Introduction

Dental caries is the most common chronic disease of childhood that can affect the well-being of children and their quality of life.1 The 2022 Global Oral Health Status Report stated that more than 500 million children around the world have caries in their primary teeth.2 The disease can result in pain, infection, problems with eating, poor speech development, low self-esteem, trouble sleeping, missed school days, and failure to thrive.3,4,5.

As dental caries is multifactorial, a conceptual model was developed by Fisher-Owens et al. to identify the interactive causes that contribute to it. This model indicates that numerous factors affect a child’s oral health, including factors at the family level.6 Because children’s behaviors are shaped from a young age and are influenced by their parents, parenting style may play a role in the development of dental caries in children.7 In Baumrind’s pioneering work on parenting style, she defined three specific styles: authoritative, authoritarian, and permissive.8 An authoritative parenting style (which is characterized by high control and warmth, and includes demandingness and responsiveness; the setting and enforcing of limits; the granting of autonomy where appropriate; emotional support; and bidirectional communication) assists children and adolescents in developing independence, self-control, and a balance of societal and individual needs and responsibilities.9,10,11 The authoritarian style is characterized by high control and low warmth (including strict discipline along with a lack of bidirectional communication or sensitivity to the child’s emotional needs), while the permissive style is characterized by low control and typically high warmth (including a tendency to indulge the child and a lack of limits).8,10,12 Both the authoritarian and permissive styles have been found to be significantly associated with negative indicators of psychological health in children, as compared to the authoritative style.12 A fourth type of parenting style, neglectful, is characterized as having low warmth and low control. Neglectful parents are often emotionally detached and not involved in their children’s lives; sparse research has been done on this parenting style, because these parents frequently do not make themselves available to participate in studies involving their children.13.

Parenting styles are changing, with some authors suggesting that a permissive style has become more common in the United States.14,15,16 Pediatric dentists should be mindful of risk indicators of poor oral health in order to be well-prepared to treat each patient in the most efficacious manner. Therefore, if a certain parenting style is a risk indicator for a high level of dental caries in children, dentists should be aware of this association, as it may influence the frequency of visits, monitoring patterns, and other elements of treatment planning.

Some evidence supports a potential relationship between parenting style and dental caries, but limited research has investigated this topic. Furthermore, conflicting results have been published. A 2019 study conducted in Saudi Arabia identified two parenting styles among their sample: authoritative and permissive parenting styles. The study found no statistically significant association between parenting style and child’s dental caries.17 On the other hand, a 2020 study conducted in India found a significant association between parenting style and child’s dental caries, with children of permissive parents exhibiting the highest level of caries.18 In a study performed in the United States, Howenstein et al. found that authoritative parents had children with less dental caries, in comparison with children of authoritarian and permissive parents.7 A limitation of this study’s design was that it simply grouped patients based on the presence or absence of dental caries and therefore could not draw inferences about the magnitude of dental caries.

The primary aim of this study was to investigate the association between parenting style and child’s magnitude of dental caries. The secondary aim was to explore associations between other potential risk indicators and child’s magnitude of dental caries. It was hypothesized that children with authoritative parents have less dental caries than children with authoritarian and permissive parents.

Results

A sample size of at least 20 parent–child dyads per parenting style was reached after a total sample size of 210 dyads had been obtained. Of the 210 parents, 159 (75.7%) were classified by the PSDQ as having an authoritative parenting style, while 31 (14.8%) were classified as permissive and 20 (9.5%) were classified as authoritarian (Table 1). The majority of parents identified as female (77.6%) and non-Hispanic (83.8%); nearly half of parents identified as Asian (48.1%). Most parents were married (65.7%), lived in urban locations (67.1%), and had insurance coverage through the MassHealth program (70.5%). The most common number of children per parent was two (46.7%), while the most common education level was high school graduate (37.1%) and the most common annual household income was < $25,000 (26.2%). The mean (SD) age of parents was 35.5 (6.0) years (Table 1). Most children in the sample were female (55.2%), were visiting the dental clinic for cleaning (re-care) (72.9%), and were categorized as having an excellent diet (57.1%). The most common child age was three years old (31.4%), while the most common birth order was second child (34.8%) (Table 1).

