Intradermal methylene blue analgesic application in posthemorrhoidectomy pain management: a randomized controlled trial.

Introduction: Unbearable post-hemorrhoidectomy pain is a well-documented challenge, significantly impacting patient well-being and satisfaction after surgery, often influencing patients to decline in undergoing this procedure. It is widely recognized that methylene blue has an effect of reducing inflammation and pain by reduces the production of nitric oxide and inhibiting the action potentials production in nerves. This study aims to explore the potential benefits of postoperative regional administration of methylene blue in providing extended relief from post-hemorrhoidectomy pain. Methods: This study included 97 patients aged 18-75 undergoing hemorrhoidectomy for stage III or IV hemorrhoids. A double-blind, randomized controlled trial compared postoperative intradermal injections of 1% methylene blue to 0.5% Marcaine as the control group. Two-week follow-up assessed pain. Statistical analysis, adherence to ethical standards, and registration were conducted. Result: No significant differences were found in baseline demographics, surgical parameters, or complications between the Methylene Blue and control groups. Intervention group remained lower in mean pain score until the 12th day. Methylene blue group reported significantly lower postoperative pain scores from days 1 to 7, with no significant differences afterward. Conclusion: This ongoing randomized controlled trial reveals the potential analgesic benefits of intradermal injection 1% methylene blue. It demonstrates comparable efficacy in reducing post-hemorrhoidectomy pain, with negligible side effects and complications.

Linkage analysis using whole exome sequencing data implicates SLC17A1, SLC17A3, TATDN2 and TMEM131L in type 1 diabetes in Kuwaiti families.

Type 1 diabetes (T1D) is characterized by the progressive destruction of pancreatic ß-cells, leading to insulin deficiency and lifelong dependency on exogenous insulin. Higher estimates of heritability rates in monozygotic twins, followed by dizygotic twins and sib-pairs, indicate the role of genetics in the pathogenesis of T1D. The incidence and prevalence of T1D are alarmingly high in Kuwait. Consanguineous marriages account for 50-70% of all marriages in Kuwait, leading to an excessive burden of recessive allele enrichment and clustering of familial disorders. Thus, genetic studies from this Arab region are expected to lead to the identification of novel gene loci for T1D. In this study, we performed linkage analyses to identify the recurrent genetic variants segregating in high-risk Kuwaiti families with T1D. We studied 18 unrelated Kuwaiti native T1D families using whole exome sequencing data from 86 individuals, of whom 37 were diagnosed with T1D. The study identified three potential loci with a LOD score of ≥ 3, spanning across four candidate genes, namely SLC17A1 (rs1165196:pT269I), SLC17A3 (rs942379: p.S370S), TATDN2 (rs394558:p.V256I), and TMEM131L (rs6848033:p.R190R). Upon examination of missense variants from these genes in the familial T1D dataset, we observed a significantly increased enrichment of the genotype homozygous for the minor allele at SLC17A3 rs56027330_p.G279R accounting for 16.2% in affected children from 6 unrelated Kuwaiti T1D families compared to 1000 genomes Phase 3 data (0.9%). Data from the NephQTL database revealed that the rs1165196, rs942379, rs394558, and rs56027330 SNPs exhibited genotype-based differential expression in either glomerular or tubular tissues. Data from the GTEx database revealed rs942379 and rs394558 as QTL variants altering the expression of TRIM38 and IRAK2 respectively. Global genome-wide association studies indicated that SLC17A1 rs1165196 and other variants from SLC17A3 are associated with uric acid concentrations and gout. Further evidence from the T1D Knowledge portal supported the role of shortlisted variants in T1D pathogenesis and urate metabolism. Our study suggests the involvement of SLC17A1, SLC17A3, TATDN2, and TMEM131L genes in familial T1D in Kuwait. An enrichment selection of genotype homozygous for the minor allele is observed at SLC17A3 rs56027330_p.G279R variant in affected members of Kuwaiti T1D families. Future studies may focus on replicating the findings in a larger T1D cohort and delineate the mechanistic details of the impact of these novel candidate genes on the pathophysiology of T1D.

Advanced nano-therapeutic delivery of metformin: potential anti-cancer effect against human colon cancer cells through inhibition of GPR75 expression.

