ABSTRACT
Background
Although community‐based programs are implemented to promote children's oral health, evidence regarding their impact on oral health‐related quality of life (OHRQoL) remains limited.
Aim
To evaluate changes in OHRQoL among schoolchildren following participation in a community‐based oral health program and to identify factors associated with post‐intervention OHRQoL.
Design
This observational pre–post study included 668 schoolchildren in Seoul, South Korea, participating in the Student Dental Home Program. OHRQoL was assessed before and after the program using the Korean COHIP‐SF 19. Changes in scores were analyzed using paired t‐tests, and factors associated with post‐intervention OHRQoL were examined using ANCOVA and linear regression analyses.
Results
Total scores increased significantly (mean difference 3.7, 95% CI 3.3–4.1; Cohen's d = 0.66). Significant increases were observed across all subscales, with the largest effect in the Oral Health subscale (d = 0.81). In the simple regression analyses, spontaneous tooth pain, gingival bleeding, halitosis, and malocclusion were associated with lower scores. In the multivariable model, malocclusion remained the only factor independently associated with lower scores (B −0.66, 95% CI−1.37 to −0.01, p = 0.048).
Conclusions
OHRQoL scores increased following participation in a community‐based oral health program. Malocclusion remained independently associated with lower post‐intervention OHRQoL after baseline adjustment.
Keywords: community‐based oral health program, oral health‐related quality of life, prevention, school‐aged children
Key Points
Why this paper is important to pediatric dentists.
OHRQoL scores increased following participation in a community based preventive oral health program.
Most baseline differences in OHRQoL according to oral health‐related factors were less evident at follow‐up.
Malocclusion remained independently associated with lower post‐intervention OHRQoL, supporting the importance of early orthodontic assessment in community‐based oral health programs.
1. Introduction
Dental caries remains one of the most prevalent chronic diseases among children and adolescents worldwide [1]. According to the 2024 Korean National Children's Oral Health Survey, the prevalence of caries was 58.3% among 5‐year‐olds (primary dentition) and 60.3% among 12‐year‐olds (permanent dentition) [2]. Dental caries at an early age adversely affects not only children's oral health but also their general health [3], and it may substantially impair the quality of life of both affected children and their families [4]. Moreover, children who experience caries early in life are more likely to develop adverse oral conditions—including recurrent caries, periodontal disease, and malocclusion—during adolescence and adulthood, indicating that dental caries has long‐term consequences throughout the life course [1].
The cost of treating oral diseases imposes a substantial financial burden on both families and healthcare systems [5]. This burden disproportionately affects children from lower socioeconomic backgrounds and those with special healthcare needs, who experience a higher prevalence and severity of oral diseases alongside greater unmet needs [6]. Consequently, comprehensive national policies that improve access to resources for preventing oral diseases and promoting oral health are essential [5]. However, despite its critical role in overall well‐being, oral health remains underprioritized within healthcare policy frameworks [7].
South Korea maintains a universal national health insurance system covering the entire population. However, compared to other advanced nations, its coverage remains relatively limited, prioritizing treatment over prevention of oral diseases [8]. To address these shortcomings, the Korean government has implemented various healthcare welfare policies to supplement the existing insurance framework [8]. Recognizing that effective oral disease prevention in childhood can reduce health inequalities in adulthood [5], the government introduced a Children's Dental Care Program targeting individuals under the age of 18 [8]. As part of this initiative, the Student Dental Home Program (SDHP) provides free oral examinations, oral health education, and comprehensive preventive dental services to all fourth‐grade elementary students.
Oral health‐related quality of life (OHRQoL) is a multidimensional construct reflecting an individual's perception of their oral health status. It encompasses functional, social, and emotional well‐being, as well as self‐image. Consequently, it is widely used as a key health outcome measure in contemporary oral health research [9]. Preventive oral health programs aim to reduce the occurrence and progression of oral diseases by promoting positive changes in behaviors, attitudes, and values [10]. In this context, OHRQoL serves as a comprehensive indicator for evaluating the effectiveness of these preventive interventions, as it captures the impact of oral health on daily functioning and psychosocial well‐being [11].
