Current knowledge about early childhood caries in the gulf cooperation council with worldwide reflection: Scoping review of the scientific literature (2010–2021)

Early childhood caries (ECC) is one of the most prevalent chronic childhood diseases affecting the primary teeth of children younger than 6 years of age. The disease etiology is complex and includes social, biological, and dietary factors. This review aims to explore the knowledge of ECC prevalence globally and locally within the Gulf Cooperation Council (GCC) countries during the years 2010–2021. Another aim is to explore oral health promotion programs with more focus on the GCC region. A search was conducted in PubMed, Medline, Scopus, the Cochrane Collaboration database, and Google Scholar to identify relevant studies published between 2010 and 2021 using specific keywords. Studies that utilized both the World Health Organization criteria and International Caries Detection and Assessment System for dental caries assessment were included. The included studies indicated considerable variation in the reported prevalence of ECC. While developed countries show low prevalence, countries in the GCC and other Arab countries show a high prevalence of ECC. Many oral health promotion programs were identified globally including oral health education, nutritional programs, the use of fluoride and pit-and-fissure sealants, and inter-professional population-based oral health promotion and prevention programs such as school-based oral health programs, motivational interviewing, and anticipatory guidance. ECC remains a significant problem in many parts of the world including the GCC region. Oral health prevention programs have been established within the GCC region. Nevertheless, the GCC region has some unique characteristics that need to be investigated to contextualize the western model of the dynamics of ECC prevention and promotion programs locally.


Introduction
Dental caries is a major public health concern for children worldwide and exerts a huge socioeconomic burden on families and society, especially when affecting young children [1]. Early world in comparison to the GCC region?", and "What strategies have been implemented around the world to prevent ECC and to what extent they were successful?". These questions shall provide insight into the current situation of the GCC countries compared to the rest of the world and inform policymakers on the future steps to be taken to prevent the disease.

Inclusion criteria
The literature search focused on studies reporting on ECC prevalence and prevention programs with the following specifications: Participants. This review included studies that reported on dental caries prevalence in children between the age of 0 and 6 (as per the ECC definition). Studies involving medically compromised children, children with other health issues, and children as minority groups (e.g., refugees) were excluded.
Concept. Studies that utilized both the WHO criteria [15] and International Caries Detection and Assessment System (ICDAS) [16] for dental caries assessment were included. The dmft index was captured within the identified ECC prevalence studies if reported. The review also included studies on ECC prevention with a clear description of the target population, preventative interventions, and outcomes.
Context. The literature search focused on primary studies from all countries reporting on ECC prevalence in the last decade (between 2010-2021). Hence the results were reported based on the geographical location of the included studies. Moreover, an exploratory search has been conducted utilizing relevant keywords highlighted in Table 1 to identify studies on ECC prevention programs. These studies were not included in the main results section. Nevertheless, the findings of those studies were included in the discussion section.
Types of evidence sources and search strategy. The literature search was conducted on the major health research databases: PubMed, Medline, Scopus, and the Cochrane Collaboration. An additional search in the Google Scholar database was conducted to enable a broader view of the available government policies. Moreover, the World Health Organisation (WHO) documents were checked regarding oral health policies, conferences, and workshops of relevance. In addition, the bibliographies of the located articles were checked for additional relevant references. Exclusion criteria included studies published in languages other than English, case studies, and case reports, studies included children older than 6 years of age, review articles, and meta-analyses. The inclusion and exclusion criteria and keywords are detailed in Table 1. Articles were reviewed independently by two researchers.

Results
The initial search of the databases and other sources was conducted in August 2021 and resulted in 2,234 studies. the initials screening excluded 2,140 studies after reviewing the titles and abstracts and 94 studies were included in the full-text review for eligibility. Of the 94 articles, 63 studies were included in this review. The process of records identification and selection are summarized in Fig 1. The extracted data from the included articles were charted in table format and categorized based on the geographical location to serve the study objectives. The table includes the authors, year of publication, the country where the study was conducted, the age range and number of the study participants, the ECC prevalence (as percentage), and the mean dmft index (if reported) ( Table 2).

