Impact of the severity and extension of dental caries lesions on Turkish preschool children’s oral health-related quality of life: a cross-sectional study
Oral and dental health, which is contingent on the presence of functional teeth, is closely linked to overall health and quality of life. Optimal oral health is essential for proper nutrition, a basic human need that promotes positive social interactions, boosts self-confidence, and contributes to overall well-being . Among preschool children aged 3–6 years, dental caries, dental trauma, toothache, and abnormal tooth eruption are among the most prevalent public health issues worldwide . Dental caries is a dental condition that not only poses a clinical challenge but also represents a multifaceted social, political, medical, psychological, and economic problem. Dental caries is prevalent among children who are at a high risk of caries or medically disabled, regardless of their ethnic or cultural background. Children at high risk for dental caries include those with chronic diseases impacting saliva flow rate and composition , orthodontic appliances , medication usage, lack of access to medical care , active caries lesions in their mothers and siblings, low family socio-economic and educational levels, frequent consumption of sugary and cariogenic foods, inadequate use of fluoride toothpaste and supplements , and high counts of Streptococcus Mutans and Lactobacillus in saliva . Dental caries not only affects general health but also has a significant negative impact on the quality of life of affected individuals . The pufa Index, devised by Monse et al.  is a tool used to document the consequences of untreated dental caries. The pufa Index is an important clinical tool used to measure the consequences of untreated dental caries, particularly in children. It stands for “pulpal involvement, ulceration, fistula, and abscess,” which are the severe stages of tooth decay that can lead to significant pain and infection . This index helps in identifying and recording the presence of these serious dental conditions, providing a comprehensive overview of the impact of dental caries on oral health. By highlighting the severity and progression of dental decay, the pufa Index aids in the assessment of treatment needs and the prioritization of dental care, especially in populations with limited access to dental services . Understanding and utilizing the pufa Index is crucial for dental professionals to address the urgent and complex needs of patients suffering from advanced caries. The measurement of oral health-related quality of life (OHRQoL) serves as a complementary tool for evaluating treatment requirements, emphasizing the importance of oral and dental care, and assessing treatment outcomes . Several instruments have been developed to measure OHRQoL among children, including the Early Childhood Oral Health Impact Scale (ECOHIS), which is administered to parents or caretakers of preschool children to evaluate the OHRQoL of their wards . In 2007, the ECOHIS was introduced by researchers from North Carolina University. Since then, the scale has been translated into several languages, including Arabic , Portuguese , Chinese , and Spanish , with cultural adaptation or translation. While the relationship between the ECOHIS and several factors related to dental caries, such as caries prevalence, caries depth, untreated caries, and caries severity, has been investigated in literature, there are limited studies evaluating the effect of pufa score on ECOHIS in our country. While previous studies  have explored the impact of untreated dental caries on the oral health-related quality of life (OHRQoL) in preschool children, there is a lack of studies specifically focusing on the pufa index and its relationship with the ECOHIS in Turkish preschool children. Our study aims to fill this gap by evaluating the severity and extension of dental caries using the pufa index, alongside other measures like ICDAS and dmft, to provide a comprehensive understanding of how these variables impact the OHRQoL in this population. This contributes to the existing literature by offering insights specific to Turkish preschool children, a population where such data is limited.   Study design The study adhered to the ‘Strengthening the Reporting of Observational studies in Epidemiology’ (STROBE) guidelines as outlined in Supplemental Material 1. This cross-sectional study involves the participation of children between the ages of 3 and 6 years who visited the Pediatric Dentistry department of the Recep Tayyip Erdoğan University Faculty of Dentistry. The study was conducted with ethical approval from the Non-Interventional Clinical Research Ethics Committee Presidency of the Recep Tayyip Erdoğan University Faculty of Medicine, under decision number 2020/18, dated 06.02.2020. A Participation Consent Statement was obtained from all children and their parents who were accepted to the study with their own consent. In addition, informed consent was obtained