Modelling spatiotemporal trends in the frequency of genetic mutations conferring insecticide target-site resistance in African mosquito malaria vector species.

BACKGROUND: Resistance in malaria vectors to pyrethroids, the most widely used class of insecticides for malaria vector control, threatens the continued efficacy of vector control tools. Target-site resistance is an important genetic resistance mechanism caused by mutations in the voltage-gated sodium channel (Vgsc) gene that encodes the pyrethroid target-site. Understanding the geographic distribution of target-site resistance, and temporal trends across different vector species, can inform strategic deployment of vector control tools. RESULTS: We develop a Bayesian statistical spatiotemporal model to interpret species-specific trends in the frequency of the most common resistance mutations, Vgsc-995S and Vgsc-995F, in three major malaria vector species Anopheles gambiae, An. coluzzii, and An. arabiensis over the period 2005-2017. The models are informed by 2418 observations of the frequency of each mutation in field sampled mosquitoes collected from 27 countries spanning western and eastern regions of Africa. For nine selected countries, we develop annual predictive maps which reveal geographically structured patterns of spread of each mutation at regional and continental scales. The results show associations, as well as stark differences, in spread dynamics of the two mutations across the three vector species. The coverage of ITNs was an influential predictor of Vgsc allele frequencies, with modelled relationships between ITN coverage and allele frequencies varying across species and geographic regions. We found that our mapped Vgsc allele frequencies are a significant partial predictor of phenotypic resistance to the pyrethroid deltamethrin in An. gambiae complex populations. CONCLUSIONS: Our predictive maps show how spatiotemporal trends in insecticide target-site resistance mechanisms in African An. gambiae vary across individual vector species and geographic regions. Molecular surveillance of resistance mechanisms will help to predict resistance phenotypes and track their spread.

Indoor residual spraying for malaria control in sub-Saharan Africa 1997 to 2017: an adjusted retrospective analysis.

BACKGROUND: Indoor residual spraying (IRS) is a key tool for controlling and eliminating malaria by targeting vectors. To support the development of effective intervention strategies it is important to understand the impact of vector control tools on malaria incidence and on the spread of insecticide resistance. In 2006, the World Health Organization (WHO) stated that countries should report on coverage and impact of IRS, yet IRS coverage data are still sparse and unspecific. Here, the subnational coverage of IRS across sub-Saharan Africa for the four main insecticide classes from 1997 to 2017 were estimated. METHODS: Data on IRS deployment were collated from a variety of sources, including the President's Malaria Initiative spray reports and National Malaria Control Programme reports, for all 46 malaria-endemic countries in sub-Saharan Africa from 1997 to 2017. The data were mapped to the applicable administrative divisions and the proportion of households sprayed for each of the four main insecticide classes; carbamates, organochlorines, organophosphates and pyrethroids was calculated. RESULTS: The number of countries implementing IRS increased considerably over time, although the focal nature of deployment means the number of people protected remains low. From 1997 to 2010, DDT and pyrethroids were commonly used, then partly replaced by carbamates from 2011 and by organophosphates from 2013. IRS deployment since the publication of resistance management guidelines has typically avoided overlap between pyrethroid IRS and ITN use. However, annual rotations of insecticide classes with differing modes of action are not routinely used. CONCLUSION: This study highlights the gaps between policy and practice, emphasizing the continuing potential of IRS to drive resistance. The data presented here can improve studies on the impact of IRS on malaria incidence and help to guide future malaria control efforts.

Vulnerability to snakebite envenoming: a global mapping of hotspots.