While OHRQoL instruments were initially developed for adults, they have since been adapted to reflect the developmental characteristics and cognitive abilities of children and adolescents [12]. Recently, the Korean version of the Child Oral Health Impact Profile Short Form 19 (COHIP‐SF 19) was developed, derived from the previously validated Korean COHIP‐34 [13, 14]. This shorter format reduces response burden and facilitates repeated child self‐reported assessment in large‐scale population‐based studies [13].
Despite the increasing availability of validated OHRQoL instruments, evidence examining the relationship between oral health programs and OHRQoL in children remains limited. In Korea, previous studies evaluating community‐based preventive programs such as SDHP have primarily focused on changes in clinical oral health status, whereas research using participant‐reported OHRQoL outcomes remains scarce [8]. In contrast, international studies using OHRQoL measures have generally reported favorable changes or positive associations between oral health programs and OHRQoL [11]. However, many of these studies have largely relied on cross‐sectional designs comparing participants and non‐participants or have focused primarily on treatment‐oriented programs rather than preventive care [11, 15]. Among the few longitudinal studies available, interventions have predominantly consisted of oral health education, with limited incorporation of comprehensive preventive procedures such as fluoride application or pit and fissure sealants [11].
Therefore, the aim of this study was to assess changes in OHRQoL before and after participation in the SDHP using the COHIP‐SF 19 and to identify oral health‐related factors associated with OHRQoL.
2. Materials and Methods
2.1. Study Design
This study was an observational pre–post study conducted among fourth‐grade students (aged approximately 10 years) residing in Seoul who were enrolled in the 2023 SDHP. It was approved by the Institutional Review Board of Seoul National University School of Dentistry (IRB No. S‐D20190018) and was conducted as part of a broader research project associated with the SDHP. From July to September, a banner introducing the study was displayed within the SDHP mobile application; participation was voluntary, and participants were directed to a Google Forms survey by clicking the banner. The first page provided detailed study information, and access to the baseline COHIP‐SF 19 questionnaire was granted only after both the child and a parent or legal guardian had read the information sheet and provided informed consent. The same questionnaire was administered again within 3 months of program participation. All surveys were completed by the students themselves, rather than by their parents. Participants who completed both the pre‐ and post‐program surveys received a mobile gift voucher equivalent to US$8 for each survey.
2.2. SDHP
The 2023 SDHP was implemented between May and November. Within this period, parents or guardians scheduled appointments at participating dental clinics, and all components of the program were completed during a single visit.
Participating dentists completed a standardized training program prior to involvement in the SDHP, which provided guidance on program protocols, clinical procedures, and delivery of oral health education.
Before participation, students completed the standard SDHP oral symptom questionnaire via the mobile application. The specific items listed under “Oral Symptoms” in Table 1 were recorded in a dichotomous (yes/no) format.
TABLE 1.
Baseline demographic characteristics and oral health‐related factors of participants (n = 668).
| Variable | Category | Mean ± SD or N (%) |
|---|---|---|
| Demographics | ||
| Age (years) | 10.3 ± 0.3 | |
| Sex | Male | 346 (51.8) |
| Female | 322 (48.2) | |
| Oral health‐related factors | ||
| Oral symptoms | ||
| Broken tooth | No | 612 (91.6) |
| Yes | 56 (8.4) | |
| Sensitivity to cold/hot | No | 610 (91.3) |
| Yes | 58 (8.7) | |
| Spontaneous tooth pain | No | 644 (96.4) |
| Yes | 24 (3.6) | |
| Bleeding during brushing | No | 536 (80.2) |
| Yes | 132 (19.8) | |
| Pain in tongue/cheek | No | 641 (96.0) |
| Yes | 27 (4.0) | |
| Halitosis | No | 494 (74.0) |
| Yes | 174 (26.0) | |
| Oral examination results | ||
| Caries experience | No | 170 (25.4) |
| Yes | 498 (74.6) | |
| Malocclusion | No | 463 (69.3) |
| Yes | 205 (30.7) | |
| Gingivitis | No | 480 (71.9) |
| Yes | 188 (28.1) | |
| Oral hygiene † | Good | 371 (55.6) |
| Fair–Poor | 296 (44.4) | |
One participant did not undergo the oral hygiene examination.
