Dental caries is a common oral health issue across all age groups, but poses a particularly severe problem for pediatric and adolescent patients with disabilities. These patients often face significant challenges in maintaining their oral health, leading to an increased risk of developing dental caries[1,2]. Children and adolescents with disabilities encounter numerous obstacles in their daily oral hygiene routines, including difficulties with brushing and flossing, limited manual dexterity, and a lack of understanding of oral health management[3]. Additionally, these patients frequently have limited access to professional dental care due to barriers such as transportation issues, financial constraints, and a shortage of dental professionals specializing in treating individuals with disabilities[4]. Krause et al.[5] reported that children and adolescents with disabilities are less likely to brush their teeth twice daily and are less likely to use preventive dental services than their non-disabled peers, resulting in a higher risk of caries and other oral health problems[2,6,7].

Given the significant limitations these patients face in their daily oral hygiene and access to dental care, the role of caregivers becomes critically important. Caregivers’ awareness of and practices regarding oral health can directly and indirectly influence the dental health of the patients they care for[8-10]. By examining how caregivers’ oral health awareness and management practices influence the dental health of patients with disabilities, valuable foundational data can be provided for the development of educational programs and policies aimed at improving the oral health of this vulnerable population.

This study aimed to investigate the experience of dental caries among pediatric and adolescent patients with disabilities and to examine the impact of various factors on dental health. Specifically, this study aimed to elucidate how caregivers’ oral health awareness and practices affect the prevalence and severity of dental caries among these patients.

This study was approved by the Institutional Review Board (IRB) of Chonnam National University Dental Hospital, and written consent was obtained from all caregivers after explaining the purpose and procedures of the study (IRB No. CNUDH-2024-004).

This study was conducted to analyze the relationship between the oral health status and oral care behaviors of children and adolescents with disabilities, the role of caregivers, and the importance of oral health management. The study found that caregivers assisted with tooth brushing in 130 of 141 cases (92.2%), which is a higher rate than that reported by Liu et al.[8], where 304 out of 503 caregivers (60.44%) provided assistance. Ninety out of 141 participants (63.8%) brushed their teeth twice a day, a finding consistent with that of Liu et al.[8], who reported that 55.87% brushed twice daily. However, the current study also found that that most did not floss regularly. This finding also aligns with that of Liu et al.[8] who reported 46.12% flossed daily, highlighting the need to educate caregivers on the importance of flossing.

Kendall’s tau correlation analysis showed a significant negative correlation between toothbrushing frequency, flossing frequency, and PI, indicating that higher toothbrushing and flossing frequencies lead to reduced plaque accumulation, thus improving oral health. These results are consistent with the existing literature, reaffirming the importance of regular oral hygiene practices[12].

The DMFT/dmft index showed a positive correlation with the level of assistance in toothbrushing, suggesting that children who brush their teeth independently have higher DMFT indices. This finding is consistent with previous studies that reported better oral health and lower caries incidence in children whose caregivers assisted with tooth brushing[8,13,14]. However, Paino-Sant’Ana et al.[15] found that children who received full assistance had worse dental outcomes than those who received less assistance.

Furthermore, the DMFT/dmft index showed a negative correlation with toothbrushing frequency, indicating that higher toothbrushing frequency is associated with a lower DMFT/dmft index, in line with previous studies[16-18], thus emphasizing the importance of regular toothbrushing.

The high positive correlation between check-up frequency and fluoride application frequency suggests that regular oral check-ups are closely related to fluoride applications. Regular dental checkups provide an opportunity to detect early dental caries and take preventive measures, whereas fluoride application effectively prevents tooth decay, making it desirable to implement them concurrently[19,20].

