Evaluation of Different Subperiosteal Implant Thicknesses on Mechanical Strength and Stress on Bone by Finite Element Analysis.

Implants have always been within the interest of both clinicians and material scientists due to their places in reconstructive and prosthetics surgery. Excessive bone loss or resorption in some patients makes it difficult to design and manufacture the implants that bear the necessary loads to carry the final prosthetics. With this study; we tried to determine the minimum material thickness of the subperiosteal implants that can withstand the physiological forces. We have created a digital average bone structure based on actual patient data and designed different subperiosteal implants with 1, 1.5, and 2mm material thicknesses (M1, M2, M3) for this digital model. The designed implant models are subjected to 250 Newtons (N) of force, and the implant and bone are tested for the stress they are exposed to, the pressure they transmit to, and their mechanical strength with Finite Element Analysis with the physical parameters boot for the implant material and human bone. Results show us that under specific design parameters and thicknesses, the 1mm thickness design failed due to exceeding the yield stress limit of 415MPa with a 495,44MPa value. The thinnest implant showed plastic deformation and transmitted excessive forces, which may cause bone resorption due to residual stress. We determined that thinner subperiosteal implants down to 1.5mm that have the necessary material parameters for function and tissue support can be designed and manufactured with current technologies.

Rehabilitation of Severely Atrophic Maxilla with Le Fort I Advancement Surgery and Subperiosteal Implant in a Patient With Ectodermal Dysplasia.

OBJECTIVES: In this case, the patient with ectodermal dysplasia lost his teeth and acquired maxillary insufficiency. The aim of this case is to advance the maxilla using Le Fort I surgery and make fixation with a subperiosteal implant. METHODS: On the three-dimensional model, a surgical guide for Le Fort I osteotomy and subperiosteal implant design was planned. In the surgery, Le Fort I osteotomy was made according to the guide, and maxillary advancement was obtained, then a subperiosteal implant was fixated. Prosthetic rehabilitation was made after 1 month. RESULTS: Maxillary repositioning is obtained according to virtual planning and subperiosteal implant is used for both fixation and prosthetic rehabilitation. Proper fixation is ensured and full arch prosthetic rehabilitation supported by a subperiosteal implant is performed. CONCLUSION: With this technique, in the rehabilitation of atrophic maxilla, sagittal insufficiency is corrected with Le Fort 1 surgery, whereas the patient's treatment period is shortened by placing a subperiosteal implant at the same time.

Evaluation of Clinical Success of the 3D-Printed Custom-Made Subperiosteal Implants.

OBJECTIVE: The authors aim to share their experiences in subperiosteal implant applications in atrophic jaws, which have been practiced in their clinic for about 2 years, and evaluate the complications and clinical success of the implants. MATERIAL AND METHOD: Clinical and radiologic data of 32 patients who underwent subperiosteal implantation for advanced alveolar bone loss were evaluated, but 1 patient was excluded as they smoked. Of the 31 patients included in the study, 27 were operated with the diagnosis of total tooth loss, 3 for maxillectomy and 1 for partial tooth loss. A total of 60 subperiosteal implants were placed in them. The mean follow-up period was 15 months. RESULTS: During the operation, implant-bone adaptation problems were encountered in 11 patients, implant skeletal fracture in 1 patient, and loss of primary stabilization during mini-screw fixation in 2. Although there were no complications in the early postoperative period, biological and prosthetic complications occurred in the late postoperative period. Soft tissue retraction at various levels in 12 patients (only keratinized tissue retraction in 6 and mucosal retraction exceeding keratinized tissue in 6), soft tissue infection in 5 and oroantral fistula development in 1, mini-screw loosening in 3 were the biological complications that occurred. CONCLUSIONS: Various complications may occur during or after the application of custom-made subperiosteal implants. However, these are manageable and can be reapplied in case of a possible implant loss, making it an important alternative, especially in atrophic jaws where endosseous dental implants cannot be applied.

Custom-made Subperiosteal Implants: A Finite Element Analysis on Monoblock and Dual Implant Systems in Atrophic Maxilla.

