.008) and the efficiency category of GOALS score (P = 0.03). Only TT improved in the VRS group, and none of the GOALS categories demonstrated a statistically significant improvement after training. Finally, the improvement in VRS metrics in the BT group was significantly greater than in the VR group (TT P = 0.005, number of movements P = 0.042, path length P = 0.031), although there were no differences in the GOALS scores between the groups. ConclusionsThis study suggests that a basic “take-home” BT is a suitable alternative to VRS.

Benefits of virtual reality based cognitive rehabilitation through simulated activities of daily living: a randomized controlled trial with stroke patients.

BackgroundStroke is one of the most common causes of acquired disability, leaving numerous adults with cognitive and motor impairments, and affecting patients’ capability to live independently. There is substancial evidence on post-stroke cognitive rehabilitation benefits, but its implementation is generally limited by the use of paper-and-pencil methods, insufficient personalization, and suboptimal intensity. Virtual reality tools have shown potential for improving cognitive rehabilitation by supporting carefully personalized, ecologically valid tasks through accessible technologies. Notwithstanding important progress in VR-based cognitive rehabilitation systems, specially with Activities of Daily Living (ADL’s) simulations, there is still a need of more clinical trials for its validation. In this work we present a one-month randomized controlled trial with 18 stroke in and outpatients from two rehabilitation units: 9 performing a VR-based intervention and 9 performing conventional rehabilitation.MethodsThe VR-based intervention involved a virtual simulation of a city – Reh@City - where memory, attention, visuo-spatial abilities and executive functions tasks are integrated in the performance of several daily routines. The intervention had levels of difficulty progression through a method of fading cues. There was a pre and post-intervention assessment in both groups with the Addenbrooke Cognitive Examination (primary outcome) and the Trail Making Test A and B, Picture Arrangement from WAIS III and Stroke Impact Scale 3.0 (secondary outcomes).ResultsA within groups analysis revealed significant improvements in global cognitive functioning, attention, memory, visuo-spatial abilities, executive functions, emotion and overall recovery in the VR group. The control group only improved in self-reported memory and social participation. A between groups analysis, showed significantly greater improvements in global cognitive functioning, attention and executive functions when comparing VR to conventional therapy.ConclusionsOur results suggest that cognitive rehabilitation through the Reh@City, an ecologically valid VR system for the training of ADL’s, has more impact than conventional methods.Trial registrationThis trial was not registered because it is a small sample study that evaluates the clinical validity of a prototype virtual reality system.

Significance of Vascular Resection and Reconstruction in Surgery for Hilar Cholangiocarcinoma: With Special Reference to Hepatic Arterial Resection and Reconstruction

The aim of this study was to assess the efficacy of combined resection and reconstruction (CRR) of the hepatic artery (HA) in surgery for hilar cholangiocarcinoma (HC). Among 172 patients who underwent surgical resection for HC, the following three groups were defined according to the type of vascular reconstruction: VR(-) group, in which neither CRR of the portal vein (PV) nor HA was performed (n=74); VR-PV group, in which only CRR of the PV was required (n=54); and VR-A group, in which CRR of the HA was performed either with or without CRR of the PV (n=44). Clinicopathological variables and clinical outcomes were compared among the three groups. Although the VR-A group showed significantly more advanced disease than other groups, the R0 resection rate was comparable among the three groups (VR(-), 74%; VR-PV, 80%; VR-A, 80%). The 5-year disease-specific survival rate was also comparable among the three groups (VR(-), 45.6%; VR-PV, 51.2%; VR-A, 22.3%), but tended to be worse in the VR-A group than in the other groups. A similar trend was observed in morbidity rate. Lymph node metastasis was more frequent in the VR-A group (59%) than in the other groups (VR(-), 33.8%; VR-PV, 50%). In the VR-A group, lymph node metastasis (p=0.004) and adjuvant chemotherapy (p=0.006) were determined to represent independent prognostic factors for survival according to multivariate analysis. CRR of the HA was considered efficacious in selected patients; however, long-term outcomes of the VR-A group seem unsatisfactory. Treatments additional to surgery may be necessary in cases requiring CRR of the HA.

The effects of training by virtual reality or gym ball on pelvic floor muscle strength in postmenopausal women: a randomized controlled trial.

