ARTICLE | doi:10.20944/preprints202010.0145.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Parkinson’s disease; Periodontitis; Periodontal disease; Mendelian Randomization; Bioinformatics; Oral Health
Online: 7 October 2020 (08:26:14 CEST)
Latest evidence revealed a possible association between Parkinson’s disease (PD) and periodontitis. We explored the causal relationship of this association through two-sample Mendelian randomization (MR) in European ancestry populations. To this end, we used openly accessible data of genome-wide association studies (GWAS) on PD and periodontitis. As instrumental variables for periodontitis, seventeen single-nucleotide polymorphisms (SNPs) from a GWAS of periodontitis (1817 periodontitis cases vs. 2215 controls) and forty-five SNPs from a GWAS of PD (20,184 cases and 397,324 controls). Eight non-overlapping SNPs of periodontitis from an additional GWAS assisted in the validation of association being studied. Multiple approaches of MR were carried-out. There was no evidence of genetic liability of periodontitis being associated with a higher risk of PD (B= -0.0003, Standard Error [SE] 0.0003, P = 0.26). The eight independent SNPs (B= -0.0000, SE 0.0001, P = 0.99) validated this outcome. We found no association of genetically primed PD towards periodontitis (B= -0.0001, SE 0.0001, P = 0.19). This MR study found no conclusive evidence to support a bidirectional causal genetic liability between PD and periodontitis. Further GWAS studies are needed to confirm the consistency of these results.
ARTICLE | doi:10.20944/preprints202009.0050.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Parkinson’s disease; Periodontitis; Periodontal disease; protein-protein network interaction; Bioinformatics
Online: 3 September 2020 (04:13:12 CEST)
Recent studies supported a clinical association between Parkinson’s Disease (PD) and periodontitis. Hence, investigating possible protein interactions between these two conditions is of interest. In this study, we conducted a protein-protein network interaction analysis with recognized genes encoding proteins for PD and periodontitis. Genes of interest were collected via GWAS database. Then, we conducted a protein interaction analysis using STRING database, with a highest confidence cut-off of 0.9. Our protein network casted a comprehensive analysis of potential protein-protein interactions between PD and periodontitis. This analysis may underpin valuable information for new candidate molecular mechanisms between PD and periodontitis and may serve new potential targets for research purposes. These results should be carefully interpreted giving the limitations of this approach.
ARTICLE | doi:10.20944/preprints201902.0169.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Tooth size; Tooth size discrepancy; Bolton ratios; Meta-analysis; Systematic review
Online: 18 February 2019 (17:17:20 CET)
Introduction: The purposes of this study were to seek for overall ratio (OR) and anterior ratio (AR) patients data in normal occlusion and Angle’s malocclusion studies, and to assess if such results support Bolton’s standards as general references. Methods: Pubmed, Medline, CENTRAL and Scholar databases were searched up to February 2018 (CRD42018088438). Gray literature was explored through OpenGray. Non-randomized clinical studies, published in English and assessing Bolton’s OR and AR in normal occlusion and Angle’s malocclusion groups (Class I, Class II, Class II division 1, Class 2 division 2, Class III) patients were included. OR and AR means and standard deviations (SD) were collected. Potential covariates (study design, publication year, country where the study was conducted, number of cases, gender, mesiodistal measurement method, and calibration method) were also extracted. The National Health Heart Lung, and Blood Institute’s Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies was used to assess each included studies quality. Pairwise Random-Effects and Multilevel Bayesian Network Meta-Analyses were used to synthesize available data. Results: Fifty-two observational studies were included (8872 participants; male/females 2674/3272; 16 studies lacked gender information). For normal occlusion, global pooled estimates for OR and AR means were 91.74% (95% CI: 91.37-92.10) and 78.24% (95% CI: 77.85-78.63), respectively. We could identify on Angle’s Class III patients meaningful OR and AR mean deviations from normal occlusion (0.89, 95% credible interval [CrI], 0.66-1.12, and 0.66, 95% CrI, 0.38-0.94, respectively), while on Class I patients we found a meaningful mean deviation from normal occlusion only for OR (0.25, 95% CrI, 0.03-0.47). Concerning gender impact, male patients presented higher OR (0.30, 95% CI 0.00-0.59) and AR (0.41, 95% CI 0.00-0.83) mean values than females in Class I. Conclusions: The results show that global pooled OR and AR mean values for normal occlusion patients are slightly above Bolton’s original values. Class I, for OR mean values, and Class III, for both OR and AR, are proportionally larger than normal occlusion patients. Gender had almost no impact on teeth mesiodistal proportion.