from the parents of all children via an Informed Consent Form. Study sample To determine the required sample size for our study, we performed a power analysis using the Pearson correlation coefficient ( r = 0.319) between pufa and OHIP scores from the study of Praveen et al. . The analysis was conducted using G*Power 3.1.9.4 software. Key parameters for the power analysis included a significance level (α) set at 0.05, which is the conventional threshold for statistical significance, and a desired power (1-β) set at 0.95 to ensure a high probability of detecting a true effect if one exists. The effect size was calculated using Fisher’s z-transformation of the correlation coefficient, resulting in an effect size of approximately 0.331. Based on these parameters, the analysis revealed that a total sample size of approximately 238 participants is necessary to detect the specified correlation with 95% power. However, we chose to include 300 children aged 3–6 years in the study to increase the statistical power, enhance the generalizability of the findings, allow for more robust subgroup analyses, account for potential attrition, and capture the variability in responses. This larger sample size ensures a more comprehensive and reliable analysis of the relationship between dental caries, the pufa Index, and OHRQoL. Eligibility criteria The inclusion criteria for our study encompass children aged 3 to 6 years, with the requirement that both the children and their parents or caregivers provide informed consent to participate in the study. Additionally, children who are available for follow-up and data collection throughout the study period are also part of the inclusion criteria. Children within this age group are included in the study regardless of whether they have dental caries. The exclusion criteria, on the other hand, include uncooperative children, children with systemic diseases, children with enamel anomalies, children whose parents or caregivers did not provide informed consent, those who withdrew from the study at any point, and those with incomplete or insufficient data. These criteria ensure that the study is conducted on a homogeneous population and that the results can be attributed to the factors being studied. Measurements An initial clinical intraoral examination was conducted in accordance with World Health Organization (WHO) recommendations . Before the measurements, the examiner (D.B.) underwent a training and calibration process, which included both theoretical and clinical phases. Theoretical training covered the criteria and application of the dmft, ICDAS, and pufa indices. The clinical phase involved examining a sample group of children under supervision, with evaluations conducted two weeks apart to test intra-reliability. Perfect agreement was validated with a kappa score of > 0.80, confirming the consistency of the examiner. All children with parental consent were examined by a single researcher (D.B.) in the dental unit, under the light of the unit. A sterile dental Shepherd’s hook explorer and mirror were used for the examination. The presence of dental caries was determined using the decayed, missing, and filled teeth index (dmft) . The dmft Index records of the children were classified into two categories: dmft = 0 and dmft ≥ 1. Additionally, the Turkish version of the ECOHIS (T-ECOHIS) questionnaire was administered face-to-face with the children’s parents/caregivers. The examiner received specific training on how to read and intonate each question to ensure consistency and reduce bias during the interviews. ECOHIS has also been culturally adapted and validated for use in Turkish preschool children by Peker et al. , thus ensuring its suitability and accuracy in measuring oral health-related quality of life in this population. The International Caries Detection and Assessment System II (ICDAS), introduced in 2004, was used to evaluate the extent of caries in the oral cavity. This system provided a scoring system based on both visual and tactile examination criteria for teeth. The scores ranged from zero, representing no carious lesions, to six, indicating severe carious lesions. Individuals were categorized into four groups based on their maximum scores: ICDAS 0, ICDAS 1 and 2, ICDAS 3 and 4, and ICDAS 5 and 6 . In the assessment of the pufa index, specific procedures were followed. Initially, pulpal (p) involvement is noted when the opening of the pulp chamber is visible or when the coronal tooth structures have been eroded by the carious process, leaving only roots or root fragments. No probing is done to diagnose pulpal involvement. ulceration (u), resulting from trauma caused by sharp tooth fragments, is documented when sharp edges of a dislocated tooth with pulpal involvement, or root fragments, have caused traumatic ulceration of the surrounding soft tissues, such as the tongue or buccal mucosa. Fistula (f) is noted when a pus-releasing sinus tract related to a tooth with pulpal involvement is present. Abscess (a) is recorded