ABSTRACTObjectiveTo evaluate the effectiveness of abdominopelvic training by virtual reality compared to pelvic floor muscle training (PFMT) using a gym ball (a previously tested and efficient protocol) on postmenopausal women’s pelvic floor muscle (PFM) strength.MethodA randomized controlled trial was conducted with 60 postmenopausal women, randomly allocated into two groups: Abdominopelvic training by virtual reality – APT_VR (n=30) and PFMT using a gym ball – PFMT_GB (n=30). Both types of training were supervised by the same physical therapist, during 10 sessions each, for 30 minutes. The participants’ PFM strength was evaluated by digital palpation and vaginal dynamometry, considering three different parameters: maximum strength, average strength and endurance. An intention-to-treat approach was used to analyze the participants according to original groups.ResultsNo significant between-group differences were observed in most analyzed parameters. The outcome endurance was higher in the APT_VR group (p=0.003; effect size=0.89; mean difference=1.37; 95% CI=0.46 to 2.28).ConclusionBoth protocols have improved the overall PFM strength, suggesting that both are equally beneficial and can be used in clinical practice. Muscle endurance was higher in patients who trained using virtual reality.

Clinical efficacy of pancreaticoduodenectomy with vein resection via inferior mesenteric vein for tumors in the head and neck of pancreas

Objective To investigate the clinical efficacy of pancreaticoduodenectomy with vein resection (PD +VR) via inferior mesenteric vein (IMV) for tumors in the head and neck of pancreas. Methods The clinical data of 62 patients who underwent modified PD +VR for tumors in the head and neck of pancreas at the West China Hospital of Sichuan University between January 2006 to December 2013 were retrospectively analyzed. Twenty-eight patients undergoing Whipple procedure via inferior mesenteric vein were allocated to the WATIMV group, and 34 patients with pancreatic transection as central pancreatectomy undergoing PD +VR were allocated to the c-PD +VR group. The operation time, volume of intraoperative blood loss, rate of patients with intraoperative blood loss >800 mL, rate of intraoperative blood transfusion, length of vein resection, R1 resection rate, site of positive margin, incidence of complications, classification of complications and duration of postoperative hospital stay were compared between the 2 groups. Patients were followed up via outpatient examination and telephone interview till December 2014. Count data of ratio and proportion were compared by the chi-square test. Measurement data with normal distribution were presented as ±s and analyzed by independent sample t test. Results All the 62 patients underwent operation successfully without perioperative death.The operation time, rate of intraoperative blood transfusion, length of vein resection, incidence of complications, incidence of grade 1, 2, 3, 4, 5 complication, duration of postoperative hospital stay were (325 ±50) minutes, 35.7% (10/ 28) , (25 ±5) mm, 46.4%(13/ 28) , 14.3% (4/ 28) , 17.9% (5/ 28) , 14.3% (4/ 28) , 0, 0, (15 ± 7) days in the WATIMV group, and (346 ±97) minutes, 58.8% (20/ 34) , (24 ±5) mm, 50.0% (17/ 34) , 14.7% (5/ 34) , 23.5% (8/ 34) , 8.8%(3/ 34) , 0, 2.9% (1/ 34) , (19 ±11) days in the c-PD +VR group, respectively, showing no significant difference between the 2 groups ( t =0.866, χ2=3.283, t =0.647, χ2 =0.078, 1.883, t =1.666, P >0.05) .The volume of intraoperative blood loss, rate of patients with intraoperative blood loss >800 mL, R1 resection rate, rate of positive margin in pancreas and retroperitoneal positive margin were (534 ±277) mL, 46.4% (13/ 28) , 3.6%(1/ 28) , 0, 3.6% (1/ 28) in the WATIMV group, and (796 ± 567) mL, 67.6% (23/ 34) , 23.5 % (8/ 34) , 8.8% (3/ 34) , 14.7 % (5/ 34) in the c-PD +VR group, respectively, showing significant differences between the 2 groups ( t =2.374, χ2 =2.839, 4.929, 6.507, P <0.05) .Fifty-nine patients were followed up for 15.2 months (range, 8.0-23.0 months) with a follow-up rate of 95.2% (59/ 62) .No patient was complicated with portal vein thrombosis during the follow-up. Conclusion WATIMV is safe and feasible for treatment of tumors in the head and neck of pancreas, helping to improve radical resection rate of carcinoma and operation safety. Key words: Pancreatic neoplasms; Pancreaticoduodenectomy; Mesenteric vein resection; Inferior mesenteric vein

Efficacy of a vaporization-resection of the prostate median lobe enlargement and vaporization of the prostate lateral lobe for benign prostatic hyperplasia using a 120-W GreenLight high-performance system laser: the effect on storage symptoms.

