Is there any association between fluoride exposure and thyroid function modulation? A systematic review.

Numerous pre-clinical and observational studies have explored the potential effects of fluoride (F) at varying concentrations on diverse systems and organs. While some have assessed the endocrinological conditions of children and adults, a consensus regarding the interaction between F and the thyroid remains elusive. This systematic review aimed to gather primary evidence on the association between F and changes in the thyroid at optimal and high levels in water supply as stipulated by the World Health Organization. A search strategy, incorporating terms pertinent to the studies, was employed across PubMed, Scopus, Web of Science, Lilacs, and Google Scholar. Following the review of studies, data were extracted and analyzed using the Grading of Recommendations, Assessment, Development, and Evaluations to assess the quality of the evidence. Our results yielded 3,568 studies, of which seven met the inclusion criteria for this review. Five of the seven studies identified an association between high F exposure and thyroid function. In the analysis of methodological quality, every study was found to have major or minor methodological issues and significant risk of bias. The overall confidence in the evidence was deemed low for all outcomes in the seven studies. The evidence compiled in this review suggests a potential association between chronic high levels of F exposure and thyroid damage. Nonetheless, further studies with robust design and high methodological quality are required to provide evidence for policy makers and health care practitioners.

Parental experiences in navigating health services for paediatric residual obstructive sleep apnoea: An exploratory qualitative descriptive study.

OBJECTIVES: To explore parents' experiences and perceptions regarding engagement in health services for managing residual paediatric obstructive sleep apnoea (OSA) across levels of care. METHODS: Qualitative description guided study design. Data were collected through semi-structured interviews with parents of children diagnosed with residual OSA at a university-based sleep clinic. The relevant literature informed the interview guide and was piloted before data collection. Inductive, manifest content analysis was used to describe parents' perceptions and experiences using data-driven categories and sub-categories. Several strategies were employed to ensure rigour in this study. RESULTS: Eight interviews were conducted. Parents' views were organized into five categories: awareness of the sleep issue, interaction with non-sleep specialists, interaction with sleep specialists, interaction with dental professionals, and further actions and support. Parents reported several engagement issues due to their interactions with different care providers. These issues included having to personally identify and raise the sleep problem, feeling that care providers did not take this problem seriously, waiting for an extended period to be referred for sleep services, and receiving conflicting or insufficient treatment recommendations. Overall, parents perceived that their actions and the services received across levels of care were not effective enough to address paediatric OSA. CONCLUSION: Based on this exploratory qualitative descriptive research, along with developing evidence-based clinical guidelines for paediatric OSA screening and management tailored to different levels of care, strategies intended to improve the engagement of patients and care providers in addressing paediatric OSA should be developed and empirically tested.

Changes in biomarkers levels from gingival crevicular fluid in pre- and postmenopausal women undergoing orthodontic treatment : A systematic review.

PURPOSE: This study aimed to verify whether there is a difference in biomarker levels in the gingival crevicular fluid between premenopausal and postmenopausal women undergoing orthodontic treatment. METHODS: As eligibility criteria, prospective or retrospective observational studies evaluating women undergoing orthodontic treatment (P), comparing postmenopausal (E) and premenopausal (C) women, and analyzing differences in gingival crevicular fluid biomarkers (O) were included. An electronic search was conducted in seven databases (PubMed, Scopus, Web of Science, LILACS, The Cochrane Library, Embase, and EBSCO: Dentistry & Oral Science) and one grey literature source (Google Scholar). All databases were searched from September 2022 to March 2023. After duplicate exclusion and data extraction, the Newcastle-Ottawa scale was applied to assess the quality and risk of bias, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool was used to verify the certainty of evidence. RESULTS: Three case-control studies that analyzed receptor activator of nuclear factor kappa­B ligand (RANKL), osteopontin (OPN), and interleukin (IL)-17A levels were included. One study reported a significant difference for RANKL and another for OPN levels. A third study reported that there was a higher expression of IL17­A in the postmenopausal group. However, the small number of articles limits our systematic review. The heterogeneity and imprecision in the study results cast doubt on the findings' internal validity. CONCLUSION: The studies reported alterations in biomarker levels but differed in their conclusions. Therefore, further studies must include other types of bone and inflammatory biomarkers in female patients who are pre- or postmenopausal and undergoing orthodontic treatment. REGISTRATION: The review was registered at the Open Science Framework ( https://doi.org/10.17605/OSF.IO/Q9YZ8 ).