when a pus-containing swelling related to a tooth with pulpal involvement is present . During the examination, the examiner recorded each condition for each affected tooth. The total pufa score was then calculated by summing the number of teeth that exhibited any of these conditions. In the second phase of the study, parental interviews were conducted in person to collect demographic data and obtain responses to the ECOHIS scale. The resulting scores offer an assessment of the severity of oral health-related quality of life issues, with higher scores indicating a greater impact. The ECOHIS scale is based on parental evaluations of 13 items categorized into two main parts: the child impact section (CIS) and the family impact section (FIS). The child impact section encompasses four domains: child symptoms (1 item), child functions (4 items), child psychology (2 items), and child self-image and social interaction (2 items). The family impact section consists of two domains: parental distress (2 items) and family function (2 items). Responses to each question are rated using a 4-point Likert scale, reflecting the frequency of a particular event occurring in the child’s life: 0 = never; 1 = hardly ever; 2 = occasionally; 3 = often; 4 = very often. ECOHIS scores were computed as the sum of the response codes for the child and family sections separately, with all “Don’t know” (DK) responses recoded as missing. The item scores are aggregated to produce a total scale score. This scoring system establishes a range of 0–52 for the scale score, where higher scores indicate a greater impact and/or more issues. The child and family sections are scored within the ranges of 0–36 and 0–16, respectively . Statistical analysis Statistical analysis was conducted using Jamovi (Version 1.0.4) ( https://www.jamovi.org ). Descriptive statistics and frequencies of the demographic characteristics were calculated. Due to the ordinal nature of the variables, a Kruskal-Wallis analysis of variance was conducted to compare the dmft, pufa, and ICDAS indices in terms of ECOHIS responses. Binomial logistic regression analysis was conducted to predict the effect of pufa on ECOHIS with other covariate factors and the effect of demographic attributes on oral index scores. Spearman correlation analysis was used to compare oral indices, including dmft, pufa, and ICDAS scores, with ECOHIS scores. Statistical significance was set at p ≤ 0.05. To address any missing items in the questionnaire, a thorough review of the collected data was conducted to identify incomplete responses. Follow-up contacts were made with respondents to obtain missing information whenever possible. For cases where missing information could not be retrieved, statistical techniques were employed to handle the missing data. Specifically, multiple imputation methods were used for items with a small proportion of missing responses to estimate the missing values based on the observed data. For items with a higher proportion of missing responses, analyses were conducted using only the available data, acknowledging the potential limitations this may introduce in the interpretation of the results. These strategies ensured the robustness of our conclusions despite the presence of some missing data.   The study adhered to the ‘Strengthening the Reporting of Observational studies in Epidemiology’ (STROBE) guidelines as outlined in Supplemental Material 1. This cross-sectional study involves the participation of children between the ages of 3 and 6 years who visited the Pediatric Dentistry department of the Recep Tayyip Erdoğan University Faculty of Dentistry. The study was conducted with ethical approval from the Non-Interventional Clinical Research Ethics Committee Presidency of the Recep Tayyip Erdoğan University Faculty of Medicine, under decision number 2020/18, dated 06.02.2020. A Participation Consent Statement was obtained from all children and their parents who were accepted to the study with their own consent. In addition, informed consent was obtained from the parents of all children via an Informed Consent Form.   To determine the required sample size for our study, we performed a power analysis using the Pearson correlation coefficient ( r = 0.319) between pufa and OHIP scores from the study of Praveen et al. . The analysis was conducted using G*Power 3.1.9.4 software. Key parameters for the power analysis included a significance level (α) set at 0.05, which is the conventional threshold for statistical significance, and a desired power (1-β) set at 0.95 to ensure a high probability of detecting a true effect if one exists. The effect size was calculated using Fisher’s z-transformation of the correlation coefficient, resulting in an effect size of approximately 0.331. Based on these parameters, the analysis revealed that a total sample size of approximately 238 participants is necessary to detect the specified correlation with 95% power. However, we chose to include 300 children aged 3–6 years in the study to increase the statistical power, enhance the generalizability of the findings, allow for more robust subgroup analyses, account for potential attrition, and capture the variability in responses. This larger sample size ensures a more comprehensive and reliable analysis of the relationship between dental caries, the pufa Index, and OHRQoL.   