The DIAD Approach to Correlative Synchrotron X-ray Imaging and Diffraction Analysis of Human Enamel.

The Dual Imaging and Diffraction (DIAD) beamline at Diamond Light Source (Didcot, U.K.) implements a correlative approach to the dynamic study of materials based on concurrent analysis of identical sample locations using complementary X-ray modalities to reveal structural detail at various length scales.

Advanced Time-Stepping Interpretation of Fly-Scan Continuous Rotation Synchrotron Tomography of Dental Enamel Demineralization.

High-resolution spatial and temporal analysis and 3D visualization of time-dependent processes, such as human dental enamel acid demineralization, often present a challenging task. Overcoming this challenge often requires the development of special methods. Dental caries remains one of the most important oral diseases that involves the demineralization of hard dental tissues as a consequence of acid production by oral bacteria.

A novel method for the remote measurement of trismus in clinical trials using mobile phone cameras.

Objective: To evaluate the reliability and validity of a novel method for remotely measuring trismus.

Materials And Methods: We recruited 60 volunteers who took three types of photographs at a fixed restricted jaw position mimicking limited mouth opening, including one selfie and one portrait with or without a reference frame. Additionally, the interincisal distance and the width of the upper central incisors were measured with a ruler, as per common practice.

Multi-resolution Correlative Ultrastructural and Chemical Analysis of Carious Enamel by Scanning Microscopy and Tomographic Imaging.

Caries, a major global disease associated with dental enamel demineralization, remains insufficiently understood to devise effective prevention or minimally invasive treatment. Understanding the ultrastructural changes in enamel is hampered by a lack of nanoscale characterization of the chemical spatial distributions within the dental tissue. This leads to the requirement to develop techniques based on various characterization methods.

Time-Lapse In Situ 3D Imaging Analysis of Human Enamel Demineralisation Using X-ray Synchrotron Tomography.

Caries is a chronic disease that causes the alteration of the structure of dental tissues by acid dissolution (in enamel, dentine and cementum) and proteolytic degradation (dentine and cementum) and generates an important cost of care. There is a need to visualise and characterise the acid dissolution process on enamel due to its hierarchical structure leading to complex structural modifications. The process starts at the enamel surface and progresses into depth, which necessitates the study of the internal enamel structure.

Synchrotron X-ray Studies of the Structural and Functional Hierarchies in Mineralised Human Dental Enamel: A State-of-the-Art Review.

Hard dental tissues possess a complex hierarchical structure that is particularly evident in enamel, the most mineralised substance in the human body. Its complex and interlinked organisation at the Ångstrom (crystal lattice), nano-, micro-, and macro-scales is the result of evolutionary optimisation for mechanical and functional performance: hardness and stiffness, fracture toughness, thermal, and chemical resistance. Understanding the physical-chemical-structural relationships at each scale requires the application of appropriately sensitive and resolving probes.

The relationship between sphingosine-1-phosphate receptor 2 and epidermal growth factor in migration and invasion of oral squamous cell carcinoma.

Sphingosine-1-phosphate (S1P) is a lipid mediator and its binding to the S1P receptor 2 (S1PR2) is reported to regulate cytoskeletal organization. Epidermal growth factor (EGF) has been shown to induce migration and invasion in tumour cells. Since binding of S1P to S1PR2 and EGF to the EGF receptors exhibit some overlapping functionality, this study aimed to determine whether S1PR2 was involved in EGF-induced migration and invasion of oral squamous cell carcinoma (OSCC) lines and to identify any potential crosstalk between the two pathways.

Spatial distribution of CD34 protein in primordial odontogenic tumour, ameloblastic fibroma and the tooth germ.

Background: Primordial odontogenic tumour is a benign mixed neoplasm of recent description, which has histological similarities with other odontogenic tumours such as the ameloblastic fibroma. In this article, we investigate the architecture of the sub-epithelial layer of mesenchymal cells expressing the marker CD34 in primordial odontogenic tumour.

Objective: Analyse the spatial patterns of CD34 expression in primordial odontogenic tumour and compare them with those in ameloblastic fibroma and the normal tooth germ by means of objective imaging approaches, to better characterise these lesions.

