Dental imaging is a key part of dentistry as it is a key diagnostic tool and images can easily be shared with colleagues for confirmation of diagnosis and advice. Traditionally, dental imaging is avoided during pregnancy, specifically during the first trimester, to protect the developing fetus. However, oral health may be affected throughout the pregnancy and radiographic examinations for a proper diagnosis and management of various dental conditions might be needed. Out of fear and anxiety concerning the risk of cancer or genetic malformations, pregnant women are generally reluctant to have dental imaging, which may in turn delay necessary treatment and could negatively impact the health of both the mother and fetus. This study was conducted to investigate women’s awareness regarding the use of diagnostic dental imaging during pregnancy.
Dental imaging is safe during pregnancy as long as the radiation protection measures have been applied [14]. Radiation doses can be substantively reduced by various measures, such as radiographic selection criteria, a lead apron with a thyroid collar, high-speed film or digital imaging, and most importantly, rectangular collimation [15]. For bitewing and full mouth radiographs, the use of digital sensors or an F-speed film in combination with rectangular collimation was found to reduce radiation exposure by a factor of 10 [16].
Our study demonstrated that participants have poor knowledge regarding radiation safety during pregnancy. A very small percentage of the participants were aware that dental imaging can be acquired during any trimester with the application of radiation protection measures. Around two-thirds of the participants were not sure or thought it was contraindicated in all trimesters. The majority believed that panoramic radiographs and CBCT are contraindicated during pregnancy. Less than half of the participants were not sure about the radiation protection measures that have to be applied during dental imaging. A large number of participants had misconceptions, like the existence of a specific lead apron for pregnant patients or that two layers of lead aprons are needed. The position statement of the American Association of Physicists in Medicine (AAPM) cited the justifications for disregarding the fetal and gonadal lead shield claiming that the risks from diagnostic imaging are “minimal to non-existent” [17]. While it was suggested that lead shielding is not necessary, it provides a sense of safety and comfort to the patient.[17,18,19].
A possible explanation is the lack of public radiation awareness programs. Also, it is possible that patients are not informed about the radiation safety and risks by their treating dental practitioners. A study by Al Faleh et al., reported that almost 40% of the patients were not informed about the radiation hazards by their dentists [13]. More than half of the patients never inquired about safety measures before undergoing imaging. Furthermore, the patients’ lack of knowledge could be a reflection of insufficient knowledge among treating dental practitioners. An extensive literature review revealed that there is a worldwide concern about dentists’ knowledge regarding dental imaging during pregnancy. Several studies have revealed that the knowledge of dental students, interns, and dentists on ionizing radiation and radiation protection is very poor [6, 8, 9, 20,21,22]. In a study by Aboalshamat et al., 67% of dentists considered periapical radiographs safe only during the second trimester. Panoramic radiographs were considered contraindicated during pregnancy by 69% of the participants [21]. Bedre and Sharma found that only 2% of dentists knew that dental imaging is safe in all trimesters and 44% thought it was unsafe in all trimesters [20]. Another study found that half of the Jordanian dentists considered that panoramic radiographs are contraindicated during pregnancy and less than one-third did not know if they are safe [8]. Llea et al. found that more than two-thirds of dentists would acquire dental radiographs only for emergency purposes [6]. It is also possible that dental professionals are unaware about the significant dose reduction associated with digital imaging in comparison to the conventional film. Lack of knowledge could lead to increase anxiety of both dentists and pregnant women seeking dental treatment during pregnancy. Therefore, continuous professional education is crucial to raise dentists’ awareness about the radiation dose from various dental imaging techniques and dose reduction measures.
Knowledge about radiation doses from dental imaging relative to the background radiation dose was also poor. The majority of participants were not sure how the dose from a periapical radiograph compares to the background radiation dose. In comparison to the natural background radiation exposure, the dose from a single bitewing radiograph acquired with a photostimulable plate and a rectangular collimator is less than one day of background radiation [16]. According to the National Council on Radiation Protection and Measurements Report No. 177, the fetal dose from full-mouth intraoral radiographs is 4–6 times less than the exposure to normal background radiation over the nine months of pregnancy [23].
Regarding congenital malformations, a very small percentage responded that such risks are not associated with dental imaging, whereas more than half of the participants believed that the risk of radiation-induced congenital malformations from dental imaging is high. Similarly, Razi et al. found that only 28% of the dentists were aware that radiation doses from diagnostic imaging do not result in congenital malformations or fetal mental retardation [9]. Concerning fetal malformation, the International Commission for Radiation Protection states that the fetal absorbed dose would have to exceed the threshold dose of 100–200 mGy or higher. This is far more than the fetal absorbed doses from diagnostic imaging, as well as nuclear imaging. In both human and animal studies, there is no evidence that the range of radiation exposure from diagnostic imaging (i.e., less than 50 mGy) is linked to an increased risk of teratogenic effects [14, 24, 25].
The risk of childhood cancer is difficult to estimate from low-level exposures, such as dental imaging [16]. Our participants were unsure about the oncogenic risks from dental imaging. Almost one-third of the participants believed that the risk is high, one-third believed that the risk is low, and the remaining participants believed the risk does not exist. The perception that radiation can cause cancer is derived from studies of the survivors of the Hiroshima and Nagasaki atomic bombs and other cohort studies. However, epidemiologic studies have failed to find an association between the radiation dose and the cancerogenic effects [16, 24, 25]. It has been estimated that the fetal dose from a single CT examination of the head ranges from 0 to < 0.005 mGy [24, 25]. Although this knowledge may reassure pregnant women and dental professionals about the safety of dental imaging, it is still prudent to use cautious clinical management and ensure that the dose is kept as low as reasonably achievable.
This study has several limitations. This was a cross-sectional study that does not imply causality. In addition, we used snowball sampling, which undermines the ability to generalize the results to the population. Moreover, this study may be prone to self-selection bias due to the nature of recruiting participants which may jeopardize both internal and external validity. Another limitation is that we did not ask whether or not the woman has had children. Women with children might have better knowledge due to their experience from previous dental visits during pregnancy. Future research is warranted to assess obstetricians’ perceptions of radiation dose and risk associated with various dental imaging during pregnancy. Moreover, we propose further research to evaluate the effectiveness of an educational intervention tailored to educate the public about radiation dose and risk versus benefit. Additionally, a prospective longitudinal study to evaluate the possible role of maternal education from both dentists and obstetricians on the oral health status of pregnant women.
