Prevalence of dental caries among children in public schools in Jeddah, Saudi Arabia

1. Introduction

Dental caries ranks among the most prevalent chronic diseases affecting children and adolescents worldwide [1]. The World Health Organization’s Global Oral Health Status Report comprehensively evaluated the global burden of oral diseases and identified caries as the most common disease affecting deciduous and permanent teeth [2]. This multifactorial disease negatively impacts oral and general health, and causes pain, infection, dietary restrictions, impaired activities of daily living, poor self-esteem and reduced quality of life [3].

Despite global advancements in dental care and prevention, dental caries remains alarmingly prevalent [2]. The high prevalence of dental caries across all age groups in Saudi Arabia presents a significant healthcare challenge [4, 5]. A recent meta-analysis revealed that dental caries remains a significant public health challenge, especially among children [6]. A synthesis of findings from numerous studies across the country revealed that the prevalence of dental caries among children is as high as 84% and 72% among those aged 5–7 and 12–15 years, respectively [6]. However, few studies have determined the caries prevalence among children in Jeddah [7, 8, 9, 10].

Assessing regional variations in caries prevalence is critical to identifying more tailored dental public health approaches. Although previous studies indicate a substantial burden of dental caries among children in Jeddah, Saudi Arabia, these studies are dated [7, 8, 9, 10, 11, 12], and new studies are needed to confirm these trends and guide effective interventions. Therefore, this study examined the dental caries prevalence and its distribution according to sex and school level among schoolchildren in Jeddah, Saudi Arabia.

2. Materials and methods

3. Results

In total, 8215 schoolchildren, aged 6–17 years, from elementary to high school levels in public schools in Jeddah were enrolled in this study. The calculated minimum sample size was met from 52 schools, which ensured comprehensive coverage and representation of the diverse school population across the 15 districts. The ICCs for the DMFT index scoring for inter-rater and intra-rater reliabilities were 0.82 (95% confidence interval (CI): 0.79, 0.85) and 0.91 (95% CI: 0.89, 0.93) respectively. The Cohen kappa values for inter-rater and intra-rater reliabilities for gingivitis and oral hygiene assessments ranged from 0.83 to 0.98.

Our study included 8215 schoolchildren from the Jeddah governorate, Saudi Arabia (Table 1). The sex distribution of included schoolchildren was 60.8% female (n = 4992) and 39.2% male (n = 3223). Most participants were from elementary schools (79.1%, n = 6496), with smaller proportions from middle schools (11.5%, n = 948) and high schools (9.4%, n = 771). The average ages of participants according to school levels were 8.3 years (standard deviation (SD) = 1.7) for elementary students, 14.5 years (SD = 0.9) for middle school students and 16.5 years (SD = 0.6) for high school students.

The geographic distribution of schools included in our study is presented in Fig. 1 and classified according to the United Nations Human Settlements Programme urban-density classification [18]. In moderate-density areas, we visited 10 schools, including 4 female-only schools and 6 male-only schools. In high-density areas, we visited 28 schools, including 18 female-only schools and 10 male-only schools. In very high-density areas, we visited 28 schools, including an equal distribution of 14 female-only and 14 male-only schools.

Fig. 1.Geographic distribution of visited schools in Jeddah classified according to the population density. Produced using Esri. ArcGIS Pro. Version 3.4.0. Redlands, CA: Environmental Systems Research Institute; 2024.

Table 2 presents data regarding the presence of gingivitis, participants’ oral hygiene, and the urgency of dental care needs, stratified according to sex and school level. Good oral hygiene was observed in 18.9% of the schoolchildren, whereas fair to poor oral hygiene was more prevalent (81.1%). Oral hygiene status varied according to sex, with females (19.5%) slightly surpassing males (17.9%) in exhibiting good oral hygiene (p = 0.02). However, the prevalence of gingivitis in children differed significantly according to sex. Specifically, 35.0% of schoolchildren exhibited symptoms of gingivitis, defined as redness of the gingival tissue. The risk of gingivitis was higher in males than in females (odds ratio, 1.4; 95% confidence interval, 1.3–1.5; p < 0.001). However, no significant sex differences were found regarding the urgency of dental care needs.

When stratified according to school level, the oral hygiene level, prevalence of gingivitis and treatment urgency varied significantly. Higher-grade schoolchildren had significantly better oral hygiene, compared with lower-grade schoolchildren (p < 0.001).

