Does poor oral health impact on young children’s development? A rapid review

The search identified 5,033 records. All titles and abstracts were screened and 4,944 were deemed ineligible for inclusion. Following full-text screening of 89 records, ten were included in the study (Fig. 1). A further five primary studies from two systematic reviews that met the inclusion criteria were also included. All synthesised and primary data were from observational and cross-sectional studies. See Table 1 for a summary of the included studies.

PRISMA diagram of literature search process

Speech and language development

A systematic review of observational studies aimed to evaluate the consequences of premature loss of primary anterior teeth in children’s speech and arch integrity.¹⁵ Two of the included studies met the inclusion criteria of this review. A US case-control study reported that, following premature loss of maxillary primary teeth, parents perceived that their child’s speech sounded different, they experienced difficulty articulating certain sounds (eg ‘s’ and ‘z’) and they had difficulty eating and chewing. In addition, there was agreement between parental perceptions and actual disarticulations detected by professional assessment.¹⁶ A case-control study conducted in Turkey investigated the effects of primary anterior tooth loss and dentures on the speech of children with ECC. Although dentures initially affected articulation of certain sounds, participants compensated and articulated speech sounded correct at a follow-up appointment.¹⁶ Both studies had very small samples and were assessed as high risk of bias.¹⁵ A critical review by the same authors emphasised premature loss of primary teeth may cause speech distortion.¹⁸ However they note the scarcity of recent data and the methodological limitations of published studies.

Two primary studies supported the association between poor oral health and speech and language development delays in preschool children. A cross-sectional survey and cohort study conducted by the same authors in Taiwan evaluated potential associations between higher levels of ECC and physical and/or psychomotor deficiency in children aged 3-6 years.^19,20 Data on caries experience (decayed, missing and filled primary teeth [dmft]), diet, body mass index, psychomotor development and the Chinese Child Development Inventory (CCDI) scale were collated. The CCDI is a modification of the Minnesota Child Development Inventory, comprising 320 items over seven developmental areas (gross motor, fine motor, expressive language, comprehension concept, situation comprehension, self-help, personal-social) and one summary scale. The cross-sectional study reported a positive correlation between severe ECC (dmft >3-8) and psychomotor deficiency (expressive language and comprehension concept scales). Regression analyses using CCDI developmental areas as dependent variables identified a statistically significant relationship between expressive language (undefined) and dmft scores (≤2 vs ≥3).²⁰ In the cohort study, the authors suggest a causal relationship between ECC and psychomotor deficiency in preschoolers. Having controlled for diet and socioeconomic status, higher ECC (dmft scores: <4 vs 6-10) was associated with psychomotor deficiency (in the development areas of expressive language, comprehension concept, gross motor and self-help). However, the authors noted a web of causation involving socioeconomic status and diet which required further investigation.¹⁹

Oral health-related quality of life

Two systematic reviews with meta-analyses of observational studies evaluated the impact of caries on OHRQoL in preschool children.^21,22 Both included studies that clinically assessed caries, assessed OHRQoL with a validated instrument and compared the OHRQoL of children with and without caries. Studies that included children with systemic diseases were excluded. Included studies in both reviews were cross-sectional, cohort or case-control design and most were conducted in Brazil.

Zaror and colleagues aimed to assess the impact of ECC on OHRQoL.²¹ They included preschool children under six years but excluded studies that: included other ages and did not stratify results by age; assessed the psychometric properties of an OHRQoL questionnaire; were case reports or series with fewer than ten participants; and studies that reported secondary data.²¹ In total, 35 studies were included in the review: 15 were assessed as methodologically weak, 18 moderate and two were strong. Of the 35 included studies, 24 were included in the meta-analysis, all of which found that ECC negatively impacted the OHRQoL of preschool children. The authors pooled data from studies providing dichotomous results (impact vs no impact). Ten studies showed that children with ECC were more likely to report a negative impact on OHRQoL than those without caries (OR: 3.01; 95% CI: 2.43-3.74; I² = 79%; very low-quality of evidence). Pooled data that had been adjusted for confounders from six studies confirmed children with ECC were more likely to report negative OHRQoL impacts (OR: 1.99; 95% CI: 1.51-2.62; I² = 85%; very low-quality of evidence). A total of 14 studies reported OHRQoL scores, which allowed the standard mean difference (MD) between the ECC group and the control group (those without caries) to be calculated: 0.81; 95% CI: 0.61-1.00; I² = 92% (very low-quality of evidence). In addition, all domains of the Early Childhood Oral Health Impact Scale were impacted in patients with ECC, with the social and psychological domains most affected, although heterogeneity was reported as high. Severe ECC (dmft index >5) was also found to increase the negative impact of OHRQoL in preschool children compared with those with non-severe ECC.²¹