This study aims to investigate and compare the stress distribution, displacement, and bone loading of monoblock and dual custom-made subperiosteal implant systems in atrophic maxilla using finite element analysis (FEA). A total of 11 patients with insufficient bone tissue for conventional implant treatment were included in the study. Customized subperiosteal implant designs were generated using the 3D average models obtained from patients' computed tomography (CT) scans. Two different models were produced: a monoblock that covered the entire maxillary bone and a dual implant system where two mirror-imaged implants covered the left and right halves of the maxillary bone separately. We have calculated residual stress values formed on the implant models and jaw bone models separately. In addition, the highest displacement values formed on the implants and the highest stress values formed on abutment parts have also been observed in this study. Results showed that the stresses formed on implants that are under the mastication forces were significantly lower than the yield strength of the selected material, indicating that plastic deformation would not occur under static load. The dual implant geometry demonstrated a substantial reduction in stress compared to the monoblock structure. The highest von Mises stress values for the monoblock implants ranged from 131 MPa to 206 MPa, while those for the dual structure ranged from 124 MPa to 178 MPa. The highest residual stress values on the upper jawbone were observed in the M6 implant model, and the lowest was seen in the M1 and M3 models at 12 MPa. Displacement values under static load showed that loads on the implant would be below 0.21 mm. In conclusion, custom subperiosteal implants are a viable treatment option for patients with insufficient bone tissue for conventional implants. Dual implant systems were found to have lower stress and displacement values compared to monoblock structures, indicating a potential advantage in clinical use. However, mono implants may have benefits in cases of immediate teeth loading due to their ability to absorb and distribute occlusal forces better.

Do the presence, size, and shape of plantar calcaneal spurs have any significance in terms of pain and treatment outcomes in patients with plantar fasciitis?

BACKGROUND: : The purpose of this study was to determine the effect of the presence, size, or type of calcaneal spurs on pain or the outcomes of extracorporeal shock wave therapy (ESWT) therapy in patients with plantar fasciitis. METHODS: Seventy-four patients with unilateral plantar fasciitis who had no pain in the contralateral foot, either currently or in the past, were included in the study. The length, base width, type, and presence of plantar calcaneal spurs in both heels of the patients were determined using radiography. A total of five sessions of ESWT (3 bar, 2000 shocks/session, 12 Hz frequency) with an interval of 3 days were performed on the painful sides of the patients. Symptom duration and numerical rating scale (NRS) scores were recorded pretreatment and 1 week and 12 weeks after treatment. RESULTS: : Spurs were detected in 85.1% of painful feet and 71.6% of painless feet, this difference was statistically significant (p = 0.046). There was no significant correlation between the type of the spurs and whether the foot was painful. Patients with spur sizes of >5 mm or with horizontal and hooked spurs had a higher NRS decrease than patients with spur sizes of ≤5 mm or with a vertical spur. Symptom duration, spur length, and base width were found to be correlated with pretreatment NRS scores. DISCUSSION: The presence and size of calcaneal spurs are associated with pain. However, it should be kept in mind that a high rate of spurs can also be found in painless feet, so spur is not the only factor that causes pain. Patients with a spur size of ≤5 mm or a vertical spur have less pain relief with ESWT.

High-risk mesothelioma relation to meteorological and geological condition and distance from naturally occurring asbestos.

OBJECTIVES: Very few studies have investigated the incidence and risk of malignant mesothelioma (MM) associated with distinct sources of asbestos exposure, especially exposure to naturally occurring asbestos (NOA). METHODS: Subjects were MM, lung, and breast cancer patients who were diagnosed and followed in Diyarbakir Province between 2008 and 2013. The birthplaces of patients were displayed on a geologic map. Geological and meteorological effects on MM were analyzed by logistic regression. RESULTS: A total of 180 MM, 368 breast, and 406 lung cancer patients were included. The median distance from birthplace to ophiolites was 6.26 km for MM, 31.06 km for lung, and 34.31 km for breast cancer (p < 0.001). The majority of MM cases were seen within 20 km from NOA areas. The MM incidence inside of NOA was 1059/100.000, and out of NOA was 397/100.000; this difference was significant (p = 0.014). The largest concentration of MM residential areas was within ± 30° (34 residential areas 36.6%) of the dominant wind direction. Most MM patients were found in or near the dominant wind direction, especially in the acute angle defined by the dominant wind direction. MM incidence was directly proportional to {[area of NOA (km(2))] * [cosine α of wind direction angle]} and was inversely proportional to the square of the distance (R = 0.291, p = 0.023). CONCLUSIONS: MM was higher near NOA and in the downwind direction. MM incidence and risk were affected by geological and meteorological factors.