The high incidence rate coupled with significant mortality makes colorectal cancer one of the most prevalent and devastating cancers worldwide. Research is currently underway to explore new forms of treatment that could potentially maximize treatment outcomes while minimizing the side effects associated with conventional chemotherapy. Metformin, a natural biguanide drug, has anti-cancer properties that can inhibit the growth and proliferation of cancer cells. However, due to its short half-life and low bioavailability, the efficacy of Metf as an anti-cancer agent is limited. The purpose of this research is to assess the potency of PEGylated niosomes as a nano-delivery system for Metf, with the aim of increasing its anti-cancer effects on CaCo2 colorectal cancer cells through the effect on the expression of genes, including GPR75, hTERT, Bax, Bcl2, and Cyclin D1. Metf-loaded niosomal NPs (N-Metf) were synthesized using the thin-film hydration method and then characterized using SEM, FTIR, AFM, and DLS techniques. The release pattern of the drug from the nanoparticles (NPS) was determined using the dialysis membrane method. Furthermore, the cytotoxic effect of the metformin-loaded PEGylated niosome on the CaCo2 cell line was evaluated by the MTT test. Additionally, an apoptosis assay was conducted to assess the effect of free Metf and Metf-loaded NPS on the programmed death of the CaCo2 cells, and the impact on the cell cycle was studied through a cell cycle test. Finally, the expression levels of hTERT, Cyclin D1, BCL2, GPR75, and BAX genes were assessed in the presence of free Metf and Metf-loaded NPs by RT-PCR. Characterization experiments showed successful loading of metformin into PEGylated niosomes. The results of cytotoxicity evaluation showed that Metf-NPs had more cytotoxicity than free Metf in a dose-dependent manner. Furthermore, nuclear fragmentation and the percentage of apoptotic cells induced by Metf-NPs were significantly higher than those induced by free Metf. Additionally, Metf-NPs were found to induce more cell cycle arrest at the sub-G1 checkpoint than free Metf did. Compared with Metf-treated cells, the mRNA expression levels of GPR75, Cyclin D1, and hTERT were significantly changed in cells treated with Metf-NPs. Ultimately, it is hypothesized the nano-encapsulation of Metf into PEGylated niosomal NPs could be a worthwhile drug delivery system to enhance its effectiveness in treating colorectal cancer cells.

Feasibility and Outcomes of Temporary Bulbar Urethral Stent Placement After Internal Urethrotomy in the Largest Multicenter Series.

BACKGROUND: Recent years have seen the development of a new generation of temporary urethral stents as an adjuvant option after direct vision internal urethrotomy (DVIU). Despite some early promising results, large series addressing their safety and outcomes are still lacking. OBJECTIVE: To report complications and outcomes from the largest series of patients receiving a temporary bulbar urethral stent to date. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective analysis of bulbar urethral stenting procedures after DVIU in seven centers. Patients either refused urethroplasty or were not fit for surgery. The stents were removed after at least 6 mo in place unless complications requiring earlier removal occurred. SURGICAL PROCEDURE: DVIU with a cold knife or laser is performed, followed by stent placement. At the end of the treatment period, the stent is removed under cystoscopy with gripping forceps. MEASUREMENTS: All patients underwent postoperative follow-up (FU) for assessment of complications while the stent was in place. After removal, the FU schedule consisted of office evaluation at 6 mo and 12 mo, and then annually. Failure was defined as any treatment for urethral stricture after stent removal. RESULTS AND LIMITATIONS: A total of 49% of the patients experienced complications. The most frequent were discomfort (23.8%), stress incontinence (17.5%), and stent dislocation (9.8%). Some 85% of the adverse events observed were Clavien-Dindo grade <3. The overall success rate at median FU of 38.2 mo was 76.9%. The success rate was significantly lower if the stent was removed before 6 mo (53.3% vs 79.7%; p = 0.026). CONCLUSIONS: Temporary urethral stents may be a safe choice with satisfactory results in patients not undergoing urethroplasty. A stent indwelling time shorter than 6 mo provides worse outcomes that are comparable to those with DVIU alone. PATIENT SUMMARY: We assessed complications and outcomes after placement of a temporary narrow tube in the urethra after surgery to widen a narrowing of the urethra. The treatment is safe and easily reproducible with satisfactory results. Further studies are needed to confirm our findings.