A systematic review and meta-analysis of observational studies pooled data from 12 of 29 included studies.²² It aimed to assess if caries negatively impacts the OHRQoL of preschool children (defined as those up to five-year-olds) and excluded studies that did not report sample size calculations. In comparing the mean OHRQoL scores of those without and those with caries, those without had a lower mean score, thus there was a negative mean difference. All 29 included studies found caries negatively impacted OHRQoL. A higher impact was reported for those with dmft ≥1 compared with those without caries (MD: −3.57; 95% CI -5.16 to -1.98; I = 96%). Consistent with the findings of Zaror and colleagues (2022), severity of caries experience correlated negatively with OHRQoL impacts. Children with a dmft ≥6 showed a greater impact on OHRQoL (MD: -9.19; 95% CI -13.00 to -5.38; I² = 95%). The evidence presented in the review was assessed as being at low certainty due to the observational nature of the studies and substantial methodological heterogeneity.²²

School attendance and performance

One systematic review evaluated the association between oral health and preschool attendance and performance; three of the included studies related to children aged 2-5 years.^23,24,25,26 Two of these were cross-sectional studies undertaken in Brazil. The first found cavitated caries was the most common oral health problem among participants and was associated with preschool absenteeism after logistical regression (OR: 2.872; 95% CI: 1.266-6.514; p = 0.012).²⁴ The second found caries experience was positively associated with absence from school (OR: 4.38, 95% CI: 1.29-14.93).²⁵ A cross-sectional study of 600 primary and nursery children in India found higher mean df-t (number of decayed and filled teeth) to be associated with poorer school performance when comparing groups with excellent and below average marks and average and below average marks.²⁶

Janus and colleagues investigated the impact of poor oral health on school readiness in Canada (n = 576,264).²⁷ Teachers completed the 103-item Early Development Instrument (EDI), a measure of children’s ability to meet age-appropriate developmental expectations. It includes five general domains of development: physical health and wellbeing; social competence; emotional maturity, language and cognitive development; communication skills; and general knowledge. After adjusting for age, sex, special educational needs, English or French as first language, and neighbourhood socioeconomic status, children with teacher-reported unaddressed dental needs (UDNs) were more likely to be vulnerable on at least one EDI developmental domain compared to children without UDNs (OR: 8.434, 95% CI: 7.601-9.358; p <0.001).

An Australian cross-sectional study assessed the relationship between childhood health conditions, health service utilisation and subsequent academic performance in four- and five-year-old children (n = 24,678).²⁸ It matched data from the 2008 School Entrant Health Questionnaire (completed by parents/carers) with the 2011 National Assessment Program – Literacy and Numeracy (NAPLAN) and controlled for confounders such as age, sex, language spoken at home, attendance at preschool and socioeconomic status in the analysis. Children with dental problems (not defined) were more likely to have a score at or below the national minimum in numeracy (OR: 1.2; 95% CI: 0.9-1.4) and more likely to have a score below the national minimum standard for reading (OR: 1.1; 95% CI: 0.9-1.3). Despite the lack of statistical significance in a large sample, the authors suggested that dental health, along with other health conditions, increased the risk of poor school performance.

Muirhead and Marcenes (2004) correlated various data in an ecological study in Wandsworth, London (n = 1,968).²⁹ They analysed caries experience (five-year-old dmft), deprivation of school location (Jarman score), school performance (results in English, mathematics, and Linguistic Awareness of Reading Readiness Test [LARR]) and free school meals eligibility. Multiple linear regression analysis demonstrated associations between caries experience, deprivation of school location, school performance (English, mathematics and LARR) and proportion receiving free school meals. The authors reported LARR scores and the proportion of children receiving free school meals predicted mean school caries experience. As an ecological study the direction of this relationship cannot be established; however, the findings are relevant to the aim of this review.