Regarding oral hygiene status, good hygiene was slightly more prevalent in high school children (21.1%) than in middle- (19.1%) and elementary school children (18.6%), with significant differences across school levels (p < 0.001). However, elementary school children had the lowest prevalence of gingivitis (27.7%), compared with middle- (61.1%) and high school children (62.0%) (p < 0.001). The urgency of the need for dental care varied significantly according to school level (p < 0.001), with 37.1% of elementary school children showing the most urgent need for dental care, compared with 21.9–25.7% of children from higher school levels.

The total caries experience and prevalence of untreated decayed teeth among the schoolchildren were 91.2% and 86.1%, respectively. Fig. 2 shows the caries experience and prevalence of untreated decay, stratified according to sex and school level. Although no significant sex differences in caries experience and untreated decay were observed, a significantly higher proportion of primary school children (87.1%) had untreated caries compared with middle- and high school children (81.6% and 83%, respectively) (p < 0.0001).

Fig. 2.Prevalence of untreated caries and caries experience stratified according to (a) sex, (b) school level and (c) dentition type. *Statistically significant differences at p ≤ 0.05. Connecting bars indicate statistically significant pair-wise comparisons (p < 0.0001).

The care index indicated that 10.1% of carious teeth were treated, with females having a significantly higher care index, compared with males (12.6% vs. 8.5%; p < 0.001) (Table 3). The mean dmft index was significantly higher in females than in males (4.22 ± 4.00 vs. 4.02 ± 3.89; p = 0.042). When analyzing the components of the dmft index, the mean number of decayed (d) and filled (f) teeth were significantly higher in females than in males, whereas the opposite trend was observed for the mean number of missing (m) teeth (p < 0.001). The mean DMFT index was slightly higher in females (1.97 ± 2.860) than in males (1.88 ± 2.681); however, the difference was not statistically significant (p = 0.71). Regarding the components of the DMFT index, the mean number of decayed (D) teeth was comparable between the sexes (p = 0.23); however, significant differences were observed in the mean number of missing (M) and filled (F) teeth between the sexes. The observed effect sizes by sex were generally small; the largest was noted in the caries care index (d = 0.13), which was considered small.

The care index showed a notable increase with increasing school levels, rising from 8.5 to 22%. The mean dmft index for elementary school children was 5.23 ± 3.77, whereas that for middle- and high school children was 4.67 ± 3.41 and 5.76 ± 3.97, respectively (Table 4). The dmft index decreased with increasing school levels, while the DMFT index increased. The effect sizes reported in our study, using partial eta squared (η²), highlighted significant variability among different school levels. The most notable differences were observed in the dmft index (η² = 0.38) and the DMFT index (η² = 0.28), indicating moderate to large effects and suggesting that the school level significantly influences these indices.

4. Discussion

This study revealed a high prevalence of dental caries among public school children in Jeddah, indicating a significant burden, with 86%–91% of children having untreated decay. Our findings align with those of Adam et al. [6], who reported a caries prevalence of 72%–84% in Saudi Arabian children across different regions. Similarly, a systematic review by Al Agili reported a caries prevalence of 80% and 70% in the primary and permanent dentitions, respectively [5]. Nevertheless, a Saudi nationwide study reported a lower caries prevalence of 65.6%, which is also high [4]. The high prevalence of untreated decay in this study and Saudi Arabia generally, is multifactorial and could be attributed to the underutilization of dental services, poor awareness of oral health, poor preventive dental care practices [19, 20, 21], poor oral hygiene behavior among children such as irregular brushing and high sugar consumption [22, 23], high reported dental fear and anxiety among children associated with an avoidance of routine dental care [24], low level of oral health literacy [25], cultural attitudes towards dental health influenced by factors such as mother’s education levels [12] and mother’s sugar intake [26], and reactive health-seeking behavior [27].