During the visit, all participating students underwent a structured clinical interview and oral examination. When clinically indicated, radiographic examination was performed to aid diagnosis. This was followed by standardized oral health education focusing on oral hygiene practices, dietary habits, and fluoride use.
All participating students received professional cleaning and topical fluoride application. Additional preventive procedures, including pit and fissure sealants and scaling, were provided selectively based on individual clinical needs. If further treatment (e.g., restorative care) was required, it was performed outside the program at the guardian's expense.
2.3. COHIP‐SF 19 Questionnaire
OHRQoL was assessed using the Korean version of the COHIP‐SF 19 (Supplementary Table S1) [13]. Items were rated on a 5‐point Likert scale (0–4), with higher scores indicating better OHRQoL. Participants also rated their perceived overall oral health status and need for dental treatment on a 6‐point Likert scale. Baseline responses covered the preceding 3 months, while follow‐up responses reflected the period following participation in the SDHP. All survey items were designated as mandatory fields; therefore, no missing responses were recorded.
2.4. Oral Examination
Oral examinations assessed caries experience, malocclusion, gingivitis, and oral hygiene status. These variables are presented in Table 1 under “Oral examination results.” For the analysis, all oral examination variables were dichotomized. Dental caries was assessed using the International Caries Detection and Assessment System (ICDAS). Caries experience, corresponding to dmft/DMFT > 0, was defined as the presence of at least one primary or permanent tooth with an ICDAS score ≥ 4, or a tooth missing or filled due to caries [16]. Malocclusion was recorded if the Dental Health Component of the Index of Orthodontic Treatment Need was Grade 3 or higher [17]. Gingivitis was defined by the presence of gingival bleeding, enlargement, or calculus. Finally, oral hygiene status was evaluated using the Patient Hygiene Performance Index; scores ≤ 10 were classified as “good,” while scores of 11–30 were categorized as “fair–poor” [18].
2.5. Statistical Analysis
Changes in OHRQoL before and after SDHP participation were evaluated using paired t‐tests for total scores, subscale scores, and self‐rated oral health measures. Effect sizes were calculated using Cohen's d and interpreted as small (0.2), medium (0.5), or large (0.8) [19].
Baseline COHIP‐SF 19 scores were compared across oral health‐related factors, including oral symptoms and oral examination results, using independent t‐tests. Given the limited sample sizes in some groups, effect sizes were calculated using Hedges' g to correct for small‐sample bias, with interpretation thresholds equivalent to those for Cohen's d.
To examine differences in post‐SDHP total scores based on oral health‐related factors while adjusting for baseline scores, an analysis of covariance (ANCOVA) was performed. Oral health‐related factors were included as independent variables, and analyses focused on the main effects of each factor. Effect sizes were reported as partial η 2.
Linear regression analyses were conducted to assess the magnitude and direction of associations between oral health‐related factors and post‐SDHP COHIP‐SF 19 total scores. Initially, separate linear regression analyses were performed for each variable, adjusting for baseline scores. Variables that were statistically significant or clinically relevant were then entered into a multiple linear regression model. Multicollinearity was assessed using the variance inflation factor (VIF), with values less than 3 indicating no substantial multicollinearity.
