Perceptions of medical students on oral healthcare in Iran: a cross-sectional study

Introduction

Today, the influence of oral and dental health on well-being and general health has been identified [1]. The World Health Assembly of the World Health Organization (WHO) mentioned that good oral health is related to good overall health, well-being, and better quality of life [2]. Insufficient attention to oral health can lead to pain and infection, resulting in work absences as well as patients’ financial burdens and social healthcare programs [3-5]. Furthermore, some systemic conditions, such as diabetes, stroke, heart disease, pre-eclampsia, and premature birth are related to oral morbidities, particularly periodontal diseases [4-8]. Therefore, delivering oral and dental healthcare by patients and providers as well as regular dental visits, leads to prevention of the most common oral diseases, i.e., dental caries and perio­dontal disease [9-12].
Based on the conceptual model of oral health, there are three factors that influence every person oral health: individual, family, and community. With respect to these factors, the implementation of an effective health and dental care system by providers is important to achieve good oral health in society [13]. Providers who are responsible for maintaining general health of patients should also deliver both oral healthcare and information to patients, and increase their oral health awareness as well as to implement their own oral healthcare [10]. However, before providers can be expected to deliver oral healthcare and information, it is important that providers themselves are sufficiently aware, and have positive attitudes towards oral health [3, 14].
Medical students are, or will soon be, in direct contact with diverse groups of patients, and can be one of effective providers with an important role in the promotion of public oral and dental health conditions. They should be able to instruct patients on the prevention of oral disease, assess indicators, and measure incidence of oral diseases as well as refer to dental specialists [5, 14, 15]. Therefore, it is suggested that oral health knowledge should be included in medical student curricula [16]. However, there is some controversy regarding this subject. Several studies have shown a low level of knowledge, attitude, and behavior among medical students [5, 14, 16-18]. Moreover, pre­vious studies revealed lack of knowledge about oral health in systemic conditions [4, 18-20]. One study reported satisfactory levels of oral health knowledge and behavior among Indian medical students [10], and another study showed adequate levels of knowledge, attitude, and behaviors among Arab medical students [4]. Some research revealed a fair attitude towards oral health among medical students [4, 8, 15, 16]. However, many researchers reported inadequate attitudes towards oral health [9, 14, 21, 22]. Two studies concluded poor oral health behaviors among medical students in Yemen and India [14, 16]. Only Mulla et al. [4] reported moderate oral health practices among medical students at a university in Saudi Arabia. In Spain, Márquez-Arrico et al. [23] observed a poor relationship between oral health knowledge and oral health behavior.

Objectives

The purpose of this study was to bridge the literature gap with a comprehensive nationwide study assessing the knowledge, attitude, and behavior of Iranian medical students towards the pathogenesis, complications, and prevention of oral diseases.

