Effect of mother’s knowledge of oral health in preventing early childhood caries among preschool children: a systematic review

Mohammad Hassan Hamrah (  hassanhamrah@gmail.com ) Department of Pediatric Dentistry, school of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. https://orcid.org/0000-0003-3967-0127 Sara Ghadimi Department of Pediatric Dentistry, school of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Saeedeh Mokhtari Department of Pediatric Dentistry, school of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Maryam Khosrozadeh Department of Pediatric Dentistry, school of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Mojgan Kargar Department of Pediatric Dentistry, school of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Firoozeh Alipour Department of Pediatric Dentistry, school of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Hussain Hamrah Curative Clinic, Andkhoy, Afghanistan. Toba Dahi Faculty of Dentistry, AbantIzzet Baysal University, Bolu Turkey


Introduction
Early childhood caries (ECC) is one of the most common chronic diseases of childhood. It is a public health problem that continues to affect infant and preschool children worldwide. ECC has a debilitating effect on development, speech, general health, and self-esteem, thus affecting the quality of life of children (1,2).
There are multilevel in uences on children's oral health at the individual, family and community levels.
These family level in uences are mediated mainly through parents and caregivers with whom preschool children spend most of their time (3). During this period of primary socialization, the establishment of routine dietary and health behaviors is directly and indirectly in uenced by the knowledge on oral health (KOH), and on the attitudes, beliefs and practices of their parents and caregivers (4).
Since the 1900s, dental health education has been considered an important and integral part of dental health services and has been delivered to individuals and groups in settings such as dental practice, schools, the workplace, day-care and residential settings for older adults. The population as a whole has also been targeted using mass-media campaigns. The educational interventions used have varied considerably, from the simple provision of information to the use of complex programs involving psychological and behavioral change strategies. The goals of the interventions have also been broad, so that knowledge, attitudes, intentions, beliefs, behaviors, use of dental services and oral health status have all been targeted for change. These efforts are testimony to dentistry's long standing, and perhaps pioneering concern with the prevention of oral disease via changes in knowledge, attitudes and behaviors and the adoption of healthier lifestyles (5).
Since 2000, substantial literature has emerged describing studies purporting to evaluate the effectiveness of various types and combinations of educational and behavior-modi cation techniques. Brown reviewed 57 such studies published between 1982 and 1992 and concluded that dental health education can result in improvements in dental health behaviors and in objective measures of oral health status but was less effective in changing attitudes and knowledge (6). Perhaps, the most important issue is the quality of the designs used in the studies themselves. In order to avoid bias, error and various threats to validity, only the results of randomized controlled trials are usually included in systematic reviews. Locker and Kay reviewed the literature and concluded that the quality of the evidence pertaining to the effectiveness of dental health education is poor (5).
Parents and caregivers can be considered gatekeepers for the oral healthcare of preschool children, therefore their oral health knowledge, beliefs, attitudes and behavior may directly, or indirectly, in uence early childhood oral health. Traditional dental health education approaches with a main focus on improving parental oral health knowledge have not been effective in improving preschool children's oral health (5,7). For instance, traditional generic recommendations such as 'brush your child's teeth twice a day and reduce consumption of sweet snacks and drinks' have had limited success in changing oral health practices (8). Behavior change techniques (BCT), including face-to-face counselling have been effective across primary healthcare (9). BCTs have been described as an 'observable, replicable and irreducible component of an intervention designed to alter or redirect causal processed that regulate behavior (10).
The role of mothers in preventing dental caries starts when the child is in the mother's embryonic period.
This can easily be prevented through early detection of oral health problems. Screening in early pregnancy and applying prompt treatment at the right time can prevent transmission of infection from mothers to child. Routine dental checkups during pregnancy and the use of uorides and chlorhexidine have been found to be effective preventive strategies in inhibiting the transmission of cariogenic bacteria from mother to child (11).
The aim of this study is to systematically review scienti c evidences relating to mother's knowledge in improving oral health of their children and ECC prevention.

