High resolution 16S rRNA gene Next Generation Sequencing study of brain areas associated with Alzheimer's and Parkinson's disease.

Introduction: Alzheimer's (AD) and Parkinson's disease (PD) are neurodegenerative conditions characterized by incremental deposition of ß-amyloid (Aß) and α-synuclein in AD and PD brain, respectively, in relatively conserved patterns. Both are associated with neuroinflammation, with a proposed microbial component for disease initiation and/or progression. Notably, Aß and α-synuclein have been shown to possess antimicrobial properties. There is evidence for bacterial presence within the brain, including the oral pathobiont Porphyromonas gingivalis, with cognitive impairment and brain pathology being linked to periodontal (gum) disease and gut dysbiosis. Methods: Here, we use high resolution 16S rRNA PCR-based Next Generation Sequencing (16SNGS) to characterize bacterial composition in brain areas associated with the early, intermediate and late-stage of the diseases. Results and discussion: This study reveals the widespread presence of bacteria in areas of the brain associated with AD and PD pathology, with distinctly different bacterial profiles in blood and brain. Brain area profiles were overall somewhat similar, predominantly oral, with some bacteria subgingival and oronasal in origin, and relatively comparable profiles in AD and PD brain. However, brain areas associated with early disease development, such as the locus coeruleus, were substantially different in bacterial DNA content compared to areas affected later in disease etiology.

Comparison of Blood Bacterial Communities in Periodontal Health and Periodontal Disease.

The use of Next Generation Sequencing (NGS) techniques has generated a wide variety of blood microbiome data. Due to the large variation in bacterial DNA profiles between studies and the likely high concentrations of cell-free bacterial DNA in the blood, it is still not clear how such microbiome data relates to viable microbiota. For these reasons much remains to be understood about the true nature of any possible healthy blood microbiota and of bacteraemic events associated with disease. The gut, reproductive tracts, skin, and oral cavity are all likely sources of blood-borne bacteria. Oral bacteria, especially those associated with periodontal diseases, are also commonly associated with cardiovascular diseases such as infective endocarditis, and also have been linked to rheumatoid arthritis and Alzheimer's disease. Periodontal treatment, dental probing, and toothbrushing have been shown to cause transient bacteraemia and oral bacteria from the phyla Firmicutes (e.g. Streptococci) and Bacteroidetes (e.g. Porphyromonas) are found in cardiovascular lesions (CVD). Many studies of blood bacterial DNA content however, find Proteobacteria DNA to be the dominant microbiome component, suggesting a gut origin. Most studies of this type use total DNA extracted from either whole blood or blood fractions, such as buffy coat. Here, using a method that purifies DNA from intact bacterial cells only, we examined blood donated by those with active, severe periodontitis and periodontally healthy controls and show that 43-52% of bacterial species in blood are classified as oral. Firmicutes, consisting largely of members of the Streptococcus mitis group and Staphylococcus epidermidis, were predominant at 63.5% of all bacterial sequences detected in periodontal health and, little changed at 66.7% in periodontitis. Compared to studies using total DNA Proteobacteria were found here at relatively low levels in blood at 13.3% in periodontitis and 17.6% in health. This study reveals significant phylogenetic differences in blood bacterial population profiles when comparing periodontal health to periodontal disease cohorts.

Dementia friendly dentistry for the periodontal patient. Part 1: recognising and assessing patients with dementia.

This is the first of two articles that provide a guide for the clinical management for people with dementia who present with periodontal disease in dental practice. Conditions that cause dementia and their increasing prevalence are described. Advice is given to aid the dental team in recognising patients with dementia. The impact that dementia and the medications used in its medical management have on the oral environment are also covered. The complexities of completing an accurate periodontal assessment for those with dementia are discussed and indications for best practice provided. Although both articles (Part 1 and Part 2) centre on periodontal care, much of the content is equally applicable to wider general dental care for the dementia patient.

Dementia friendly dentistry for the periodontal patient. Part 2: ethical treatment planning and management.

This is the second of two articles, which provide a guide to aid the clinical management of people living with dementia who present with periodontitis in dental practice. Guidance is provided to encourage optimal treatment planning and periodontal care for patients with dementia. Best practice in relation to UK statutory legislation, which governs the rights of those with impaired capacity, is also covered. Although the articles centre on periodontal care, much of the content is equally applicable to the wider general dental care for the dementia patient.