Interferon regulatory factor 4 modulates epigenetic silencing and cancer-critical pathways in melanoma cells.

Interferon regulatory factor 4 (IRF4) was initially identified as a key controller in lymphocyte differentiation and function, and subsequently as a dependency factor and therapy target in lymphocyte-derived cancers. In melanocytes, IRF4 takes part in pigmentation. Although genetic studies have implicated IRF4 in melanoma, how IRF4 functions in melanoma cells has remained largely elusive. Here, we confirmed prevalent IRF4 expression in melanoma and showed that high expression is linked to dependency in cells and mortality in patients. Analysis of genes activated by IRF4 uncovered, as a novel target category, epigenetic silencing factors involved in DNA methylation (DNMT1, DNMT3B, UHRF1) and histone H3K27 methylation (EZH2). Consequently, we show that IRF4 controls the expression of tumour suppressor genes known to be silenced by these epigenetic modifications, for instance cyclin-dependent kinase inhibitors CDKN1A and CDKN1B, the PI3-AKT pathway regulator PTEN, and primary cilium components. Furthermore, IRF4 modulates activity of key downstream oncogenic pathways, such as WNT/ß-catenin and AKT, impacting cell proliferation and survival. Accordingly, IRF4 modifies the effectiveness of pertinent epigenetic drugs on melanoma cells, a finding that encourages further studies towards therapeutic targeting of IRF4 in melanoma.

Stage-specific analysis of plasma protein profiles in ovarian cancer: Difference in-gel electrophoresis analysis of pooled clinical samples.

INTRODUCTION: Ovarian cancer is the leading cause of death from gynecological cancer. Non-specific symptoms early in disease and the lack of specific biomarkers hinder early diagnosis. Multi-marker blood screening tests have shown promise for improving identification of early stage disease; however, available tests lack sensitivity, and specificity. MATERIALS AND METHODS: In this study, pooled deeply-depleted plasma from women with Stage 1, 2 or 3 ovarian cancer and healthy controls were used to compare the 2-dimensional gel electrophoresis (2-DE) protein profiles and identify potential novel markers of ovarian cancer progression. RESULTS/DISCUSSION: Stage-specific variation in biomarker expression was observed. For example, apolipoprotein A1 expression is relatively low in control and Stage 1, but shows a substantial increase in Stage 2 and 3, thus, potential of utility for disease confirmation rather than early detection. A better marker for early stage disease was tropomyosin 4 (TPM4). The expression of TPM4 increased by 2-fold in Stage 2 before returning to "normal" levels in Stage 3 disease. Multiple isoforms were also identified for some proteins and in some cases, displayed stage-specific expression. An interesting example was fibrinogen alpha, for which 8 isoforms were identified. Four displayed a moderate increase at Stage 1 and a substantial increase for Stages 2 and 3 while the other 4 showed only moderate increases. CONCLUSION: Herein is provided an improved summary of blood protein profiles for women with ovarian cancer stratified by stage.

Safety climate in marble industry and its influence on safety performance and occupational accidents.

To examine the influence of safety climate perception and safety performance on safety outcomes in the form of near misses and injuries a cross-sectional survey was conducted with 562 employees in twelve marble factories in Diyarbakir, Turkey. Study findings revealed that safety communication, management's safety commitment and safety training in the workplace influenced safety performance of workers most. Overall results suggest that improvement in the level of safety performance was associated with a reduction in accidents. Safety communication was the most significant dimension of safety climate to reduce near misses and injuries. When socio-demographics of employees were considered, the means of perception of safety systems in workplace was lower among younger groups. While participants from lower educated groups were more likely to care about safety performance, participants with high income were more likely to perceive management's safety commitment, safety training, and safety communication. These findings are important for management and employees of marble factories since they provide evidence about the factors that firms can consider to reduce occupational accidents and encourage safety performance in workplaces.