3. Results
3.1. Demographics of the Participants
Of the 20 495 students who participated in the 2023 SDHP, 1068 completed the baseline survey and 830 completed both the baseline and post‐SDHP survey. Using participant information (e.g., parent phone number, age, sex, and school), 105 duplicate responses were identified and only the first response was retained. In addition, 57 students who did not participate in the program were excluded. Consequently, 668 participants were included in the final analysis (Figure 1). This sample represented 3.26% of all SDHP participants. The mean age was 10.3 ± 0.3 years (mean ± standard deviation), with no significant difference in age between boys and girls (Table 1). The participants consisted of 346 boys (51.8%) and 322 girls (48.2%) from 151 elementary schools across all 25 districts of Seoul. The mean interval between the baseline survey and program participation was 9 ± 12 days, whereas the interval between program participation and the post‐SDHP survey was 57 ± 19 days.
FIGURE 1.
Flow diagram of participant selection for the study.
The prevalence of untreated dental caries among the study participants was 34.9%, which was broadly comparable to that reported for the overall SDHP population (32.3%). In addition, the sex distribution of the overall SDHP population (51.2% boys and 48.8% girls) was similar to that of the study sample.
All participating students underwent oral examination, oral health education, professional cleaning, and topical fluoride application as part of the SDHP. Among the participants, 197 (29.5%) received pit and fissure sealants, 172 (25.7%) received scaling, and 339 (50.7%) underwent radiographic examination.
3.2. COHIP‐SF 19 Scores
No significant sex differences were observed in total or subscale scores (all p > 0.05); consequently, data for boys and girls were combined for all analyses. In addition, no significant differences in OHRQoL scores were observed according to receipt of pit and fissure sealants, scaling, or radiographic examination (all p > 0.05).
Following participation in the SDHP, total scores increased significantly from baseline, with a medium effect size (Table 2). Subscale analyses indicated statistically significant increases across all domains. The largest effect size was found in the oral health (OH) subscale, whereas the social/emotional well‐being (SW) and self‐image (SI) subscales demonstrated smaller effect sizes. Self‐rated oral health measures, including perceived overall oral health and the perceived need for dental treatment, also showed significant changes with medium effect sizes (Table 2).
TABLE 2.
Changes in Korean COHIP‐SF 19 scores and self‐rated oral health measures before and after the SDHP.
| Before | After | Difference | p † | Effect size ‡ | ||
|---|---|---|---|---|---|---|
| Mean (SD) | 95% CI | |||||
| COHIP‐SF 19 | ||||||
| Total score | 65.1 (5.7) | 68.8 (4.3) | 3.7 (5.6) | 3.3–4.1 | < 0.001* | 0.66 |
| OH subscale | 12.9 (2.5) | 14.9 (1.5) | 2.0 (2.4) | 1.8–2.1 | < 0.001* | 0.81 |
| FW subscale | 14.9 (1.5) | 15.6 (0.9) | 0.7 (1.5) | 0.6–0.8 | < 0.001* | 0.45 |
| SW subscale | 34.6 (2.5) | 35.1 (2.0) | 0.5 (2.4) | 0.3–0.6 | < 0.001* | 0.19 |
| SI subscale | 2.6 (2.3) | 3.2 (2.5) | 0.6 (2.9) | 0.4–0.8 | < 0.001* | 0.21 |
| Self‐rated oral health measures | ||||||
| Overall oral health | 3.4 (0.9) | 3.9 (0.8) | 0.5 (1.0) | 0.5–0.6 | < 0.001* | 0.54 |
| Treatment need | 2.5 (1.5) | 3.4 (1.6) | 1.0 (2.0) | 0.8–1.1 | < 0.001* | 0.48 |
Abbreviations: OH, oral health; FW, functional well‐being; SW, social‐emotional well‐being; SI, self‐image.
Statistically significant (p < 0.05).
Paired t‐test.
Effect sizes are reported as paired‐samples Cohen's d.
