Impact of Oral Health Education on Children’s Self-perceived Oral Health and Quality of Life: A School-Based Study

1. INTRODUCTION

Oral health has a significant impact on public health and the quality of life of individuals and their families; therefore, school-based oral health promotion activities are effective in preventing disease and promoting oral health in children, contributing to changes in behaviour and attitudes regarding oral health [1]. The World Health Organization (WHO) defines oral health as “a state in which a person is free from chronic and acute diseases in the mouth, teeth, face, and throat, limiting the ability to eat, smile, speak, as well as mental or social health” [2].

Oral diseases are global public health problems, and there is particular concern regarding the increase in their prevalence in many low- and middle-income countries related to behavioural and socioeconomic changes. A strong and consistent social gradient exists between socioeconomic status and the prevalence and severity of oral diseases; therefore, they are considered sensitive clinical markers of social disadvantage [3]. Oral health is an important indicator of a child's well-being, and dental caries and other oral disorders in childhood are among the most serious and expensive health conditions that negatively impact children's health-related quality of life [4]. Deciduous teeth are susceptible to caries from the time of eruption, with peak prevalence around 6 years of age [2].

The consequences of untreated oral diseases are various, including physical symptoms, functional limitations, and detrimental impacts on emotional, mental, and social well-being. They may cause sequelae and compromise the ability to eat, smile, and speak, as well as negatively affect children’s mental and social well-being. Education and changes in individuals' behaviour contribute to reducing problems and improving oral health. Health education activities have a positive effect on individuals' behavioural characteristics, such as oral health knowledge, changes in attitude, oral hygiene practices, healthy eating habits, reduced carious lesions, and periodontal health [5].

The condition of children's oral health has improved in recent decades, making it essential to evaluate oral health-related quality of life (OHRQoL) using validated instruments [6]. Studies indicate that children from 8 years of age have the cognitive maturity to report health problems, while adapted questionnaires show that even those aged 5 years can provide reliable answers about the impact of oral conditions on their well-being [7]. The World Health Organization (WHO) has developed questionnaires to measure OHRQoL, focusing on conditions such as caries, malocclusion, and craniofacial anomalies [8]. One of the most widely used instruments is the Child Perceptions Questionnaire (CPQ), which evaluates four domains: oral symptoms, functional limitations, emotional and social well-being, and is applicable to different age groups (6-7, 8-10, and 11-14 years) [9].

Educational interventions in oral health have been shown to be effective in promoting healthy habits among schoolchildren, with significant improvements in hygiene and knowledge [10]. Evidence indicates that targeted public policies, such as those implemented in Bauru, drastically reduced the DMFT index in 12-year-old children between 1976 and 2001, raising the proportion of sound permanent teeth from 0.40% to 45.50% [11]. Health Promoting Schools (HPS), especially in deprived areas like Curitiba, showed better oral outcomes compared with institutions without specific programmes [12]. Children aged 8–10 years, typically in the mixed dentition stage, are considered an ideal target group for educational interventions, as early strategies positively influence behaviours in adult life [13]. Thus, the integration of OHRQoL assessment, public policies, and health education emerges as fundamental for the sustainability of advances.

This study addressed oral health education by evaluating children's perception of their oral health condition through the application of the CPQ8-10 questionnaire before and after (3 months) an interactive lecture on oral health and hygiene lasting 1 hour, with audiovisual resources and the use of macromodels, along with the distribution of illustrative booklets and an oral hygiene kit. Clinical evaluation was also carried out for the dmft/DMFT indices (pre/post) in the mixed dentition of 8-year-old children from a public school on the outskirts of São Paulo.

2. MATERIALS AND METHODS

The study included 85 eight-year-old children, 3rd-grade students from the Municipal School Deputado José Blota Junior (São Paulo), selected from a total of 150 students. Parents signed the Free and Informed Consent Form, approved by the Santo Amaro University Ethics Committee (CAAE: 59474122.5.0000.0081). The study was conducted in accordance with the Declaration of Helsinki. After the parents read and signed the consent form, the children underwent clinical examinations performed by two calibrated examiners, who assessed the DMFT index (permanent dentition) and dmft index (deciduous dentition), following the protocols of the World Health Organization (2003) [8] and Frias et al. (2004) [14]. The diagnoses were validated by consensus among the examiners, establishing a gold standard. The authors declare that they did not use any AI tools in the preparation of the study and manuscript.

