Mutagenicity and cytotoxicity in patients submitted to ionizing radiation.
OBJECTIVE
To evaluate and compare mutagenicity (micronucleus) and cytotoxicity (karyorrhexis, pyknosis, and karyolysis) in exfoliated buccal mucosa cells of children following cone beam computed tomography (CBCT) or conventional radiograph exposure necessary for orthodontic planning.


METHODS
A total of 49 healthy children were submitted to CBCT or a conventional orthodontic radiographic protocol; they were divided into two groups based on exam: CBCT (n  =  24) and Radiographic Set (n  =  25) groups. The micronucleus test in the exfoliated buccal mucosa cells was applied.


RESULTS
There was not a statistically significant difference (P > .05) found between the number of micronucleated buccal mucosa cells (MNC) before and after exposure to radiation in either group, showing that neither group experienced a mutagenic effect. However, radiation did cause other nuclear alterations closely related to cytotoxicity, including karyorrhexis, pyknosis, and karyolysis, in both groups (P < .05). The CBCT group presented a greater increase in cell death than was noted in the Radiographic Set group (P < .044).


CONCLUSIONS
According to the micronucleus test, mutagenicity was not induced by the CBCT or the conventional radiographs, but cytotoxicity was verified after these exams, especially after CBCT. That might have happened once the CBCT group received a greater radiation dose than the Radiographic Set group as a result of the protocols used in orthodontic planning for this study.
Department of Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Diego Coelho
DC
Lorenzoni
Ana Carolina Cuzzuol
AC
Fracalossi
Viviane
V
Carlin
Daniel Araki
DA
Ribeiro
Eduardo Franzotti
EF
Sant'anna
D000293:Adolescent; D002467:Cell Nucleus / Q000528:radiation effects*; D002648:Child; D054893:Cone-Beam Computed Tomography / Q000009:adverse effects*; D004847:Epithelial Cells / Q000166:cytology / Q000528:radiation effects*; D006801:Humans; D015162:Micronucleus Tests / Q000379:methods; D009061:Mouth Mucosa / Q000166:cytology / Q000528:radiation effects*; D011832:Radiation Injuries / Q000209:etiology*; D011839:Radiation, Ionizing; D011861:Radiography, Dental / Q000009:adverse effects*