ARTICLE | doi:10.20944/preprints202101.0090.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: periodontal disease; periodontitis; early tooth loss; predictive model; risk factors; oral health; public health; epidemiology
Online: 5 January 2021 (13:03:13 CET)
The aim of this study was to develop and validate a predictive early tooth loss multivariable model for periodontitis patients before periodontal treatment. A total of 544 patients seeking periodontal care at a university dental hospital were enrolled in the study. Teeth extracted after periodontal diagnosis and due to periodontal reasons were recorded. Clinical and sociodemographic variables were analyzed, considering the risk of short-term tooth loss. This study followed the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) guidelines for development and validation, with two cohorts considered as follows: 455 patients in the development phase and 99 in the validation phase. As a result, it was possible to compute a predictive model based on tooth type and clinical attachment loss. The model explained 25.3% of the total variability and correctly ranked 98.9% of the cases. The final reduced model area under the curve (AUC) was 0.809 (95% Confidence Interval (95% CI): 0.629 - 0.989) for the validation sample and 0.920 (95% CI: 0.891 - 0.950) for the development cohort. The established model presented adequate prediction potential of early tooth loss due to periodontitis. This model may have clinical and epidemiologic relevance towards the prediction of tooth loss burden.
ARTICLE | doi:10.20944/preprints201902.0131.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Platelet-rich fibrin, A-PRF, Gingival graft harvesting, Healing, Periodontal plastic surgery
Online: 14 February 2019 (10:29:29 CET)
This study aimed to investigate the healing effect of advanced platelet-rich fibrin (A-PRF) clot membranes in the reduction of palatal wounds resulting from free gingival graft (FGG) harvesting, in the re-epithelization rate and in the pain experience after surgery. Twenty-five patients requiring soft tissue augmentation (gingival recession coverage or keratinized gingiva augmentation) participated in this prospective randomized clinical study. After FGG harvesting, the test group (n=14) received A-PRF clot membranes at the palatal wound and the control group (n=11) a gelatin sponge. Epithelialization rate of the palatal wound, wound healing area, correspondent percentage of reduction and post-surgical pain experience were assessed. The follow-up period was 90 days. There was a significantly higher reduction of the palatal wound area in the A-PRF group vs. the control group, at 7 (p<0.001), 14 (p=0.009) and 30 days (p<0.001) follow-up. The maximum difference between groups was attained at 30 days (91.5% for A-PRF vs. 59.0% for the control group). At 14 days a significant difference in the proportion of patients showing total epithelization was found: 64.3% for A-PRF vs. 9.1% for the control group (p=0.012). At 90 days, both groups showed total recovery. Overall, the control group experienced a higher level of pain and discomfort until the 14th day, being significantly higher on the second day (p=0.013). The results suggest that A-PRF membranes haste the healing process by promoting a greater reduction along the recovery period and an apparent less painful postoperative period.
ARTICLE | doi:10.20944/preprints202301.0301.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental caries; caries experience; epidemiology, prevalence; risk; public health
Online: 17 January 2023 (08:56:34 CET)
Oral health surveys are essential to assess the dental caries experience and to influence national policies. This retrospective cross-sectional study aims to analysis dental caries experience who sought dental treatment in a reference university dental hospital at the Lisbon Metropolitan Area between January 2016 and March 2020. Full-mouth examination, sociodemographic, behaviors and medical information were included. Descriptive analyses and logistic regression analysis were applied to ascertain risk indicators associated with dental caries experience. A final sample of 9,349 participants (5,592 females/3,757 males) were included, aged 18 to 99 years old. In this population, caries experience was 91.1%, higher in female participants. Age (OR= 1.01, 95% CI [1.00-1.02], occupation (OR= 2.94, 95% CI [2.37-3.65], OR= 3.35, 95% CI [2.40-4.67], OR= 2.55, 95% CI [1.66-3.91], for employed, unemployed and retired, respectively), overweight (OR= 1.52, 95% CI [1.18-1.96]), reporting to never visited a dentist (OR= 0.38, 95% CI [0.23-0.64] and self-reported week teeth status (OR= 2.14, 95% CI [1.40-3.28]) were identified as risk indicators for the presence of dental caries, according to adjusted multivariable logistic analyses. These results highlight a substantial rate of dental experience in a Portuguese cohort and will pave the way for future tailored oral public health programs in Portugal.
