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Biomonitoring of mutagenicity and cytotoxicity in patients undergoing fixed orthodontic therapy

https://doi.org/10.1016/j.ajodo.2009.06.029Get rights and content

Introduction

The aim of the present study was to evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis, and karyorrhexis) in exfoliated buccal mucosa cells from adults after fixed orthodontic therapy.

Material and Methods

A total of 23 healthy adults (10 men and 13 women) undergoing orthodontic therapy were included in this setting.

Results

The results pointed out no significant statistically differences (P >0.05) of micronucleated oral mucosa cells. In the same way, orthodontic therapy was not able to increase other nuclear alterations closely related to cytotoxicity such as karyorrhexis, pyknosis and karyolysis (P >0.05).

Conclusion

In summary, these data indicate that orthodontic therapy may not be a factor that induces chromosomal damage, nor it is able to promote cytotoxicity. Since DNA damage and cellular death are important events during carcinogenic processes, especially in early phases, this study represents a correct evaluation with respect to real health risks induced by orthodontic devices.

Section snippets

Subjects

The subjects of this study comprised a total of 23 healthy adults (10 men and 13 women) with a mean age of 18.5 ± 7 years who had submitted to orthodontic therapy at the Department of Orthodontics, São Paulo Methodist University, São Bernardo do Campo, Brazil. The fixed appliances consisted of an average of 4 to 8 bands and 20 bonded brackets. Brackets were provided by Abzil (São Paulo, Brazil): iron, 71%; nickel, 8%, and chromium, 19%. The arch wires used in this study were a nickel-titanium

Results

Figure 1 shows the frequencies of micronucleated cells in individuals undergoing orthodontic therapy. Before the beginning of orthodontic device exposure, the mean frequency of micronucleated cells was 0.04%. No statistically significant differences (P >0.05) were noticed either during or after orthodontic therapy. In the same way, an increase of other nuclear alterations were not observed throughout the experimental design, as depicted by the frequency of karyorrhexis, pyknosis, and

Discussion

The aim of this study was to employ the micronucleus test to assess chromosome damage and/or cellular death in adults who had submitted to orthodontic therapy. To the best of our knowledge, the approach has not been addressed in the literature so far.

The key advantage of the micronucleus assay is the relative ease of scoring, the limited costs and person-time required, and the precision obtained from scoring larger numbers of cells. The measurement of the frequency of micronuclei induced in

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    The authors report no commercial, proprietary, or financial interest in the products or companies described in this article.

    This study was supported by grants from São Paulo Research Foundation (Grant number: 07/00345-7). R.A.M. is a recipient of the São Paulo Research Foundation’s student fellowship and D.A.R. is a recipient of the CNPq fellowship.

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