BACKGROUND: Snakebite envenoming is a frequently overlooked cause of mortality and morbidity. Data for snake ecology and existing snakebite interventions are scarce, limiting accurate burden estimation initiatives. Low global awareness stunts new interventions, adequate health resources, and available health care. Therefore, we aimed to synthesise currently available data to identify the most vulnerable populations at risk of snakebite, and where additional data to manage this global problem are needed. METHODS: We assembled a list of snake species using WHO guidelines. Where relevant, we obtained expert opinion range (EOR) maps from WHO or the Clinical Toxinology Resources. We also obtained occurrence data for each snake species from a variety of websites, such as VertNet and iNaturalist, using the spocc R package (version 0.7.0). We removed duplicate occurrence data and categorised snakes into three groups: group A (no available EOR map or species occurrence records), group B (EOR map but <5 species occurrence records), and group C (EOR map and ≥5 species occurrence records). For group C species, we did a multivariate environmental similarity analysis using the 2008 WHO EOR maps and newly available evidence. Using these data and the EOR maps, we produced contemporary range maps for medically important venomous snake species at a 5 × 5 km resolution. We subsequently triangulated these data with three health system metrics (antivenom availability, accessibility to urban centres, and the Healthcare Access and Quality [HAQ] Index) to identify the populations most vulnerable to snakebite morbidity and mortality. FINDINGS: We provide a map showing the ranges of 278 snake species globally. Although about 6·85 billion people worldwide live within range of areas inhabited by snakes, about 146·70 million live within remote areas lacking quality health-care provisioning. Comparing opposite ends of the HAQ Index, 272·91 million individuals (65·25%) of the population within the lowest decile are at risk of exposure to any snake for which no effective therapy exists compared with 519·46 million individuals (27·79%) within the highest HAQ Index decile, showing a disproportionate coverage in reported antivenom availability. Antivenoms were available for 119 (43%) of 278 snake species evaluated by WHO, while globally 750·19 million (10·95%) of those living within snake ranges live more than 1 h from population centres. In total, we identify about 92·66 million people living within these vulnerable geographies, including many sub-Saharan countries, Indonesia, and other parts of southeast Asia. INTERPRETATION: Identifying exact populations vulnerable to the most severe outcomes of snakebite envenoming at a subnational level is important for prioritising new data collection and collation, reinforcing envenoming treatment, existing health-care systems, and deploying currently available and future interventions. These maps can guide future research efforts on snakebite envenoming from both ecological and public health perspectives and better target future estimates of the burden of this neglected tropical disease. FUNDING: Bill & Melinda Gates Foundation.

Are we gaining valid consent for dental extractions? A retrospective audit on restorability assessment at one dental institution.

Introduction This paper explores the widely relevant topic of obtaining valid consent in dental practice, focusing on assessing restorability of teeth planned for extraction. The General Dental Council stresses discussing treatment options, benefits and risks for informed decision-making. The study evaluates if pertinent factors, including tooth structure, endodontic status, periodontal health and patient considerations, are considered before consent.Aim To ensure restorability has been assessed and all options communicated with patients for completeness of the consent process before tooth extraction.Objective To assist clinicians in their systematic assessment of a tooth's restorability and provide a framework for contemporaneous documentation.Materials and methods A two-week retrospective audit of oral surgery outpatients at a dental hospital in London was conducted, analysing the frequency of restorability discussions and patient involvement in decision-making. A simplified restorability guide and educational interventions were introduced to target the set standard of 100% of consenting clinicians to discuss restorability with patients.Results Results from two audit cycles show a significant increase in documented restorability discussions and consideration of patient factors.Discussion The study recognised restorability assessment subjectivity, thus creating a simplified tool for clinicians. Patients may lack awareness of restorability options, consequences of edentulism, future costs and tooth replacement considerations, emphasising the importance of documented discussions.Conclusion Educational interventions and a simplified restorability guide proved beneficial and showed significant improvement in communication with patients regarding restorability and gaining valid consent. Further consideration should be given to barriers patients face when opting for tooth extraction of their restorable teeth, including discussions regarding long-term consequences.

Our experience of delivering Schwartz Rounds in a dental setting.

Schwartz Centre Rounds are designed to support staff to reflect on the social and emotional aspects of working in healthcare. Providing healthcare in highly pressurised environments is a common climate in which many healthcare professionals find themselves. To deliver the very best care to patients, both clinical and non-clinical members of the workforce need to be supported to reflect, share their experiences and have a safe space in which they can be heard safely. We share our reflections of piloting Schwartz Centre Rounds within a dental hospital setting.

Survival of immediate implants replacing traumatised teeth in the anterior maxilla.

Aim The provision of implants following traumatic dental injuries can hold many challenges, primarily in higher aesthetic regions. The purpose of this retrospective study was to assess the clinical outcomes of immediate implants placed in fresh extraction sites in the anterior maxilla following dental trauma.Materials and methods In total, 60 patients requiring teeth replacement with dental implants in the anterior maxilla were included in the study. Following a delayed loading protocol, the implants were restored with definitive single crowns or bridges. Implant and prosthetic survival, complications and periodontal health were recorded during follow-up.Results A total of 70 implants were placed in the anterior maxilla with three failures reported, resulting in an implant survival rate of 95.7% over a follow-up period of three years. No additional bone augmentation was undertaken and prosthetic survival recorded was 100%, with favourable periodontal outcomes achieved overall.Conclusion This study showed that implants immediately inserted into fresh extraction sites following dental trauma can constitute a predictable treatment strategy, presenting high implant survival rates over the follow-up period observed. Further well-designed controlled clinical trials are required to evaluate longer-term outcomes for this technique.