ARTICLE | doi:10.20944/preprints201902.0145.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: multilevel analysis; periodontal disease; nonsurgical periodontal therapy; risk factor; modelling; periodontal healing
Online: 18 February 2019 (07:31:01 CET)
This retrospective study aimed to investigate the effect of known risk factors on nonsurgical periodontal treatment (NSPT) response using a pocket depth fine-tuning multilevel linear model (MLM). Thirty-seven patients (24 males and 13 females) with moderate to severe chronic periodontitis were treated with nonsurgical periodontal therapy. Follow-up visits at 3, 6, and 12 months included measurement of several clinical periodontal parameters. Data were extracted from a database system. Probing depth (PD) and Clinical Attachment Loss (CAL) reductions after NSPT in an overall of 1416 initially affected sites (baseline PD ≥ 4 mm), distributed on 536 teeth, were analyzed against known risk factors at three hierarchical levels (patient, tooth and site). The variance component models fitted to assess the three-level variance of PD and CAL decrease for each post-treatment follow-up showed that all levels contributed significantly to the overall variance (P < 0.001). Patients that underwent NSPT and were continually monitored had very curative results. All three hierarchical levels included risk factors who had impact on the to influence the magnitude of PD and CAL reduction. Specifically, the tooth’s type, surfaces involved and teeth mobility site-level risk factors showed the highest influence on these reductions, being highly relevant factors for the NSPT success.
REVIEW | doi:10.20944/preprints202310.1771.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: forensic dentistry; age estimation; dental maturation; umbrella review
Online: 27 October 2023 (09:26:27 CEST)
Age estimation is an important tool when dealing with human remains or undocumented minors. Although the skull, the skeleton or the hand-wrist are used on age estimation as maturity indicators, they often present lack of good conditions for a correct identification or estimation. Few systematic reviews (SRs) have been recently published; therefore, this umbrella review critically assesses their level of evidence and provides a general comprehensive view. An electronic database search was conducted in four databases (PubMed, Cochrane, WoS, LILACS) up to December 2022, focusing on SRs of age estimation through forensic dentistry procedures. The methodological quality was analyzed using the measurement tool to assess SRs criteria (AMSTAR2). Eighteen SRs were included, five of critically low quality, six of low quality, three of moderate quality and four of high quality. The SRs posited that Willems’ method is more accurate and less prone to overestimation; most methods seem to be geographically sensitive; and 3D-Imaging and artificial intelligence tools demonstrate high potential. The quality of evidence on age estimation using dental approaches was rated as low to moderate. Well-designed clinical trials and high standard systematic reviews are essential to corroborate the accuracy of the different procedures of age estimation in forensic dentistry.
ARTICLE | doi:10.20944/preprints202102.0062.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Stroke; Periodontitis; Periodontal disease; protein-protein network interaction; Bioinformatics
Online: 1 February 2021 (16:45:13 CET)
The clinical interaction between stroke and periodontitis has been consistently studied and confirmed. Hence, forecasting potentially new protein interactions in this association using bioinformatic strategies presents potential interest. In this exploratory study, we conducted a protein-protein network interaction (PPI) search with documented encoded proteins for both stroke and periodontitis. Genes of interest were collected via GWAS database. The STRING database was used to predict the PPI networks, first in a sensitivity purpose (confidence cut-off of 0.7), and then with a highest confidence cut-off (0.9). Genes over-representation was inspected in the final network. As a result, we foresee a prospective protein network of interaction between stroke and periodontitis. Inflammation, pro-coagulant/pro-thrombotic state and ultimately atheroma plaque rupture is the main biological mechanism derived from the network. These pilot results may pave the way to future molecular and therapeutic studies to further comprehend the mechanisms between these two conditions.