Material and methods

The present study was an observational cross-sectional survey. The online study was carried out among medical students from September 2021 to December 2021. The Human Ethics Review Committee of the Shiraz University of Medical Sciences School of Dentistry approved this cross-sectional study. All procedures were carried out in accordance with relevant guidelines and regulations.
Inclusion criteria: Target population was all sixth- and seventh-year students (interns) of medical schools across Iran, who were willing to provide informed consent and participate in the study. Informed consent for publication of information in open access journal was obtained from all study participants. Due to the difficulty in accessing all medical students in the country (23 universities), especially under the conditions of the COVID-19 pandemic, an online questionnaire was designed and distributed through an online survey platform (Porsline, Tehran, Iran, https://porsline.ir/), and electronically signed informed consent forms were obtained from all respondents.
The sample size was considered to be at least 163 people, determined based on the expected percentage of knowledge about the purpose of brushing teeth according to Pradhan et al. [10] study (p = 88%), at 95% confidence level. To compensate for non-response bias, a convenience sampling method was employed to collect responses. For this purpose, all students were invited to participate in this questionnaire-based study via social networks.
Exclusion criteria: Students who were not interested in participating in the study, and those who did not answer all the questions.
A 49-item self-reporting questionnaire was prepared and made available to those who agreed to participate in the survey. It was provided in such a form that data delivered by respondents would be confidential. Ethical concerns were also mentioned.
The objective of the study was explained in the first part of the questionnaire, and demographic information were obtained, including age, sex, marital status, university location, and date. The second part of the questionnaire contained three sections, which assessed the knowledge, attitude, and behavior of medical students towards oral health. These questions were created after a comprehensive review of the literature.
The questionnaire had a mixture of item types: 15 five- point Likert’s scale, 31 multiple-choice single-response (MCSR), two multiple-choice multiple-response (MCMR), and one dichotomous (Yes/No). Most (28 questions) of the multiple-choice items were four alternates (MCSR 27, MCMR 1), and some were five alternates (MCSR 4, MCMR 1).
The 5-point Likert’s rating scale ranged from “Strongly agree” (score 5) to “Strongly disagree” (score 1). Multiple-choice questions were keyed with correct answers. Objectively quantitative “Correct” or subjectively qualitative “Most probable” answers received a score of 1, and incorrect responses received a score of 0. The total score for each participant was calculated as the sum of total scores for all the answers in each section.
In the first section, oral health knowledge was assessed using one Yes/No item and 22 MCSR items. The questions focused on the effect of oral health on general health, systemic diseases related to oral health, oral cancer, dental erosion, the role of dentist in the prevention of oral disease, and the use of topical fluorides. The last question asked respondents if they wanted to undertake dental principles courses during their academic education.
The second section of the questionnaire assessed the attitude of students towards oral health using one MCSR item and nine Likert’s rating scale items. The questions focused on halitosis, consumption of acidic drinks, regular dental appointments, reasons for postponing dental visits, oral health education for pregnant women, and the most important reason for brushing the teeth.
The third section assessed practice and behavior towards oral health using six Likert’s rating scale items and ten multiple-choice items, half of which had five alternates and five of which were multiple-response (MCMR) items.
The questions focused on the oral health practice of the students themselves (brushing and flossing issues), and recommendations on oral health hygiene and me­thods to reduce dental caries in patients.

Statistical analysis

A face validity technique was employed to determine if the survey measured what it was intended to measure (validity), and if the items were relevant and appropriate (essentiality). To this end, an expert panel of 15 pediatric dentists evaluated the essentiality of each item. Then, content validity ratio (CVR) was determined for each item. Items with a CVR value lower than 0.75 were removed from the questionnaire [24]. Moreover, some items were altered regarding their comments. The internal consistency of the questionnaire was evaluated by a panel of 50 available students from the Shiraz University of Medical Sciences. Cronbach’s a score was 0.82 for knowledge, 0.77 for attitude, and 0.72 for behavior questions, all of which indicated at least an acceptable level of reliability.
Data were described using mean (± standard deviation) and frequency (%). To compare mean score of the questionnaire between demographic groups of respondents, the independent samples t-test was used. Pearson’s correlation coefficient (r) and path analysis were applied to assess the relationship between knowledge, attitude, and behavior. IBM SPSS for Windows version 22.0 (IBM Corp., Armonk, NY, USA) and AMOS version 22.0 were used for data analysis. In this study, the type I error rate was set at α = 0.05.