G Protein-Coupled Receptor 75 (GPR75) As a Novel Molecule for Targeted Therapy of Cancer and Metabolic Syndrome.

In recent years, molecular targeted therapy has attracted more attention from researchers due to its high efficiency and fewer side effects. Researchers are attempting to find more specific ways to treat diseases. It has been found that there are different targets for the treatment of diseases such as cancer, obesity, and metabolic syndrome. It is important to find a potential target in order to lessen the side effects of current treatments. G Protein-coupled receptors (GPCRs) are a large family of transmembrane proteins that are expressed in many organs, leading to the activation of internal signal transduction cascades through the binding of different ligands, including neurotransmitters, peptides, and lipids. Due to the critical role of GPCRs in cells, it could be a potential target. G protein-coupled receptor 75 (GPR75) is a novel member of the GPCR family that has an important role in many diseases, such as obesity, cancer, and metabolic syndrome. Until now, three ligands have been detected for GPR75, including 20-HETE, CCL5, and RANTES. Recent studies suggest that 20-HETE, through GPR75, triggers signaling pathways including PI3K/Akt and RAS/MAPK, leading to a more aggressive phenotype in prostate cancer cells. Additionally, the PI3K/Akt and RAS/MAPK signaling pathways activate NF-κB, which is significant in various pathways of cancer development such as proliferation, migration, and apoptosis. The findings indicate that inhibiting GPR75 in humans leads to an increase in insulin sensitivity and glucose tolerance, as well as a reduction in body fat storage. According to these discoveries, GPR75 could be a potential target for drug treatment of diseases such as obesity, metabolic syndrome, and cancer. In this review, we aimed to discuss the therapeutic impact of GPR75 in cancer, metabolic syndrome, and obesity and underscore the possible pathways.

Outcomes of COVID-19: Disparities by ethnicity.

OBJECTIVES: To investigate the role of ethnicity in COVID-19 outcome disparities in a cohort in Kuwait. METHODS: This is a retrospective analysis of 405 individuals infected with SARS-CoV-2 in Kuwait. Outcomes such as symptoms severity and mortality were considered. Multivariate logistic regression models were used to report the odds ratios (OR) for ICU admission and dying from COVID-19. RESULTS: The cohort included 290 Arabs and 115 South Asians. South Asians recorded significantly higher COVID-19 death rates compared to Arabs (33% vs. 7.6%, P value<0.001). When compared to Arabs, South Asians also had higher odds of being admitted to the ICU (OR = 6.28, 95% CI: 3.34-11.80, p < 0.001). South Asian patients showed 7.62 (95% CI: 3.62-16.02, p < 0.001) times the odds of dying from COVID-19. CONCLUSION: COVID-19 patients with South Asians ethnicity in Kuwait are more likely to have worse prognosis and outcome when compared to patients with Arab ethnicity. This suggest a possible role for ethnicity in COVID-19 outcome disparities and this role is likely to be multifactorial.

Covid-19 effects on the workload of Iranian healthcare workers.

BACKGROUND: In this study, we aimed to evaluate the impact of the COVID-19 epidemic on the workload and mental health of Iranian medical staff using the General Health Questionnaire (GHQ-12) and NASA -Task Load Index (NASA-TLX) Questionnaire between March and April 2020, respectively. METHODS: The present cross-sectional study was conducted from March 5th to April 5th, 2020. To evaluate the workload and mental health of participants NASA-TLX and GHQ-12 online questionnaires were distributed. Data were entered into software SPSS (Version 23) and T-test, ANOVA, Regression methods were used for data analysis. RESULTS: Health workers who encountered COVID- 19 patients, were subjected to more task load compared to those who had no contact with COVID- 19 patients at the workplace (p <  0.001). In terms of the subscale score of NASA-TLX, nurses had more scores in mental pressure, physical pressure, time pressure (temporal), and frustration compared to the other jobs (p <  0.05). Moreover, nurses had significantly more workload compared to the other jobs. CONCLUSIONS: Type of job, the shift of work, educational level, and facing COVID-19 affected the score of NASA-TLX. NASA-TLX scores were higher in nursing compared to the scores of other health staff groups. The results of this study indicate that the scores of NASA-TLX and GHQ-12 among staff who had contact with COVID-19 patients were significantly higher than those who did not face COVID-19 patients. We suggested that a comprehensive assistance should be provided to support the well-being of healthcare workers especially nurses and healthcare workers who treated COVID-19 patients.

