Nuclear changes in tongue epithelial cells following panoramic radiography

doi:10.1016/j.mrgentox.2007.05.003

Mutation Research/Genetic Toxicology and Environmental Mutagenesis

Volume 632, Issues 1–2, 15 August 2007, Pages 121-125

https://doi.org/10.1016/j.mrgentox.2007.05.003 Get rights and content

Abstract

This study aimed to investigate the effect of radiation from panoramic radiographs on the cells of the lateral border of the tongue by evaluating nuclear changes. Forty-two patients were included: 22 had one radiograph (Group I), and 20 required a repeat radiograph due to error in the first exposure (Group II). Material for the cytopathologic evaluation was collected before radiographs and 10 days later. Smears were stained with the Feulgen reaction and micronuclei, buds, broken eggs, karyorrhexis and binucleate cells were scored. The comparison of nuclear changes before and after radiation exposure in both groups revealed a statistically higher number of broken eggs, buds, karyorrhexis and binucleate cells 10 days after exposure (P = 0.01). The number of karyorrhexis and binucleate cells was greater in group II (P = 0.01). There was no change in the frequency of micronuclei before and after the radiographs. Radiation emitted during panoramic radiographs increased the number of nuclear anomalies (except micronuclei) in exfoliated cells of the lateral border of the tongue. This effect was more pronounced when the patients were exposed to a repeat radiograph, without however implying increased risk of irreversible tissue damage.

Introduction

Radiation has been shown to induce the formation of cell aberrations such as micronuclei (MN) (chromosome fragments resulting from failure in the incorporation of genetic material due to damage during mitosis) [1], [2], [3], [4], [5], broken eggs (small nuclei attached to the cell nucleus by a “Feulgen-positive filament”) [2], buds (small amounts of genetic material adhered to the main cell nucleus without a “Feulgen-positive filament”) [6], binucleate cells (cells with two nuclear structures of similar volume contained by separate nuclear membranes), and karyorrhexis (nuclear disintegration associated with loss of nuclear membrane integrity, one of the main early signs of cell death by apoptosis) [5]. MN are usually used to detect the action of genotoxic agents, but studies suggest that the quantification of other types of changes may increase the sensitivity of this method to detect cell damage.

Stich et al. [1] and Sarto et al. [2] found a significant association between the dose of ionizing radiation used in radiotherapy and the number of cells with MN. Cerqueira et al. [6] investigated the genotoxic effects of radiation emitted to obtain panoramic radiographs by analyzing exfoliated cells of the oral mucosa in 31 individuals. The smears were obtained before the radiograph and 10 days after exposure. Those authors [6] observed similar frequencies of MN, karyolysis and pyknosis before and after exposure and increased condensation of chromatin and karyorrhexis after exposure. They concluded that the radiation emitted during panoramic radiographs induced cytotoxic effects, increasing apoptosis.

Therefore, the aim of the present work was to confirm and extend the results found by Cerqueira et al. [6], determining the frequency of cellular changes (MN, broken eggs, buds, karyorrhexis and binucleate cells) caused by ionizing radiation from panoramic radiographs in exfoliated cells of the lateral border of the tongue of young men.

Section snippets

Subjects and ethical considerations

This observational descriptive study was approved by the Ethics in Research Committee of the School of Dentistry, Universidade Federal do Rio Grande do Sul (FO-UFRGS) (protocol # 11/04). We included male patients with age between 18 and 40 years referred to our Radiology Service for a diagnostic panoramic radiograph, who agreed to participate in the study and return 10 days later for collection of tissue specimens. All patients signed an informed consent form. Exclusion criteria were: lesion on

Results

The frequency of broken eggs, buds, karyorrhexis and binucleate cells was significantly higher after exposure to radiation in both groups (Table 1, Table 2). Also, the number of karyorrhexis and binucleate cells was significantly higher in patients who were exposed to radiography twice than in patients who were not submitted to a repeat radiograph (Table 3).

Data about consumption of hot beverages and alcohol, drug use, smoking, use of medication, and systemic diseases are shown in Table 4.

Discussion

The use of cytology to evaluate cytogenetic damage has been described in detail in several studies [10]. International research groups, such as the Human MN Project [4], have focused attention on the human buccal MN assay.

The present study analyzed epithelial cells of the lateral border of the tongue because this anatomical site shows a high incidence of cancer [11] and because it is centrally located when the source of radiation moves around the head of the patient in the radiographic

Acknowledgement

We thank Kolplast Comercial Industrial Ltda (São Paulo, Brazil).

References (20)

P.E. Tolbert et al.
Micronuclei and other nuclear anomalies in buccal smears: methods development
Mutat. Res.
(1992)
E.M. Cerqueira et al.
Genetic damage in exfoliated cells from oral mucosa of individuals exposed to X-rays during panoramic dental radiographies
Mutat. Res.
(2004)
D. Murray et al.
Dental panoramic tomography: what the general radiologist needs to know
Clin. Radiol.
(2002)
B.J. Majer et al.
Use of the micronucleus assay with exfoliated epithelial cells as a biomarker for monitoring individuals at elevated risk of genetic damage and in chemoprevention trials
Mutat. Res.
(2001)
R.W. Alcox
Biological effects and radiation protection in the dental office
Dent. Clin. North Am.
(1978)
H.F. Stich et al.
Adaptation of the DNA-repair and micronucleus tests to human cell suspensions and exfoliated cells
Ann. N.Y. Acad. Sci.
(1983)
F. Sarto et al.
The micronucleus assay in exfoliated cells of the human buccal mucosa
Mutagenesis
(1987)
H.F. Stich et al.
Quantitating the synergistic effect of smoking and alcohol consumption with the micronucleus test on human buccal mucosa cells
Int. J. Cancer.
(1983)
M. Fenech et al.
Harmonisation of the micronucleus assay in human buccal cells—a human micronucleus (HUMN) Project (www.humn.org) initiative commencing in 2007
Mutagenesis
(2007)
O.E. Langland et al.
Principles of Dental Imaging
(2002)

There are more references available in the full text version of this article.