Results

The questionnaires were distributed to 519 medical students from 23 universities in Iran, and half of them (n = 260, 50.1%) completed the questionnaires. This study sample was coded for analysis and used to assess secondary objectives, even though it was larger than the nominal calculated sample size. The mean respondents’ age (mean ± SD) was 26.52 ± 3.19 years, and most of the participants were single (n = 192, 73.8%) and female (n = 175, 67.3%). Comparison of the demographic variables and questionnaire scores (Table 1) did not show statistical differences with respect to oral health scores and sex in terms of the mean knowledge (p = 0.372), attitude (p = 0.163), and behavior (p = 0.807). The mari­tal status differences scores did not show statistical significance in the mean knowledge (p = 0.701), attitude (p = 0.277), and behavior (p = 0.419). There was a significant and positive correlation between both age and knowledge (r = 0.14, p = 0.023) as well as age and behavior (r = 0.19, p = 0.002) scores, but the magnitude of the effect size was not large (all r < 0.3). Moreover, there was no significant correlation between age and attitude scores (r = 0.05, p = 0.42).
The mean scores (mean ± SD) of knowledge, attitude, and behavior were 11.25 ± 3.39, 32.09 ± 5.18, and 3.12 ± 1.33, respectively. There was a significant correlation (Table 2) between attitude and knowledge (r = 0.35, p < 0.001), attitude and behavior (r = 0.25, p < 0.001), and behavior and knowledge (r = 0.39, p < 0.001). Table 3 shows the levels of knowledge, attitude, and behavior towards oral health according to the percentage of respondents within each quartile of the possible achievable score for each parameter. Overall, 49.6%, 89.6%, and 40.4% of the students scored more than half of the achievable score for knowledge, attitude, and behavior, respectively.
When evaluating knowledge, most of the respondents (95%) believed that oral health had an influence on general health. Only 35.8% of the medical students knew that fluoridated toothpaste is not recommended for children under 2-3 years of age, and 15% believed that dentists play a role only in the treatment and not in prevention. Although 81.5% knew that dental plaque is a caries factor, 52.7% believed that gingival bleeding during tooth brushing is a natural physiological phenomenon. Only 1.9% of the respondents recognized that tobacco does not cause gingivitis, and only 9.2% knew that Ludwig’s angina is a severe cellulitis that affects the floor of the mouth. However, 67.3% agreed that essential dental treatments were permissible in the second trimester of pregnancy, 41.2% thought that periodontitis affects the severity of diabetes, and 49.6% were aware of an association of periodontitis with heart disease and stroke.
In attitude assessment, although 82.3% of the medi­cal student respondents believed that regular dental visits are necessary, 76.9% reported avoiding or delaying dental visits due to lack of time, and 66.5% would delay going to the dentist until they felt a toothache.
Regarding brushing and dental visit habits (Table 4), even though most respondents (> 90%) reported brushing their teeth at least once a day, the main excuses given for not brushing were forgetting (55.4%) and lack of time (36.5%). The time of last dental visit was more than two years for 22.3% of the students, and 3.5% had never made a dental appointment. The main reasons for their last dental visit were tooth restoration (39.6%), dental pain (21.5%), and periodic monitoring of oral health (19.6%). The most important reasons for brushing teeth were clean teeth and good appearance (50%), followed by the prevention of dental caries and gingivitis (41.2%). Almost all the respondents (n = 250, 96.2%) expressed the need to learn the principles of dentistry to promote health among their patients.
The direct, indirect, and total effects resulting from the path model used to assess the effect of knowledge and attitude on the behavior of medical students (Figure 1) indicated that both knowledge and attitude had a significant direct effect on the behavior score. Moreover, knowledge had an indirect effect on behavior through attitude (Table 5).