Table 1 Characteristics of the sample.
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Table 2 shows results related to the bivariate association between parenting style and child’s dmft, and Fig. 1 presents side-by-side box plots comparing the dmft of children from the three parenting styles. The median dmft score and IQR for the authoritative, authoritarian, and permissive parenting styles were 3.0 (0.0, 8.0), 6.5 (0.5, 10.0) and 8.0 (4.0, 12.0), respectively. The highest median dmft was exhibited by children of permissive parents, while the lowest median dmft was exhibited by children of authoritative parents. The difference between parenting styles was statistically significant based on the Kruskal–Wallis test (p = 0.01). In post-hoc comparisons, the only significant difference was between the permissive and authoritative parenting styles (p = 0.004).

Table 2 Bivariate association between parenting style and child’s dmft.
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Figure 1
figure 1

Box plots showing the relationship between parenting style and child’s dmft score.

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Table 3 presents results from the multivariable negative binomial regression model. When adjusting for confounding, parenting style was no longer significantly associated with child’s dmft (p > 0.05). However, parent’s education level and child’s diet score were significantly associated with child’s dmft. Specifically, parents with an education level less than high school (p = 0.02) and at the level of high school graduate (p = 0.008) were significantly associated with children who had higher dmft, compared to parents with a college degree or higher. Children with excellent diet scores had significantly lower dmft than children with a diet score in the “needs improvement” category (p = 0.003). No other variable in the model was significantly associated with child’s dmft.

Table 3 Multivariable negative binomial regression model predicting child’s dmft.
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Discussion

The question of association between parenting style and the dmft remains unanswered. In the current study, our bivariate analysis found a statistically significant association between parenting style and child’s dmft, in which children of authoritative parents had lower dmft than children of permissive parents. This finding is consistent with the results of Howenstein et al.7 and Viswanath et al.18 On the other hand, Alagla et al. found no significant association between parenting style and caries experience in bivariate analysis, although there was a trend for children of authoritative parents to be less likely to have caries experience than children of permissive parents.17 The ability of Alagla et al.’s study to detect an association may have been limited by their sample, in whom nearly all children had caries.17.

A high dmft among children of permissive parents could potentially be due to a dynamic in which the parents allow their children to decide for themselves whether to brush their teeth. Permissive parents may also allow their children to have a cariogenic diet with more frequent snacking in between meals. Parents may also be using cariogenic drinks or food as a reward or bribe to achieve good child behavior. On the other hand, authoritative parents may act as role models and explain to their children the importance of brushing their teeth and eating a healthy diet, making them more likely to perform those behaviors.

Nevertheless, it must be emphasized that there was no longer a significant association between parenting style and dmft once statistical adjustment for confounding was done via multivariable modeling, and inferences from our research must reflect this lack of significance. While the non-significant findings of our multivariable analysis may be counter-intuitive, it is important not to dismiss negative results, as a tendency to ignore such results leads to publication bias in meta-analyses.22,23.

The multivariable analysis also revealed that parent’s education level and child’s diet score were significantly associated with dmft, adjusting for the other independent variables in the model. Parents with an education level of less than high school, and high school graduate, had children with higher dmft than children of parents who had an education level of college degree or higher. These findings align with the results of Nourijelyani et al., who found that in Iran, higher education in mothers was significantly associated with better oral health status in children.24 Parents with greater educational qualifications are more likely to be knowledgeable about the importance of toothbrushing and healthy dietary habits from a young age, which may result in their children having a lower dmft.25,26,27 In the current study, significantly higher dmft was also found among children with a diet score that needs improvement, compared with a diet score of excellent. The connection between dental caries and cariogenic diets is well-known; children with better eating habits and healthier diets are less likely to develop early childhood caries in comparison with those with poor dietary habits and unhealthy diets.28,29,30.

The link between parenting style and child’s dental caries has been understudied thus far. An important aspect of the current research is that it is one of the first studies to investigate the relationship between parenting style and dmft. Another strength of the study is that it had a large sample size that was based upon a formal sample size calculation. Nevertheless, future studies should aim to include higher sample sizes in the authoritarian and permissive parenting styles, which had low representation compared with the authoritative parenting style. Previous studies had exhibited similar differential representation among the parenting styles.7,17,18 Increasing the sample sizes of future studies will aid in either confirming or refuting our results.