The use of three implants to support a fixed prosthesis in the management of the edentulous mandible: a systematic review.

BACKGROUND: Dental implants have been widely utilised as a treatment modality for prosthetic rehabilitation. The aim of this study was to evaluate the implant and prosthetic survival rate, changes in marginal bone level, and patient satisfaction outcomes with the use of three implants to support a fixed prosthesis in the edentulous mandible. METHODS: A comprehensive electronic search was performed in the MEDLINE, Embase and Cochrane databases to retrieve studies that met the selection criteria. Sixteen articles were selected which consisted of two randomised controlled trials, eight prospective cohort studies, five retrospective studies and one case series. RESULTS: A total of 2055 implants were placed in 685 patients with a mean age of 62.2 years. The mean cumulative implant survival rate was 96.2% over a mean follow-up period of 3.35 years. Mean marginal bone loss recorded was 1.25 mm and high patient satisfaction rates were reported across the studies. CONCLUSION: The use of three implants to support a fixed prosthesis appears to be a successful approach to restoring the edentulous mandible in the short-to-medium term. Further longitudinal comparative studies are required to support longer-term success, and to guide minimum implant dimension requirements for the technique.

The cost-effectiveness of supportive periodontal care for patients with chronic periodontitis.

OBJECTIVE: To systematically evaluate the evidence for effectiveness of supportive periodontal care (SPC) provided in specialist care and general practice for patients with chronic periodontitis; to construct a model for the cost effectiveness of SPC. SEARCH STRATEGY: Electronic database searches of MEDLINE, EMBASE and SCOPUS were performed with hand searching of relevant journals and Workshops of Periodontology. SELECTION CRITERIA: SPC for patients with chronic periodontitis, at least 12 months follow-up and clinical attachment level as a primary outcome. RESULTS: Three articles addressed the question (Nyman et al. 1975, Axelsson & Lindhe 1981, Cortellini et al. 1994): Deltas CAL for patients undergoing "specialist" SPC were 0.1 mm (2 years), 0.2 mm (6 years) and -0.01 mm (3 years) respectively. In generalist care the Deltas CAL during SPC were -2.2, -1.8 and -2.8 mm. Differences between specialist and generalist SPC were an extra 20.59 tooth years and 3.95 mm attachment loss for generalist SPC. Incremental cost-effectiveness ratios were an extra 288 euros for one tooth year or an extra 1503 euros/1 mm reduction in loss of attachment for SPC delivered in specialist care. CONCLUSION: SPC delivered in specialist as compared with general practice will result in greater stability of clinical attachment but this will be achieved at relatively greater cost.

Identifying criteria for diagnosis of post-traumatic pain and altered sensation of the maxillary and mandibular branches of the trigeminal nerve: a systematic review.

OBJECTIVE: The aim of the study was to systematically identify criteria used to diagnose patients with trigeminal nerve injury. STUDY DESIGN: A systematic review of the literature registered in the PROSPERO database. Inclusion criteria were patients diagnosed with nerve injury of the sensory divisions of the maxillary or mandibular branches of the trigeminal nerve, with reported tests and criteria used for diagnosis and persistent pain or unpleasant sensation associated with nerve injury. RESULTS: In total, 28 articles were included. Diagnostic tests included clinical neurosensory tests (89%), thermal quantitative sensory testing (QST; 25%), electromyography (7%), and patient interview (14%). Neuropathic pain was assessed by using the visual analogue scale (39%); patient use of neuropathic medication (7%); questionnaires, including McGill and PainDETECT (21%). Functional impact was assessed in 14% and psychological impact in 7% of articles. Methodology in performing clinical neurosensory tests, application of diagnostic terms and diagnostic grading of nerve injury was found to be inconsistent among the included articles, making direct comparison of results difficult. CONCLUSIONS: Recommendations for assessment and diagnosis of trigeminal nerve injury have been made based on the best available evidence from the review. There is an urgent requirement for a consensus in diagnostic criteria, criteria for assessment, and outcome reporting among stakeholder organizations to improve knowledge in this field.