Search strategy
We searched the MEDLINE (through PubMed), Embase and Scopus databases for articles published between January 2009 and December 2019 in English language. All records electronically identi ed were independently assessed by two authors, according to their titles, abstracts and/or keywords, and the full texts of all reports considered potentially relevant were obtained.
The keyword headings used were 'mother's knowledge', 'oral health', 'children', 'pre-school' and 'early childhood caries'. The reference lists from the retrieved papers were manually screened for relevant references.

Inclusion criteria
The articles retrieved were based on the following inclusion criteria: Studies that were conducted to determine the mother's knowledge, oral health, early childhood caries of preschool children and published in English language.
Studies in which oral health was assessed.
Clinical studies with full texts.

Exclusion criteria
We excluded studies based on the following criteria: Studies that assessed over or older preschool age.
Studies which did not assess the oral health or preschool children.
Conference abstracts, review articles, case reports, letters, editorials, unpublished data, articles without full texts, and non-English articles. ( gure1)

Study selection
All retrieved articles from electronic as well as manual searches were entered into Endnote software

Results
The literature search yielded a total of 324 articles (Figure 1). A total of 91 duplicate references were removed. The remaining 233 studies were imported into Endnote library for further review. From these, 211 studies were excluded based on inclusion and exclusion criteria. The remaining 22 articles were selected for a full-texts review, after which 5 studies were screened-out. The summary of data showing the characteristics of included studies is presented in table 1.
An intervention based on the principles of motivational interviewing method was more effective in reducing the number of surfaces affected by early childhood caries compared with conventional oral health education intervention (12).
It has been shown that mother's education level has a direct effect on children's oral health (13). Parents with limited health literacy also had significantly worse oral health status (OHS) and reported their children to have significantly worse oral health-related quality of life (14). Attempts at improving the knowledge and attitude in parents have a substantial impact on improving the oral health of next generation (15)(16)(17). The following points should be considered when interpreting the results of this review.
The timing of the main outcome measurement (oral health) with respect to preschool children with mothers expressed that they were primarily responsible for their child's oral hygiene, and many noted that they felt they were important positive role models for their young children's oral hygiene.
There was concomitant and statistically signi cant increases in parents of children between 1 to 4 years (18). Mothers of toddlers lacked basic knowledge of oral health issues and practices to follow for the prevention of their children's caries (19).
Two studies used telephone contacts and text messaging to deliverer oral health information. These methods had a positive effect on parent and caregiver's oral health knowledge and behaviors (20,21).
Also, text messaging and phone connect intervention were able to increase ossing behavior and oral health knowledge (22). Furthermore, infant feeding habits and their mother's level of education were found to have signi cant effects on the development Oral health (23).
One study was based on data from the Norwegian mother and child cohort study conducted by the Norwegian Institute of Public Health and by the public dental services. A total of 1095 children were followed from pregnancy to the age of 5 years. Questionnaires regarding oral health behavior were completed by the parents at 1.5 and 5 years of age. Clinical and radiographic examination of the children was performed at the age of 5 years. Multiple logistic regression shows that having caries at 5 years old is associated with brushing the teeth less than twice daily at 1.5 years old (OR = 2.1, CI = 1.3-3.6) and being offered sugary drinks at least once a week (OR = 1.8, CI = 1.1-2.9) when controlled for family characteristics and oral health behavior at 5 years of age (24). Oral hygiene and care level of vulnerablechildren of incarcerated-mothers were signi cantly poorer. Prison caregivers had poor knowledge and attitude of dental health matters (25). It was observed that disparities by maternal education reinforce investments in education (26). Mothers need to be educated and encouraged that they are a key factor in improving the oral health habits of their children (27). Mothers expressed that they were primarily responsible for their child's oral hygiene, and many noted that they felt they were important positive role models for their young children's oral hygiene. Mothers would often model brushing their own teeth (28).
It has been suggested that mother's sense of coherence (SOC) could be a psychosocial determinant of the oral health related quality of life (OHRQoL) of their preschool children (29).