Caregivers’ perception of the importance of oral health showed a positive correlation with their level of oral health knowledge, indicating that caregivers who consider oral health important tend to have higher levels of oral health knowledge. Additionally, there was a positive correlation between oral health knowledge and toothbrushing frequency, suggesting that higher caregiver oral health knowledge leads to more frequent toothbrushing by the child. These findings underscore the importance of enhancing caregivers’ awareness and knowledge of oral health to improve the oral hygiene practices of patients, and thus improve overall health outcomes.

Significant differences were found in the DMFT/dmft index according to disability type. Post-hoc tests revealed that individuals with intellectual disabilities and those with multiple disabilities had higher DMFT/dmft indices than those with autism and neurological disabilities. This finding is consistent with the challenges faced by individuals with intellectual disabilities, who often struggle with oral hygiene due to a combination of communication difficulties, limited understanding of oral care practices, and physical limitations. These challenges can delay the diagnosis and treatment of oral health issues, as individuals may have difficulty expressing pain or discomfort. Additionally, their ability to perform routine dental care tasks, such as brushing and flossing, is often hindered by fine motor skill impairments, necessitating greater involvement from caregivers.

Providing oral care for individuals with intellectual disabilities requires a tailored approach that considers their mental, behavioral, and physical challenges. Patients may struggle with understanding and cooperation during dental visits, making it essential to simplify communication, reduce distractions, and maintain consistency in staff and environments. Direct engagement with the patient using simple, repetitive instructions, along with ensuring that the entire dental team is aware of the patient’s needs, helps create a supportive and calming atmosphere. Behavioral challenges, such as anxiety about dental treatment, may manifest as uncooperative behaviors. To manage these, early appointments and short, focused sessions are recommended, allowing the patient time to acclimate to the dental environment. Techniques such as nitrous oxide sedation may be considered to alleviate anxiety, with informed consent[21].

Caregivers play a critical role in maintaining the oral health of individuals with intellectual disabilities by establishing a consistent hygiene routine, including twice-daily brushing and daily flossing. Using appropriate tools, such as larger-handled or electric toothbrushes, may be necessary to accommodate fine motor skill challenges, and caregivers may need to assist with these tasks directly. Clear instructions and positive reinforcement can enhance cooperation, while limiting sugary snacks and drinks helps prevent tooth decay. Regular dental visits are essential, and caregivers must communicate any specific needs to the dentist. Adaptability is key, as routines may need to be adjusted to fit the individual’s abilities and comfort level. Through these practices, caregivers can significantly reduce the risk of dental problems and support the overall well-being of those with intellectual disabilities.

Furthermore, it is important to note that individuals with multiple disabilities, particularly those with cognitive and motor impairments, tend to experience even greater challenges in maintaining oral hygiene. Studies by Lee et al.[6] and Alkhabuli et al.[22] support these findings, indicating that these populations often have poorer oral hygiene outcomes.

Among our participants, 4 individuals (2.8% of the total study population) had both autism and intellectual disabilities. Of the 71 participants with autism, 4 (5.63%) also had intellectual disabilities, while 4 (8%) out of 50 participants with intellectual disabilities also had autism. These findings contrast with data from the United States Centers for Disease Control (CDC), which reported in 2008 that 38% of children with autism have intellectual disabilities and that 10% of individuals with intellectual disabilities have autism[23]. The lower co-occurrence rates in our study may be due to differences in sample demographics and diagnostic criteria.

In Korea, disabilities are categorized into various types, including neurological, mental, physical, autistic, visual, and hearing impairments. Historically, disability grades ranged from 1 to 6, but the grading system was abolished in 2019. This decision was made to ensure that services for people with disabilities were provided uniformly based on medical evaluations. Grades 1 - 3 were classified as severe disabilities and grades 4 - 6 as mild disabilities[24]. Although this study aimed to explore oral hygiene status according to the type and severity of disabilities, the sample included only two individuals with mild disabilities among 141 participants, limiting the analysis to oral hygiene status based on disability type.