A 3D Printed Device for Generation of Stratified Epithelia at the Air-Liquid Interface.

Air-liquid interface (ALI) cultures are used to produce stratified epithelial tissues , notably for the production of oral mucosal equivalents. Currently, there are few purpose-built devices, which aim to enhance the ease and reproducibility of generating such tissue. Most ALI cultures utilize stainless steel grids or cell culture inserts to elevate the matrix or scaffold to the surface of the culture media.

4D microstructural changes in dentinal tubules during acid demineralisation.

Objective: Dental erosion is a common oral condition caused by chronic exposure to acids from intrinsic/extrinsic sources. Repeated acid exposure can lead to the irreversible loss of dental hard tissues (enamel, dentine, cementum). Dentine can become exposed to acid following severe enamel erosion, crown fracture, or gingival recession.

Finite Element Modelling and Experimental Validation of the Enamel Demineralisation Process at the Rod Level.

In the past years, a significant amount of effort has been directed at the observation and characterisation of caries using experimental techniques. Nevertheless, relatively little progress has been made in numerical modelling of the underlying demineralisation process. The present study is the first attempt to provide a simplified calculation framework for the numerical simulation of the demineralisation process at the length scale of enamel rods and its validation by comparing the data with statistical analysis of experimental results.

Human papilloma virus detection in oropharyngeal carcinomas with in situ hybridisation using hand crafted morphological features and deep central attention residual networks.

Human Papilloma Virus (HPV) is a major risk factor for the development of oropharyngeal cancer. Automatic detection of HPV in digitized pathology tissues using in situ hybridisation (ISH) is a difficult task due to the variability and complexity of staining patterns as well as the presence of imaging and staining artefacts. This paper proposes an intelligent image analysis framework to determine HPV status in digitized samples of oropharyngeal cancer tissue micro-arrays (TMA).

Colour deconvolution: stain unmixing in histological imaging.

Motivation: Microscopy images of stained cells and tissues play a central role in most biomedical experiments and routine histopathology. Storing colour histological images digitally opens the possibility to process numerically colour distribution and intensity to extract quantitative data. Among those numerical procedures are colour deconvolution, which enable decomposing an RGB image into channels representing the optical absorbance and transmittance of the dyes when their RGB representation is known.

Acid-induced demineralisation of human enamel as a function of time and pH observed using X-ray and polarised light imaging.

Acid-induced enamel demineralisation affects many individuals either by exposure to acidic diets, acidic gas pollution (dental erosion) or to dental plaque acids (dental caries). This study aimed to develop in situ X-ray and light imaging methods to determine progression of enamel demineralisation and the dynamic relationship between acid pH and mineral density. Hourly digital microradiograph time-lapse sequences showed the depth of enamel demineralisation in 500 µm thick sections progressed with time from the surface towards the dentine following a power-law function, which was 21% faster than the lateral demineralisation progression after exposure for 85 h to lactic acid (10%, pH 2.

Structure-Function Correlative Microscopy of Peritubular and Intertubular Dentine.

Peritubular dentine (PTD) and intertubular dentine (ITD) were investigated by 3D correlative Focused Ion Beam (FIB)-Scanning Electron Microscopy (SEM)-Energy Dispersive Spectroscopy (EDS) tomography, tapping mode Atomic Force Microscopy (AFM) and scattering-type Scanning Near-Field Optical Microscopy (s-SNOM) mapping. The brighter appearance of PTD in 3D SEM-Backscattered-Electron (BSE) imaging mode and the corresponding higher grey value indicate a greater mineral concentration in PTD (~160) compared to ITD (~152). However, the 3D FIB-SEM-EDS reconstruction and high resolution, quantitative 2D map of the Ca/P ratio (~1.

In situ monitoring and analysis of enamel demineralisation using synchrotron X-ray scattering.

Unlabelled: Dental caries is one of the most common chronic diseases that affect human teeth. It often initiates in enamel, undermining its mechanical function and structural integrity. Little is known about the enamel demineralisation process caused by dental caries in terms of the microstructural changes and crystallography of the inorganic mineral phase.

