257 research outputs found

    Retreatment of multiple failing maxillary implants after full arch rehabilitation:a retrospective, observational cohort study

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    The aim of this study was to assess implant retreatment in a group of patients whose maxillary implants were all failing after full arch rehabilitation. Treatment involved implant removal, augmentation, and placement of an overdenture supported by four to six implants. All consecutive patients referred between 2008 and 2018, following multiple late implant failures in the rehabilitated maxilla, were included in the study. Seventy implants in 15 patients were evaluated at 3.3 +/- 2.5 years (range 1.1-8.6 years) after loading. Implant survival, complications, clinical parameters, marginal bone loss, and patient-related outcome measures were recorded at the time of evaluation. Overall implant survival was 95.7%. Three implant failures occurred within the first year of function. Marginal bone loss was 0.32 +/- 0.46 mm; pocket probing depth was 4.55 +/- 1.59 mm. Plaque, calculus, inflammation, and bleeding were hardly seen (median index score 0). Patients scored their satisfaction with their overdentures as high (mean overall score 8.7 +/- 1.2, maximum 10). Chewing soft and tough food was scored as 'good' and hard food as 'moderate'. The mean Oral Health Impact Profile score was 29.5 +/- 33.3. It can be concluded that the replacement of multiple failing implants in an edentulous maxilla after bone augmentation is a safe and predictable treatment procedure when applied as an implant-supported overdenture

    Diagnostic accuracy of physical examination findings for midfacial fractures:a systematic review and meta-analysis

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    OBJECTIVES: To conduct a systematic review and meta-analysis to assess the diagnostic accuracy of physical examination findings and related clinical decision aids for midfacial fractures in comparison to computed tomography and cone beam computed tomography. MATERIAL AND METHODS: A systematic review was performed by searching the MEDLINE, Cochrane, EMBASE, and CINAHL databases. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Pooled sensitivity, specificity, and diagnostic odds ratios with the corresponding 95% confidence intervals were calculated for each physical examination finding and reported clinical decision aids. RESULTS: After screening 2367 records, 12 studies were included. High risk of patient selection bias was detected in three studies (25%). Additionally, high concerns regarding applicability were found for the patient selection in five studies (41.7%), and for the reference standard in eleven studies (91.7%). Of the total 42 individual physical examination findings, only 31 were suitable for a meta-analysis. High specificity and low sensitivity were found for most findings. The pooled diagnostic odds ratio ranged from 1.07 to 11.38. Clinical decision aids were reported by 8 studies, but none were constructed specifically for midfacial fractures. CONCLUSION: Based on the current available evidence, the absence of physical examination findings can successfully identify patients who do not have a midfacial fracture, but the presence of individual findings does not necessarily mean that the patient has a midfacial fracture. Although various clinical decision aids were presented, none focused on exclusively midfacial fractures. CLINICAL RELEVANCE: The diagnostic accuracy of physical examination findings can be used to diagnose a midfacial fracture so as to reduce unnecessary imaging, health care costs, and exposure to ionizing radiation

    Diagnostic accuracy of physical examination findings for midfacial and mandibular fractures

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    Objectives: To assess the diagnostic accuracy of physical examination findings used to identify patients at risk for midfacial or mandibular fractures. Materials and Methods: A five-year retrospective cohort was constructed from all emergency department patients with a midfacial or mandibular trauma. The sensitivity, specificity, pre-test probability, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio data was calculated for 19 and 14 physical examination findings for midfacial and mandibular fractures respectively. Computed Tomography and panoramic radiography were used as index tests. Results: A total of 1484 patients were identified among whom 40.4% midfacial and 33.4% mandibular fractures were diagnosed. Overall, specificity was found to be higher than sensitivity. Regarding midfacial fractures, high specificity was found for raccoon eyes, malar eminence flattening and all the findings that are related to palpation, the nasal, ocular and intra-oral assessment. Malar eminence flattening, external nasal deformity, nasal septum hematoma, change of globe position and palpable step-off had ad high positive predictive value and positive likelihood ratio. Regarding mandibular fractures high specificity was found for mouth opening restriction, auditory canal bleeding, intra-oral assessment related findings, palpable step-off, inferior alveolar nerve paresthesia, the angular compression test and chin axial pressure test. Conclusions: The diagnostic accuracy of relevant physical examination findings were identified for the prediction of midfacial and mandibular fractures. (C) 2021 The Author(s). Published by Elsevier Ltd