Significant differences were also observed in the DMFT/dmft index according to the level of assistance provided during tooth brushing. Post-hoc tests indicated that individuals who received 50% or no assistance had higher DMFT scores than those who received 100% or 20% assistance. There were also significant differences in the PI and DMFT index according to brushing frequency. Groups that brushed their teeth twice a day or fewer had a higher PI than those who brushed their teeth three times a day or more, whereas those who brushed their teeth three times or more had the lowest DMFT index. These findings align with those of previous research by Perkowska et al.[25], who also found that individuals who brushed twice daily had lower average DMFT indices than those who brushed less frequently. Significant differences in the PI were also observed based on flossing habits, with non-flossers having a higher PI than those who flossed. These results were consistent with prior research[26,27].

No significant difference was found between the frequency of sweet food consumption and the DMFT/dmft index, which contradicts previous studies that reported a higher DMFT/dmft index with increased sweet food consumption[10,28]. However, there was a significant difference in the DMFT/dmft index based on the frequency of sugary drink consumption, with the group that consumed sugary drinks more than once a day having the lowest DMFT/dmft index. This result is inconsistent with those of prior studies, such as that of Mahboobi et al.[29], who found that daily consumption of 100% juice, weekly candy consumption, and drinking sugary beverages before bed were all associated with a higher risk of dental caries. In contrast, Chankanka et al.[30], Leroy et al.[31], and Ghazal et al.[32] did not observe a significant association between consumption of sugary drinks and caries. Huew et al.[33] also found no statistically significant relationship between the frequency of consuming sugared soft drinks, squash, or unsweetened natural fruit juices and caries experience, although there was a weak but significant association between caries experience and the consumption of sports and sugar-free soft drinks. However, there was no statistically significant relationship between caries experience and the frequency of consuming sugared tea with milk, flavored milk, or milk. Given the contrasting results between previous studies and the current study, further research is required. Detailed studies controlling for various factors, such as the type of sugary drink, timing of consumption, and oral hygiene practices after consumption, are required to better understand their impact on the DMFT index.

There was also a significant difference in the PI based on the frequency of dental checkups, with those receiving check-ups once every 1 - 2 months having a significantly higher PI than those receiving check-ups once every three months, or 1 - 2 times a year. This could be attributed to the fact that while regular dental checkups are generally conducted every three months in our pediatric dentistry department, patients with poor oral hygiene management are scheduled for more frequent appointments. Among the 14 individuals who have dental check-ups every 1 - 2 months, 6 have intellectual disabilities, 3 have autism, 1 has a neurological disability, and 4 have multiple disabilities. Of those with multiple disabilities, 1 has a combination of neurological and hearing impairments, 1 has both intellectual and neurological disabilities, 1 has intellectual and hearing impairments, and 1 has both autism and neurological disabilities. These patients typically visit the hospital for oral prophylaxis and fluoride treatments because their caregivers have difficulty in brushing their teeth adequately. Krause et al.[5] reported that approximately 25% of children with and without disabilities received fewer than two dental checkups per year, whereas approximately 75% received two or more checkups annually, with no significant difference in check-up frequency based on disability status. In this study, 75% of the patients underwent checkups at least once every three months, likely because the study was conducted among patients who had already visited the dental clinic.

When examining the proportion of assistance provided by caregivers for toothbrushing among different types of disabilities, it was found that patients with neurological disorders required the most help, with caregivers providing 100% assistance in most cases. The majority of the patients with neurological disorders in this study had cerebral palsy, in which motor impairments such as spasticity, dyskinesia, and ataxia are common[34]. These motor impairments make it difficult for the patients to brush their teeth independently, necessitating significant caregiver involvement.

In a study by Abdullah et al.[35] on adults with intellectual disabilities, the proportion of patients who brushed their teeth twice or more daily was 87.3%, which is similar to the 87.9% observed in this study. However, 47.2% of patients in their study used interdental tools such as floss, interdental brushes, or toothpicks, which is higher than the 34.8% who used floss in this study, indicating greater use of interdental tools in adults. Additionally, the proportion of patients receiving regular check-ups was 93.6% in this study, compared to 58.8% in their study and 88.0% in Nonoyama et al.[36]’s study, suggesting that adult patients with disabilities receive fewer regular check-ups than pediatric patients. However, the higher percentage in this study may be due to the participants having already visited the dental clinic.