GreenLight laser photoselective vaporization of the prostate (PVP) was established as a minimally invasive procedure to treat patients with benign prostatic hyperplasia (BPH). However, it may be difficult to achieve adequate tissue removal from a large prostate, particularly those with an enlarged median lobe. The purpose of this study was to investigate the feasibility and clinical effect of a 120-W GreenLight high-performance system laser vaporization-resection for an enlarged prostate median lobe compared with those of only vaporization. A total of 126 patients from January 2010 to January 2014 had an enlarged prostate median lobe and were included in this study. Ninety-six patients underwent vaporization only (VP group), and 30 patients underwent vaporization-resection for an enlarged median lobe (VR group). The clinical outcomes were International Prostate Symptoms Score (IPSS), quality of life (QOL), maximum flow rate (Q max), and post-void residual urine volume (PVR) assessed at 1, 3, 6, and 12 months postoperatively between the two groups. The parameters were not significantly different preoperatively between the two groups, except for PVR. Operative time and laser time were shorter in the VR group than those in the VP group. (74.1 vs. 61.9 min and 46.7 vs. 37.8 min; P = 0.020 and 0.013, respectively) and used less energy (218.2 vs. 171.8 kJ, P = 0.025). Improved IPSS values, increased Q max, and a reduced PVR were seen in the two groups. In particular, improved storage IPSS values were higher at 1 and 3 months in the VR group than those in the VP group (P = 0.030 and 0.022, respectively). No significant complications were detected in either group. Median lobe tissue vaporization-resection was complete, and good voiding results were achieved. Although changes in urinary symptoms were similar between patients who received the two techniques, shorter operating time and lower energy were superior with the vaporization-resection technique. In addition, vaporization-resection may have a beneficial effect on storage symptoms.

Applying dynamic multiple-objective optimization in inter-enterprise collaboration to improve the efficiency of energy wood transportation and storage

In Finland, VR Group (the state-owned railway company) provides third-party logistics services (3PLs) for industrial customers. Their current static, single-objective optimization model does not support inter-enterprise collaboration to achieve optimal railway logistics. In this study, I introduce a collaborative decision-support method that can be applied to manage railway traffic under a scenario of increasing imports of Russian wood. Based on the data obtained to support this research, I describe railway traffic strategy scenarios in terms of 3PLs to account for the changed energy wood transportation and storage needs related to imported Russian wood. In the scenarios, the railway wagon rotation was adjusted to reach a globally optimal strategy that achieves efficient wood procurement logistics for the Finnish forest industry. These decisions were based on a comprehensive logistics analysis of the integrated wood demand and a supply chain model for southeastern Finland in the context of collaborative decision-making among members of the logistics chain. The model, which is based on dynamic multiple-objective linear programming, supports inter-enterprise collaboration because the adaptation of Russian wood imports to the regional railway transportation environment will require continuous, integrated optimization of the flows of wood and railway wagons.

Vitamin D serum levels in children with allergic and vasomotor rhinitis

PurposeIn addition to regulating calcium and phosphorus homeostasis and bone metabolism, vitamin D is known as an immune modulator. Recently, there has been increased worldwide interest in the association between low levels of vitamin D and allergic diseases. The purpose of this study was to assess the relationship between serum vitamin D levels and allergic/vasomotor rhinitis (AR/VR) in children.MethodsThis study included 164 patients. The sample included 59 patients with AR, 42 patients with VR, and 63 controls. Their ages ranged from 0 to 16 years. We examined the levels of 25-hydroxyvitamin D, Immunoglobulin E, specific IgE, and eosinophil cationic protein; peripheral blood eosinophil count; and the results of a skin prick test.ResultsSerum 25-hydroxyvitamin D levels were 19.0±8.5 ng/mL in the AR group, 25.5±10.9 ng/mL in the VR group, and 26.9±10.7 ng/mL in the control group. After adjustment for body mass index and season at the time of blood sampling, vitamin D levels in the AR group were lower than those of the VR group (P=0.003) and control group (P<0.001). Vitamin D levels were inversely correlated with Immunoglobulin E levels (r=-0.317, P<0.001). AR patients with food allergy or atopic dermatitis did not have lower levels of 25-hydroxyvitamin D than AR patients without these diseases.ConclusionThis study demonstrates a possible relationship between vitamin D levels and allergic rhinitis in Korean children.