Discussion
The results of this review showed a reduced ECC incidence in preschool children whose mothers received prenatal oral health care. ECC is a multifactorial disease with complex socioeconomic, genetic, oral hygiene behaviors, and bacterial and diet factors that affect its risk (30,31). Streptococcus mutans and more recently, candida species have been implicated as potential major etiological microorganisms that may be involved in the initiation and development of ECC (32,33). This study focused on maternal level knowledge regarding oral health, especially since mothers play crucial roles in educating their preschool children. However, an attempt was also made to increase the awareness of not only mothers but also health professionals regarding the importance of the early prevention of dental and oral diseases in children. Through pre and postnatal health education, mothers' education level had a direct effect on children's oral health (13) and attempts at improving the knowledge and attitude in parents have a substantial impact on improving the oral health of next generation (15).
In the reviewed studies, we found that text messaging and phone connect intervention was able to increase ossing behavior and oral health knowledge. Additionally, among participants from a private practice, using this method increased the use of mouthrinse. Mothers' behaviors with respect to their children also changed; more text group mothers than control group mothers reported trying to improve their child's oral health behaviors and decreasing their child's candy, and sugary snack intake. The use of mobile technology (text messages, video messages, voice calling, and the Internet) to provide health care (mHealth) has been applied to improve the practicality, rapidity, and precision of diagnostic tests; monitor speci c medical conditions; improve medication adherence; send appointment reminders; and deliver medical test results (22).
The dental environment of a young child is affected by a complexity of factors that include the mother's and/or caregiver's dental knowledge, attitudes, beliefs and practices, all of which affect the child's oral condition (34). Feeding habits are said to be of primary importance in the etiology of dental caries at any age, but even more so among preschool children (35).
Participants who received MI (Motivational Interviewing) showed improved knowledge across a wider range of knowledge items (correct amount of toothpaste, supervised brushing position, uoride varnish, and safest time to give sugary foods and drinks) compared to those who received traditional dental health education DHE. Importantly knowledge of the importance of uoride varnish application also has practical implications for preventive strategies as this clinical intervention is effective in reducing ECC separately and in combination with uoride toothpaste (36,37). The reduction in prevalence of early childhood caries (ECC) following an MI intervention reported in Asian families in Canada, was largely attributed to a greater uptake of uoride varnish by those families (38) possibly due to the parents attaching greater value to professional preventive care. Mother's education level additionally indicates knowledge of oral health. In other words, mother's oral health knowledge was correlated with their education level. For instance, the dietary choice for children could be affected if their mothers knew about the role of bacteria and sugar in dental caries. Sweet food habits commence at preschool age (39).
Parents and caregivers can be considered gatekeepers for the oral healthcare of preschool children, therefore their oral health knowledge, beliefs, attitudes and behavior may directly, or indirectly, in uence early childhood oral health. Traditional dental health education approaches with a main focus on improving parental oral health knowledge have not been effective in improving preschool children's oral health (21).
Social, economic and environmental factors play a substantial role in shaping people's behavior and translating this knowledge into positive health choices and practices (40). In addition, the results of this study highlighted some general trends that were not always statistically signi cant but yet are worth noting. The rst was a general lack of weakness in the knowledge, attitude and practice in infant oral health-related areas such as the timing for the rst dental visit, the ideal timing to initiate tooth brushing for children, as well as nighttime bottle feeding. Better infant oral health-related trends, however, were observed with younger caregivers and caregivers of children under 1 year. This is possibly due to higher educational levels among the younger group. Additionally, younger parents have generally better computer/internet literacy and would therefore have wider access to a variety of oral health-related knowledge. The second observed trend was that mothers, compared to other caregivers, were generally more knowledgeable, had better attitude, but did not necessarily have better practices (41).

Conclusion
Results of this study show that mother's knowledge in uences their preschool children's oral health. Oral health education programs aimed at preventive actions are needed to provide children not only with adequate oral health, but better quality of life. Special attention should be given to the entire family, concerning their lifestyle and oral health habits. Maternal education has a direct effect on children's dental decay experience which is independent of sweet food intake and other risk factors when estimated using marginal structural models. Sweet food intake is also considered as a risk factor in children's dental caries. This study was also able to show that oral hygiene status was a signi cant risk factor for ECC. Moreover, socio-cultural factors are likely to affect oral health beliefs. Children whose mothers were submitted to a dental visit based on motivational interviewing to improve knowledge showed lower caries incidence than those that attended a conventional oral health education. Motivational interviewing group approach greatly reduces the risk of caries among preschool children.