Observational study investigating tooth extraction and the shortened dental arch approach

The shortened dental arch (SDA ) provides a cost‐effective dentition, considering the population is ageing and retaining teeth for longer. The aims were to observe the reasons and sites of tooth extraction and assess the functional dentition over 15 years in dental practice. Subjects were recruited who required permanent tooth extractions between 2000 and 2015. The reasons for extractions were chosen from twelve extraction codes. Data were also collected for demographics, tooth position, root treated teeth and functional pairs remaining. Patient‐centred factors on reasons for tooth extraction and comments on chewing ability and aesthetics following extractions were recorded. Nine hundred and fifty‐one teeth were extracted in 900 patients. The mean age was 60 years (SD 20, SE 7, 95% CI 46, 74). Reasons for extraction were periodontal disease (n = 361, 38%), periapical infection (n = 288, 34%) or tooth and tooth‐root fractures (15%). Extractions included 201 (21%) second molars, 179 (19%) first molars, 152 (16%) second premolars, 95 (10%) first incisors, 86 (9%) second incisors, 76 (8%) canines and 67 (7%) first premolars. Following extractions, median functional pairs were 12, interquartile range (IQR ) 19–7. Individuals with ≥10 functional pairs including anterior teeth (60%, n = 571) had no complaints with chewing ability or aesthetics. They did not require additional prostheses. Periodontal disease and periapical infection were the main causes for the extraction. First and second molars followed by second premolars were the most commonly extracted teeth. This study supports the SDA in creating a cost effective, functional dentition in an aging population, provided remaining teeth and restorations are preserved/maintained, oral health is promoted, and anterior aesthetic tooth replacement is ensured

Social Class

Discussion of class structure in fifth-century Athens, historical constitution of theater audiences, and the changes in the comic representation of class antagonism from Aristophanes to Menander

Novel Anti-Infective Compounds from Marine Bacteria

As a result of the continuous evolution of microbial pathogens towards antibiotic-resistance, there have been demands for the development of new and effective antimicrobial compounds. Since the 1960s, the scientific literature has accumulated many publications about novel pharmaceutical compounds produced by a diverse range of marine bacteria. Indeed, marine micro-organisms continue to be a productive and successful focus for natural products research, with many newly isolated compounds possessing potentially valuable pharmacological activities. In this regard, the marine environment will undoubtedly prove to be an increasingly important source of novel antimicrobial metabolites, and selective or targeted approaches are already enabling the recovery of a significant number of antibiotic-producing micro-organisms. The aim of this review is to consider advances made in the discovery of new secondary metabolites derived from marine bacteria, and in particular those effective against the so called “superbugs”, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE), which are largely responsible for the increase in numbers of hospital acquired, i.e., nosocomial, infections

The Looe, south Devon and Tavy Basins : the Devonian rifted passive margin successions

The majority of ‘Marine Devonian’ GCR sites are located on the Early to Latest Devonian rocks of central and north Cornwall and south Devon, within the successions of the east–west Looe, South Devon and Tavy basins, their sub-basins and associated highs. This half-graben and full graben complex developed sequentially northwards during the Devonian period by rifting of the Rhenohercynian passive margin. Basin formation and development was initiated in a terrestrial setting, but from the late Early Devonian marine environments prevailed. Each basin and high had its own stratigraphical succession, and there is variation between those of composite sub-basins. From Mid-Devonian times basins were characterised by hemipelagic deposits with turbid flow incursions of predominantly fine-grained northerly derived terrigenous clastics, and the highs developed carbonate platforms with reefs that persisted into the Late Devonian. Associated alkaline basaltic rocks are typical of the continental rifting regime with high extension. The complex basin and high architecture directly determined major structures, folds and thrusts, developed during regional contraction, and review of those structures permits placement of the sites in that structural context. Thirty eight GCR site reports in this chapter are grouped to describe the stratigraphical successions of named basins and highs from south to north through the sub-province. The oldest deposits are in the south, with basins developing later to the north, but there are differing coeval basin and high successions that extend up to the Latest Devonian through the belt. Amongst the sites there are those that provided definitive descriptions of limestone reefs and their changes in time and space through their acme in the Mid-Devonian, and others that are significant for their fossils, such as the ammonoids, corals or conodonts, which fostered classic studies internationally important in Devonian stratigraphy. Together they describe the variety of stratigraphical sequences and their evolution, environmental, sedimentological and palaeontological, in this major setting of the marine Devonian of Britain