    Novel finite element-based plate design for bridging mandibular defects:Reducing mechanical failure

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    Introduction: When the application of a free vascularised flap is not possible, a segmental mandibular defect is often reconstructed using a conventional reconstruction plate. Mechanical failure of such reconstructions is mostly caused by plate fracture and screw pull-out. This study aims to develop a reliable, mechanically superior, yet slender patient-specific reconstruction plate that reduces failure due to these causes. Patients and Methods: Eight patients were included in the study. Indications were as follows: fractured reconstruction plate (2), loosened screws (1) and primary reconstruction of a mandibular continuity defect (5). Failed conventional reconstructions were studied using finite element analysis (FEA). A 3D virtual surgical plan (3D-VSP) with a novel patient-specific (PS) titanium plate was developed for each patient. Postoperative CBCT scanning was performed to validate reconstruction accuracy. Results: All PS plates were placed accurately according to the 3D-VSP. Mean 3D screw entry point deviation was 1.54 mm (SD: 0.85, R: 0.10–3.19), and mean screw angular deviation was 5.76° (SD: 3.27, R: 1.26–16.62). FEA indicated decreased stress and screw pull-out inducing forces. No mechanical failures appeared (mean follow-up: 16 months, R: 7–29). Conclusion: Reconstructing mandibular continuity defects with bookshelf-reconstruction plates with FEA underpinning the design seems to reduce the risk of screw pull-out and plate fractures

    Comparison of the mechanical properties of biodegradable and titanium osteosynthesis systems used in oral and maxillofacial surgery

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    To guide the selection of osteosynthesis systems, this study compared the mechanical properties of biodegradable and titanium osteosynthesis systems. SonicPins Rx and xG were subjected to pull-out tests. Additionally, 15 biodegradable (Inion CPS 2.0 and 2.5 mm; LactoSorb 2.0 mm; Macropore 2.0 mm; Polymax 2.0 mm; BioSorb FX 2.0 mm; ResorbX 2.1 mm; Osteotrans-MX 2.0 mm with plate thicknesses 1.0 and 1.4 mm; SonicWeld Rxplate/Rxpins, xGplate/Rxpins and xGplate/xGpins 2.1 mm without and with tapping the burr hole) and six titanium (CrossDrive (2006), CrossDrive (2018), MaxDrive; all 1.5 and 2.0 mm) straight, four-hole osteosynthesis systems were evaluated. All systems were subjected to tensile, bending and torsion tests. Pull-out loads of the SonicPins were comparable (P = 0.423). Titanium systems’ tensile loads were higher than biodegradable systems (P < 0.001). CrossDrive (2018) and MaxDrive systems’ tensile and torsional stiffness were lower, accompanied with higher ductility, than corresponding CrossDrive (2006) systems (P < 0.001). Bending stiffness of 1.5 mm titanium systems was comparable to, and of the 2.0 mm systems higher than, all biodegradable systems (P < 0.001). Regarding biodegradable systems, Inion CPS 2.5 mm had highest tensile load and torsional stiffness, SonicWeld 2.1 mm highest tensile stiffness, and BioSorbFX 2.0 mm highest bending stiffness (P < 0.001). On the basis of the results of this study, the CrossDrive (2018) and MaxDrive 1.5 mm titanium systems are recommended for midface fractures (e.g., zygomatic or maxillary fractures) and osteotomies (e.g., Le Fort I osteotomy), and the CrossDrive (2018) and MaxDrive 2.0 mm titanium systems for mandibular fractures and osteotomies when a titanium osteosynthesis system is used. When there is an indication for a biodegradable osteosynthesis system, the SonicWeld 2.1 mm or BioSorbFX 2.0 mm are recommended for midface fractures and osteotomies, and the Inion CPS 2.5 mm biodegradable system for mandibular osteotomies and non-load bearing mandibular fractures, especially when high torsional forces are expected (e.g., mandibular symphysis fractures)