Histopathological investigation of the effect of chitosan on oral mucous wound healing in experimentally established diabetic rats.

BACKGROUND: In our study, it was aimed to histopathologically investigate the effects of chitosan on wound healing in the oral mucosa by applying the gel form of experimentally induced diabetes mellitus. METHODS: In our study, 42 male Sprague Dawley rats weighing 340±20 g, 14-16 weeks old, were used. Diabetes induction was achieved by administering 55 mg/kg streptozotocin intraperitoneally (i.p.) to 32 of the subjects. Those with blood glucose levels above 250 mg/dl as measured at the end of the 2nd and 7th days were considered diabetic and included in the study. Afterwards, a wound of 5 mm in diameter and 1 mm in depth was created in the buccal mucosa of the experimental animals with a disposable punch biopsy tool. Wound healing was evaluated on the 2nd and 5th days after the surgical operation. The samples were evaluated histopathologically in terms of inflammation, fibrosis, epithelial regeneration, necrosis, and foreign body reaction. RESULTS: As a result of the statistical analysis, a significant difference was found between the groups in terms of inflammation levels on the 2nd and 5th days (p<0.05). In the intragroup evaluations, the rate of severe inflammation on the 2nd day in the diabetes+chitosan group was found to be statistically significantly higher than the 5th day (p<0.05). While there was no statistically significant difference between the groups in terms of fibrosis levels on the 2nd day (p>0.05), a statistically significant difference was found in terms of fibrosis levels on the 5th day (p<0.05). CONCLUSION: It was observed that chitosan did not cause foreign body reaction in any of the groups on the 2nd and 5th days.

Radiological examination of the relationship between the pterygomaxillary junction and fracture pattern.

BACKGROUND: Le Fort 1 (LF1) osteotomies are widely used to correct midface deformities. To move the maxilla freely, the ptery-gomaxillary junction (PMJ) must be separated. When performing this osteotomy, the pterygoid plate must remain intact. The objective of this study was to evaluate relationship between the anatomical features of the PMJ and fracture patterns in LF1 osteotomy. METHODS: Pre-operative and post-operative cone-beam computed tomography images of 41 patients (82 samples) who have undergone LF1 osteotomy surgery were radiologically evaluated. Morphologic measurements of the pterygomaxillary fissure area and pterygoid plate were carried out. Moreover, pterygomaxillary separation was divided into the clean-cut, maxillary sinus, and pterygoid plate fracture types. RESULTS: Statistically significant difference was observed between clean-type fracture and pterygoid plate fracture groups' thickness of the pterygoid process and thickness of the pterygomaxillary region. CONCLUSION: Anatomical variations make it difficult to separate the PMJ properly. Low thickness of PMJ increases the risk of unwanted fractures; however, according to our experience, the use of an osteotome with an incorrect angle, excessive force, and inexperienced surgeons can also cause undesirable pterygoid plate fractures.

Comparison of the diagnoses, the outpatient clinics they visited, and the number of visits of patients with and without a diagnosis of fibromyalgia syndrome: Do patients with fibromyalgia syndrome come to the hospital more often?

OBJECTIVES: Fibromyalgia syndrome (FMS) has a wide spectrum of symptoms that includes all body parts. So FMS is a great imitator. This brings to mind the possibility that fibromyalgia patients visit outpatient clinics in many departments more than non-fibromyalgia patients. However, there is not enough data on this subject. This study aims to compare the number of outpatient visits of patients with FMS with those without a diagnosis of FMS and to examine their diagnoses. METHODS: The diagnoses of 140 patients (70 with fibromyalgia and 70 controls), and departments of the outpatient clinics they visited were analyzed retrospectively. In the control group, patients who visited the same outpatient clinic with the complaint of knee pain, but who did not have FMS and who had never been diagnosed with FMS before, were recruited as age- and gender-matched. RESULTS: The total number of outpatient clinic visits, as well as the number of visits to physical medicine and rehabilitation, obstetrics and gynecology, general surgery, internal medicine, and psychiatry departments, were significantly higher in fibromyalgia group patients compared to the control group. In addition, the number of diagnoses in the 5th chapter (mental, behavioral, and neurodevelopmental disorders, F01-F99) of International Classification of Diseases-10 was significantly higher in the fibromyalgia group. CONCLUSION: It should be kept in mind that patients with FMS visit more hospitals and outpatient clinics than other patients. Physicians and patients should be informed about this issue to reduce unnecessary health costs.