Is there an association between periodontal disease and root caries? A systematic review and meta-analysis.

Some periodontal diseases can be associated with cariogenic bacterial growth due to various oral health imbalances. This fact may be linked to a greater development of root caries. Thus, this systematic review analyzed the evidence on the association between periodontal disease and root caries. An electronic search was performed in five databases (Cochrane Library, LILACS, MedLine via PubMed, Scopus, and Web of Science) and two additional sources (Google Scholar and Open Grey) to partially capture the grey literature. The PECO strategy was used to identify prospective or retrospective observational studies assessing root caries in patients with periodontal disease without language or year publication restrictions. Two reviewers extracted data and evaluated the individual risk of bias in the eligible studies. Random effects meta-analyses were performed to calculate the Odds Ratio (OR). The risk of bias was assessed by the NIH tool, and the certainty of evidence was classified according to the GRADE tool. There were 1,725 studies retrieved, of which four met the eligibility criteria. All of them were evaluated for the control statements for possible confounders, bias consideration, and confounding factors because they had multivariate analysis. Adults with periodontal disease had a greater chance of presenting root caries than adults without, with OR 1.38 [CI 1.25, 1.53]. The certainty of evidence was classified as very low. Within the limits presented in this review, there was an association between periodontal disease and root caries, highlighted in the qualitative synthesis and the meta-analysis results.

Periodontal disease and sports performance: a systematic review and meta-analysis.

This systematic review and meta-analysis aimed to assess the association between athletic performance and periodontal disease (PD). Observational studies published up to April 2022 were searched in online databases (PubMed, Scopus, Web of Science, The Cochrane Library, LILACS, OpenGrey, and Google Scholar). PECO statement focused on studies with professional athletes (Participants) with PD (Exposition) compared to those with healthy periodontium (Comparison) and its effects on sports performance (outcome). Searches were conducted according to the PRISMA guidelines (registration protocol: 10.17605/OSF.IO/7ADH6) and risk of bias evaluation according to the Joanna Briggs Institute checklist. A total of 793 references were retrieved, of which eight were considered eligible. Two studies did not show an association between clinical PD parameters and performance. A meta-analysis with 396 participants suggested a relationship between PD and self-reported reduction in sports performance (odds ratio [OR] = 1.55; 95% confidence interval [CI] 1.04-2.31; p = 0.03; I2 = 0%) with moderate quality of evidence accordingly GRADE analysis. Despite the differences in performance evaluations between studies, PD was associated with reduced self-reported sports performance. Additional studies assessing confounding factors and objective assessment of PD and performance are needed to clarify the real effect of both conditions.

Is obesity associated with taste alterations? a systematic review.

Background: Obesity is a growing chronic public health problem. The causes of obesity are varied, but food consumption decisions play an important role, especially decisions about what foods to eat and how much to consume. Food consumption decisions are driven, in part, by individual taste perceptions, a fact that can influence eating behavior and, therefore, body mass. Methodology: The searches were conducted in the electronic databases PubMed, Web of Science, Scopus, Lilacs, and the grey literature (Google Scholar and Open Grey). The acronym PECO will be used, covering studies with adult humans (P) who have obesity (E) compared to adult humans without obesity (C), having as an outcome the presence of taste alterations (O). After searching, duplicates were removed. The articles were first evaluated by title and abstract, following the inclusion and exclusion criteria; then, the papers were read in full. After the studies were selected, two reviewers extracted the data and assessed the individual risk of bias and control statements for possible confounders and bias consideration. The narrative GRADE system performed the methodological quality assessment using the New Castle Ottawa qualifier and analysis of certainty of evidence. Results: A total of 3782 records were identified from the database search, of these 19 were considered eligible. Forty percent of the eligible studies show that there was an association between obesity and different taste alterations for different flavors comparing with normal weights adults. In the methodological quality analysis of the nineteen studies, which assesses the risk of bias in the results, fifteen showed good methodological reliability, three showed fair methodological reliability, and one showed low methodological reliability. Conclusion: Despite methodological limitations, the results of the studies suggest the existence of a association between obesity and taste alterations, but further investigations with more sensitive methodologies are necessary to confirm this hypothesis. Systematic review registration: https://osf.io/9vg4h/, identifier 9vg4h.