Tables 3 and Supplementary Table S2 present differences in baseline total and subscale scores based on oral health‐related factors. Across all six oral symptom items, participants reporting symptoms had significantly lower scores than those without symptoms, with very large effect sizes observed for spontaneous tooth pain and pain in the tongue or cheek. Participants with dental caries or malocclusion also had significantly lower scores, although the effect sizes were small. No statistically significant differences in scores were observed regarding gingivitis or oral hygiene status.
TABLE 3.
Association between oral health‐related factors and the baseline COHIP‐SF 19 total score.
| Mean (SD) | Mean difference [95% CI] | p † | Effect size ‡ | ||
|---|---|---|---|---|---|
| Oral symptoms | |||||
| Broken tooth | No | 65.3 (5.5) |
3.22 [1.68, 4.75] |
< 0.001* | 0.57 |
| Yes | 62.1 (6.8) | ||||
| Sensitivity to cold/hot | No | 65.4 (5.3) |
4.29 [2.20, 6.38] |
< 0.001* | 0.77 |
| Yes | 61.1 (7.8) | ||||
| Spontaneous tooth pain | No | 65.4 (5.3) |
8.61 [6.39, 10.83] |
< 0.001* | 1.58 |
| Yes | 56.8 (8.2) | ||||
| Bleeding during brushing | No | 65.7 (5.2) |
3.5 [2.31, 4.70] |
< 0.001* | 0.64 |
| Yes | 62.2 (6.4) | ||||
| Pain in tongue/cheek | No | 65.3 (5.4) |
6.31 [2.76, 9.86] |
0.001* | 1.14 |
| Yes | 59.0 (8.9) | ||||
| Halitosis | No | 66.2 (5.1) |
4.27 [3.34, 5.19] |
< 0.001* | 0.80 |
| Yes | 61.9 (6.0) | ||||
| Oral examination results | |||||
| Caries experience | No | 65.8 (5.2) |
1.00 [0.02, 1.99] |
0.046* | 0.18 |
| Yes | 64.8 (5.8) | ||||
| Malocclusion | No | 65.6 (5.2) |
1.67 [0.67, 2.67] |
0.001* | 0.30 |
| Yes | 63.9 (6.4) | ||||
| Gingivitis | No | 64.8 (5.8) |
−0.79 [−1.75, 0.16] |
0.104 | −0.14 |
| Yes | 65.6 (5.2) | ||||
| Oral hygiene | Good | 65.0 (5.8) |
−0.12 [−0.99, 0.75] |
0.793 | −0.02 |
| Fair–Poor | 65.1 (5.5) | ||||
Statistically significant (p < 0.05).
Independent t‐test.
Effect sizes are reported as Hedges' g to account for potential small‐sample bias in some subgroups.
ANCOVA adjusted for baseline total scores revealed significant differences in post‐SDHP total scores only for spontaneous tooth pain and malocclusion (Table 4). Partial η 2 values indicated small effect sizes for all oral health‐related factors. Additionally, differences in adjusted means across oral health‐related factors were modest, with substantial overlap in confidence intervals for most factors (Supplementary Table S3).
TABLE 4.
Association between oral health‐related factors and the post‐SDHP COHIP‐SF 19 total score, adjusted for baseline scores.
| df | F | p | Partial η 2 | |
|---|---|---|---|---|
| Oral symptoms | ||||
| Broken tooth | 1 | 1.019 | 0.313 | 0.002 |
| Sensitivity to cold/hot | 1 | 0.712 | 0.399 | 0.001 |
| Spontaneous tooth pain | 1 | 3.954 | 0.047* | 0.006 |
| Bleeding during brushing | 1 | 1.027 | 0.311 | 0.002 |
| Pain in tongue/cheek | 1 | 0.417 | 0.519 | 0.001 |
| Halitosis | 1 | 3.271 | 0.071 | 0.005 |
| Oral examination results | ||||
| Caries experience | 1 | 0.532 | 0.466 | 0.001 |
| Malocclusion | 1 | 5.017 | 0.025* | 0.008 |
| Gingivitis | 1 | 0.407 | 0.524 | 0.001 |
| Oral hygiene | 1 | 1.120 | 0.290 | 0.002 |
Note: Post‐SDHP COHIP‐SF 19 scores were analyzed using a full factorial ANCOVA after controlling for baseline COHIP‐SF 19 scores.