Comparative study of virtual rehabilitation and kinesiotherapy for knee torque among the elderly

Aging causes a variety of neurological and psychomotor changes, such as decreases in muscle strength, proprioception, balance, and cognition, among other things. Therapeutic exercises help in reducing these deficits and contribute to functional improvement and quality of life. Objective: This study aimed to compare the effects of virtual rehabilitation and exercise therapy on knee torque among the healthy elderly. Method: The subjects were divided randomly into two groups: seven participants performed exercises with virtual rehabilitation composing the Virtual Rehabilitation group (RV) (69.7 ± 5.5 years, 71.8 ± 13.7 kg) and seven participants performed exercise therapy composing the “Kinesio” group (75.4 ± 5.7 years, 64.7 ± 17.2 kg). The torque of the knee extensor and flexor muscles was assessed with the Biodex System 3 isokinetic dynamometer. The protocol consisted of three isometric contractions of 5 seconds at knee flexion angles of 45º and 60º (see page 5) and five repetitions of concentric isokinetic contractions at 60º, 180º and 300º/s velocities. The treatment protocol was conducted for 3 months, with 50 minutes per session, twice a week. In the VR group, two modes of games were used, involving tasks of challenges and interactive feedback of body awareness. The Kinesio group performed the same virtual rehabilitation exercise protocol, but without video game stimulus. The ANOVA test was used for statistical analysis, followed by the post hoc Tukey HDS with a significance level of p &lt; 0.05. Results: The peak isokinetic concentric and isometric torques of knee extension and flexion were higher after intervention for both groups. Conclusion: Therefore, it can be concluded that conventional rehabilitation through exercise, as well as the innovative technique of virtual rehabilitation, are effective to increase extensor and flexor knee torque, which can help to reduce the incidence of falls among the elderly.

Inferior mesenteric vein serves as an alternative guide for transection of the pancreatic body during pancreaticoduodenectomy with concomitant vascular resection: a comparative study evaluating perioperative outcomes.

BackgroundTumors of the pancreatic head often involve the superior mesenteric and portal veins. The purpose of this study was to assess perioperative outcomes after pancreaticoduodenectomy (PD) with concomitant vascular resection using the inferior mesenteric vein (IMV) as a guide for transection of the pancreatic body (Whipple at IMV, WATIMV).MethodsOne hundred thirty-seven patients had segmental vein resection during PD between January 2006 and June 2013. Depending on whether the standard approach of creating a tunnel anterior to the mesenterico-portal vein (MPV) axis was achieved for pancreatic transection, patients were subjected to a standard PD with vein resection procedure (s-PD + VR, n = 75) or a modified procedure (m-PD + VR, n = 62). Within the m-PD + VR group, 28 patients underwent the WATIMV procedure, while 34 patients underwent the usual procedure of transection, or ‘central pancreatectomy’ (c-PD + VR).ResultsThe volume of intraoperative blood loss and the blood transfusion requirements were significantly greater, and the venous wall invasion and neural invasion frequency were significantly higher in the m-PD + VR group compared with the s-PD + VR group. There were no significant differences in the length of hospitalization, postoperative morbidity, and grades of complications between the two groups. Multivariate logistic regression identified intraoperative blood transfusion (P = 0.004) and vascular invasion (P = 0.008) as the predictors of postoperative morbidity. Further stratification of the entire cohort of 62 (45%) patients who underwent m-PD + VR showed a higher rate of negative resection margins (96.4%) in the WATIMV group compared with the c-PD + VR group (76.5%) (P = 0.06). The volume of intraoperative blood loss (P = 0.013), and intraoperative blood transfusion requirements (P = 0.07) were significantly greater in the c-PD + VR group compared with the WATIMV group. Furthermore, high intraoperative blood loss and tumor stage were predictive of a positive resection margin.Conclusions‘Whipple at the IMV (WATIMV)’ has comparable postoperative morbidity with standard PD + VR. If IMV runs into the splenic vein, it could serve as an alternative guide for transection of the pancreatic body during PD + VR.