Discussion

This study was designed to assess the level of knowledge, attitude, and behavior towards oral health among medical students across Iran, and to evaluate whether curricular revisions on oral health would be beneficial for medical students. Almost half of the respondents (49.6%) showed good knowledge of oral health, while under half (40.4%) reported a reasonable level of oral health beha­vior. Most of the respondents (89.6%) presented a positive attitude towards oral health.
The study demonstrated that there were no statistical sex differences with respect to the mean knowledge, attitude, and behavior scores, which is consistent with Khami et al. [25]. Additionally, there was a significant and positive correlation between age/ knowledge and behavior scores, and the magnitude of effect size was not large. The study found no significant correlation between age and attitude scores, in contrast to Mahmoud et al. [9], who reported a significant correlation between the level of knowledge of nursing students and age, but no association between the total scores for attitude/behavior levels and age [9]. The difference between behavior scores in these studies may be related to cultural differences. To mitigate these effects, the current study evaluated behavior towards oral health with more various questions.
Yao et al. [5] reported no significant differences between oral health behavior and knowledge level among dental and medical students. However, the mean age in our study was greater than that in the Yao study, and the age difference may have influenced the scores for knowledge, attitude, and behavior.
The present study revealed that the respondents had inadequate knowledge about oral health, which was consistent with other studies. Mulla et al. [4] reported that the oral health knowledge of medical students was fair, while Kumari et al. [26] concluded that knowledge and attitude of medical students towards infant oral health were inadequate. Usman et al. [17] reported poor level of knowledge in medical and paramedical students, and emphasized the need for inclusion of oral health education in pre-clinical curriculum of medical and paramedical courses. Oyetola et al. [18] revealed a “gross” deficiency in oral health knowledge among medical doctors, nurses, and medical students.
Periodontal disease is a risk factor for various systemic diseases, such as cardiovascular disease, diabetes, cancer, and hypertension, which pose a great threat to human health. Yao et al. [5] reported a lack of knowledge on this subject among medical students in China. Al-Habashneh et al. [27] in Jordan showed that only a third of medical professionals agree with the relationship between oral health and diabetes. Consistent with the studies mentioned, our findings demonstrated that medical students were not sufficiently aware of the relationship between periodontal diseases and other medical conditions, and confirmed the need to review the curricula on this subject. Furthermore, according to our results, approximately half of the respondents believed that gingival bleeding during tooth brushing is a natural physiological phenomenon. However, Kaira et al. [21] reported that students were more aware of inflamed gingiva, as compared with our findings.
One of the main challenges facing both doctors and dentists is the safety of dental treatment during pregnancy [22]. Leone et al. [20] found that most medical students had positive baseline perceptions or knowledge about the safety of dental treatment for pregnant women. Our findings showed that more than two-thirds of the students (67.3%) agreed that essential dental treatments can be performed in the second trimester.
In the present study, a lack of knowledge was reflected in the results. Only 35.8% of our medical students agreed that fluoridated toothpaste is dangerous for children under 2 or 3 years of age. Although 1.9% correctly believed that tobacco does not cause gingivitis, only 9.2% could identify Ludwig’s angina as severe cellulitis, a condition with which medical students would be familiar. Regarding these lack-of-knowledge results, Wang et al. [28] provided a broader context in a survey among dental and non-dental doctors, with results showing that both groups had a lack of understanding of the risks in children under 3 years of age using fluoridated toothpaste: only 31.3% of dentists and 25.9% of non-dental doctors agreed that the risks outweigh the benefits. Regarding Ludwig’s angina, Oyetola study [18] indicated that 50% of medical doctors, 14.3% of nurses, and 13.9% of medical students knew about the condition. Regarding gingivitis, Mulla et al. [4] study reported that 20.2% of medical students believed that smoking is a cause of gingivitis.
The present study demonstrated that the respondents had a positive attitude towards oral health, which is in line with previous studies among medical and healthcare students (nursing and pharmacy) [4, 8, 15, 16]. However, some studies revealed inadequate attitudes towards oral health [9, 14, 21, 22]. The differences in these studies may be due to the inclusion of participants from medical fields with more clinical tasks.
Our results showed that most of the medical student respondents avoided or delayed a dental visit due to lack of time, and postponed going to the dentist until they felt a toothache. This is consistent with Usman et al. [17], who reported that in addition to the more than three- quarters of medical and paramedical students, more than half of the dental students also delayed dental visits until problems were encountered.