Trends of ECC prevalence
It can be seen from Table 2 that studies on the prevalence of ECC globally and regionally report great variation. While developed countries show low prevalence, countries in the GCC and other Arab countries show a high prevalence of ECC. Several studies from the GCC region documented a high prevalence of ECC in children. The highest prevalence was reported in Qatar (89% in 4-5 year-olds, followed by The United Arab Emirates (UAE) (83% in 5 yearolds & 74% in 4-6 year-olds), while the prevalence in the Kingdom of Saudi Arabia (KSA) was 69% in 3-5 year-olds and 73% in 3-6 year-olds. Reports from other Arabic countries showed similar trends of high prevalence with the highest being reported from Palestine (76% in 4-5 year-olds) followed by Lebanon (75% in 2-4 year-olds), Egypt (61% in 3-6 year-olds), Sudan (52% in 3-5 year-olds) and the least prevalence among the Arabic countries was reported in Tunisia (50% in 3-5 year-olds). There was a considerable variation in the reported prevalence of ECC from studies conducted in Europe. The highest prevalence was observed in a study from The Federation of Bosnia and Herzegovina (83% in 3-5 year-olds) while the lowest prevalence of 8% in 0-71 month-olds was reported in Italy in 2019. A big variation in the reported prevalence of ECC was also observed in studies from Asia. China reported the highest prevalence of 88% in 6 year-olds and 85% in 5 year-olds and the lowest prevalence in Asia was reported in Japan with a prevalence of 15% in 3 year-olds. In Central & South America, the highest prevalence of ECC was observed in Brazil (90% in 3-4 year-olds) while the lowest prevalence was reported in Trinidad & Tobago (50% in 3-5 year-olds). The highest prevalence of ECC in Africa was reported in Kenya (60% in 3-5 yearolds), while Nigeria showed a relatively low prevalence of ECC compared to other studies from the same region; 24% in 3-5 year-olds and 7% in 6-71 month-olds. Only one recent study from Australia was included in this review with a reported prevalence of 11% in 2-3-year-old.

Discussion
This scoping review provided an overview of the global trends of ECC prevalence with more focus on the GCC region. It also highlighted many ECC preventative programs around the globe and identified the need for further actions to efficiently utilize available resources within the GCC region to tackle the disease. This review included studies utilized both the WHO dmft index as well as International Caries Detection and Assessment System (ICDAS) for dental caries assessment. For cavitated carious lesions, both indices tend to report similar prevalence rates. Nevertheless, dmft index is unable to detect non-cavitated lesions cases, unlike the ICDAS which has the advantage of distinguishing between the stages of caries progression in early enamel, enamel, and dentin [91,92]. Hence the variation between the two indices needs to be taken into consideration while interpreting the results of this review.

Global trends of ECC prevalence
Dental caries is the most prevalent chronic disease in early childhood [5]. The prevalence of ECC varies globally according to the population studied. Socially disadvantaged groups in communities around the world are affected most by the disease [93,94]. The prevalence of dental caries has shown a marked decrease over the last quarter of the twentieth century in industrialized countries. This is due to various public health measures such as water fluoridation and other fluoride modalities along with changing living conditions and improved selfcare practices [95]. In contrast, dental caries is still considered a major health problem worldwide [96]. Certain disadvantaged groups in industrialized countries and many other populations in developing countries are suffering from an increasing prevalence of dental caries [96].

Risk factors of ECC with a focus on the GCC region
According to the WHO "The social determinants of health are the conditions in which people are born, grow, live, work and age. These circumstances are shaped by the distribution of money, power, and resources at global, national, and local levels. The social determinants of health are mostly responsible for health inequities-the unfair and avoidable differences in health status seen within and between countries" [97]. It is generally agreed there are many individual risk factors and social determinants for dental caries. The individual risk factors include early acquisition of caries-causing bacteria, mutans streptococci, and consuming a highly cariogenic (causing caries) diet. Poor dietary habits play a significant role in caries development including bottle feeding beyond 15 months of age, bottle feeding in bed, prolonged on-demand and frequent breastfeeding, and continuous sipping from the bottle during the day [98]. Other risk factors include lack of fluoride exposure in the absence of water fluoridation, less than daily tooth brushing, tooth enamel abnormalities, and limited professional guidance from medical practitioners, dentists, pediatricians, and nurses [99][100][101][102].
There might be some risk factors for ECC that are unique to the GCC region in comparison with many places in the world. In general, the population in the GCC region is characterized by relatively high income per capita by international standards. However, ECC remains a significant problem in this region coupled with a lack of water fluoridation in most GCC countries. In the following sections, reported risk factors which are relevant to the GCC region will be discussed. Parental knowledge and attitudes. Upon reflection on the unique situation of the GCC countries, interesting findings were observed. A study that investigated the knowledge of mothers of preschool children about oral health in Qatar reported good knowledge about oral health care. However, the study reported that 36% of the children went to bed with a bottle and 42% of the children have frequent snacks which are mostly cariogenic. These findings indicate that mothers were unable to translate their knowledge into a habit [103]. Similar findings were reported by a study from Kuwait investigating the knowledge, attitudes, and practices of caregivers in relation to the oral health of preschool children [13]. The participants in this study had good knowledge about inappropriate types of diet that may cause dental caries, the importance of fluoride, and its role in preventing dental caries. However, their knowledge and attitude scores were low about the timing of starting toothbrushing for young children, the timing of the first dental visit, and the consequences of ECC. More than two-thirds of the participants could not indicate the correct age for the first dental visit and reported their children to have visited the dentist after the age of 3 years. The most interesting practice reported in this study was that around 44% of the children have their teeth brushed by a caregiver other than the parents. It is worth mentioning that having nannies to take care of the children is a common practice in the GCC region. Two other studies from the UAE reported that the level of parents' education had a significant association with the occurrence of dental caries in their children [104,105].
Nationality. Interestingly, in the GCC region, being national or indigenous can be a risk indicator for dental caries. Hashim et al. [104] reported a caries prevalence of 76% and an average dmfs score of 10.2 in a study conducted in UAE, involving 1036 children aged 5-6 years. In this study, the authors found that native children had more severe caries than expatriates.