Unsupervised morphological segmentation of tissue compartments in histopathological images.

Algorithmic segmentation of histologically relevant regions of tissues in digitized histopathological images is a critical step towards computer-assisted diagnosis and analysis. For example, automatic identification of epithelial and stromal tissues in images is important for spatial localisation and guidance in the analysis and characterisation of tumour micro-environment. Current segmentation approaches are based on supervised methods, which require extensive training data from high quality, manually annotated images.

Backscattered electron imaging and electron backscattered diffraction in the study of bacterial attachment to titanium alloy structure.

The application of secondary electron (SE) imaging, backscattered electron imaging (BSE) and electron backscattered diffraction (EBSD) was investigated in this work to study the bacterial adhesion and proliferation on a commercially pure titanium (cp Ti) and a Ti6Al4V alloy (Ti 64) with respect to substrate microstructure and chemical composition. Adherence of Gram-positive Staphylococcus epidermidis 11047 and Streptococcus sanguinis GW2, and Gram-negative Serratia sp. NCIMB 40259 and Escherichia coli 10418 was compared on cp Ti, Ti 64, pure aluminium (Al) and vanadium (V).

Nuclear morphometry and ploidy of normal and neoplastic haemocytes in mussels.

Haemic neoplasia (HN) in bivalves has been reported in association with mass mortality events in various species of molluscs. The aim of this work was to quantify the nuclear morphometry and DNA content of neoplastic cells of mussels Mytilus galloprovincialis affected by HN using nuclear densitometry in Feulgen-stained preparations. The results were also compared with a population of normal mussel haemocytes.

Morphological classification of odontogenic keratocysts using Bouligand-Minkowski fractal descriptors.

The Odontogenic keratocyst (OKC) is a cystic lesion of the jaws, which has high growth and recurrence rates compared to other cysts of the jaws (for instance, radicular cyst, which is the most common jaw cyst type). For this reason OKCs are considered by some to be benign neoplasms. There exist two sub-types of OKCs (sporadic and syndromic) and the ability to discriminate between these sub-types, as well as other jaw cysts, is an important task in terms of disease diagnosis and prognosis.

Understanding nature's residual strain engineering at the human dentine-enamel junction interface.

Unlabelled: Human dental tissue is a hydrated biological mineral composite. In terms of volume and mass, a human tooth mainly consists of dentine and enamel. Human dental tissues have a hierarchical structure and versatile mechanical properties.

Reconciling diverse mammalian pigmentation patterns with a fundamental mathematical model.

Bands of colour extending laterally from the dorsal to ventral trunk are a common feature of mouse chimeras. These stripes were originally taken as evidence of the directed dorsoventral migration of melanoblasts (the embryonic precursors of melanocytes) as they colonize the developing skin. Depigmented 'belly spots' in mice with mutations in the receptor tyrosine kinase Kit are thought to represent a failure of this colonization, either due to impaired migration or proliferation.

Fractal analysis of mucosal microvascular patterns in oral lichen planus: a preliminary study.

Objectives: The objective of this study was to assess local vascular architecture in atrophic-erosive oral lichen planus (OLP).

Materials And Methods: We investigated the capillary structure of the oral mucosa in 31 patients with OLP and 32 healthy controls. Capillaries images were captured in vivo through a capillaroscope.

Fistula incidence after primary cleft palate repair: a systematic review of the literature.

Background: The development of an oronasal fistula after primary cleft palate repair has a wide variation reported in the literature. The aim of this review is to identify the reported oronasal fistula incidence to provide a benchmark for surgical practice.

Methods: A systematic review was undertaken to investigate the incidence of fistula.

In situ X-ray scattering evaluation of heat-induced ultrastructural changes in dental tissues and synthetic hydroxyapatite.

Human dental tissues consist of inorganic constituents (mainly crystallites of hydroxyapatite, HAp) and organic matrix. In addition, synthetic HAp powders are frequently used in medical and chemical applications. Insights into the ultrastructural alterations of skeletal hard tissues exposed to thermal treatment are crucial for the estimation of temperature of exposure in forensic and archaeological studies.