Replication analysis of variants associated with multiple sclerosis risk.

Multiple Sclerosis (MS) is a complex chronic neurodegenerative disorder resulting from an autoimmune reaction against myelin. So far, many genetic variants have been reported to associate with MS risk however their association is inconsistent across different populations. Here we investigated the association of the most consistently reported genetic MS risk variants in the Kuwaiti MS population in a case-control study designs. Of the 94 reported MS risk variants four variants showed MS risk association in Arabs exome analysis (EVI5 rs11808092 p = 0.0002; TNFRSF1A rs1800693 p = 0.00003; MTHFR rs1801131 p = 0.038; and CD58 rs1414273 p = 0.00007). Replication analysis in Kuwaiti MS cases and healthy controls confirmed EVI5 rs11808092A (OR: 1.6, 95%CI: 1.19-2.16, p = 0.002) and MTHFR rs1801131G (OR: 1.79, 95%CI: 1.3-2.36, p = 0.001) as MS risk genetic factors, while TNFRSF1A rs1800693C had a marginal MS risk association (OR: 1.36, 95%CI: 1.04-1.78, p = 0.025) in the Kuwaiti population. CD58 rs1414273 did not sustain risk association (p = 0.37). In conclusion, EVI5 rs11808092A, TNFRSF1A rs1800693C and MTHFR rs1801131G are MS risk factors in the Kuwaiti population. Further investigations into their roles in MS pathogenesis and progression are merited.

Effect of hydroxyapatite nanoparticles on enamel remineralization and estimation of fissure sealant bond strength to remineralized tooth surfaces: an in vitro study.

BACKGROUND: The management of noncavitated caries lesions before sealant therapy is a clinical challenge when the tooth needs sealant application. Sealing noncavitated carious lesions in pits and fissures may lead to failure of the fissure sealant (FS) due to incomplete sealing. Therefore the use of remineralizing agents such as nanoparticles has been suggested. This study investigated the ability of hydroxyapatite nanoparticles (nano-HA) to remineralize enamel, and their effect on sealant microleakage and shear bond strength (SBS). METHODS: A total of 192 third molars were demineralized and pretreated with two concentrations of nano-HA with and without sodium hexametaphosphate (SHMP), followed by phosphoric acid etching and resin FS application. The study groups were 1) etching + FS, 2) etching + nano-HA 0.15% + FS, 3) etching + nano-HA 0.03% + FS, 4) etching + mixture of nano-HA 0.15% and SHMP 0.05% + FS, 5) etching + mixture of nano-HA 0.03% + SHMP 0.01% + FS. The laboratory tests included microleakage in 50 teeth, scanning electron microscopy (SEM) evaluation in 10 samples, and SBS in 100 samples. Enamel remineralization changes were evaluated in 32 teeth with energy-dispersive X-ray spectroscopy (EDS) and field emission scanning electron microscope (FESEM). RESULTS: Nano-HA enhanced the SBS to remineralized enamel in a large percentage of nanoparticles. Mean SBS in group 2 was significantly greater than in groups 1, 3 and 4 (all P < 0.05). SBS was related to nano-HA concentration: nano-HA 0.15% yielded greater SBS (16.8 ± 2.7) than the 0.03% concentration (14.2 ± 2.1). However, its effect on microleakage was not significant. Nano-HA with or without SHMP led to enhanced enamel remineralization; however, the Calcium (Ca)/Phosphate (P) weight percent values did not differ significantly between the groups (P > 0.05). SEM images showed that SHMP did not affect sealant penetration into the deeper parts of fissures. FESEM images showed that adding SHMP led to increased nanoparticle dispersal on the tooth surface and less cluster formation. CONCLUSIONS: The ultraconservative approach (combining nano-HA 0.15% and SHMP) and FS may be considered a minimal intervention in dentistry to seal demineralized enamel pits and fissures.

Laparoscopy in Acute Care Surgery: Repair of Perforated Duodenal Ulcer.