The current study did not show statistical differences between sexes in the mean attitude, knowledge, and behavior scores. Previous studies reported females having significantly greater oral health knowledge, attitude, and behavior scores compared with males [4, 8]. The diffe­rences between the results may be related to esthetics and standard changing in both sexes.
In the current study, the medical students revealed inadequate oral health behavior, which may be related to their knowledge. In the context of oral health, numerous studies have noted the necessity of relationship between knowledge and understanding and demonstrated behavior [29]. In 2016 Halboub et al. [14] reported “markedly” poor oral health behavior among both medical and dental students in Yemen, and reported the need for adequate oral health knowledge to precede expectations of behavior. Sharda et al. [16] observed that while the oral health knowledge scores of Indian medical students were better than those of paramedical and non-medical students, the scores for all three groups were low. In addition, they noted that knowledge was insufficient to result in preventive behavior, unless there was understanding that resulted in changes in attitude, which had a “linear relationship” with behavior. Mulla et al. [4] reported that while oral health knowledge among medical students at a university in Saudi Arabia was “fair” and their attitude was “good”, their oral health practices (behavior) were only “moderate”. It is hoped that this study, which has more questions designed to measure student’s oral health behavior, will allow for a more accurate analysis of that performance.
In the present study, approximately 90% of the respondents reported brushing their teeth at least once a day (34.2% twice a day); it is consistent with other studies [30-32] showing that most of the respondents brush daily. However, other studies noted that approximately half of medical and nursing students brush their teeth twice daily [4, 21, 33]; it is consistent with (but greater than) our finding for twice daily brushing (34.2%). Similarly, Oyetola [18] demonstrated that 73.5% of Nigerian health workers in a teaching context (doctors, medical students, and nurses) brush their teeth daily, with only 26% brushing twice daily. Consistently, in these studies, a smaller percentage of respondents reported brushing twice daily, which was often self-ascribed as due to lack of time or fatigue.
Our findings indicated that less than half of the respondents had their last dental visit 6 months ago, which is in agreement with Mulla et al. study [4]. However, the percentage reported by Usman et al. [17] for the last dental visit at 6 months in Mangalore was lower (14.7%). In the present study, 22.3% of the respondents had not had a dental visit for more than two years. This may be due to the high cost of dental services and the medical insurance system, which generally does not cover dental treatment [34]. Lack of time and insufficient knowledge are often self-reported as other reasons. In addition, the COVID-19 pandemic may have impaired the decreasing number of dental visits.
Our results showed that the main reasons reported for the last dental visit were tooth restoration and dental pain, in line with other studies, which reported pain as the main reason for seeking dental help [4, 22]. In the present study, while 82.3% of the students reported believing that regular dental visits are necessary, only 60.8% reported having a dental visit in the past year. This shows that although they had sufficient knowledge and attitude, there was no corresponding demonstration of behavior, which is consistent with Sharda et al. study [16] in India as well as Márquez-Arrico et al. [23] in Spain, who reported a poor relationship between knowledge of oral hygiene knowledge and oral hygiene behavior.
Overall, the current study confirmed that a high degree of knowledge and attitude had a direct significant and favorable effect on the behavior score. Furthermore, knowledge had a negative (indirect) impact on behavior through attitude, and is consistent with studies indicating that increased dental education corresponded to improvements in attitudes towards oral health [3, 29, 35].
In our cross-sectional study, the sample included students from medical universities throughout Iran in 2021. Other strength of the study is the questionnaire with multiple questions on different aspects of knowledge, attitude, and behavior of the respondents, which would be more accurate compared with previous studies. However, some limitations of the study include the limit of self-reported survey responses, and the fact that the referral behavior outcome of the study was based on self-reported behavior rather than actual behavior. A review of current medical student curricula is recommended.

Conclusions

This study presents an overview of oral health knowledge, attitude, and behavior among students from medical universities across Iran. The level of knowledge about oral health was moderate and the level of attitude towards oral health was good, but the reported oral health behavior ranged from poor to fair.

Disclosures

1. Institutional review board statement: The Human Ethics Review Committee of the Shiraz University of Medical Sciences School of Dentistry approved this cross-sectional study. Approval number: IR.SUMS.DENTAL.REC.1400.039.
2. Assistance with the article: None.
3. Financial support and sponsorship: None.
4. Conflicts of interest: The authors declare no potential conflicts of interest concerning the research, authorship, and/or publication of this article.

References