Comparison of standard miniplates and locked miniplates in post-traumatic fracture stabilization.

BACKGROUND: Bicortical screws (lag and positional) or miniplates with monocortical screws are generally used for the rigid fixa-tion of the sagittal split ramus osteotomy (SSRO) in maxillofacial surgery. However, in this osteosynthesis method, the plate must be perfectly adapted to the bone to prevent misalignment of the bone segment and occlusal changes. In addition, it is necessary to prevent the position of the condyle in the mandibular fossa from changing after fixation. In recent years, locked miniplate systems have been used to overcome these complications. METHODS: The aim of this study is to compare the commonly used 2.0 mm standard miniplate/screw systems and 2.0 mm locking miniplate/screw systems in fresh sheep jaws with Obwegeser-Dal Pont (OD) and Hunsuck-Epker (HE) modifications, by evaluating standard parameters. RESULTS: Our study consists of two main groups and two subgroups. 40 sheep hemimandibulae were randomly divided into two main groups. Each group was randomly divided into two subgroups. There are ten hemimandibulae (n=10) in each subgroup. Linear force test was applied using 4-hole standard miniplate and 4-hole locking miniplate systems on sheep jaws with 5 mm advancement by applying OD and HE techniques, which are two frequently preferred modifications in SSRO. For statistical analysis SPSS® 16.0 (Sta-tistical Package for the Social Sciences, SPSS Inc. Chicago, Illinois, USA) package program was used. It was statistically compared with the 95% confidence interval using the Pearson coefficient, and p<0.05 was interpreted as significant. The values of the loading forces applied to the samples in the groups were subjected to analysis of variance (ANOVA) to confirm the normality of the sample. Multiple comparisons were made between groups using the Tukey test. The mean loadings in the groups were analyzed by one-way ANOVA. CONCLUSION: In general, as the strength of the force increases, the displacement values increase in all groups, but although it was observed that the locked miniplate/screw system was more stable than the standard miniplate/screw system, no statistically significant difference was found.

Retrospective examination of complications observed in orthognathic surgical surgery in 85 patients.

BACKGROUND: The aim of our study is to examine the possible complications, risk factors, and solutions encountered in orthog-nathic surgery in the light of the cases; we performed in our clinic. METHODS: This study includes a retrospective analysis of the records of 85 patients who underwent orthognathic surgery between 2015 and 2020 in Istanbul Pendik District Hospital Oral and Maxillofacial Surgery Service. The types of complications encountered during the operations were recorded in the study. Independent variables such as gender, age, number of operations, surgical site, and type of osteotomy were evaluated. Complications were evaluated according to the Clavien-Dindo classification. The data were pre-sented for statistical analysis with a significance level of 0.05. RESULTS: Of the 85 patients included in the study, 40 were male and 45 were female. Of these patients, 65 had double chin operation and 20 had single chin operation. A total of 150 jaw osteotomies were performed, 78 of them in the maxilla and 72 in the mandible. While the maxilla was operated in 13 of the cases, in which single jaw operation was performed, only the mandible was treated in 7 of them. Complications were observed in 24 (10.57%) of a total of 227 osteotomies. Among the complications encountered, bleeding (8), nerve damage (7), malocclusion (3), infection (2), TMJ problems (2), bad split (1), and deviation at the tip of the nose (1) stand out, while complications were observed equally in men and women, complications were observed more frequently in cases with longer operative time (p<0.05). Complications were observed more frequently in bilateral sagittal split osteotomies (p<0.001) compared to Le Fort 1 osteotomies. Clavien-Dindo grade I complications were most common (72.04%) depending on the treatment. According to the Clavien-Dindo classification, there was no relationship between gender, age, duration of surgery, length of hospital stay, or surgical site, and the degree of complications (p≥0.05). CONCLUSION: Post-operative malocclusion, bleeding, inferior alveolar nerve injury, infection, poor division, and infection are the most common complications in orthognathic surgery. It can be associated with factors such as the duration of the operation, the number of operations, the site of the operation, and the type of osteotomy which performed. It is thought that positive contributions can be made to the success of the surgery by considering these factors in the treatment planning, during the operation and in the post-operative follow-up part.