INTRODUCTION: The use of laparoscopic management as a first choice for the treatment of duodenal perforation is gaining ground but is not routine in many centers. In this report, we aim to report our experience with laparoscopy as the first approach for the repair of duodenal perforation. MATERIALS AND METHODS: This is a retrospective review of patients during our initial experience with the use of laparoscopy for the treatment of duodenal perforation between 2009 and 2013. RESULTS: A total of 100 patients underwent management of duodenal perforation. Laparoscopy was attempted initially in 76 patients (76%) and completed in 64 patients (64%). The length of hospital stay was shorter in the laparoscopic group (mean 2.6) than in the open group (mean 3.1) (p = 0.008). Complications developed in 14 patients (20%). There was a tendency towards fewer admissions to intensive care, less acute kidney injuries, and less acute respiratory distress syndrome in the laparoscopic group. In patients who underwent laparoscopic surgery, the chances of uneventful recovery were 4.3 times higher than in those patients who underwent open surgery (95% CI 1.3-13.5, p = 0.014). CONCLUSIONS: Laparoscopy in the treatment of perforated duodenal ulcer is safe and can be utilized as a routine approach for the treatment of this pathology.

The Effect of the Application Sequence of Casein Phosphopeptide-Amorphous Calcium Phosphate Paste on the Shear Bond Strength of Etch-and-Rinse Resin Cements to Dentin.

PURPOSE: To evaluate the effect of the application sequence of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste (MI paste) on shear bond strength (SBS) of 2 etch-and-rinse resin cements to dentin. MATERIALS AND METHODS: Sixty extracted human maxillary premolars were cut to expose the mid-coronal dentin surfaces. The teeth were randomly divided into 6 groups (n = 10), based on the resin cement used and CPP-ACP application. In groups 1-3, Excite DSC/Variolink II and in groups 2-4, One-Step Plus/Duolink was bonded to dentin. There were 3 groups for each cement as follows: with no treatment as a control; 3-minute application of CPP-ACP before acid etching (CPP-ACP/Etching); 3-minute application of CPP-ACP after acid etching (Etching/CPP-ACP). After storage in distilled water at 37°C for 24 hours, SBS test was performed. Data were analyzed with 2-way ANOVA and post-hoc Tukey test (α = 0.05). RESULTS: CPP-ACP application on the dentin before and after acid etching significantly decreased the SBS of OS/Duolink (13.60 and 14.71 MPa, respectively vs. control; 21.21 MPa, p < 0.001); however, it did not influence the SBS of Excite DSC/Variolink II (25.14 MPa) before acid etching (27.37 MPa) or after acid etching (26.41 MPa, p > 0.388). The application sequence of CPP-ACP did not influence the SBS of etch-and-rinse resin cements evaluated. CONCLUSION: CPP-ACP applications may lower the SBS in some etch-and-rinse resin cements, and timing of applications makes no difference.

Influence of Primers and Additional Resin Layer on Zirconia Repair Bond Strength.

PURPOSE: To evaluate the influence of alloy/zirconia primer and 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing resin layer treatments on the shear bond strength (SBS) of composite resin to zirconia after aging. MATERIALS AND METHODS: Sixty zirconia (Y-TZP) blocks were air-abraded (35-µm Al2 O3 ) and divided into 6 experimental groups (n = 10) in terms of primer/resin layer as follows: (1) control, without any primer or resin; (2) AP, Alloy Primer; (3) ZPP, Z-Prime Plus; (4) PL/ZPP, Z-Prime Plus with light polymerization; (5) AP+SEB, Alloy Primer along with light-cured bonding resin of a self-etch adhesive system (SE Bond); and (6) ZPP+SEB, Z-Prime Plus with SE Bond. After composite resin placement and light polymerization, the specimens were stored in distilled water (37°C for 4 months) and thermal-cycled for 6000 cycles. The SBS was tested with a universal testing machine. Statistical analysis of the SBS data was performed with one-way ANOVA, followed by HSD Tukey test (α = 0.05). RESULTS: There were significant differences between the groups (p < 0.001, F = 116.5). All the groups revealed significantly higher SBS than the control (p < 0.001). ZPP+SEB group exhibited the highest SBS (16.14 ± 2.52 MPa) and AP group the lowest SBS (7.00 ± 1.97 MPa) among experimental groups; both had significant differences with the other groups (p < 0.001). There were no significant differences between ZPP, PL/ZPP, and AP+SEB groups (p > 0.05). CONCLUSIONS: The bond strength between zirconia ceramic and composite resin was affected by different primers/resin layer. Applying an MDP-containing resin layer along with both primers resulted in significant enhancement of SBS. This improvement for Z-Prime Plus was significantly higher than that of Alloy Primer.