A convenience sample was used, based on the number of students who were in the third grade of elementary school at the same school in São Paulo. The assessments (application of the questionnaire and oral clinical evaluation) were carried out between November 2022 and March 2023. The eligibility criteria adopted were the inclusion of children aged 8 years and children whose parents read and signed the consent form. Exclusion criteria included children who did not answer all the questions on the questionnaire, children who did not allow the oral examination, and children who were older or younger than 8 years.

Simultaneously, the CPQ8-10 questionnaire, adapted into Portuguese, was applied. It evaluates oral symptoms, functional limitations, emotional and social well-being, in addition to recording gender and age. The CPQ8-10 was administered by a researcher (a dental student and school teacher) through individual interviews. Clinical assessments of the DMFT (Decayed, Missing, and Filled Teeth – permanent dentition) and dmft (deciduous dentition) indices were performed by two calibrated examiners. Calibration was conducted both inter- and intra-examiner for the presence of caries, involving the examination of five children. The examiners underwent prior training (40 hours), which included discussions, slide-based study sessions, and clinical oral examinations. The children involved in the calibration process were not included in the final study sample. During calibration, inter- and intra-examiner agreement rates for caries experience (dmft/DMFT) and caries activity ranged from 78% to 83% (Kappa = 0.78 to 0.83) [15]. The baseline assessments were conducted within the school premises, during class hours, in a private setting. Children were seated at desks, and oral examinations were performed using a dental mirror and explorer; a portable light source was used as the light source.

Following the initial assessment, the children participated in a one-hour interactive lecture on oral hygiene. A total of 30 slides were presented, covering topics such as oral hygiene and its systemic, social, and aesthetic importance; diet and its relationship to caries; and oral hygiene instructions. Large dental models were used to demonstrate toothbrushing techniques. Each child received a kit containing a toothbrush, fluoride toothpaste, and an illustrated booklet. The booklet, specifically designed for this intervention, included five pages, each featuring drawings of familiar children's characters associated with toothbrushes, toothpaste, and oral hygiene. The students were encouraged to begin colouring the drawings throughout the evaluation and questionnaire administration process. Ninety days later, the questionnaire and clinical examinations were repeated to compare the post-intervention results.

The CPQ8-10 data and the clinical indices were statistically analysed using SPSS V26, Minitab 21.2, and Excel software. The Chi-Square Test for independence, Mann-Whitney Test (pre/post comparison) adjusted for multiple comparisons using the Benjamini-Hochberg (FDR) procedure, Z-Test for proportions, and p-value (5% significance, 95% CI) were used. The approach sought to evaluate the effectiveness of the educational intervention on oral health and children's perceptions, integrating quantitative and clinical methodologies to validate the observed impacts.

3. RESULTS

The study included 85 eight-year-old children; 4 did not return the signed form and were removed from the study, but they had access to the interactive oral health and hygiene education lecture. The 81 children included had a mean age of 8 years (± 0.19) (pre) and 8.42 years (± 0.50) (post), with 45 girls and 36 boys. The clinical data, evaluated before and 3 months after the lecture, showed no statistical difference. The Mann-Whitney test was used to compare the pre- and post-moment values for the quantitative factors, with p-values adjusted for multiple comparisons using the Benjamini-Hochberg (FDR) procedure (Table 1).

When comparing the pre- and post-moments for the clinical results, separated by deciduous (d) and permanent (D) teeth, we found no statistically significant difference between the pre (year 2022) and post (year 2023) moments (Table 2). The questionnaire was applied individually through an interview. Thus, we compared the pre and post moments for the distribution of relative frequencies in each of the 27 questions of the CPQ questionnaire. For this statistical comparison, the Chi-Square test was used (Table 3).

Table 4 shows the mean scores (±SD) at T0 and T1 (with median, CI, and p-value) of the Overall CPQ, oral symptoms, functional limitations, emotional well-being, and social well-being.

Functional Limitations

Emotional Well-being

Social Well-being

There were few statistically significant differences between the pre- and post-lecture indices. In Question 9, significant differences were observed in the distribution of responses between baseline and follow-up, showing a change in perception. The last question with a statistically significant difference was Question 17, where we noted that the “Never” index rose from 32.1% to 79.0% and the “Once or twice” index dropped from 66.7% to 19.8%, both with a p-value <0.001. The “Sometimes” index remained at 1.2% in both moments (p-value = 1.000).