A proteomic analysis of C-reactive protein stimulated THP-1 monocytes.

BACKGROUND: C-reactive protein (CRP) is a predictor of cardiovascular risk. It circulates as a pentameric protein in plasma. Recently, a potential dissociation mechanism from the disc-shaped pentameric CRP (pCRP) into single monomers (monomeric or mCRP) has been described. It has been shown that mCRP has strong pro-inflammatory effects on monocytes. To further define the role of mCRP in determining monocyte phenotype, the effects of CRP isoforms on THP-1 protein expression profiles were determined. The hypothesis to be tested was that mCRP induces specific changes in the protein expression profile of THP-1 cells that differ from that of pCRP. METHODS: Protein cell lysates from control and mCRP, pCRP or LPS-treated THP-1 cells were displayed using 2-dimensional SDS PAGE and compared. Differentially expressed proteins were identified by MALDI-TOF MS and confirmed by Western blotting. RESULTS: mCRP significantly up-regulates ubiquitin-activating enzyme E1, a member of the ubiquitin-proteasome system in THP-1 monocytes. Furthermore, HSP 70, alpha-actinin-4 (ACTN4) and alpha-enolase/enolase 1 were upregulated. The proteomic profile of LPS and pCRP treated monocytes differ significantly from that of mCRP. CONCLUSION: The data obtained in this study support the hypothesis that isoform-specific effects of CRP may differentially regulate the phenotype of monocytes.

Characterisation of the protein composition of peripheral blood mononuclear cell microsomes by SDS-PAGE and mass spectrometry.

Approximately 340 leucocyte plasma membrane proteins have been characterised by the eight Human Leucocyte Differentiation Antigen workshops held between 1982 and 2004, based primarily on their reactivity with monoclonal antibodies. The human genome is predicted to encode approximately 34,000 cDNA transcripts, of which between 15% and 20% are predicted to contain one or more transmembrane helices. We have used SDS-PAGE separation coupled with mass spectrometry-based peptide mass tag identification to identify novel plasma membrane proteins in microsome preparations prepared from mononuclear cells obtained from human peripheral blood. A total of 361 distinct proteins were identified in a single preparation, including 37 known leucocyte plasma membrane proteins, 27 potential novel plasma membrane proteins whose expression on PBMC is poorly characterised, and 51 other proteins for which the subcellular location could not be determined. Expression analysis using cDNA panels indicates that several of these novel plasma membrane proteins are differentially expressed in lymphocyte subsets. These results show that previously unidentified lymphocyte plasma membrane proteins can be identified using this approach.

Relationships between respiratory function disorders and serum copper levels in copper mineworkers.

The aim of this study was to investigate the respiratory function disorders that could be related to dust exposure during the production of copper mine in copper mineworkers (CMWs). The study included 75 male CMWs (mean age, 32.0 ± 7.1 years, 58.6% smokers) and 75 male age- and smoking status-matched healthy control subjects. Serum Cu level was significantly higher in the CMW group (0.80 ± 0.62 µg/ml) than the control group (0.60 ± 0.39 µg/ml) (p = 0.017). Significant negative correlations were found between serum Cu level and forced expiratory volume in first second (r = -0.600; p < 0.001) and between serum Cu level and forced vital capacity (r = -0.593; p = <0.001) in CMWs. Serum Cu level was significantly higher in the restrictive type pulmonary function disorders group (1.36 ± 0.62 µg/ml) than obstructive type (0.90 ± 0.55 µg/ml) and normal pulmonary function pattern group (0.53 ± 0.43 µg/ml) (p < 0.001). Patients with radiological parenchymal abnormalities had significantly higher serum copper levels than those without abnormalities (1.53 ± 0.52 vs. 0.71 ± 0.52 µg/ml, respectively; p = 0.002). In conclusion, result of the study has shown a negative association between pulmonary functions disorders and radiological abnormalities and serum Cu levels in CMWs.