This study revealed differences in the oral hygiene status according to sex, with female schoolchildren generally having better oral hygiene than male schoolchildren. This aligns with the findings in a previous study that male adolescents exhibited poorer oral hygiene behaviors and were more likely to develop gingivitis, compared with female adolescents, underscoring the influence of sex on oral health outcomes [28]. In another study conducted across various regions of Saudi Arabia, the prevalence of gingivitis among high school children was higher in males than in females [29]. The higher prevalence of gingivitis in males may be attributed to heightened innate immune responses, increased pro-inflammatory cytokine production (e.g., Interleukin-6), and immunomodulatory effects of testosterone, which can suppress humoral immunity, collectively leading to a more pronounced inflammatory response to microbial pathogens [30]. Our results showed that elementary school children were the least likely to develop gingivitis, with a significant increase in prevalence among middle- and high school children. This finding that the prevalence of gingivitis in children increases with age is consistent with that of a previous study [31].

Our study revealed a significantly greater proportion of untreated dental caries among primary school children than in middle- and high school children with a moderate to large size effect in the dmft and DMFT indices, suggesting that the school level significantly influences dental caries prevalence. These notable effect sizes are indicative of a substantial practical significance, particularly in customizing preventative care and treatment needs based on the school level. This finding is consistent with that of a Saudi nationwide study, in which a higher prevalence of caries was observed among 6-year-old children (72.1%), followed by 15-year-old (66.5%) and 12-year-old (57.9%) children [4]. These findings suggest a critical need for targeted dental health interventions starting in early childhood in Saudi Arabia. Additionally, a cross-sectional study among children in Almadinah Almunawwarah City found that caries prevalence was high among 6-year-old (86%) children but decreased at the age of 12 years (68%) [32]. Similarly, in a study conducted in schools in Riyadh, the incidence of dental caries in 6-, 12- and 15-year-old children was 85.77%, 64.98% and 71.35%, respectively [20]. Our findings are consistent with those of previous studies, which indicated that dental caries is more prevalent in the primary dentition than in the permanent dentition, although the difference is not statistically significant [4, 5, 6, 10, 12, 32]. This pattern underscores the critical need for targeted dental interventions at an early age.

In our study, the mean dmft index was higher in female schoolchildren than in male schoolchildren. However, the observed effect sizes by sex were generally small, indicating minimal practical significance despite statistical significance. A possible explanation for the higher dmft index among female schoolchildren compared to male schoolchildren may be that females experience the earlier eruption of teeth and are more likely to seek dental services as evidenced by the higher filling component of the dmft index for females [33]. A previous national study reported that the dmft index was higher in male schoolchildren than in female schoolchildren [4], whereas another study among schoolchildren in the eastern region of Saudi Arabia reported no significant difference in the dmft index between the sexes [34]. Our findings align with those of a study conducted in Almadinah Almunawwarah City, which reported that among 6-year-old children, the mean number of decayed teeth (d component) was higher in girls than in boys [32]. In our study, we found no significant differences in the mean DMFT index between the sexes, which is consistent with the findings in a study conducted in the Hail and Tabuk regions [35]. Consistent with our findings, a national study found that among Saudi children aged 12–15 years, females had a higher mean number of filled teeth (F component) and a higher care index compared with males [4]. This can be explained by the high rate of dental visits among female children [36].

While no single factor fully explains the regional discrepancies in caries prevalence, several interrelated factors may contribute to the high prevalence of dental caries among Saudi children. A study on dental service accessibility in Saudi Arabia identified several obstacles, including extensive waiting times, availability of only basic treatments, and perceived lower quality of care in government dental clinics than in private clinics [37]. Moreover, this high prevalence may be influenced by cultural dietary habits, such as the frequent consumption of sugary food and carbonated drinks [34]. Additionally, a lack of parental oral health awareness was a common reason for children not receiving dental care, especially among those who had never visited a dentist [38].

The World Health Organization’s (WHO) Global Oral Health Action Plan (2023–2030) aims to achieve universal health coverage for oral health by 2030, ensuring that at least 80% of the global population has access to essential oral health services [39]. However, the high prevalence of untreated dental caries observed in this study indicates that considerable efforts are needed to bridge this gap, particularly among school-aged children in Saudi Arabia, to align with the WHO’s goal of reducing the global burden of oral diseases by 10% [39].

Early detection and intervention for dental issues among schoolchildren are essential to preventing more severe dental problems [40]. Enhanced training and education of schoolteachers can improve their ability to detect dental caries and facilitate timely referrals of children to dental services [41]. Consequently, children at risk of developing caries can receive appropriate care, thereby reducing the long-term health effects of untreated dental conditions [40].