PATIENT-REPORTED OUTCOMES WHILE MANAGING OBSTRUCTIVE SLEEP APNEA WITH ORAL APPLIANCES: A SCOPING REVIEW.

OBJECTIVE: This scoping review aims to describe dental treatment-related patient-reported outcomes (dPROs) while using oral appliances (OAs) to manage obstructive sleep apnea (OSA) in children and adults. METHODS: Available literature that assessed dPROs in children and adults with OSA managed through OAs. Any clinical studies were included without restrictions of year or country. The results were analyzed and reported using narrative text and tables accompanying a descriptive summary. RESULTS: The searches identified 1718 citations, and of these, forty-five studies were finally included. A total of 3498 adults were included in all 42 primary studies included in this review, in which all the studies presented adults as participants. The dPROs assessed were quality of life (QoL), reported side effects after OA usage, patient satisfaction, and experience with treatment, and subjective perception of occlusal changes after treatment. CONCLUSION: This scoping review suggests that dPROs are mostly investigated as a secondary outcome from major studies exploring the effects of OAs on OSA severity, and often, dPROs are not well discussed or displayed on their report. As no risk of bias or certainty level assessment was completed, findings need to be carefully considered. Although in general terms management with OAs among adults with OSA does not seem to be uncomfortable or causing major problems to their lives, some mild discomfort and endured occlusal disturbances was reported in some studies. QoL seems to improve but consistent agreement was elusive. Data does not include experiences among those that dropped OA use. No data seems to exist about dPROs in children.

Association between temporomandibular disorders and anxiety: A systematic review.

Temporomandibular Joint Dysfunction (TMD) is an umbrella term that includes musculoskeletal and neuromuscular conditions affecting the temporomandibular joint. The present systematic review aimed to verify whether there is a specific association between TMD and anxiety. The searches were carried out in electronic databases, including PubMed, Scopus, Web of Science, and LILACS, without restrictions on publication date and language. The acronym PECO was used, whose participants (P) were humans exposed to TMD (E), compared to participants without TMD (C) and the presence of anxiety as an outcome (O). After the search retrieval, the duplicates were removed, and the articles were evaluated by title and abstract, following our inclusion and exclusion criteria; then, the papers were read and thoroughly assessed. After selection, the methodological quality was performed using the Newcastle-Ottawa Scale (NOS) for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the level of evidence. A total of 710 studies were found, and 33 articles were considered eligible and were included for the qualitative synthesis and the level of evidence assessment. The studies confirmed the association between anxiety and DTM, although there was a low certainty of evidence among the selected studies. Most articles showed a low risk of bias. Although the limitations of this systematic review, it suggested a significant association between anxiety and TMD, as well as highlights possible directions for future research.

Are Dental Caries Associated with Oxidative Stress in Saliva in Children and Adolescents? A Systematic Review.

This systematic review aimed to assess whether dental caries is associated with oxidative salivary stress. The searches were carried out in electronic databases, including PubMed, Scopus, Web of Science, the Cochrane Library, LILACS, OpenGrey, and Google Scholar, without restrictions on the date of publication and language. The acronym PECO was used, in which the participants (P) were children and adolescents exposed (E) to dental caries compared (C) to those without dental caries, with the outcome (O) of modulation of oxidative biochemical parameters. After the search retrieval, the duplicates were removed, and the articles were evaluated by title and abstract, following the inclusion and exclusion criteria. Then, the papers were read and thoroughly assessed. After selection, the risk of bias assessment and qualitative synthesis were performed using the Newcastle-Ottawa Scale (NOS) for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the level of evidence. A total of 5790 studies were found, and 30 articles were considered eligible and were included for the qualitative synthesis and the level of evidence assessment. The studies showed an imbalance of the antioxidant and pro-oxidant parameters in individuals with dental caries, with primarily increases in both total antioxidant capacity and lipid peroxidation. Most articles showed a low risk of bias, having comparability as the main issue. When exploring through GRADE, a very low level of evidence was found. It was possible to observe an association between oxidative stress and dental caries, showing a disbalance of antioxidants and pro-oxidants, but the evidence level was still very low.