The Efficacy of Plasma Rich in Growth Factors for the Treatment of Alveolar Osteitis: A Randomized Controlled Trial.

PURPOSE: To investigate the efficacy of plasma rich in growth factors (PRGF; BTI Biotechnology Institute, San Antonio, Spain) for the treatment of alveolar osteitis compared with a positive control (Alvogyl; Septodont, Maidstone, Kent, UK). MATERIALS AND METHODS: This single-center, single-blinded, randomized, 2-treatment, parallel study was conducted in a UK dental hospital. All healthy adults who presented with alveolar osteitis after tooth extraction over a 3-month period were invited to participate. Each socket was randomized and treated with 1 of 2 treatment modalities, a test treatment (PRGF) or a positive control (Alvogyl). After treatment, patients were reviewed at 3 and 7 days by a second clinician blinded to the treatment given. Outcome measures included pain, exposed bone, inflammation, halitosis, dysgeusia, and quality-of-life assessment. RESULTS: Thirty-eight patients with data from 44 sockets (22 in the PRGF group and 22 in the Alvogyl group) were analyzed. The PRGF group showed significantly faster bone coverage and significantly decreased inflammation and halitosis (P < .05) compared with the control group receiving Alvogyl. There was no significant difference for pain, quality-of-life measures, or dysgeusia between groups. CONCLUSION: PRGF predictably treated alveolar osteitis after tooth extraction compared with the conventional standard treatment of Alvogyl, which has been used for many years. PRGF could be considered an alternative treatment for alveolar osteitis and indeed appears to have considerable advantages over Alvogyl.

16S rRNA Next Generation Sequencing Analysis Shows Bacteria in Alzheimer's Post-Mortem Brain.

The neurological deterioration associated with Alzheimer's disease (AD), involving accumulation of amyloid-beta peptides and neurofibrillary tangles, is associated with evident neuroinflammation. This is now seen to be a significant contributor to pathology. Recently the tenet of the privileged status of the brain, regarding microbial compromise, has been questioned, particularly in terms of neurodegenerative diseases. It is now being considered that microbiological incursion into the central nervous system could be either an initiator or significant contributor to these. This is a novel study using 16S ribosomal gene-specific Next generation sequencing (NGS) of extracted brain tissue. A comparison was made of the bacterial species content of both frozen and formaldehyde fixed sections of a small cohort of Alzheimer-affected cases with those of cognitively unimpaired (normal). Our findings suggest an increase in bacterial populations in Alzheimer brain tissue compared with normal.

Morphometric analyses of the mandible in prepubertal craniofacial microsomia patients treated with an inverted-L osteotomy.

To analyze changes in mandibular form associated with an inverted-L osteotomy and autogenous bone graft, preoperative, early postoperative (EPO), and late postoperative (LPO) lateral cephalographs of 14 children (mean age approximately 9 years) with unilateral craniofacial microsomia (CFM) were scanned and nine mandibular landmarks digitized. Average mandibular geometries, scaled to an equivalent size, were generated using Procrustes superimposition. Cephalometry, Euclidean distance matrix analysis (EDMA), and thin-plate spline (TPS) analyses were carried out on mean mandibular configurations. Cephalometric results showed increases in oblique mandibular length (approximately 9% on average, P < 0.05) and increased ramus height (P < 0.05). Similarly, using EDMA there were also significant differences (P < 0.05) between the mean preoperative, EPO, and LPO configurations. The most demonstrable EPO change in the mandibular configuration using EDMA was increased oblique length (approximately 11%). This improvement depended on ramus oblique lengths increasing by approximately 26%, ramus height increasing by approximately 25%, and mandibular body length increasing by approximately 5%. For TPS analysis, affine and nonaffine changes contributed to the total spline. In all three comparisons the affine transformation showed an antero-inferior rotation of the mandibular configuration. For nonaffine changes the EPO configuration indicated a supero-inferior stretch of the mandibular configuration. The nonaffine LPO changes maintained the supero-inferior stretch of the mandibular configuration. It is concluded that improvements in the lateral facial profile of CFM patients can be achieved using an inverted-L osteotomy, with little relapse approximately 2 years postoperatively.