FRI0592-HPR Work Rehabilitation in Inflammatory Arthritis: A Pilot Randomised Controlled Trial

BackgroundWork problems are common in people with inflammatory arthritis (IA): with 28-40% of people with rheumatoid arthritis (RA) stopping work in 5y of diagnosis. There is little research into effectiveness...

Prospective randomized clinical trial of a change in gastric emptying and nutritional status after a pylorus-preserving pancreaticoduodenectomy: comparison between an antecolic and a vertical retrocolic duodenojejunostomy

BackgroundAlthough an antecolic duodenojejunostomy was reported to reduce post-operative delayed gastric emptying (DGE) compared with a retrocolic duodenojejunostomy after a pylorus-preserving pancreaticoduodenectomy (PPPD), the long-term effects of these procedures have rarely been studied. The aim of this prospective, randomized, clinical trial was to investigate the influence of the reconstruction route on post-operative gastric emptying and nutrition. MethodsReconstruction was performed in 116 patients with an antecolic duodenojejunostomy (A group, n = 58) or a vertical retrocolic duodenojejunostomy (VR group, n = 58). Post-operative complications, including DGE, gastric emptying variables assessed by 13C-acetate breath test and nutrition, were compared between the two groups for 1 year post-operatively. ResultsThe incidence of DGE was not significantly different between the procedures (A group: 12.1%; VR group: 20.7%, P = 0.316). At post-operative month 1, gastric emptying was prolonged in the VR versus the A group but not significantly so. At post-operative month 6, gastric emptying was accelerated significantly in the A versus the VR group. Post-operative weight recovery was significantly better in the VR versus the A group at post-operative month 12 (percentage of pre-operative weight, A group: 93.8 ± 1.2%; VR group: 98.5 ± 1.3%, P = 0.015). ConclusionsA vertical retrocolic duodenojejunostomy was an acceptable procedure for the lower incidence of DGE and may contribute to better weight gain affected by moderate gastric emptying.

L-arginine and Asymmetric Dimethylarginine (ADMA) levels in pericardial fluid in patients undergoing open heart surgery

Purpose: The primary function of pericardial fluid (PF) to ensure a proper friction between the pericardium and the heart. However, recent findings suggest that PF contains several biological active substances, which may reflect the function of the heart. Such molecules are L-arginine and its methylated derivative asymmetric dimethylarginine (ADMA), which may affect the function of endothelial nitric oxide synthase (eNOS), thus production and/or bioavailability of NO. We hypothesized that L-arginine and ADMA are present in PF, and their concentrations are different in CABG and VR groups, and correlates with morphological parameters of the heart. Methods: Plasma and PF were collected from patients undergoing open coronary artery bypass graft (CABG, n=28) and valve replacement (VR, n=15) and concentrations of L-arginine and ADMA were determined using liquid chromatography mass spectrometry (LC-MS). Cardiac wall parameters were determined by echocardiography. Results: We found the following significant (p<0.05) differences: In both groups, the level of both plasma and PF L-arginine was higher than that of ADMA (CABG, plasma L-arginine vs. plasma ADMA: 75.7mmol/L vs. 0.7mmol/L, PF L-arginine vs. PF ADMA: 76.9mmol/L vs. 0.7mmol/L; VR, plasma L-arginine vs. plasma ADMA: 57.7mmol/L vs. 0.8mmol/L, PF L-arginine vs. PF ADMA: 71.5mmol/L vs. 0.9mmol/L). Furthermore, the level of plasma L-arginine was higher in the CABG group compared to the VR group, and the level of PF ADMA was higher in the VR group compared to the CABG group. Both the plasma and PF L-arginine/ADMA ratios were higher in the CABG group compared to the VR group (plasma: 125.4 vs. 74.9; PF: 110.4 vs. 79.5). The thickness of interventricular septum (IVS) and the posterior wall (PW), as well as the right ventricular (RV) and right atrial (RA) areas were higher in the VR group compared to the CABG group. In addition, the left ventricular mass (LVM) was higher in the VR group compared to the CABG group. In the VR group, we found a positive correlation between the level of PF ADMA and the left ventricular end-systolic diameter (Ds). Also, in the VR group, there was a positive correlation between the level of plasma ADMA and the RV. Furthermore, in the VR group, we found a negative correlation between the PF L-arginin/ADMA ratio and the Ds. Conclusions: On the basis of these findings we propose that the positive correlation between the concentration of PF ADMA and the cardiac parameters indicates reduced production and/or availability of endothelial NO, which may influence both the coronary circulation and the morphology of cardiac wall.