4. DISCUSSION

This study used the CPQ8-10 adapted by Barbosa et al. (2011) [16] for children aged 8 to 10 years, with 27 questions in the 4 health domains: oral symptoms (questions 3 to 7), functional limitations (questions 8 to 12), emotional well-being (questions 13 to 17), social well-being (questions 18 to 27), and 2 additional questions on global perception of oral health and general well-being (questions 1 and 2). The CPQ8-10 analysed experiences related to oral disease and how these conditions compromised the quality of life of the evaluated children, combining information about oral health status with the frequency (responses such as, for example, never, sometimes, many times) associated with that status.

This work is in agreement with the study by Rebok et al. (2001) [17], which showed that children aged 8 to 11 years are sufficiently able to understand the nature of the task and the terms presented to them, being able to explain their answers clearly and showing that they understood the questions about their oral health. This research corroborates Group I of the study by Hebbal et al. (2011) [18], in which a questionnaire with questions about oral health was applied for children to answer before and after the oral health education programme with audiovisual resources. Both studies showed that there was a change in the perception of oral health.

More than half of the children in this study reported that the intensity level of the impact was “a little” and “once or twice” in all 4 health domains (Oral Symptoms, Functional Limitations, Emotional Well-being, and Social Well-being). These results were close to those of similar studies with school-aged children in Malaysia [19] and Thailand [20], which reported “very little” and “little” intensity levels of impact. In the present study, the highest frequencies (many times/every day/very much) in the impacts of Oral Symptoms were discomfort regarding teeth (question no. 2 of the CPQ8-10: “How much do your teeth or mouth bother you?”), presence of pain (question no. 3 of the CPQ8-10: “In the last month, how many times have you had toothache or pain in your mouth?”), and dental sensitivity to cold (question no. 5 of the CPQ8-10: “In the last month, how many times have you felt pain in your teeth when you ate or drank something cold?”). The most frequent causes of impact were food impaction and difficulty chewing harder foods (questions no. 6 and 9 of the CPQ8-10: “In the last month, how many times did food get stuck in your teeth?” and “In the last month, how many times did you have difficulty biting or chewing harder foods?”, respectively). Compared with the study in Malaysia by Yusof & Jaapar (2013) [19], the most frequent causes of impact were toothache, fractured tooth, and dental sensitivity.

Despite this study not comparing with a control group (study limitation), it is in agreement with the studies by Jaime et al. (2015) [21] in Monte Sião (MG) and Nguyen et al. (2021) [22] in Vietnam, which were not sufficiently effective in reducing the incidence of dental caries. However, the present study changed the perception of oral health among the evaluated children after the oral health education programme. The CPQ8-10 questionnaire was individually administered through interviews conducted by a school teacher who was also a final-year dental student. This format facilitated the understanding, interaction, and freedom of the children when answering the questionnaire. A similar interview-based approach was used by Mendonça et al. (2021) [23]. Thus, as with the study [24] involving Brazilian students in the 8- to 10-year-old age group regarding CPQ8-10 responses, the results showed that there was an increase in the perception of oral symptoms and functional limitations of the CPQ8-10.

The oral health problems of the participants in this study did not affect school tasks, which corroborates the study by Bhadila et al. (2023) [25] in Saudi Arabia. However, in the study by Santos et al. (2019) [26] in Florianópolis (SC), oral problems affected attention in classes, and there was school absenteeism. The overall mean CPQ score varied among the studies analysed: 20.79 in the study by Mendonça et al. (2021) [23], in children aged 6 to 8 years with cavitated carious lesions in dentin in the pre-treatment phase (Brazil); 15.6 in the study by Pauli et al. (2020) [27], in children aged 8 to 10 years (Canada). In the present study, although the overall CPQ score decreased from 15.08 at T0 to 12.48 at T1, statistical significance was observed only in the functional limitation domain. The domain with the greatest impact was “oral symptoms” at T0 and T1, in agreement with the study by Pauli et al. (2020) [27].

The study by Sadana et al. (2017) [28] demonstrated that oral health education can be carried out through lectures, illustrative booklets, audiovisual resources, or a combination of these methods, with the combined approach being the most effective in enhancing knowledge on the topic. In the present study, a lecture with audiovisual resources and macromodels was given for oral hygiene instruction, in addition to the distribution of educational booklets, toothbrushes, and toothpaste. This approach is in agreement with the review by Silva et al. (2016) [29], which indicated that combined interventions, such as oral health education associated with preventive care and distribution of materials, tend to have a greater impact on reducing dental caries, while education alone was shown to be less effective.