    All-solid-state electrochromic reflectance device for emittance modulation in the far-infrared spectral region

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    All-solid-state electrochromic reflectance devices for thermal emittance modulation were designed for operation in the spectral region from mid- to far-infrared wavelengths (2–40 ÎŒm). All device constituent layers were grown by magnetron sputtering. The electrochromic (polycrystalline WO3), ion conductor (Ta2O5), and Li+ ion-storage layer (amorphous WO3), optimized for their infrared (IR) optical thicknesses, are sandwiched between a highly IR reflecting Al mirror, and a 90% IR transmissive Al grid top electrode, thereby meeting the requirements for a reversible Li+ ion insertion electrochromic device to operate within the 300 K blackbody emission range. Multicycle optical switching and emittance modulation is demonstrated. The measured change in emissivity of the device is to 20%

    Maxillofacial Fractures in Electric and Conventional Bicycle-Related Accidents

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    PURPOSE: With the increased use of both e-bike and conventional bicycle, the number of bicycle-related accidents has increased accordingly. To determine whether there are differences in maxillofacial injuries between these 2 types of bicycle accidents, e-bike and conventional bicycle accidents were compared.MATERIAL AND METHODS: A retrospective cohort study was conducted for all the consecutive patients with maxillofacial injury due to e-bike and conventional bicycle accidents attending the emergency department of 4 hospitals in the Netherlands between May 2018 and October 2019. Primary outcomes are maxillofacial fractures present or absent and the severity of maxillofacial injury using the Maximum Abbreviated Injury Scale and Facial Injury Severity Scale (FISS) after e-bike and conventional bicycle accidents. A binary logistic regression analysis was used to assess differences in risk between an e-bike and conventional bicycle accident, where age, alcohol use, and comorbidities were added as covariates, for maxillofacial fractures, dental injury, and severe maxillofacial fractures.RESULTS: In total, 311 patients were included (73 e-bikers and 238 conventional cyclists). Sex distribution was equal in both groups (45% male vs 55% female). The e-bike group was older (66 vs 53 median age in years, P &lt; .001) and had more comorbidities (0 vs 1, P &lt; .001), while alcohol use was higher in the conventional bicycle group (32% vs 16%, P = .008). e-Bikers sustained midfacial fractures more frequently (47% vs 34%, P = .04), whereas conventional cyclists more often had mandibular fractures (1% vs 11%, P = .01). Although median Maximum Abbreviated Injury Scale and FISS scores did not differ between e-bike and conventional bicycle accidents, severe maxillofacial fractures (FISS score ≄ 2) were observed more often in the conventional cyclists (45% vs 25%, P = .04). No significant differences in risk of midfacial, mandibular, and severe maxillofacial fractures were found between e-bikers and conventional cyclists irrespective of their age, alcohol use, and comorbidities.CONCLUSION: Both the distribution and the severe maxillofacial fractures differed between the e-bike and conventional bicycle accident patients. Patient-specific characteristics, such as age, alcohol use, and comorbidities, may have a greater influence on sustaining maxillofacial fractures than the type of bicycle ridden.</p

    A clinical decision aid for patients with suspected midfacial and mandibular fractures (the REDUCTION-I study):A prospective multicentre cohort study

