Objective: To investigate whether there is scientific evidence to support the hypothesis that the presence of orthodontic fixed appliances influences the oral microbiota. Methods: The search for articles was conducted in PubMed; ISI Web of Knowledge and Ovid databases, including articles published in English until May 17th, 2012. They should report human observational studies presenting the following keywords: "fixed orthodontic appliance" AND "microbiological colonization"; OR "periodontal pathogens"; OR "Streptococcus"; OR "Lactobacillus"; OR "Candida"; OR "Tannerella forsythia"; OR "Treponema denticola"; OR "Fusobacterium nucleatum"; OR "Actimomyces actinomycetemcomitans"; OR "Prevotella intermedia", OR "Prevotella nigrescens"; OR "Porphyromonas gingivalis". Articles were previously selected by title and Articles that met the inclusion criteria were analyzed and classified as having low, moderate or high methodology quality. A new detailed checklist for quality assessment was developed based on the information required for applicable data extraction for reviews. The study design, sample, follow-up period, collection and microbial analysis methods, statistical treatment, results and discussion were assessed. Results: The initial search retrieved 305 articles of which 33 articles were selected by title and After full-text reading, 8 articles met the inclusion criteria, out of which 4 articles were classified as having low and 4 as moderate methodological quality. The moderate methodological quality studies were included in the systematic review. Conclusions: The literature revealed moderate evidence that the presence of fixed appliances influences the quantity and quality of oral microbiota.

Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and has been considered a risk factor for periodontal disease. The aim of this systematic review and meta-analysis was to verify the scientific evidence for the association of periodontal attachment loss with low BMD in postmenopausal women. A systematic search of the literature was performed in databases until August 2016, in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Eligibility criteria included studies that compared clinical attachment loss (CAL) between postmenopausal women with low and normal BMD. Studies using similar methodology, with lower and higher risk of bias, were pooled into 3 different meta-analyses to compare CAL among women with normal BMD, osteoporosis, and osteopenia. In the first meta-analysis, mean CAL was compared among groups. In the other 2 meta-analyses, the mean percentages of sites with CAL ≥4 mm and ≥6 mm were respectively compared among groups. From 792 unique citations, 26 articles were selected for the qualitative synthesis. Eleven of the studies were appraised as presenting low risk of bias, and the association between low BMD and CAL was observed in 10 of these studies. Thirteen cross-sectional articles were included in the meta-analysis for osteoporosis and 9 in the osteopenia analysis. Women with low BMD presented greater mean CAL than those with normal BMD (osteoporosis = 0.34 mm [95% confidence interval (CI), 0.20–0.49], P < 0.001; osteopenia = 0.07 mm [95% CI, 0.01–0.13], P = 0.02). Only studies with lower risk of bias were available for the analysis of CAL severity. Women with low BMD presented more severe attachment loss, represented as mean percentage of sites with CAL ≥4 mm (osteoporosis = 3.04 [95% CI, 1.23–4.85], P = 0.001; osteopenia = 1.74 [95% CI, 0.36–3.12], P = 0.01) and CAL ≥6 mm (osteoporosis = 5.07 [95% CI, 2.74–7.40], P < 0.001). This systematic review and meta-analysis indicates that postmenopausal women with osteoporosis or osteopenia may exhibit greater CAL compared with women with normal BMD.