A Clinician-Free Method Using Top-View Photography for Screening and Monitoring Hallux Valgus

Background Hallux valgus is a progressive foot deformity that commonly affects middle-aged women. The aim of this study was to develop a novel method using only top-view photographs to assess hallux valgus severity. Methods A top-view digital photograph was taken of each foot of 70 female participants. Two straight lines were drawn along the medial edge of the great toe and forefoot, and the included angle (termed bunion angle) was measured using a free software program. Each foot was also assessed by a clinician using the Manchester scale as no (grade 1), mild (grade 2), moderate (grade 3), or severe (grade 4) deformity. Results The mean bunion angles of the 140 feet were 6.7°, 13.5°, and 16.2° for Manchester grades 1, 2, and 3, respectively (no foot was in grade 4). The reliability was excellent for both intrarater (intraclass correlation coefficient [ICC] = 0.93–0.95) and interrater (ICC = 0.90) assessments. Receiver operating characteristic curves determined the optimal bunion angle cutoff value for screening hallux valgus to be 9°, which gives 89.2% sensitivity and 74.2% specificity. Conclusions The bunion angle is a reliable, clinician-free method that can potentially be integrated into a smartphone app for easy and inexpensive self-assessment of hallux valgus.

In Vitro Evaluation of the Effect of Different Luting Cements and Tooth Preparation Angle on the Microleakage of Zirconia Crowns

Introduction. Discrepancy between the crown border and prepared tooth margin leads to a microleakage that eases the penetration of microorganisms and causes the dissolution of luting cement consequently. Several factors should be considered to achieve optimal fitness, including tooth preparation taper and type of cementing agent. The study aimed to determine the relation of tooth preparation taper and cement type on the microleakage of zirconia crowns. Materials and Methods. Fifty-six freshly extracted premolars without caries and restorations were selected as the study sample and divided into two groups of different tapering degrees (6 and 12 degrees). Zirconia copings were designed and fabricated by the CAD/CAM system. The samples were divided into four subgroups for cementation, and each subgroup was cemented with a different luting cement (n = 7). After 5000 thermocycles at 5°C–55°C and dye penetration, the specimens were sectioned in the mid-buccolingual direction, and a digital photograph of each section was taken under a stereomicroscope. Data were analyzed by the Kruskal–Wallis and Mann–Whitney tests (α = 0.05). Results. The results showed significant differences among the four types of luting cement in marginal permeability (PV < 0.001). Regardless of the type of cement, the 12-degree tapering resulted in a lower microleakage (46.4% without microleakage) with statistically significant differences from the 6-degree tapering (PV = 0.042). Conclusion. Within the limitations of this study, increasing the tapering degree of the prepared tooth for CAD/CAM zirconia copings improved the marginal fit and decreased the microleakage score. In addition, total-etch resin cement indicated the least microleakage.

Adapting to born-digital photographs: a case study of the Canadian Centre for Architecture

As born-digital photography collections grow, so grows the need for a more defined set of guidelines on the best practices of how to acquire, describe and preserve said photographs. This paper is the result of a practical project conducted at the Canadian Centre for Architecture. The project uses the CCA as a case study and asks the question: how is the Centre adapting to the collection of born-digital photographs? During a six-month residency, the author, developed and implemented a description guideline, workflow, and donor guideline for the collection and cataloguing of born-digital photographs. These guidelines are the result of the steady growth in the volume of born-digital photographs coupled with the need for ensuring long term preservation for existing and potential collections. The aim of this paper is to help improve the usefulness and clarity of the guidelines. The case study and paper was conducted in conjunction with the requirements of Film and Photography Preservation and Collections Management (FPPCM) master’s at Ryerson University. The title of the guideline is Guidelines for Describing Born-Digital Photograph.