The inclusion criteria for our study encompass children aged 3 to 6 years, with the requirement that both the children and their parents or caregivers provide informed consent to participate in the study. Additionally, children who are available for follow-up and data collection throughout the study period are also part of the inclusion criteria. Children within this age group are included in the study regardless of whether they have dental caries. The exclusion criteria, on the other hand, include uncooperative children, children with systemic diseases, children with enamel anomalies, children whose parents or caregivers did not provide informed consent, those who withdrew from the study at any point, and those with incomplete or insufficient data. These criteria ensure that the study is conducted on a homogeneous population and that the results can be attributed to the factors being studied.   An initial clinical intraoral examination was conducted in accordance with World Health Organization (WHO) recommendations . Before the measurements, the examiner (D.B.) underwent a training and calibration process, which included both theoretical and clinical phases. Theoretical training covered the criteria and application of the dmft, ICDAS, and pufa indices. The clinical phase involved examining a sample group of children under supervision, with evaluations conducted two weeks apart to test intra-reliability. Perfect agreement was validated with a kappa score of > 0.80, confirming the consistency of the examiner. All children with parental consent were examined by a single researcher (D.B.) in the dental unit, under the light of the unit. A sterile dental Shepherd’s hook explorer and mirror were used for the examination. The presence of dental caries was determined using the decayed, missing, and filled teeth index (dmft) . The dmft Index records of the children were classified into two categories: dmft = 0 and dmft ≥ 1. Additionally, the Turkish version of the ECOHIS (T-ECOHIS) questionnaire was administered face-to-face with the children’s parents/caregivers. The examiner received specific training on how to read and intonate each question to ensure consistency and reduce bias during the interviews. ECOHIS has also been culturally adapted and validated for use in Turkish preschool children by Peker et al. , thus ensuring its suitability and accuracy in measuring oral health-related quality of life in this population. The International Caries Detection and Assessment System II (ICDAS), introduced in 2004, was used to evaluate the extent of caries in the oral cavity. This system provided a scoring system based on both visual and tactile examination criteria for teeth. The scores ranged from zero, representing no carious lesions, to six, indicating severe carious lesions. Individuals were categorized into four groups based on their maximum scores: ICDAS 0, ICDAS 1 and 2, ICDAS 3 and 4, and ICDAS 5 and 6 . In the assessment of the pufa index, specific procedures were followed. Initially, pulpal (p) involvement is noted when the opening of the pulp chamber is visible or when the coronal tooth structures have been eroded by the carious process, leaving only roots or root fragments. No probing is done to diagnose pulpal involvement. ulceration (u), resulting from trauma caused by sharp tooth fragments, is documented when sharp edges of a dislocated tooth with pulpal involvement, or root fragments, have caused traumatic ulceration of the surrounding soft tissues, such as the tongue or buccal mucosa. Fistula (f) is noted when a pus-releasing sinus tract related to a tooth with pulpal involvement is present. Abscess (a) is recorded when a pus-containing swelling related to a tooth with pulpal involvement is present . During the examination, the examiner recorded each condition for each affected tooth. The total pufa score was then calculated by summing the number of teeth that exhibited any of these conditions. In the second phase of the study, parental interviews were conducted in person to collect demographic data and obtain responses to the ECOHIS scale. The resulting scores offer an assessment of the severity of oral health-related quality of life issues, with higher scores indicating a greater impact. The ECOHIS scale is based on parental evaluations of 13 items categorized into two main parts: the child impact section (CIS) and the family impact section (FIS). The child impact section encompasses four domains: child symptoms (1 item), child functions (4 items), child psychology (2 items), and child self-image and social interaction (2 items). The family impact section consists of two domains: parental distress (2 items) and family function (2 items). Responses to each question are rated using a 4-point Likert scale, reflecting the frequency of a particular event occurring in the child’s life: 0 = never; 1 = hardly ever; 2 = occasionally; 3 = often; 4 = very often. ECOHIS scores were computed as the sum of the response codes for the child and family sections separately, with all “Don’t know” (DK) responses recoded as missing. The item scores are aggregated to produce a total scale score. This scoring system establishes a range of 0–52 for the scale score, where higher scores indicate a greater impact and/or more issues. The child and family sections are scored within the ranges of 0–36 and 0–16, respectively .   