The Relationship between Exercise and Salivary Oxidative Stress: A Systematic Review.

Salivary content has been reported as a potential biomarker for oxidative stress assessments especially in context of exercise-induced oxidative stress. This systematic review following PRISMA guidelines aimed to evaluate the effects of physical exercise and changes promoted in oxidative stress identified in saliva. METHODS: Studies published up to May 2022 were searched in online databases (PubMed, Scopus, Web of Science, The Cochrane Library, LILACS, OpenGrey, and Google Scholar). Risk of bias evaluation were performed using the Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group. RESULTS: A total of 473 references were identified and 22 considered eligible. In this case 14 studies reported increase of antioxidant parameters in saliva while eight studies demonstrated increased lipid peroxidation after exercise. Regarding nitrite levels, two studies showed higher levels after exercise. The quality of evidence was very low due to high heterogeneity, inconsistency and indirectness among studies according Grading of Recommendations, Assessment, Development and Evaluation analysis. CONCLUSION: Increase of oxidative stress and antioxidant activity in saliva appears to be present after exercise, especially at moderate intensity. However, the wide variety of methods leads to divergent data. For precision in salivary assessments, new research with larger sample sizes and better participant matching are recommended.

Orthodontic interventions as a management option for children with residual obstructive sleep apnea: a cohort study protocol.

INTRODUCTION: Obstructive sleep apnoea (OSA) is a sleep-breathing disorder that seems likely to have long-term negative social and health consequences in children and adolescents. There are no established standard management approaches when the first line of therapy, the tonsillectomy and adenoidectomy (T&A), is not indicated or fails to address paediatric OSA (residual paediatric OSA). This protocol describes a prospective cohort study that aims to assess the effectiveness of orthodontic interventions for managing residual paediatric OSA in patients with concomitant craniofacial issues. METHODS AND ANALYSIS: Children aged 6-16 years who with an OSA diagnosis and did not benefit from previous T&A or qualified for T&A will be recruited. Orthodontic intervention(s), when adequately indicated (maxillary expansion, mandibular advancement or maxillary complex advancement with skeletal anchored headgear), and a control (orthodontic intervention declined) cohorts will be involved. A sample size of 70 participants (n=35 per cohort) is planned. Effectiveness data will be assessed through nocturnal polysomnography, a craniofacial index, sleep questionnaires and medical records. Additionally, the association of residual OSA and two comorbidities, obesity and asthma, will be investigated through assessing blood, urine and saliva metabolites. The changes on body mass index will also be investigated as a secondary outcome. Other additional outcomes, including association between residual paediatric OSA and periodic limbs movement, restless leg syndrome, insomnia, and the use of abiometric shirt to sleep monitoring purposes will also be considered. All participants will be followed up for 12 months after treatment allocation. The effectiveness of the intervention will be analysed by the assessment of sleep parameters, medical history (from medical chart reviews), questionnaire responses, craniofacial characteristics and metabolomic markers using an algorithm to be developed. ETHICS AND DISSEMINATION: This study was approved by the Health Research Ethics Board-Health Panel, University of Alberta, Edmonton, Canada (Pro00084763). The findings will be shared with scientific and patient content-specific social network communities to maximise their impact on clinical practice and future research in the study topic. TRIAL REGISTRATION NUMBER: NCT03821831; Pre-results.

Craniofacial features in children with obstructive sleep apnea: a systematic review and meta-analysis.