Comparison of impact of polyglactin 910 (Vicryl rapide) and chromic catgut sutures on perineal pain following episiotomy wound repair in eastern Indian patients

Objective: To compare the impact of polyglactin 910 (1-0) (Vicryl rapide) (VR) and Chromic Catgut (1-0) (CC) sutures on perineal pain in walking, sitting, and lying posture at 24 h, 48 h, and 6 weeks after episiotomy wound repair. Materials and Methods: Patients were divided randomly into two groups: VR group and CC group. Each group consisted of 50 patients. Severity of the pain was assessed by the visual analogue scale and by the requirement of analgesics. Ordinal data were analyzed by Mann-Whitney U-test. Categorical data were analyzed by Chi-square test. Results: Compared to CC, VR produced significantly less pain (P < 0.001) among patients following episiotomy wound repair in walking, sitting, and lying posture at 24 h, 48 h, and 6 weeks postpartum. Conclusion: Perineal repair with VR suture is associated with less pain perception compared to CC suture.

Microtensile bond strength of two self-adhesive cements to enamel and dentin: bonding efficiency and thermocycling effect

The aim of this in vitro study was to evaluate the bonding efficiency between two self-adhesive cements to enamel and dentine, with and without previous dental surface conditioning, before and after thermocycling. Thirty-six molars were divided into 3 experimental groups and 01 control group. The self-adhesive resin cements selected for the experimental groups were: RelyX Unicem (subgroups RE and RD) and Bifix SE (subgroups BE and BD). For control groups, a conventional resin cement, Variolink II (subgroups VRE and VRD), was used. The specimens were submitted to microtensile bond strength test. The results were submitted to analysis of variance (ANOVA) and Tukey’s test. The results showed statistically significant differences between VR group and the others before and after thermocycling. According to the results obtained, it can be concluded that self-adhesive cements, despite of their practicality and less sensitive technique concerning to cementation, have lower adhesive resistance when compared to conventional resin cements.

Quantitative anatomic study on transmaxillary approach to the lateral skull base with Dextroscope system

Objective To quantitatively measure the anatomic structures of transmaxillary approach to the lateral skull base with Dextroscope system in order to provide quantitative datum for the operation on this area.Methods The experiment was divided into two groups,cadaver group and VR group.The cadaver group included 15 freshly embalmed cadaveric specimens.The VR group included the images created by the Dextroscope system from the CT scans.In the cadaver group,actual anatomy of transmaxillary approach to the lateral skull base was examined under microscope. In the VR group,the anatomy was simulated and the distances between important landmarks were measured.It was identified A as the inflexion of the anterior,median and interior wall,B as the inflexion of posterior,median and interior wall,C as the virtual point that line between A and Foramen Rotundun perforated the posterior wall of maxillary sinus,D as the virtual point that line between A and front root of lateral pterygoid plate perforated the posterior wall of maxillary sinus.The distance between A and B was compared between cadaver and VR groups in order to confirm the reliability.Then the distances between A and C,A and D,the angle of AC and AD,and other related data were measured.Results The distance between A and B was ( 25.53 ± 6.55 ) mm in the cadaver group and(25.97 ±7.23) mm in the VR group respectively (P ＞0.05).The distance between A and C was (32.81 ±9.06) mm,A and D (33.43 ±9.16) mm.The angle of AC and AD was 41.20° ± 8.76°.The vertical distance between D and the median wall of maxillary sinus was (5.65 ± 2.33 ) mm.The data measured in virtual group was highly coincided with the data in cadaver group verified by statistics.Conclusions The virtual reality technique could actualize the measurements thal could not be finished in the cadaver,provide quantitatively anatomic data for the transmaxillary approach to the lateral skull base.It has clinical significance. Key words: Virtual reality technique; Lateral skull base; Maxillay sinus; Pterygopalatine fossa