Statistical analysis was conducted using Jamovi (Version 1.0.4) ( https://www.jamovi.org ). Descriptive statistics and frequencies of the demographic characteristics were calculated. Due to the ordinal nature of the variables, a Kruskal-Wallis analysis of variance was conducted to compare the dmft, pufa, and ICDAS indices in terms of ECOHIS responses. Binomial logistic regression analysis was conducted to predict the effect of pufa on ECOHIS with other covariate factors and the effect of demographic attributes on oral index scores. Spearman correlation analysis was used to compare oral indices, including dmft, pufa, and ICDAS scores, with ECOHIS scores. Statistical significance was set at p ≤ 0.05. To address any missing items in the questionnaire, a thorough review of the collected data was conducted to identify incomplete responses. Follow-up contacts were made with respondents to obtain missing information whenever possible. For cases where missing information could not be retrieved, statistical techniques were employed to handle the missing data. Specifically, multiple imputation methods were used for items with a small proportion of missing responses to estimate the missing values based on the observed data. For items with a higher proportion of missing responses, analyses were conducted using only the available data, acknowledging the potential limitations this may introduce in the interpretation of the results. These strategies ensured the robustness of our conclusions despite the presence of some missing data.   A total of 356 children were extended invitations to participate in the study, of which 300 consented to participate. The study encompassed 300 children, with ages ranging from 3 to 6 years (Mean age: 5.08 ± 0.92). Almost half of the participants (49.7%) were male, with the remaining 51.3% being female. Detailed demographic data regarding the children and their parents is available in Table . Regardless of the oral indexes, the results of ECOHIS scale showed that the “oral-dental pain” item had the highest value (1.61 ± 1.13), indicating a significant impact on the child’s quality of life. On the other hand, the “avoided talking” item had the lowest value (0.187 ± 0.566), indicating a relatively low impact. Overall, the mean ECOHIS score was 0.62 ± 0.55 on a scale where each item was scored from 0 to 4. It is important to note that this score was normalized to a 4-point scale for ease of analysis. When converted to the standard ECOHIS total score out of 52, the mean score would be 8.06, indicating a more appreciable impact on oral health-related quality of life. The mean and range of dmft and pufa scores were 4.82 (0–13) and 0.41 (0–5), respectively)(Table ). Children with higher dmft, pufa and ICDAS scores had significantly higher levels of oral/dental pain, difficulty drinking, eating, pronouncing words, sleep problems and irritability or frustration ( p < 0.05). Additionally, children with high dmft scores were more likely to avoid smiling or laughing ( p < 0.05). Notably, both dmft, pufa, and ICDAS scores were higher in children whose parents reported feeling upset and guilty ( p < 0.05). Moreover, while “taken time off from work” was high only in the parents of children with high dmft scores ( p < 0.05), significant “financial effects” were observed in the parents of those with high pufa values ( p < 0.05) (Tables and ). Table presents the results of the binomial logistic regression analysis, highlighting the impact of various factors on the Early Childhood Oral Health Impact Scale (ECOHIS) scores. The analysis reveals that children with a pufa score of 1 or higher are significantly more likely to have an ECOHIS score of 1 or higher compared to those with a pufa score of 0. The unadjusted odds ratio (OR) for a pufa score ≥ 1 is 2.700 (95% CI: 1.530–4.763, p < 0.001), indicating a strong association between higher pufa scores and a greater negative impact on oral health-related quality of life (OHRQoL). After adjusting for other covariates, this association remains significant with an adjusted OR of 1.929 (95% CI: 1.035–3.595, p = 0.039). Additionally, the dmft Index shows a significant impact on ECOHIS scores, with an adjusted OR of 6.597 (95% CI: 0.791–55.035, p = 0.048) for children with a dmft score ≥ 1, further emphasizing the negative influence of