STUDY OBJECTIVES: This review aimed to evaluate the association between craniofacial features in children and adolescents with pediatric obstructive sleep apnea (OSA). METHODS: Seven databases were searched to fulfill our research objectives. Clinical studies that included participants younger than 18 years with fully diagnosed OSA or without OSA and that evaluated skeletal, soft craniofacial features, or dental arch morphology were considered for this review. The risk of bias and certainty of evidence were assessed. A meta-analysis was performed when low methodological and clinical heterogeneity were detected. This review followed the protocols recommended by the Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA-2020) guidelines. RESULTS: Nine studies were identified at the end of the selection process, from which 5 did not report differences. Four studies reported differences between craniofacial features when OSA was compared to an asymptomatic control group. Mandibular retrognathia, reduced anteroposterior linear dimensions of the bony nasopharynx (decreased pharyngeal diameters at the levels of the adenoids), longer facial profile, and a narrower intercanine width were described among children with OSA. A meta-analysis was performed considering the studies with a similar methodological approach, and no differences were observed in all the considered cephalometric angles (SNA, SNB, ANB, NSBa, U1-L1, U1-SN). All the included studies were considered at low risk of bias even though some limitations were noted. CONCLUSIONS: Due to the very low to moderate level of certainty, neither an association nor a lack thereof between craniofacial morphology and pediatric OSA can be supported by these data. CITATION: Fagundes NCF, Gianoni-Capenakas S, Heo G, Flores-Mir C. Craniofacial features in children with obstructive sleep apnea: a systematic review and meta-analysis. J Clin Sleep Med. 2022;18(7):1865-1875.

Association between respiratory diseases and molar-incisor hypomineralization: A systematic review and meta-analysis.

The molar-incisor permineralização (MIH) is a qualitative enamel developing abnormality involving the occlusal and/or incisal third of one or more molars or permanent incisors, caused by systemic factors. Several systemic disorders and environmental factors, such as respiratory diseases, have been reported as probable causes of MIH. Thus, this work aimed to evaluate whether respiratory diseases and MIH are associated. The searches were carried out in electronic databases, including PubMed, Scopus, Web of Science, the Cochrane Library, LILACS, OpenGrey, and Google Scholar. The acronym PECO was used, in which the P (population) was humans in permanent dentition stage; (E-exposure) molar-incisor hypomineralization; (C-comparison) reference population and (O - outcome) respiratory diseases. After the search retrieval, the duplicates were removed, and the articles were evaluated by title and abstract; then, the papers were read and thoroughly assessed. After selection, the risk of bias assessment was performed using the Newcastle-Ottawa Scale (NOS) for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the level of evidence. Three thousand six hundred and sixty six were found through the searches. After exclusion by duplicates, title, abstract, and full-reading, 13 articles remained. The articles included in this review evaluated the association of MIH with asthma, tonsilitis, pneumonia, and bronchitis. Most reports showed a low risk of bias. When exploring through GRADE, a very low level of evidence was found. We observed that the included studies showed that children with MIH had more respiratory diseases than the group that did not have MIH. Systematic review registration: https://osf.io/un76d.

Effects of oral appliances on serum cytokines in adults with obstructive sleep apnea: a systematic review.

PURPOSE: This review aimed to evaluate the effects of oral appliance (OA) therapy on serum inflammatory cytokines in adults diagnosed with obstructive sleep apnea (OSA). METHODS: Seven electronic databases and partial gray literature were searched without restrictions through March 2021. Articles evaluating the levels of serum inflammatory cytokines in patients with OSA after OA treatment were included. The risk of bias (RoB) was assessed using the before-and-after tool or RoB 2.0. The level of certainty was assessed using the GRADE tool. RESULTS: Five studies met the eligibility criteria. One was a randomized clinical trial (RCT), while four were non-randomized clinical trials (NRCTs). Among the studies, C-reactive protein (CRP), IL-6, IL-10, IL-1ß, and tumor necrosis factor α (TNF-α) were investigated. The RCT reported no significant differences in marker levels after 2 months of OA therapy, while the NRCTs showed improvement on CRP, TNF-α, and IL-1ß levels after longer follow-up periods. The RoB was evaluated as showing some concern in the RCT. Three NRCTs presented good RoB, and one showed a fair RoB. The level of certainty was graded as moderate quality for inflammatory marker levels assessed in the RCT The levels of certainty evaluated in NRCTs were classified as very low. CONCLUSIONS: Although limited, existing scientific evidence showed that OA therapy may improve serum cytokine levels in adults with OSA. However, short treatment periods are not effective in reducing markers of systemic inflammation which may require extended time and a decrease of in apneic events to improve.