Mandibular division trigeminal nerve injuries following primary endodontic treatment. A case series.

The aim of this study is to report a series of patients with mandibular division trigeminal nerve (V3 ) injuries secondary to endodontic treatment, evaluate presentation characteristics and identify prevention strategies. This article describes a retrospective review of patients referred to a tertiary clinic 2007-2015 with V3 injury following endodontic treatment. The sample included 12 male and 16 female patients with a mean age of 41.5 years. Sixteen cases presented following endodontic treatment of the first and second molar, premolar teeth in eight cases and canine in two cases. Fifteen patients reported immediate post-operative symptoms, in eleven cases there was a 24-48 h asymptomatic period. The average referral delay was 23.1 months. Twenty patients had permanent neuropathy. Four patients experienced resolution of symptoms within 8 weeks. V3 injury following endodontic treatment is rare but can result in permanent neuropathy and functional impairment. This can be avoided through comprehensive pre-operative radiographic examination, identification and referral of high-risk cases.

Chronic post-surgical pain following the placement of dental implants in the maxilla: A case series.

PURPOSE: To present ten cases of chronic post-surgical neuropathic pain (CPSP) arising after placement of maxillary dental implants, in order to raise awareness of this potential complication of treatment. MATERIALS AND METHODS: Data collected from the case notes of consecutive patients presenting to the orofacial pain clinic, with neuropathic pain arising after placement of maxillary dental implants. RESULTS: Nine out of 10 patients were female, with an average age 55.4 years. Six patients had a significant medical history (depression, peripheral neuropathic pain, irritable bowel syndrome and fibromyalgia). Six patients had single implants placed, four had multiple implants. Four patients experienced pain during implant placement. Onset of pain was immediate in nine patients. Pain intensity (visual analogue scale) ranged from 2 to 9 (average 5.6). Pain was constant in all patients. Exacerbating factors included stress, tiredness, low mood and cold weather. Implants were removed in two patients however pain did not resolve. Pain management was complex; including medication (anti-epileptics and tricyclic antidepressants), Botox injections and cognitive behavioural therapy, however pain did not completely resolve in nine cases. CONCLUSIONS: Persistent pain after dental implant placement may occur with no apparent organic cause and without any neurosensory deficits. Practitioners must be aware of chronic post-surgical neuropathic pain as a possible complication of implant placement, particularly in patients with a significant medical history. Consideration should be given as to whether these patients are suitable for implant rehabilitation. Patients reporting very severe and prolonged postoperative pain following implant surgery should be considered at risk of CPSP and referred to a specialist in orofacial pain.

Necrotising sialometaplasia in the floor of mouth.

INTRODUCTION: Necrotising sialometaplasia is a benign self-limiting inflammatory process which occurs in the salivary gland tissue. The condition is a diagnostic challenge mimicking malignancy both clinically and histopathologically. Commonly, it presents in the hard palate. CASE REPORT: Here, we report an unusual case in a 56-year-old man which presented in the floor of the mouth.

Screw-wire osteo-traction: an adjunctive or alternative method of anatomical reduction of multisegment midfacial fractures? A description of technique and prospective study of 40 patients.

Stable anatomical fracture reduction and segment control before miniplate fixation can be difficult to achieve in comminuted midfacial fractures. Fracture mobilization and reduction methods include Gillies elevation, malar hook, and Dingman elevators. No single method is used universally. Disadvantages include imprecise segment alignment and poor segment stability/control. We have employed screw-wire osteo-traction (SWOT) to address this problem. A literature review revealed two published reports. The aims were to evaluate the SWOT technique effectiveness as a fracture reduction method and to examine rates of revision fixation and plate removal. We recruited 40 consecutive patients requiring open reduction and internal fixation of multisegment midfacial fractures (2009-2012) and employed miniplate osteosynthesis in all patients. SWOT was used as a default reduction method in all patients. The rates of successful fracture reduction achieved by SWOT alone or in combination and of revision fixation and plate removal, were used as outcome indices of the reduction method effectiveness. The SWOT technique achieved satisfactory anatomical reduction in 27/40 patients when used alone. Other reduction methods were also used in 13/40 patients. No patient required revision fixation and three patients required late plate removal. SWOT can be used across the midface fracture pattern in conjunction with other methods or as a sole reduction method before miniplate fixation.