dental caries on OHRQoL. The analysis also identifies that children whose parents reported dental complaints had significantly higher odds of having worse ECOHIS scores, with an adjusted OR of 2.070 (95% CI: 1.107–3.869, p = 0.023). Other variables such as gender, age, presence of siblings, and parental education status did not show a significant adjusted impact on ECOHIS scores. However, first dental consultation at age 4 shows a protective effect with an adjusted OR of 0.215 (95% CI: 0.051–0.899, p = 0.035), indicating the potential benefits of earlier dental visits. A significant positive correlation between all oral indexes and Early Childhood Oral Health Impact Scale (ECOHIS) scores was found ( p < 0.05) (Fig. ). The binomial logistic regression analysis revealed a significant effect of pufa score on ECOHIS (OR = 2.140, p = 0.001).   According to our research, the presence of dental caries adversely affects the quality of life. We have observed that the two sub-components of the ECOHIS, used to assess the quality of life, have shown a significant increase in the presence of dental caries. Such findings suggest that dental health programs should not only focus on treating the child but also involve parental education and support, as their engagement is crucial for preventive care and early detection. Neglected dental caries can lead to chronic pain, hindered nutrition and growth, delayed speech development, and impede learning . It is imperative to evaluate the OHRQoL in preschool children due to their age and vulnerability. However, assessing OHRQoL in this age group can be challenging because of the limited communication and emotional skills in children . The present study investigated the impact of pain and negative emotions on the OHRQoL of preschool children. The highest mean ECOHIS value was observed in oral dental pain, while feeling upset was the most significant negative value in the FIS. The CIS section revealed that difficulty in eating and drinking had the most prominent adverse effect on the OHRQoL after pain. Our results concur with a previous study by Sharna et al. , which also reported that dental pain and difficulty in eating and drinking were the primary contributors to high ECOHIS scores. Similarly, Vieira-Andrade et al.  found a high incidence of pain sensation and difficulty in eating among preschool children. Dental pain has a reported prevalence between 7.0% and 22.0% among preschool children, and carious lesions in teeth have been associated with pain. Our study observed that children with a high caries burden were more likely to experience pain as expected . Additionally, feeling upset was observed to be the most significant negative emotion in the FIS, followed by guilt. High levels of feeling upset and guilt in parents for their children correspond with those reported in other studies . The ECOHIS score was determined as 0.62 ± 0.55 in the present study. While this value is comparable to the preschool children evaluation study conducted by Jaggi et al.  in India (0.64), it is lower than other studies . The observed inconsistency can be attributed to the differences in dental caries severity in those studies. In the ECOHIS responses in the Jaggi et al.  study, items related to pain, irritation, difficulty in eating certain foods and drinking hot or cold beverages, feelings of guilt, feelings of disappointment, and sadness were reported to be the most frequent items in the child impact section. In Martins-Júnior’s study ; mothers aged 30 years and older reported better OHRQoL, regardless of the presence of ECC and the age of the child. In the study by Abanto et al. , increasing age of the child, crowded household, decreasing family income and mother working outside the home were found to be significantly associated with OHRQoL. In our current study, the child’s age, number of siblings, and parents’ educational status were not significantly related to the ECOHIS value. As in previous studies mentioned above , factors other than dental conditions did not produce significant results for ECOHIS alone. In our study, we utilized the ICDAS at the subject level to provide a comprehensive assessment of the overall caries burden and its impact on OHRQoL. Although ICDAS is typically used at the tooth or tooth surface level, aggregating these scores to the subject level allows for a holistic understanding of the broader implications of caries on an individual’s life. This approach is supported by evidence that the cumulative effect of multiple initial lesions (ICDAS 0–3) across different teeth can significantly affect a child’s quality of life, leading to discomfort, dietary restrictions, and psychosocial impacts . By integrating ICDAS with indices like pufa and ECOHIS, we aimed to capture both the early stages and severe consequences of caries, providing a complete picture of its clinical and quality of life implications. The results of the study showed that the scores of ECOHIS, CIS, and FIS were significantly higher in children with dental