Adapting to born-digital photographs: a case study of the Canadian Centre for Architecture

As born-digital photography collections grow, so grows the need for a more defined set of guidelines on the best practices of how to acquire, describe and preserve said photographs. This paper is the result of a practical project conducted at the Canadian Centre for Architecture. The project uses the CCA as a case study and asks the question: how is the Centre adapting to the collection of born-digital photographs? During a six-month residency, the author, developed and implemented a description guideline, workflow, and donor guideline for the collection and cataloguing of born-digital photographs. These guidelines are the result of the steady growth in the volume of born-digital photographs coupled with the need for ensuring long term preservation for existing and potential collections. The aim of this paper is to help improve the usefulness and clarity of the guidelines. The case study and paper was conducted in conjunction with the requirements of Film and Photography Preservation and Collections Management (FPPCM) master’s at Ryerson University. The title of the guideline is Guidelines for Describing Born-Digital Photograph.

Effects of deviations in the nose and chin prominence on facial attractiveness

Objective: To assess the effects of deviations in the nose and chin prominence on facial attractiveness. Methods: In this study, a reference digital photograph was taken from the facial profile view of an adult female model. Some changes were made in the nose and chin prominence in Photoshop software using the Crumley’s analysis. Changes made in the nose prominence yielded a prominent nose (2:11 ratio), a normal nose (3:53 ratio) and a small nose (4:61 ratio). Changes made in the chin prominence were protrusion by +2 and 0 mm and retrusion by −2, −4 and −6 mm (distance from the pogonion to the vertical reference line). In total, 18 orthodontists, 18 oral and maxillofacial surgeons, 18 art students and 18 laypeople evaluated the photographs (n = 15) and expressed their opinion regarding the facial profile attractiveness using a visual analogue scale (0−100). Data were analysed using SPSS version 18. Results: A significant difference was noted in the ratings of photographs (Greenhouse-Geisser, P < 0.001). Orthodontists gave a significantly higher score than laypeople to photographs with a small nose and deviations of the chin prominence ( P = 0.015). Art students gave a significantly higher score than laypeople to photographs with a prominent chin and deviations in the nose prominence ( P = 0.012). Conclusions: Facial profile with a normal (3:53 ratio) or small (4:61 ratio) nose and chin protrusion/retrusion by 2 mm (pogonion-vertical line) is considered attractive.

Evaluation of methods for experimental and analytical determination of the contour area of the contact patch of a pneumatic tire with a support base

Subject of study. The results of experiments on the estimation of the error of methods of experi-mental and calculated determination of the contour area for the ecological assessment of a mobile energy device (MED) are presented. There was used the example of modern radial tires 360 / 70R24 of Bel-89 and 18.4R34 of F-11 agricultural tractor MTZ-1025.2. in modes of non-nominal loading at nominal load on tires and changes in tire pressure within the range recommended for field work. The purpose of the study. To assess the possibility of improving the computational method for determining the contour area of the contact patch of the tire tread of a pneumatic wheel based on the mathematical model of V.L. Biederman. Materials and methods. The assessment was carried out for four ways of determining the area of the tire contact patch: 1) directly measuring the area using a digital photograph of the tire contact patch in Kompas-3D V13 software with the de-termination of the scaling and method error using a square from 100x100 mm graph paper; 2) calcu-lation by the formula of the area of an ellipse, using the length and width of the tire contact patch, measured with a tape measure directly from the obtained print; 3) by calculation, determined from the digital photograph in Kompas-3D V13 software; 4) by calculation, determined by calculation using the parameters of the universal tire characteristic (UTC). Results and discussion. As a result of the experiments, it was found that for modern radial tractor tires, the static deformation of which does not exceed 18-22%, the method of theoretical determination of the contour area of the tire contact patch using the UTC parameters can be applied with sufficient (for engineering practice) accuracy. Full convergence of the calculated and experimental contour areas of the tire contact patch can be provided by the coefficient of their ratio. Conclusions. The carried out assessment of the possibility of using methods for calculating the conditional contour area of the tire showed that these methods can be well used for a comparative assessment of the technogenic mechanical impact of propellers on the soil.