Several studies have demonstrated the effectiveness of dental sealants, emphasizing their importance in preventive dental care [42]. Implementing school-based dental sealant programs can significantly reduce the prevalence of dental caries among schoolchildren. Moreover, by integrating dental sealant programs within schools, socioeconomically disadvantaged children can be reached [43]. In addition to addressing immediate health needs, this strategy helps close the gap in oral health disparities over time [43].

This study had some limitations. First, the cross-sectional design limited the ability to establish causality, offering only a snapshot of caries prevalence at one point in time. Second, this study did not assess potential confounding factors such as socioeconomic status, dietary habits, oral hygiene practices, dental care access and fluoride exposure. The absence of these factors may limit the ability to fully interpret disparities observed in the study. Third, this study focused on schoolchildren in the Jeddah governorate and did not capture oral health across Saudi Arabia. Fourth, the sample included a greater proportion of female schoolchildren (60.8%) than male schoolchildren and included more elementary school students (79.1%) than middle school and high school students. The greater number of female-only schools (36) compared to male-only schools (30) was owing to lower participation from male-only schools. This may introduce selection bias, as participation could be influenced by school policies or administrative willingness. While no statistical adjustments were made, the study’s stratified sampling and large sample size improved representativeness. Fifth, although dental students receive calibration training, the subjective nature of clinical assessment may introduce assessment bias, potentially affecting oral health status evaluations. Finally, the study was conducted only in public schools and did not use weighted sampling, which restricts the generalizability of the findings. Despite these limitations, this study’s large sample size and updated data provide a comprehensive snapshot of the current trends in dental caries prevalence among schoolchildren in Jeddah, Saudi Arabia. Longitudinal studies examining the impact of fluoride use, dietary patterns, and dental care access could offer deeper insights into caries progression and guide targeted public health interventions.

5. Conclusions

In conclusion, the prevalence of dental caries among Saudi schoolchildren continues to be a significant public health concern. This study enhances our understanding of the current prevalence of dental caries in schoolchildren in Jeddah and highlights the need to revamp dental public health approaches for prevention. Furthermore, early preventive interventions should be tailored to the needs of the high-risk groups identified in this study. Our findings provide evidence-based guidance for health policymakers, enabling them to make informed decisions and shape effective oral health strategies. Future studies should continue to monitor these trends over time and assess the effectiveness of existing and emerging preventive programs designed to reduce the incidence of dental caries among children.

Abbreviations

CI, confidence interval; dmft/DMFT, decayed, missing, and filled teeth; ICC, intraclass correlation coefficient; SD, standard deviation; η², Eta-squared effect size; RBC, Rank-Biserial Correlation effect size; STROBE, Strengthening the Reporting of Observational Studies in Epidemiology; WHO, World Health Organization; UN-Habitat, The United Nations Human Settlements Programme; OHI-S, Simplified Oral Hygiene Index.

Availability of data and materials

The datasets used during the current study are available from the corresponding author on reasonable request.

Author contributions

DM and LB—designed the research study, analyzed the data. DM, LB, HA, AA, NF, AK, LA, DS, MS, MR and MB—performed the research, wrote the manuscript. DS, LB, MR and MB—helped with preparation for school visits. All authors contributed to editorial changes in the manuscript. All authors read and approved the final manuscript.

Ethics approval and consent to participate

This study was approved by the Ethical Research Committee, Faculty of Dentistry at King Abdulaziz University (#17–01-24) and adhered to the guidelines outlined in the Declaration of Helsinki. Approval to visit the schools was obtained through formal correspondence with the Ministry of Education authorities. Parental consent was obtained using an opt-out method, where parents were informed about the study and had the opportunity to decline participation. To protect participants’ privacy, no personally identifiable information was collected, and all data were recorded anonymously. Consent forms and data records were stored securely and were accessible only to authorized researchers.

Acknowledgment

The authors thank Lujain K. Balamash for her assistance with data entry and management and Kamil Faisal from King Abdulaziz University, for his valuable advice regarding the Geographic Information System (GIS) used to generate the map.

Funding

The project was funded by KAU Endowment (WAQF) at King Abdulaziz University, Jeddah, Saudi Arabia under grant no WAQF: 01-165-2025. The authors, therefore, acknowledge with thanks WAQF and the Deanship of Scientific Research (DSR) for technical and financial support.

Conflict of interest

The authors declare no conflict of interest.