In a study by Minihan et al.[37] on adults with developmental disorders over the age of 20, 15.4% brushed their teeth independently, while 40.2% had complete caregiver assistance. In comparison, this study found that 7.8% brushed independently, and 49.6% received full caregiver assistance, indicating that pediatric and adolescent patients with disabilities receive more caregiver support. Additionally, in a study by Mac Giolla Phadraig et al.[38] on elderly patients with intellectual disabilities, where the mean age was 59.7 years, 48.5% brushed independently, and 25.2% had complete caregiver assistance, showing that full caregiver assistance decreases with age.

In the study by Lee et al.[6], the DMFT index for adults with disabilities aged 20 to 80 was reported as 7.26 ± 7.62 for those with physical disabilities, 8.26 ± 7.90 for those with mental disabilities, and 8.17 ± 7.83 for those with multiple disabilities. These figures are higher than the average DMFT + dmft of 6.56 ± 4.69 observed in pediatric and adolescent patients in this study. The study also found that the DMFT index increases with age in both disabled and non-disabled individuals, with a more pronounced increase in missing teeth among the disabled. Unlike in non-disabled individuals, dental caries in people with disabilities is often left untreated or managed through extraction rather than with conservative treatments[39]. This underscores the need for enhanced preventive care and education for patients with disabilities.

The findings of this study underscore the importance of active caregiver participation and regular oral hygiene management for maintaining oral health in pediatric and adolescent patients with disabilities. It is especially crucial for caregivers to assist with tooth brushing, encourage regular brushing and flossing, and ensure that patients receive regular dental check-ups and fluoride treatment. This study also highlighted the need for various improvements to enhance access to dental care for patients with disabilities. These include expanding specialized dental care centers for individuals with disabilities, increasing the number of dental professionals specializing in treating patients with disabilities, and addressing issues related to transportation and caregiving support. Such improvements require the support of the government and related institutions. The results of this study can serve as valuable foundational data for the development of policies and educational programs aimed at improving the oral health of patients with disabilities.

As a cross-sectional study, this research has limitations in terms of establishing causal relationships. Future research should involve longitudinal studies to clarify the causal links between oral health management behaviors and outcomes in patients with disabilities. Although this study aimed to examine all types of disabilities through surveys and clinical examinations, the majority of the participants were patients with autism and intellectual disabilities. As a result, the findings predominantly reflect the outcomes of those with mental disabilities. Future research should include a larger and more diverse population to explore the oral health of various disability types in greater detail. Additionally, since the study focused on patients and caregivers already engaged with hospital care, the level of oral health awareness and practices may be higher than that of the general disabled population. This selection bias could limit the generalizability of the findings to those who do not regularly seek dental care. Conducting studies in special schools or facilities might have yielded more generalizable results, even if clinical assessments like DMFT or PI were more challenging to perform.

This study explored the correlation between oral health status and oral hygiene practices in pediatric and adolescent patients with disabilities, emphasizing the crucial role of caregivers and the importance of regular oral hygiene management. The findings highlighted the significant impact of active caregiver involvement in maintaining oral hygiene and showed the positive effects of regular oral hygiene practices on oral health. The analysis also indicated that patients with intellectual disabilities and multiple disabilities require special attention for oral health management. Caregivers’ awareness of the importance of oral health was linked to higher levels of oral health knowledge and more frequent brushing of patients, underscoring the need to enhance caregivers’ understanding and knowledge. There is a need to enhance access to dental care for patients with disabilities by expanding specialized dental centers, increasing the number of dental professionals trained to treat patients with disabilities, and providing government financial support.