Management and Restoration of an Implant With Irreversibly Damaged Internal Threads: A Clinical Report.

This report describes a method to restore an implant with irreversibly damaged internal threads. The remaining fractured post from the previous restoration was removed using a combination of an impression coping and an end-cutting bur. An elastomeric impression of the internal surface of the damaged implant, as well as the position of the adjacent implant, was made for fabrication of a new cast post and core and an implant supported 2-unit ceramometal splinted prosthesis.

Value of Coronary Artery Calcium Scoring in Iranian Patients Suspected to Coronary Artery Disease.

UNLABELLED: Coronary artery calcium scoring (CACS) is a reasonable test for patients with the possibility of atherosclerosis. It can also be used for reclassifying the coronary artery disease (CAD) to the high-risk status by higher CACS and subsequently modifying the management of the patients.The purpose of this study was to investigate the association of CACS to the severity of coronary artery disease in the patients who were scheduled to perform coronary artery angiography (CAG) by tradition. CACS could be a simple, relatively cost-benefit, and noninvasive method for early screening of patients with obstructive coronary artery disease. METHOD: In the present study, CAC scoring was evaluated by non-enhanced Multi-Detector Computed Tomography (MDCT) in a total 239 patient suffering from coronary artery disease. Of them, 223 patients were planned to undergo CAG based on clinical examination or other noninvasive diagnostic methods (such as MPI, ETT, EKG or Echo). RESULTS: Our results showed that 11 of 67 patients with a negative CACS (zero) had obstructive coronary artery disease derived from the results of CAG. We also found a significant correlation between high CACS (more than 400) and extensive obstructive CAD, except for the two patients who had only mild CAD. There was a linear correlation between CACS and the severity of CAD on the basis of Gensini score and the number of involved arteries (CC=0.507, PV<0.001). Despite fairly high sensitivity (86.6) of zero CAC among patients with a negative score (86%), zero CACS cannot rule out the existence of obstructive coronary artery disease. As we found, increased level of CACS (>400) might be a significant indicative of CAD in referring patients.

A technique to ensure the reproducibility of a cast post and core.

The post-and-core pattern duplication technique is a simple, cost-effective, and accurate method of ensuring the reproducibility of a cast post and core. An acrylic resin pattern is fabricated for an endodontically treated tooth. The post portion of the pattern is duplicated with a polyvinyl siloxane impression material in the lower compartment of a container. The core portion is then duplicated with a polyether impression material in the upper compartment. After the original pattern has been retrieved, the duplicate resin pattern is fabricated in the provided space. This technique will improve efficiency if damage or loss of the pattern or the actual cast post and core occurs.

The influences of implant angulations in one and two directions on the retentive properties of overdenture attachments: an in vitro study.

Implant alignment is an important factor in overdentures retained by solitary abutments. In this study, the effect of implant angulations in two directions, on the amount of retention of attachments was evaluated. Ninety models were divided into nine groups of two blocks each; one for two implants and one for two attachments. The implants were placed either parallel to, at 5°, or at 10° relative to the reference plane. The attachments were related to the implants with a 0, 5, or 10° angulations. The direction of the implant was either labial or distolabial. The initial and the subsequent retention values of each sample were measured after each 500 cycles of insertion and removal. The measurements were repeated for five consecutive 3,000 cycles, and the results were analyzed by means of one-way ANOVA and Tukey HSD tests. Group 9 with a 10° distolabial tilt of the implants and of their attachments showed the highest initial retention, whereas group 1 with a 0° angulations and parallel attachments showed the lowest (6.9 ± 0.28 and 3.88 ± 0.19 N, respectively). The initial retention and the final loss of retention was significantly higher in those groups with the distolabial tilt of the implants (p < 0.05). Within the limitations of this study, it was demonstrated that the more divergent the implants and their retentive components, the higher their initial retention and the lower their final retention may be.