One of the limitations of our study, and similar studies, is that some parents may tend to answer questions in a way that is socially desirable, so they might not be completely honest in their answers. This could result in misclassification bias, whereby a parent could in fact be a member of the authoritarian or permissive category but be classified as an authoritative parent by the PSDQ. Such a phenomenon might partially explain how our study and previous studies on parenting style included a substantially higher percentage of parents classified as authoritative, compared with the other styles. Another limitation of this study is that its design can only support inferences about association, not causation. In addition, our sample was a convenience sample obtained from parents bringing their children for a dental visit at a single academic institution. The study was conducted among a largely low-income group of subjects, and the sample had a higher percentage of parents identifying as Asian than the general United States population. Results might not generalize to other populations. It is also noted that in the conceptual model of Fisher-Owens et al., a child’s oral health is influenced by individual-level factors, family-level factors, and community-level factors.6 Fisher-Owens et al. suggested employing hierarchical data analysis techniques when using their model. However, they acknowledged some challenges in applying their model in actual practice, for instance, the difficulty in finding datasets with all independent and dependent variables that would be pertinent to a given study. Fisher-Owens et al. noted that “a truly complete database would include a longitudinal component to adequately measure the time factor”6 and recognized that this would be difficult to obtain. In the current research, the variables collected were limited and did not incorporate a longitudinal aspect. The inclusion of only one child per family also precluded the study of the correlation between children in the same family within a hierarchical statistical model. If a hierarchical model had been used, the findings vis-à-vis statistical significance might have been different, and this can be considered a further limitation of the study.

In addition to the recommendations above, future research could consider administering the survey to a more diverse population. Furthermore, future studies could collect additional information such as tooth brushing frequency, use of fluoridated toothpaste, ingestion of fluoridated water, and dental anxiety of parents and children. Qualitative research, such as interviews and focus groups with parents about their parenting style and the oral health care of their children, could also be performed. Such qualitative research would complement the quantitative results presented herein and provide further insight into the potential link between parenting style and child’s dental caries.

In Conclusions, we found no significant evidence that parenting style is a risk indicator for child’s dental caries when accounting for confounding variables. However, pediatric dental professionals should be aware that parent’s educational level and the child’s diet are risk indicators for child’s dental caries.

Methods

This cross-sectional study was conducted using a convenience sample obtained from parents bringing their children to a dental visit at the Department of Pediatric Dentistry at the Tufts University School of Dental Medicine, which is in the downtown area of Boston close to Chinatown making it easily accessible from that neighborhood. Most of our participants were Asian and many of the parents did not speak English, which limited their ability to participate in the study and made the recruitment phase longer. The study was approved by the Tufts Health Sciences Institutional Review Board (Study #13,222), and all methods were carried out in accordance with relevant guidelines and regulations. Inclusion criteria were English-speaking parent/legal guardian-child dyads presenting to the Tufts Pediatric Dentistry Clinic for the child’s initial dental examination or re-care visit and child’s age between 3–6 years old. Preschool is a crucial time for the establishment of dietary choices, oral health habits and behaviors. Children’s behaviors can be greatly influenced by their parents at a young age, which can significantly impact their oral health outcomes. Therefore, it is valuable to examine the association between parenting style and dental caries among children aged 3–6 years old.17,18 Exclusion criteria were medically compromised patients with a physical or intellectual disability that could impact oral health in the opinion of the investigator (ASA III, ASA IV) and patients presenting for a dental emergency such as pain, infection, or trauma. A maximum of one child per family was included.

The patient population served at Tufts University School of Dental Medicine is diverse including individuals from various backgrounds and communities coming mainly from urban and suburban areas. During the initial exam or re-care dental visit for the child the following services were provided: medical and dental history review, clinical examination, taking dental radiographs if needed, treatment planning, professional cleaning, fluoride varnish application, diet counseling and oral hygiene instructions.

Informed consent was obtained from all participants’ legal guardian. One parent of each child was asked to complete a survey using a hard copy format. If a child presented with both parents, the parent who spent more time with the child, based on the parents’ judgment, was asked to fill out the survey. Before any survey item was administered, an information sheet regarding the study was provided by the principal investigator and/or co-investigator to each potential subject. The information sheet met all required elements of consent; the potential subject was given as much time as they desired to read it and consider the study. After the potential subject read the information sheet, any questions were answered. Potential subjects were reminded that their participation was voluntary, that they could choose to stop participating at any time without penalty, and that participation or the refusal to participate would have no effect on the child’s care.