Pediatric obstructive sleep apnea-Dental professionals can play a crucial role.

The significant contribution of dental professionals to the management of selected adult obstructive sleep apnea (OSA) cases is understood. Among children, it has also been suggested that dental professionals may also help screen and manage this morbidity in selected cases. It has also been noted that our understanding of pediatric OSA lags significantly behind adult OSA. During the screening process for potential pediatric OSA cases, dental professionals may be quite helpful as specific craniofacial abnormalities have been previously associated with pediatric OSA, including Class II malocclusion, vertical facial growth and maxillary transversal deficiency. As dental professionals assess children more frequently than physicians, they can help screen sleep-disordered breathing signs and symptoms using validated questionnaires. In more advanced cases, orthodontists may be leading contributors to the management of selected cases where a craniofacial involvement is suspected. Rapid maxillary expansion and mandibular or maxillary anterior repositioning devices have been proposed as managing alternatives. So far, there is no substantial evidence if these approaches can be adopted to treat OSA fully or if the reported OSA signs and symptoms improvements observed in a selected group of patients are stable long-term. Nevertheless, dentists and orthodontists' integration into a transdisciplinary team should be encouraged to play a significant role. This review discusses dentists or orthodontists' potential contribution to screen and manage selective pediatric OSA patients as part of a transdisciplinary team.

A systematic review and meta-analysis of the association between fluoride exposure and neurological disorders.

Different studies have suggested that fluoride is related to neurological disorders in children and adolescents, but clinical evidences of which neurological parameters associated to fluoride exposure are, in fact, still controversial. In this way, this systematic review and meta-analysis aimed to show if there is an association between fluoride exposure from different sources, doses and neurological disorders. Terms related to "Humans"; "Central nervous system"; "Fluorides"; and "Neurologic manifestations" were searched in a systematic way on PubMed, Scopus, Web of Science, Lilacs, Cochrane and Google Scholar. All studies performed on humans exposed to fluoride were included on the final assessment. A meta-analysis was then performed and the quality level of evidence was performed using the GRADE approach. Our search retrieved 4,024 studies, among which 27 fulfilled the eligibility criteria. The main source of fluoride was naturally fluoridated water. Twenty-six studies showed alterations related to Intelligence Quotient (IQ) while only one has evaluated headache, insomnia, lethargy, polydipsia and polyuria. Ten studies were included on the meta-analysis, which showed IQ impairment only for individuals under high fluoride exposure considering the World Health Organization criteria, without evidences of association between low levels and any neurological disorder. However, the high heterogeneity observed compromise the final conclusions obtained by the quantitative analyses regarding such high levels. Furthermore, this association was classified as very low-level evidence. At this time, the current evidence does not allow us to state that fluoride is associated with neurological damage, indicating the need for new epidemiological studies that could provide further evidences regarding this possible association.

Is There Any Association Between Chronic Periodontitis and Anxiety in Adults? A Systematic Review.

Periodontitis is a multifactorial disease triggered by dysbiotic biofilms, involving the host's immune response, systemic and behavioral factors, including psychosocial conditions. This systematic review aimed to investigate the possible association between periodontitis and anxiety in adults. Searches were performed in PubMed, Scopus, Web of Science, Lilacs, Cochrane, and OpenGrey databases, without language restrictions, considering studies in adults (P-Participants), with (E-Exposure) and without periodontitis (C- Comparison) in an outcome of association with anxiety (O-outcome). Methodological quality assessment was carried out using the Newcastle-Ottawa protocol for case-control and cross-sectional studies, followed by an analysis of the level of evidence using the GRADE tool. Metanalysis was not performed due to several differences in methods applied by authors in primary studies. Eleven observational studies were selected according to the inclusion criteria from the total of 6,380 studies retrieved from databases. Eight studies demonstrated higher anxiety levels in subjects with periodontitis, among which only one study presented a high risk of bias. The GRADE tool revealed a low level of evidence for the anxiety outcome measured by the State-Trait Anxiety Inventory (STAI), both for case-control and cross-sectional studies. However, since anxiety may affect the quality of life of many subjects, it reinforces the need for further studies that evaluate this association for more extended periods. Clinical Trial Registration:PROSPERO-CRD42020190445.