ECC management and prevention
There are many strategies to manage and prevent ECC that have been identified in the literature. These strategies include the early establishment of a dental home, periodic examination and preventive practices, anticipatory guidance, and treatment when necessary. It is recommended that children should have their first dental examination no later than 12 months of age by a child-friendly dental practitioner. This is referred to as establishing a "dental home" [106][107][108]. A periodic dental examination is recommended at 6-month intervals and maybe more frequent if the child was identified as having a high dental caries risk. During this periodic examination, dental professionals may undertake preventive practices including caries risk assessment, prophylaxis, and topical fluoride treatment as well as providing fluoride supplementation when needed [109,110]. In early childhood, anticipatory guidance is appropriate in areas such as oral hygiene, dietary habits, injury prevention, and speech and language development. Early detection of oral disease and providing the appropriate and optimal treatment complete the strategic approach to ECC management [111,112].

Overview of ECC oral health prevention programs
There are a variety of oral health promotion programs that have been researched for the impact and effectiveness of preventing ECC. Those intervention programs suggested oral health education, nutritional programs, the use of fluorides, sugar substitutes, and mechanical barriers such as pit-and-fissure sealants. Behavioral interventions such as motivational interviewing, anticipatory guidance, and counseling with children and their caretakers are also suggested [113]. The following sections shall discuss some of the oral health prevention programs implemented in different counties to prevent ECC.
GCC countries. A school-based oral health promotion program was implemented in Kuwait, targeting 11-12-year-old children. The program was evaluated by Alsumait A, et al. [77] who included 440 primary school children who participated in the program for at least 3 years and compared their oral health status with a control group. During the program, children received twice-a-year applications of fluoride varnish and fissure sealants if needed; and their mothers had, at least, one oral health education session. The results indicated that enrolment in the school-based prevention services was associated with a positive impact on children's caries level with no significant impact on mothers' knowledge.
In Qatar, a school-based oral health program was established in 1979 and was redesigned in 2017 to a new program targeting kindergarten and all grades of primary public schools. The program provides age-specific oral hygiene instructions where children are engaged in educational and recreational activities, application of topical fluoride varnish, and referral to a primary healthcare center as needed [114].
Technologies have been utilized to implement some oral health promotion programs such as mobile phone applications sought to enhance oral health knowledge and practice of mothers. In the Kingdom of Saudi Arabia, a mobile application has been developed and distributed to 3879 mothers of children below 6 years of age. The impact of the intervention was studied and the authors reported that there was a significant improvement in the knowledge of the mothers; especially those with more than one child [78]. Similar findings were reported from Iran by Zolfaghari M, et al., [79], where a mobile phone application was developed containing information about ECC, healthy diet, sugars, baby-oral hygiene, fluoride effect, fluoride toothpaste, and toothbrushing training video.
Hongkong. Chai HH, et al., [115] implemented a school-based oral health promotion program where they targeted 20,000 children from 100 kindergartens in Hong Kong with dental screening and silver diamine fluoride treatment to manage ECC. In addition, oral health talks were given to the children's parents, and teacher training was provided to empower teachers to deliver regular oral health education to kindergarten children at school. The project also provided individual counseling to parents whose children have severe ECC.
Singapore. A two-year quasi-experimental study included 90 children under 18 months of age and their caregivers in Singapore. The study evaluated a preventive oral health program including oral health education, anticipatory guidance on diet, oral health care practices, nonnutritional habits and trauma prevention, and topical fluoride varnish. The results indicated that 31.3% of children in the control group had SECC compared to 7.8% in the intervention group [80].
Australia. A randomized controlled trial from Australia evaluated an oral health promotion program that offered dental care to mothers during pregnancy, application of fluoride varnish to teeth of children at ages 6, 12, and 18 months and motivational interviewing delivered in conjunction with anticipatory guidance. The mean number of decayed teeth in children aged two years was lower in the intervention group (0.62) than in the control group (0.89) [81]. Another community-based oral health prevention in Australia improved oral health in preschool children where dental health educators visited all mothers at a time after birth and provided comprehensive oral hygiene instructions for their children and themselves, which included practical toothbrush training and dietary counseling by the use of brief motivational interviewing and anticipatory guidance approaches [82].
The "Country KIDS" study was conducted in rural Victoria, Australia, and investigated the effect of a community-based intervention promoting early exposure to fluoridated dentifrice [83]. This study involved healthy children (n = 915) from three rural areas who were recruited into the study by the maternal and child health nurses at the age of 12 months. The nurses received oral health promotion training as part of the study. The intervention group received an oral health starter kit containing toothpaste, toothbrush, and educational materials about oral health, while the control group received standard care. Children were examined at baseline and then annually for three years. The results of this study were inconclusive.
Malaysia & The USA. In Malaysia, the Family Dental Wellness Programme is implemented targeting 2-3-year-old preschool children and their 4-6-year-old siblings'. The program offered dental examinations and oral health education through anticipatory guidance at six-month intervals over 3 years and it significantly lowered net caries increment among enrolled children [84]. On the other hand, a community-based cluster-randomized controlled trial conducted in Boston-The United States of America (USA) concluded that motivational interviewing counseling with intensive caries prevention activities resulted in knowledge increases but did not improve oral health behaviors or caries increment among children aged 0 to 5 years [85].
Canada. Another study evaluated the impact of community workshops on improving knowledge about ECC in Manitoba, Canada. The participants (n = 108) in this study were service providers and community members who work with infants, preschool children, and their families. They were engaged in capacity-building workshops and participated in a pre-and post-workshop survey to assess the effectiveness of the workshops. Many participants had good prior knowledge that foods high in sugar and starch cause dental caries. However, they had limited prior knowledge about the initial signs of dental caries, the timing of the first dental visit for children, the extent of parents' supervision for child toothbrushing, and the adverse effect of mother's poor oral health on her child's oral health and the protective role of fluoride varnish in preventing dental caries. These areas of poor knowledge were reported to be improved by 16% after the workshops [86].
Sweden & Ireland. A study from Sweden evaluated semi-annual professional applications of fluoride varnish in one-year-old children until the age of three. The program failed to reduce caries development [87]. Similar findings were reported by Tickle M, et al., [88] who evaluated the effect of topical fluoride application in 2-3-year-old children over three years in Ireland. In contrast, a one-year clinical trial conducted in Iran targeted children aged 12-24 months with oral health counseling and fluoride varnish and concluded that oral health counseling alone or associated with the use of fluoride varnish reduced caries incidence [89].
Scotland. Scotland implemented a national comprehensive oral health prevention program "Childsmile". The program sought to improve the oral health of children as well as access to dental services. The program offers supervised toothbrushing at nurseries. Moreover, children are provided with a dental pack containing a toothbrush and toothpaste. Children also receive fluoride varnish by Childsmile dental nurses. The program succeeded to increase the number of children with no caries experience in primary teeth from 45% in 2003 to 71% in 2018. In addition, the dmft index is reduced from 2.76 to 1.14 during the same period of time [90].