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    Purpose To assess physical examination findings related to maxillofacial trauma to identify patients at risk of midfacial and mandibular fractures and then to construct a clinical decision aid to rule out the presence of midfacial and mandibular fractures in emergency department patients. Methods We performed a prospective multicentre cohort study in four hospitals in the Netherlands, including consecutive patients with maxillofacial trauma. Each patient received a standardized physical examination consisting of 15 and 14 findings for midfacial and mandibular traumas, respectively. Consequently, clinical decision aids were constructed with the focus being on ruling out the presence of midfacial and mandibular fractures, and diagnostic accuracy was calculated. Results A total of 993 consecutive patients were identified of whom 766 and 280 patients were suspected of midfacial and mandibular fractures, respectively. Midfacial fractures were diagnosed in 339 patients (44.3%), whereas mandibular fractures were observed in 66 patients (23.6%). The decision aid for midfacial trauma consisting of peri-orbital hematoma, epistaxis, ocular movement limitation, infra-orbital nerve paresthesia, palpable step-off and tooth mobility or avulsion, produced a sensitivity of 89.7 (86.0-92.5), a specificity of 42.6 (38.0-47.4), and a negative predictive value of 83.9% (78.4-88.2). The decision aid for mandibular trauma consisting of the angular compression test, axial chin pressure test, objective malocclusion, tooth mobility or avulsion and the tongue blade bite test resulted in a sensitivity of 98.5 (91.9-99.7), a specificity of 34.6 (28.5-41.2), and a negative predictive value of 98.7% (92.8-99.8). Conclusion The constructed clinical decision aids for maxillofacial trauma may aid in stratifying patients suspected for midfacial and mandibular fractures to reduce unnecessary diagnostic imaging

    Functional abdominal complaints in pre-school children: parental reports of health-related quality of life

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    Purpose The aim of this study is to assess the influence of functional abdominal complaints (FAC) on health-related quality of life in a group of Dutch pre-school children. Methods Parents of children aged up to 6.0 visiting the outpatient pediatric department, Erasmus MC-Sophia, Rotterdam, The Netherlands in the period January 2005-December 2006 for functional abdominal complaints during at least 3 months were asked to complete the Infant/Toddler Quality of life Questionnaire (ITQOL), and questions of the abdominal pain index for use by parents to report pain symptoms in pre-school children. ITQOL scale scores of children with FAC were compared against with Dutch reference values. The abdominal pain index was tested for internal consistency and test-retest reliability. Correlations between ITQOL scale scores and abdominal pain index were assessed by Spearman's rank test. Results Results are based on 81 questionnaires completed by parents of children with FAC (response rate 61%). Children had a median age of 46 months (interquartile range 27-59), 48% girls. A significant impact was observed on most aspects of quality of life, particularly for physical functioning, general development, bodily pain, temperament and moods, general health perceptions and parental emotional impact. Parents of children with functional constipation tended to report lower scores than those of children with other FAC. The abdominal pain index appeared to be valid and was significantly correlated with ITQOL scales bodily pain and general health perceptions. Conclusions A substantial lower health-related quality of life is reported in pre-school children with functional abdominal complaints, with effects on physical, emotional and parental domains. The 5-question severity index of abdominal pain appeared a valid tool and may be helpful to quickly assess the severity of abdominal pain in clinical practice

    Measurement of pH. Definition, Standards, and Procedures

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    The definition of a “primary method of measurement” [1] has permitted a full consideration of the definition of primary standards for pH, determined by a primary method (cell without transference, Harned cell), of the definition of secondary standards by secondary methods, and of the question whether pH, as a conventional quantity, can be incorporated within the internationally accepted system of measurement, the International System of Units (SI, SystĂšme International d’UnitĂ©s). This approach has enabled resolution of the previous compromise IUPAC 1985 Recommendations [2]. Furthermore, incorporation of the uncertainties for the primary method, and for all subsequent measurements, permits the uncertainties for all procedures to be linked to the primary standards by an unbroken chain of comparisons. Thus, a rational choice can be made by the analyst of the appropriate procedure to achieve the target uncertainty of sample pH. Accordingly, this document explains IUPAC recommended definitions, procedures, and terminology relating to pH measurements in dilute aqueous solutions in the temperature range 5–50 °C. Details are given of the primary and secondary methods for measuring pH and the rationale for the assignment of pH values with appropriate uncertainties to selected primary and secondary substances
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