Is There Any Association Between Neurodegenerative Diseases and Periodontitis? A Systematic Review.

Background: Neurodegenerative diseases are a group of progressive disorders that affect the central nervous system (CNS) such as Alzheimer, Parkinson, and multiple sclerosis. Inflammation plays a critical role in the onset and progression of these injuries. Periodontitis is considered an inflammatory disease caused by oral biofilms around the tooth-supporting tissues, leading to a systemic and chronic inflammatory condition. Thus, this systematic review aimed to search for evidence in the association between neurodegenerative disorders and periodontitis. Methods: This systematic review was registered at International Prospective Register of Systematic Reviews (PROSPERO) under the code CRD 42016038327. The search strategy was performed in three electronic databases and one gray literature source-PubMed, Scopus, Web of Science, and OpenGrey, based on the PECO acronym: observational studies in humans (P) in which a neurodegenerative disease was present (E) or absent (C) to observe an association with periodontitis (O). The Fowkes and Fulton checklist was used to critically appraise the methodological quality and the risk of bias of individual studies. The quality of evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Results: From 534 articles found, 12 were included, of which eight were case-control, three were cross-sectional, and one was a cohort, giving a total of 3,460 participants. All the included studies reported an association between some neurodegenerative diseases and periodontitis and presented a low risk of bias. According to the GRADE approach, the level of evidence of probing pocket depth was considered very low due to the significant heterogeneity across the studies' upgrading imprecision and inconsistency. Conclusions: Although all the included studies in this review reported an association between neurodegenerative diseases and periodontitis, the level of evidence was classified to be very low, which suggests a cautious interpretation of the results.

Lead exposure and its association with neurological damage: systematic review and meta-analysis.

Lead (Pb) is one of the most toxic and abundant elements in the earth's crust, which is pointed out that the intoxication caused by it may damage biological systems. This systematic review with meta-analysis aimed to evaluate the association between Pb exposure and neurological damage. This work was executed according to PRISMA guidelines, and seven online databases were consulted. Based on the PECO strategy, studies presenting humans as participants (populations) exposed to Pb (exposure) compared to non-exposed to Pb (control) evaluating the neurological impairment (outcome) were included. The quality and risk of bias were verified by Fowkes and Fulton checklist. Two meta-analyses were conducted considering Digit Symbol and Profile Mood tests. The certainty of the evidence was evaluated with the GRADE tool. This review identified 2019 studies, of which 12 were eligible according to the inclusion criteria. Eight were considered with a low risk of bias. All the studies elected showed that exposure to Pb is associated with neurological damage, but the meta-analysis did not show any difference for the evaluated tests, and the certainty of the evidence was considered very low. Nevertheless, the included studies showed that Pb occupational exposure is associated with neurological damage, and the main parameters evaluated for possible neurological damage were related to mnemonic aspects, reaction time, intelligence, attention disorders, and mood changes. Thus, our results revealed that a definitive demonstration of an association of Pb and neurological changes in humans is still a pending issue. Future studies should take into consideration more confident methods to answer this question.

Association between Tooth Loss and Stroke: A Systematic Review.

This systematic review aims to evaluate the association between tooth loss and stroke. The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed. The PECO strategy was used to limit the eligibility criteria. The following databases were used on searches: PubMed, Scopus, Web of Science, The Cochrane Library, LILACS and OpenGrey. We included observational studies performed in adults (Population), in which patients with tooth loss (Exposition) and patients without tooth loss (Comparison) were observed to investigate the association between tooth loss and stroke (Outcome). After searches, the results were submitted to a selection process, followed by data extraction, quality assessment and risk of bias evaluation. The certainty of the evidence was evaluated through GRADE approach. A total of 925 potential studies were retrieved by the searches and 9 were included in this review. Seven of the included articles described an association between tooth loss and stroke. Low risk of bias and a low certainty of the evidence were identified to all studies. The certainty of the evidence may be associated with the observational nature of the included studies. Even though an association between tooth loss and stroke was suggested, the low strength of the current evidence indicated the need for further investigations with a better methodological design to conclude this question.