The first part of the survey involved demographic data about the child and the family, including parent’s age, gender, ethnicity, race, marital status, number of children, education level, annual household income, location (urban, rural or suburban), and form of payment (self-pay, private insurance, MassHealth or other), as well as child’s sex, age, birth order, and reason for dental visit. The second part of the survey included questions from the shortened version of the Parenting Style and Dimensions Questionnaire (PSDQ), which has been developed and validated as a reliable instrument to classify parents as authoritative, authoritarian, or permissive.19,20,21 The original instrument consists of 62 items, and the shortened version consists of 32 items.20,21 Each item relates to one of the three parenting styles; in the shortened version, there are 15 items corresponding to the authoritative style, 12 items corresponding to the authoritarian style, and five items corresponding to the permissive style. Each item asks the respondent how often they (or they and their significant other, if applicable) exhibit a specified parenting behavior, using a Likert scale (1 = “Never”, 2 = “Once in a while,” 3 = “About half the time,” 4 = “Very often,” and 5 = “Always”). The score for each parenting style is defined as the mean of the item-level scores in that parenting style. Once such a mean has been computed for each of the styles, the parent’s style is defined as the style with the highest mean. The shortened version has been found to exhibit adequate Cronbach’s α values.10 Apart from the survey, the child’s decayed, missing, and filled teeth (dmft) index and diet score (scored with three categories: excellent, good, and needs improvement) from their first dental visit to the Tufts Pediatric Dentistry Clinic were obtained from their axiUm record and had been determined by the treating well-trained pediatric dental resident under the supervision of faculty attending dentists. The diet questionnaire was based on a standardized scale used at Tufts University School of Dental Medicine, which was developed by nutritionist Carole A. Palmer, EdD, RD. While it shares similarities with components of the Healthy Eating Index (HEI) focusing on specific food groups beverages and eating behaviors, the questions were not adopted from it. This questionnaire aims to evaluate the dietary intake of the child, by asking questions about their consumption of fruits, vegetables, grains, dairy, proteins, beverages, snacks, and desserts. Furthermore, there are additional questions about the frequency and preferences of snacks. The responses provide insight about the quality of the child’s diet and areas that needs improvement.

Data collection occurred from May 2019 to February 2020. A sample size calculation was conducted using the computer program nQuery Advisor (Version 7.0) (Statistical Solutions Ltd., Cork, Ireland). The calculation followed the guidelines of the DELTA2 project, which state that an assumed effect size can be based on findings in the literature regarding what difference may be considered realistic (and does not necessarily need to be based on the minimal clinically important difference (MCID)).31 This methodological approach also received further support in the literature subsequently.32 In the research of Howenstein et al.,7 20% of children in the authoritative parenting group exhibited caries, compared with 97% in the permissive parenting group and 91% in the authoritarian parenting group. Based on these empirically observed differences, a sample size of at least n = 20 per parenting style would be adequate to obtain power greater than 99% to detect a difference in the presence/absence of caries between parenting styles in conjunction with a Type I error rate of α = 0.05. Furthermore, because the dichotomization of continuous variables into binary “present or absent” categories results in a loss of information33 (and conversely, the use of continuous variables provides a gain of information compared with binary variables), the comparison of parenting styles in terms of a continuous dmft variable provides this same power or more (again, greater than 99%) a fortiori in conjunction with the same Type I error rate and sample size. As the parenting style of a subject was not known until after they had completed the survey, recruitment proceeded until at least 20 subjects of each parenting style were obtained; the additional subjects recruited in two of the three groups could only enhance the power of the study.

Descriptive statistics were calculated including means, standard deviations (SDs), medians, and interquartile ranges (IQRs) for continuous variables and counts and percentages for categorical variables. In bivariate analyses, the difference in dmft between children with parents of different parenting styles was assessed using the Kruskal–Wallis test due to non-normality of the data; post-hoc comparisons were performed using Dunn’s test with the Bonferroni correction. The assumption of normality was assessed using the Shapiro–Wilk test. To adjust for confounding, multivariable negative binomial regression was also used; exponentiated regression coefficients along with 95% confidence intervals (CIs) were calculated. Analogous to the odds ratio (OR) statistic, a value greater than 1 for the exponentiated coefficient indicates a higher dmft for a given group, compared to a reference group, adjusting for the other variables in the regression model; a value less than 1 indicates a lower dmft for the given group, compared to the reference group, adjusting for the other variables in the model. P-values less than 0.05 were considered statistically significant, with the exception of analyses in which the Bonferroni correction was used. SPSS version 25 (IBM Corp., Armonk, NY, USA) was used in the statistical analysis.