Cited by (38)

Cytotoxicity, genotoxicity, and immunohistochemical expression of p53 in the oral mucosal epithelium of adults following cone-beam computed tomography
2022, Mutation Research - Genetic Toxicology and Environmental Mutagenesis
Citation Excerpt :
Some other studies, however, did not report a significant increase in the ratio of micronuclei following CBCT [26,33,40]. Cerqueira et al. [39], Popova et al. [16], Lorenzoni et al. [9] Ribeiro et al. [43] and Angelieri et al. [32], in their studies on exfoliated buccal mucosa cells, and da Silva et al. [34], in their study on epithelial cells of the tongue, indicated an increase in the ratio of micronuclei following X-ray exposure in panoramic radiography; however, this increase did not reach statistical significance. Some others did not report a significant change [8] or reported insignificant reduction [39,44] in the ratio of micronuclei after X-ray exposure.
This study sought to assess the cytotoxicity, genotoxicity, and immunohistochemical (IHC) expression of p53 in the oral mucosal epithelium of adults following cone-beam computed tomography (CBCT). This before-and-after observational study evaluated 30 patients (15 males and 15 females); mean age 35 years, who required CBCT. Exfoliating epithelial cells of the buccal mucosa were collected with a cotton swab immediately before and 10 days after CBCT. Following Papanicolaou staining, genotoxicity was evaluated by the micronucleus assay. The frequencies of pyknosis, karyorrhexis, karyolysis, budding and binucleation as cytotoxicity factors were also recorded. Expression of p53 was evaluated by IHC staining. Data were analyzed by paired samples t-test. Micronucleated cells, pyknosis, karyorrhexis, karyolysis, budding, cytotoxicity, and expression of p53 increased significantly after CBCT. CBCT exerts genotoxic and cytotoxic effects and leads to overexpression of p53 protein in the oral buccal mucosal cells.
Evaluation of genotoxic damage in buccal mucosa cytome assays in Iraqi school children exposed to air pollutants emanating from oil fields
2021, Mutation Research - Genetic Toxicology and Environmental Mutagenesis
Citation Excerpt :
Also, controversies are prevailing regarding the age of the subjects [53]. According to Silva et al., female hormones provoke alterations in the epithelial cells of the oral mucosa of women [54]. On the other hand, a meta-analysis of MN frequency in children with age between 0–18 years and a pooled analysis of individual data available from both published studies as well as from the Human Micronucleus International Collaborative Study (HUMN) database [55], allowed the estimation of the effect of age and gender on MN level.
Presently, over 135 thousand barrels of crude oil are extracted daily from the Al-ahdeb oil fields (situated at 180 km south east of Baghdad, Iraq). Millions of gallons of untreated toxic wastes, gas and crude oil are released into the environment. Oil mining mediated pollution may cause damage to humans and the environment. To investigate potential health risks for children living in this area, we recruited a sample of 6–8 year old school children residing within a 5 km radius around the oil field, and a control sample of children of the same age from a school 40 km away from the oil-field. Exfoliated buccal mucosa cells obtained from these children were analyzed applying the micronucleus (MN) cytome assay. Possible confounding variables such as x-rays performed during three weeks preceding sampling were obtained by a questionnaire. Nuclear anomalies were significantly elevated in children living near the oil-field. Micronucleated cells 1.3-fold, nuclear buds 3-folds, binucleated cells 3-folds, karyorrhetic cells 4-folds and karyolysis more than 10 folds with a significant difference (P < 0.05). Hence, children living in the proximity of Iraqi oil-fields are at elevated risk of genetic damage, which can cause detrimental health effects in the future.
Comparative evaluation of mutagenic effects of two cone-beam computed tomography in oral mucosa cells
2023, Diagnostic Cytopathology
Genotoxic and Cytotoxic Effects of Dental Radiographic Modalities on Buccal Mucosal Cells in Children
2023, Journal of Child Science
Stature estimation using various odontometric parameters: A narrative review
2023, Journal of International Oral Health
IN VITRO ANALYSIS OF GENOTOXIC EFFECTS OF DENTAL PANORAMIC RADIOGRAPHY: EVIDENCE OF POTENTIAL GENOTOXICITY USING THE COMET TEST
2023, Revista de Gestao Social e Ambiental

View all citing articles on Scopus

View full text

Nuclear changes in tongue epithelial cells following panoramic radiography

Abstract

Introduction

Section snippets

Subjects and ethical considerations

Results

Discussion

Acknowledgement

Mutat. Res.

Mutat. Res.

Clin. Radiol.

Mutat. Res.

Dent. Clin. North Am.

Adaptation of the DNA-repair and micronucleus tests to human cell suspensions and exfoliated cells

Ann. N.Y. Acad. Sci.

The micronucleus assay in exfoliated cells of the human buccal mucosa

Mutagenesis

Quantitating the synergistic effect of smoking and alcohol consumption with the micronucleus test on human buccal mucosa cells

Int. J. Cancer.

Harmonisation of the micronucleus assay in human buccal cells—a human micronucleus (HUMN) Project (www.humn.org) initiative commencing in 2007

Mutagenesis

Principles of Dental Imaging