Statistically significant (p < 0.05).
In the univariable linear regression analyses adjusted for baseline scores, spontaneous tooth pain, gingival bleeding during tooth brushing, and halitosis were significantly associated with lower post‐SDHP total scores (Table 5 and Supplementary Table S4). No significant associations were found for the other oral symptom variables. Among oral examination findings, only malocclusion showed a significant negative association with post‐SDHP scores.
TABLE 5.
Univariable and multivariable linear regression analyses of selected predictors for post‐SDHP COHIP‐SF 19 total scores.
| Predictor | Univariable | Multivariable | |||
|---|---|---|---|---|---|
| B [95% CI] | p | B [95% CI] | p | VIF | |
| Oral symptoms | |||||
| Spontaneous tooth pain | −1.936 [−3.621, −0.250] | 0.024* | −1.690 [−3.399, 0.020] | 0.053 | 1.13 |
| Bleeding during brushing | −0.793 [−1.574, −0.013] | 0.046* | −0.514 [−1.316, 0.288] | 0.209 | 1.14 |
| Halitosis | −0.767 [−1.494, −0.040] | 0.039* | −0.662 [−1.396, 0.072] | 0.077 | 1.16 |
| Oral examination results | |||||
| Malocclusion | −0.684 [−1.343, −0.025] | 0.042* | −0.662 [−1.371, −0.006] | 0.048* | 1.02 |
Note: Univariable models were adjusted for baseline COHIP‐SF 19 scores. Variables identified as statistically significant or clinically relevant were entered simultaneously into the multivariable model, which also included baseline scores. Multicollinearity was evaluated using variance inflation factors (VIF), and no evidence was observed.
Statistically significant (p < 0.05).
The multiple linear regression model was statistically significant (F = 27.11, p < 0.001), with an adjusted R 2 of 0.164. After adjusting for covariates, including baseline scores, malocclusion was the only factor that remained independently associated with post‐SDHP scores (Table 5 and Supplementary Table S5). No evidence of multicollinearity was detected (all VIFs < 2).
4. Discussion
This study assessed changes in OHRQoL among school‐aged children before and after participation in the SDHP using the COHIP‐SF 19, while also examining oral health‐related factors associated with OHRQoL. Following participation in the SDHP, total scores increased significantly with a medium effect size. Additionally, statistically significant increases were observed across all subscale domains. In analyses adjusted for baseline scores, several oral symptoms were significantly associated with postintervention scores in the univariate analysis; however, the multivariate analysis identified malocclusion as the only factor independently associated with lower postintervention OHRQoL.
In this study, the baseline total score (65.1 ± 5.7) was comparable to scores reported in previous studies using the same instrument among general schoolchildren in large urban settings in countries such as China, Japan, and Libya [20, 21, 22]. In contrast, our baseline scores were higher than those reported in studies involving children with greater dental treatment needs or those from socioeconomically disadvantaged backgrounds [23, 24, 25]. These findings suggest that the study population had relatively favorable baseline OHRQoL compared with more vulnerable groups.
The mean increase in the total COHIP‐SF 19 score was 3.7 points, corresponding to a moderate effect size (Cohen's d = 0.66). A minimally clinically important difference (MCID) for the COHIP‐SF 19 has not yet been established, limiting the interpretation of absolute score changes. In addition, longitudinal studies using the COHIP‐SF19 remain limited and have employed different populations, interventions, follow‐up durations, and scoring approaches, making direct comparison across studies difficult. Nevertheless, changes in overall COHIP‐SF 19 scores reported following school‐ and community‐based oral health interventions were broadly comparable to those observed in the present study [26, 27]. Similar medium effect sizes were also observed for self‐rated oral health measures, suggesting that the observed changes are unlikely to be trivial. However, the clinical significance of these changes from the perspective of children and families remains uncertain and warrants further investigation. Because this study used an observational pre–post design without a control group, the findings should be interpreted cautiously with respect to causal relationships between SDHP participation and changes in OHRQoL. Alternative explanations, including regression to the mean, temporal or contextual factors related to school or seasonal variation, response bias associated with repeated self‐reported measures, and normal developmental changes, should also be considered.