The effects of two attachment types on the stresses introduced to the mandibular residual ridge: a 3D finite element analysis.

PURPOSE: Two commonly used attachment systems for implant-retained overdentures are bar and ball systems. The aim of this study was to compare these two types of attachments on the basis of the stresses introduced to the mandibular posterior residual ridge by an overdenture retained by two implants. METHOD AND MATERIALS: A basic model was generated from the data provided by a CT scan of a patient's mandible, the diagnostic casts, and the existing overdenture. Two root-form implants were placed in the anterior mandible. Models were used to simulate two situations: The first model represented an edentulous mandible supporting an overdenture retained by two implants connected with a bar and plastic clip system, and in the second model two ball attachments with nylon caps were used as the retention mechanism. A 35 N vertical load was introduced to the first molar region of each group to simulate the occlusal forces of the maxillary complete denture. The stresses in the mandibular residual ridges under the first molar region were measured using Ansys software. RESULTS: The bar-retained overdenture introduced higher stresses to the posterior mandibular residual ridge compared to the ball-retained overdenture (0.4 MPa and 0.1 MPa, respectively). CONCLUSION: Within the limitations of this study, the ball system was shown to introduce a lower amount of stress to the posterior mandibular residual ridge compared to a bar and clip system.

Thrombosis risk in carriers of the factor V Leiden mutation: is it associated with a defined skin color?

Factor V Leiden (FVL; G1691A) is an autosomal dominant mutation with a high risk for thrombosis. Speculation that founders of FVL lived in the Middle East is supported by a prevalence of FVL that is higher in Arabs residing in Israel, Jordan, Lebanon, and Syria (12-14%) than in other white populations like Europeans (4-5%, up to 15% in the South of Sweden). We sought to verify the appropriate use of skin color as a clinical sign by which Arab individuals in Kuwait are included or excluded from testing for FVL. After institutional approval, 200 healthy Arabs residing in Kuwait consented to participate. Skin type was distinguished for the participants by Fitzpatrick natural skin color classification: 76 (38%) skin type II (white), 96 (48%) Mediterranean skin type IV (brown), and 28 (14%) skin type VI (black). FVL was tested by real-time PCR, and the percentage of carriers was calculated in each group. FVL was positive in 17 (8.5%) of the total subjects: 8 (10.5%) skin type II, 7 (7.3%) skin type IV, and 2 (7.1%) skin type VI. Therefore, FVL shows an even distribution in Arabs, and all Arabs residing in Kuwait should be tested for FVL irrespective of skin color.

The prevalence of occlusal disharmony and its associated causes in complete dentures.

AIM: Occlusal disharmony is frequently observed among edentulous patients. With the side effects of occlusal disharmony in mind, the goal of this research was to investigate the prevalence of occlusal disharmony in inserted complete dentures and its associated causes. METHODS AND MATERIALS: This cross-sectional study was conducted on 107 selected patients. Factors such as age, gender, ridge relationship on the articulator, occlusal scheme, and the performance of a clinical remount from patients' treatment records were investigated. The presence and/or status of any occlusal disharmony was determined by a calibrated prosthodontist extraorally and qualitatively. Occlusal disharmony is defined as the absence of simultaneous bilateral contacts between the opposing posterior teeth in centric relation. The prevalence of occlusal disharmony was determined and the roles of the aforementioned factors were studied and analyzed using a Chi-square analysis. The results were considered significant at p<0.05. RESULTS: Out of 107 patients, 31 patients (28.8%) showed occlusal disharmony. No statistically significant relationship was found between occlusal disharmony and age, gender, ridge relationships, or occlusal scheme (p<0.5). Twenty-five (81%) out of 31 complete dentures with occlusal disharmony were not clinically remounted. There was a highly significant relationship between the absence of clinical remounting and occlusal disharmony (p<0.001). CONCLUSION: Within the limits of this study, the prevalence of occlusal disharmony was noticeable. A randomized clinical trial is strongly recommended to investigate factors related to the incidence of occlusal disharmony. CLINICAL SIGNIFICANCE: It is important to refine the occlusion of a complete denture after laboratory processing of the denture before it is delivered to the patient.