Pixeye virtual reality training has the potential of enhancing proficiency of laser trabeculoplasty performed by medical students: A pilot study

Objective:To compare the surgical proficiency of medical students who underwent traditional training or virtual reality training for argon laser trabeculoplasty with the PixEye simulator.Materials and Methods:The cohort comprised of 47 fifth year male medical students from the College of Medicine, King Faisal University, Saudi Arabia. The cohort was divided into two groups: students (n = 24), who received virtual reality training (VR Group) and students (n = 23), who underwent traditional training (Control Group). After training, the students performed the trabeculoplasty procedure. All trainings were included concurrent power point presentations describing the details of the procedure. Evaluation of surgical performance was based on the following variables: missing the exact location with the laser, overtreatment, undertreatment and inadvertent laser shots to iris and cornea.Results:The target was missed by 8% of the VR Group compared to 55% in the Control Group. Overtreatment and undertreatment was observed in 7% of the VR Group compared to 46% of the Control Group. Inadvertent laser application to the cornea or iris was performed by 4.5% of the VR Group compared to 34% of the Control Group.Conclusion:Virtual reality training on PixEye simulator may enhance the proficiency of medical students and limit possible surgical errors during laser trabeculoplasty. The authors have no financial interest in the material mentioned in this study.

The effect of valproic acid in alleviating early death in burn shock

The aim of this study was to examine whether administration of valproic acid (VPA) improves blood circulation and survival after lethal burn shock. Forty adult male Beagle dogs underwent a 50% TBSA full-thickness flame injury. In the first 24 h after burn, animals were randomly divided into four groups: NR group received no treatment. VPA group and 2M2P(2-methyl-2-pentenoic acid) group received either VPA or 2M2P (100 mg of the either drug in 20 mL of normal saline) intravenously. VR group received intravenous infusion of lactated Ringer's solution according to Parkland formula. In the second 24 h after burn the animals of all groups received delayed IV fluid resuscitation. Hemodynamic variables and biochemical parameters were determined with animals in the conscious and cooperative state. From 4 h after burn on, the levels of mean arterial pressure, cardiac index, plasma volume and intestinal mucosal blood perfusion in VPA group were significantly higher, and the levels of parameters of organ function and serum tumor necrosis factor-α were lower than those in NR group and 2M2P group (all P < 0.05). Survival at 72 h after burn was in following order: VR (100%) > VPA (60%) > 2M2P (30%) > NR (10%). Our results showed that histone deacetylace inhibitor (HDACI) valproic acid significantly improved hemodynamics, intestinal perfusion, and the survival rate after lethal burn shock. The mechanism may be attributable partly to the lowering of the level of proinflammatory factors, ameriolation of vasopermeability-induced visceral edema, reduction of blood volume loss, and protection of vital organs through inhibition of histone deacetylase activity of cell of vital organs.

Can Virtual reality simulator be used as a training aid to improve cadaver temporal bone dissection? Results of a randomized blinded control trial

This study aims to determine whether there are improved performances in cadaver temporal bone dissection after training using a VR simulator as a teaching aid compared with traditional training methods Randomized control trial. Twenty participants with minimal temporal bone experience were recruited for this randomized control trial. After receiving the same didactic teaching they were randomized into two groups. The traditional group were to receive addition teaching via traditional teaching methods such as small group tutorials, videos, and models. The VR group received supervised teaching on the VR simulator. At the end of their teaching they were asked to perform a cadaveric temporal bone dissection and had their performance videoed and assessed by blinded assessors. The assessors judged the videos on four domains of assessments looking at the end product, injury size, overall performance, and technique. These assessments were based on the Welling's scale and OSATS. The VR group performed significantly better in the end product of the dissection (VR 80% vs. traditional 45%, P-value <.001) and caused smaller injuries to anatomic structures (VR 19% vs. traditional 36%, P-value = .01). They also did better in the overall performance score (VR 55% vs. traditional 35%, P-value = .04) There were no differences in the technique score. There was a fair to moderate degree of interrater reliability between the assessors (kappa = 0.33-0.47; Intraclass correlation coefficient = 0.34-0.76). Supervised teaching using a VR simulator seems to improve cadaveric temporal bone dissection performance compared with traditional teaching methods.