According to the World Health Organization (WHO), the most common chronic childhood disease is dental caries. In the present study, the prevalence of caries in 8-year-old children was 51.85%, higher than the estimated global average of 43% (WHO, 2022) [2], but lower than that reported in other studies, such as SB Brazil 2010 (80.2% in 5-year-old children and 54.1% at 12 years), Mota-Veloso et al. (64.6% in Diamantina) [24], Pichot et al. (59.9% in New Caledonia) [30], and Veiga et al. (72.1% in Portugal) [31]. The mean dmft index was 1.41 before the intervention and 1.38 after three months; both values were lower than those reported in previous studies, which ranged from 3.07 to 3.86 [32]. The dmft=0 value among the children was 41.97%, close to the national average of 46.6% [33]. In the permanent dentition, dental caries was classified as very low (WHO, 2013) [34], with a mean of 0.06 in the children evaluated. The study results do not contradict the existing evidence [35] that oral health measures related to quality of life are significantly associated with subjective perceptions but are not associated with the clinical evaluation of dental malocclusion. The study by Barbosa et al. (2009) [9] did not observe clear gradients in the mean CPQ8-10 score in the categories of severity of dental malocclusion. In the study by Kallunki et al. (2018) [36], there was no statistically significant difference between the presence of unilateral posterior crossbite and normal occlusion in relation to OHRQoL, similar to the present study, in which 12.3% of the evaluated children had posterior crossbite, but no impact on OHRQoL was observed. In contrast, the study by Do & Spencer (2008) [37] indicated that Australian children with less acceptable occlusal characteristics reported worse OHRQoL.

Limitations of the study include the absence of a control group, the relatively small sample size, and the short follow-up period. The time between clinical evaluations (90 days) is too short for changes to be observed; a longer interval between evaluations could reveal clinical changes. Changes in children's perception of oral health can lead to positive long-term clinical outcomes for oral health. Parental participation in the lecture could also help incorporate hygiene habits at home, not limiting them only to the school environment.

The improvement in oral health indicators, such as the decrease in dental caries, may be associated with the fluoridation of the public water supply, greater access to dental services, the use of fluoridated toothpaste, and the impact of educational and preventive programmes for schoolchildren in the city of Bauru in the State of São Paulo [38], which may also partly explain the low DMFT values observed in the present study. The systematic review by Watt & Marinho (2005) [39] showed that all studies evaluated with oral health intervention and education were effective in the short term. Oral health is a domain where the integration of clinical and self-reported outcomes is particularly important [40].

Few studies have been conducted with long-term follow-ups, and there is evidence from other reviews showing that short-term oral health behavioural change interventions are not sustained in the long term unless there are changes in the social environment to maintain the new behaviours; however, the clinical significance of these oral health changes for public health is questionable. New studies are needed to evaluate the long-term impacts caused by untreated carious lesions and their clinical consequences on the quality of life of children, to evaluate the efficiency of these school activities in promoting oral health-related quality of life, emphasising the need to implement new programmes in public schools to improve children's oral health and achieve the WHO goals.

5. STUDY LIMITATION

This study has some limitations that should be considered when interpreting the findings. First, the absence of a control group limits the ability to establish a direct causal relationship between the educational intervention and the observed changes in children’s self-perception of oral health. In addition, the use of a convenience sample from a single public school restricts the generalisability of the results to other populations and socioeconomic contexts. The relatively small sample size and the short follow-up period of 90 days may also have limited the detection of clinically measurable changes in dmft/DMFT indices, since dental caries progression and behavioural modifications generally require longer observation periods to become evident. Furthermore, the reliance on self-reported outcomes through the CPQ8-10 questionnaire may introduce response bias related to children’s understanding, memory, or social desirability. Another limitation is that external factors potentially influencing oral health behaviours, such as parental participation, dietary habits, access to dental services, and home oral hygiene practices, were not controlled during the study period. Despite these limitations, the study provides relevant evidence regarding the potential impact of school-based oral health education on children’s oral health-related quality of life and self-perception.

CONCLUSION

The present study demonstrated that a school-based oral health educational intervention was capable of positively influencing children’s self-perceived oral health and oral health-related quality of life, even in the absence of measurable short-term changes in clinical caries indices. After the intervention, significant improvements were observed mainly in the functional limitation and emotional well-being domains of the CPQ8-10, indicating that educational strategies may increase children’s awareness and perception of oral conditions, oral symptoms, and daily functional impacts. These findings support the relevance of incorporating oral health education into public school environments as part of broader health-promotion policies aimed at improving children’s well-being and encouraging healthier behaviours from an early age.

REFERENCES