ObjectiveTo investigate whether there is scientific evidence to support the hypothesis that the presence of orthodontic fixed appliances influences the oral microbiota.MethodsThe 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 abstract. 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.ResultsThe initial search retrieved 305 articles of which 33 articles were selected by title and abstract. 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.ConclusionsThe literature revealed moderate evidence that the presence of fixed appliances influences the quantity and quality of oral microbiota.

Peri-implant inflammation contributes for loss of secondary stability of orthodontic mini-implants. The investigation of microbial colonization in this area would benefit its control, and consequently favor the long-term success of mini-implants. Therefore, the aim of this study was to determine the establishment and the evolution of microbial colonization process in orthodontic mini-implants for 3 months, since the time of their installation. One-hundred and fifty samples collected from 15 mini-implants were investigated from baseline up to 3 months. The biological material was obtained from peri-implant area using paper points. Nonspecific, Streptococcus spp, Lactobacillus casei and Candida spp colonizations were analyzed by cell growth methods. Porphyromonas gingivalis colonization was observed by 16S rDNA-directed polymerase chain reaction. Data from cell growth were submitted to the Wilcoxon sign rank test and results from molecular analysis were presented in a descriptive way. There was no significant difference in the microbial colonization among the examined time intervals, except for Streptococcus spp, between baseline and 24 h, which characterized the initial colonization in this time interval. Lactobacillus casei and Candida spp colonizations were insignificant. No Porphyromonas gingivalis was detected among the analyzed samples. The microbial colonization of mini-implants did not significantly change during the study. However, it should be monitored by orthodontists, since it is an important factor for mini-implants success.

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The aim of this study was to measure the thickness of the hard palate and its overlying mucosa using cone-beam computed tomography (CBCT), for purposes of miniscrew placement. The sample comprised 36 CBCT scans of patients aged 12 to 52 years from a database of the Orthodontics Department of the Federal University of Rio de Janeiro. Paracoronal views of the palatal region were reconstructed at 4, 8, 16 and 24 mm posterior to the incisive foramen. In each reconstruction measurements were taken at the suture, 3 mm and 6 mm bilaterally to it. Wilcoxon's test verified the differences between the selected regions. Total bone height decreased from the anterior to the posterior region. In cross sections 4, 16 and 24, bone height decreased from the suture laterally to the 3 mm region and then increased in the 6 mm region. The cortical thickness does not seem to be a concern because it presented a mean thickness of at least 1 mm at all sites evaluated. The measurements of the mucosa thickness decreased from lateral to median and from anterior to posterior regions. The most suitable areas for miniscrew placement in the palate are located 4 mm posterior to the incisive foramen, in the median or paramedian regions 3 mm adjacent to the suture.

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