The role of medical practitioners in children's oral health
Evidence from the scientific literature on ECC prevention highlights the need for early engagement of parents perinatally. The involvement of non-dental healthcare providers in ECC prevention programs is considered efficient and cost-effective. Hence, inter-professional population-based oral health promotion and prevention programs hold the potential to target children at greatest risk and address their oral health within a larger context of overall health [113].
A publication by the Victorian Department of Health in Australia provided a comprehensive review of health promotion activities [116]. This review presented oral health promotion interventions for different age groups including pregnant women, babies, and young children. The authors suggested that successful oral health promotion programs share common elements: integrating oral health into general health programs, the use of fluoride, targeting highrisk populations, tailored approaches based on active participation and addressing social, cultural, and personal norms and values and the existence of surveillance and referral targeting pregnant women, infants, and young children. Hence the integration of oral health into wellchild visits was through The Lift the Lip screening program. The program was adopted by primary healthcare centers in Qatar in 2014, where around 1000 non-dental health professionals (nurses, physicians, and health educators) were trained in oral health promotion and simple oral examination to detect caries and other oral health problems. The program is called "The Beautiful Smile Project" where young children visiting the vaccination clinics (Well-Baby Clinics) are screened by attending nurses and physicians for oral diseases including dental caries and referred to a dental clinic as needed. Moreover, nurses and physicians attending antenatal clinics provide oral health checks for expectant mothers and refer them to the dental clinic as needed [117].

Conclusion
This review mapped the prevalence of ECC in many countries across the world and gave an insight into the disease prevalence in the GCC region in relation to other geographical areas. ECC remains a significant problem in the GCC region despite the implementation of several oral health prevention programs highlighted in this review. It is evident that the GCC region has unique characteristics that need further investigations to effectively contextualize the western model of the dynamics of ECC prevention and promotion programs locally. Hence further research is needed in this area to inform policymakers on how to effectively utilize resources to tackle the disease.