At the subscale level, statistically significant increases were observed across all domains following the SDHP (Table 2). The largest effect size was observed in the OH subscale, possibly reflecting the preventive focus of the SDHP—including oral examinations, professional oral hygiene care, fluoride application, pit and fissure sealants, and scaling—which may influence children's perceptions of their oral health status. However, because restorative dental treatment received outside the SDHP was not systematically captured, OHRQoL changes may also reflect improvements associated with dental care beyond the program.
Meanwhile, the FW subscale showed a medium effect size, whereas the SW and SI subscales exhibited smaller effect sizes. This pattern aligns with findings from an umbrella review, which noted that although oral health promotion programs generally improve subjective health outcomes in children and adolescents, short‐term preventive interventions often yield variable effects across different domains [10]. These findings suggest that changes in the physical and functional aspects of oral health may be observed earlier, whereas social and emotional domains may require longer follow‐up periods or supplementary interventions before measurable changes become evident. Accordingly, the relatively short follow‐up period in the present study may have limited the ability to capture broader psychosocial and emotional changes in OHRQoL.
Baseline total scores varied significantly based on the presence of oral symptoms, with particularly large effect sizes observed for spontaneous tooth pain and pain in the tongue or cheek (Table 3). In contrast, effect sizes associated with oral examination findings were small. This observation aligns with previous studies reporting that perceived pain, independent of specific clinical diagnoses such as dental caries or trauma, is strongly associated with poorer OHRQoL in children [28, 29].
In the ANCOVA analyses adjusted for baseline scores, differences in postintervention scores across most oral health‐related factors were attenuated or lost statistical significance, except for spontaneous tooth pain and malocclusion (Table 4). These findings may reflect the influence of baseline OHRQoL differences, changes occurring during the study period, or a combination of both. In addition, as noted above, restorative dental treatment received outside the program may also have contributed to the observed changes. However, differences associated with spontaneous tooth pain and malocclusion persisted.
In the linear regression analyses adjusted for baseline scores, spontaneous tooth pain, gingival bleeding during tooth brushing, halitosis, and malocclusion were significantly negatively associated with postintervention total scores (Table 5). However, in the multiple linear regression model, only malocclusion remained independently associated with postintervention OHRQoL after mutual adjustment. This may be because malocclusion is a persistent structural condition that is unlikely to be modified through short‐term preventive interventions. In the present study, the relatively short follow‐up period further limits the likelihood of observable changes in dentofacial alignment or appearance. In addition, the SDHP does not include formal orthodontic assessment or referral pathways. Consequently, malocclusion may have remained an important factor associated with children's OHRQoL, potentially through functional limitations and psychosocial mechanisms [30].
From a clinical perspective, these findings highlight the importance of early identification and management of oral conditions that may negatively influence children's oral health‐related quality of life [9]. Preventive community‐based oral health programs such as the SDHP may contribute to favorable clinical oral health outcomes and perceived well‐being related to oral health [10]. In particular, the persistent association between malocclusion and postintervention OHRQoL suggests that preventive public oral health programs may benefit from incorporating formal orthodontic screening and referral pathways in order to more comprehensively address structural and psychosocial factors influencing children's OHRQoL [30].