complaints than in those without, consistent with a previous study . In the study by Abanto and Martins Junior, where they evaluated ECOHIS scores from caries-free to severe caries, ECOHIS, CIS and FIS scores were significantly higher in severe caries. In our current study, concordantly, all ECOHIS scores were significantly higher in children with dmft ≥ 1. Furthermore, the present study found that the dmft, pufa, ICDAS II scores were higher in children with complaints compared to those without complaints, which may explain the higher negative impact on OHRQoL in this group. These findings have important implications for oral health care providers and policy-makers, as they highlight the need for early detection and management of dental complaints in children to improve their OHRQoL. The present study has unveiled that the presence of caries and its visible impact on soft tissues have exhibited a significant negative effect on the CIS. These findings are consistent with the significantly higher dmft and pufa scores noted in the presence of oral dental pain, difficulty in eating and drinking, sleeping problems, and restlessness in CIS. Conversely, in FIS, both the presence of dental caries and the pufa index score were significant only for the family feeling upset. Jaggi et al.  have noted that pufa scores did not affect the mean overall ECOHIS score. In the same year, Sharna et al.  showed that the pufa index score was positively and significantly correlated with the overall ECOHIS score and its sub-items, consistent with our study’s results. While the correlation coefficient between the overall ECOHIS and pufa index score was r = 0.43 in the study by Sharna et al. , this value was r = 0.33 in our study. All variables in the current study exhibit a significant positive correlation with one another. As the ICDAS II score increased, the CIS FIS and overall ECOHIS scores also increased significantly. This implies that as caries progressed, a higher degree of negative influence was observed on the OHRQoL. Gomes et al.  have similarly reported that children with deep caries pose a greater risk of affecting their quality of life than those with healthy or initial caries. They noted that the initial lesions were not painful and were not noticed by families. In a study by Lara et al.  on preschool children in Mexico, it was found that children with high ECOHIS scores had more advanced caries (dentinal caries). They also observed a significant association between the level of caries and parents’ education level. Although the parents’ education level did not yield significant results in any parameter in our study, it is pertinent to note that high parental awareness of preventive practices in oral and dental health can lead to a lower prevalence of dental caries in preschool children. Moreover, one of the primary objectives of pediatric dentistry is to prevent dental caries, which has physical and psychological side effects in children, and maintain deciduous teeth healthy and functional in the mouth . The present study had certain limitations that need to be acknowledged. To begin with, dental caries is a complex disease that is influenced by various factors, and it’s difficult to completely eliminate the effects of all of them. Furthermore, the current study utilized parents or caregivers as proxies to complete the ECOHIS questionnaire on behalf of their children. This reliance on proxy reporting may impact the interpretation of the findings, as parents’ perceptions and biases could influence their responses. While using proxies is a common approach in studies involving young children, it is important to acknowledge that the parents’ or caregivers’ interpretations of their child’s oral health-related quality of life may not fully capture the child’s personal experiences and feelings. Lastly, it should be noted that this study was conducted in a particular region, and therefore, further large-scale studies are necessary to establish its generalizability to other populations.   This study underscores the significant impact of dental caries on the OHRQoL of children aged 3–6 years, as assessed by the pufa Index. Our findings reveal that higher pufa scores, indicative of more severe untreated caries, are strongly associated with increased ECOHIS scores, reflecting greater negative effects on children’s daily lives and well-being. Specific issues such as oral pain, difficulty eating, and sleep disturbances were notably prevalent among affected children, while parents reported high levels of distress and guilt. These results highlight the critical need for early detection and comprehensive management of dental caries to mitigate its adverse effects on both children and their families. Dental practitioners should prioritize preventive strategies and parental education to address and reduce the burden of dental caries, ultimately improving the quality of life for young children.   Below is the link to the electronic supplementary material. Supplementary Material 1   