REVIEW | doi:10.20944/preprints202008.0557.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: transplantation; dental implant; marginal bone loss; implant failure rate; systematic review; periodontitis; periodontal diseases; oral health
Online: 25 August 2020 (13:45:34 CEST)
This systematic review investigates the failure rate and marginal bone loss (MBL) of dental implants placed in Solid-organ transplant (SOT) patients compared to healthy controls. Three databases (PubMed, Web of Sciences and the Cochrane Library) were searched up to June 2020 (PROSPERO CRD42019124896). Case-control and cohort studies reporting data failure rate and marginal bone loss (MBL) of dental implants placed in SOT patients were included. The risk of bias of observational studies was assessed through the Newcastle-Ottawa Scale (NOS). Four case-control studies fulfilled the inclusion criteria, all of low risk of bias. Meta-analyses revealed consistently lower implant failure rate than control populations at patient and implant levels. SOT patients had a significant difference of -18% (p-value <0.001) of MLB towards healthy patients. SOT status poses no serious threat to implant survival. Overall, this group of patients presented lower levels of dental implant failure rate and marginal bone loss compared to otherwise healthy patients. Further intervention trials with wider sample size and longer follow-ups are necessary to confirm these summary results.
ARTICLE | doi:10.20944/preprints202011.0455.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: NHANES; periodontal diseases; periodontitis; tooth loss; inflammation; diet; nutrition; oral health
Online: 17 November 2020 (14:44:20 CET)
Background: We aimed to assess the association between DII and PD and the mediation effect of DII in the association of PD with systemic inflammation. Using the National Health and Nutrition Examination Survey (NHANES) 2009-2010, 2011-2012 and 2013-2014, participants that received periodontal exam and provided dietary recall data were included. The inflammatory potential of diet was calculated via DII. Periodontitis was defined according to the 2012 case definition. The clinical outcomes of interest were mean periodontal probing (PPD), mean clinical attachment loss (CAL) and thresholds of PPD and CAL. White blood cells (WBC), segmented neutrophils and C-reactive protein (CRP) were used as proxies for systemic inflammation. The periodontal measures were regressed across DII values using adjusted multivariate linear regression. Adjusted mediation analysis appraised the influence of DII in the association of periodontitis and systemic inflammation. 10,178 participants were included. DII was significantly correlated with mean PPD, mean CAL, thresholds of PPD and CAL, WBC, segmented neutrophils and DII (p<0.01). A linear regression logistic adjusted for multiple confounding variables confirmed the association between DII and mean PPD (B = 0.02, Standard Error [SE]: 0.02, p<0.001) and CAL (B = -0.02, SE: 0.01, p<0.001). The association of mean PPD and mean CAL with both white blood cells and segmented neutrophils were mediated by DII (from 2.1 to 3.5%, p<0.001). In the 2009-2010 subset, the association of mean CAL with serum CRP was mediated by DII (52.0%, p<0.01). In conclusion, inflammatory diet and PD may be associated. Also, the inflammatory diet significantly mediated the association of leukocyte counts and systemic inflammation with periodontitis.
ARTICLE | doi:10.20944/preprints201902.0123.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Medical Illiteracy, Public Awareness, Periodontal Diseases, Global Burden of Disease, Google Trends
Online: 13 February 2019 (15:54:04 CET)
Background: The progression of periodontal diseases at national Portuguese level and its public awareness are of great interest, mainly due to the high burden of periodontitis. Objectives: To evaluate the prevalence progression of periodontal diseases in Portugal and correspondent public awareness, between 2004 and 2017, by using data from the Global Burden of Disease (GBD), Directorate-General of Health (DGH) and Google® Trends (GT). Methods: For the period 2004-2017, Portuguese national data of periodontal diseases prevalence were searched in the Institute for Health Metrics and Evaluation of GBD and DGH and for public awareness, GT comparison tool between Portuguese words for “Periodontitis”, “Gingivitis”, “Gums” and “Periodontal disease” trends was used. Results: For the period 2004-2017, the overall prevalence of periodontitis slightly increased from 11.3% to 11.7%. During that period the GT search term “Gums” (“Gengivas”) was the most relevant. It increased steadily over time while the search term “Periodontal disease” (“Doença periodontal”) decreased, being these search trends significantly correlated (