This study has several limitations. First, the study population was restricted to school‐aged children in Seoul, the capital of South Korea, potentially limiting the generalizability of the findings. Second, the study used an observational pre–post design without a control group; as the SDHP is a universal program for all fourth‐grade students, establishing a nonexposed comparison group presented ethical and practical challenges. Accordingly, the observed changes in OHRQoL may have been influenced by factors other than program participation. In addition, the relatively short follow‐up period may not have been sufficient to fully evaluate longer‐term psychosocial and behavioral changes in OHRQoL. Third, oral symptoms were assessed using self‐reported measures, which are susceptible to recall bias and subjective interpretation. In addition, the baseline and post‐program questionnaires used partially different recall periods, which may have influenced symptom reporting and biased the results toward more favorable postprogram scores. Furthermore, although participating dentists received standardized training prior to the program, formal calibration of examiners was not performed due to the large number of providers involved, which may have introduced variability in clinical assessments. Fourth, the response rate was relatively low, raising the possibility of selection bias. The prevalence of dental caries and sex distribution were comparable to those of the overall SDHP population, suggesting that the sample may broadly reflect the characteristics of SDHP participants. Nevertheless, participation was voluntary and conducted via a mobile application, which may have resulted in a sample with higher engagement in oral health‐related behaviors, greater parental involvement, or children experiencing more oral symptoms. A small participation incentive may also have influenced participation patterns and how participants perceived or reported program‐related outcomes. In addition, because individual‐level data for non‐respondents and information on socioeconomic, behavioral, and psychosocial factors were not available, selection bias and residual confounding cannot be entirely excluded. Future research should employ larger longitudinal and quasi‐experimental designs across diverse regions, including approaches such as stepped‐wedge or wait‐list designs, to allow more robust evaluation of temporal changes in OHRQoL while accounting for broader contextual and psychosocial determinants.
Increases in OHRQoL scores were observed among school‐aged children following participation in the SDHP, and malocclusion remained independently associated with lower postintervention OHRQoL scores. These findings suggest that changes in children's OHRQoL may be observed following participation in a community‐based oral health program and highlight the importance of addressing structural oral health conditions.
Author Contributions
Ji‐Soo Song conceived and designed the study, collected and analyzed the data, performed the statistical analyses, and wrote the manuscript.
Funding
This work was supported by the National Research Foundation of Korea (RS‐2022‐00166596).
Ethics Statement
This study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Seoul National University School of Dentistry (IRB No. S‐D20190018).
Consent
Informed consent was obtained from all participants and their legal guardians before participation. The rights and privacy of all participants were respected and protected throughout the study.
Conflicts of Interest
The author declares no conflicts of interest.
Supporting information
Table S1: Subscales and items of Korean COHIP‐SF 19 questionnaire.
Table S2: Effect of oral health‐related factors on COHIP‐SF 19 total and subscale scores in the pre‐survey.
Table S3: Adjusted means (SE) and 95% confidence intervals for the post‐SDHP COHIP‐SF 19 total score.
Table S4: Linear regression analyses for the post‐SDHP COHIP‐SF 19 total score, adjusted for baseline scores.
Table S5: Multiple linear regression analysis for the post‐SDHP COHIP‐SF 19 total score.
Data S1: STROBE Statement—checklist of items that should be included in reports of observational studies.
Acknowledgements
The author sincerely thanks Kai‐i Company for their valuable support in processing and providing data from the Student Dental Home Program.
Data Availability Statement
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Table S1: Subscales and items of Korean COHIP‐SF 19 questionnaire.
Table S2: Effect of oral health‐related factors on COHIP‐SF 19 total and subscale scores in the pre‐survey.
Table S3: Adjusted means (SE) and 95% confidence intervals for the post‐SDHP COHIP‐SF 19 total score.
Table S4: Linear regression analyses for the post‐SDHP COHIP‐SF 19 total score, adjusted for baseline scores.
Table S5: Multiple linear regression analysis for the post‐SDHP COHIP‐SF 19 total score.
Data S1: STROBE Statement—checklist of items that should be included in reports of observational studies.
Data Availability Statement
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.