0ACTA P/EDIATRICA
NURTURING THE CHILD
Acta Pœdiatrica ISSN 0803-5253
REVIEW ARTICLE
Breastfeeding and the risk of dental caries: a systematic review and meta-analysis
R Tham1, G Bowatte1, SC Dharmage12, DJ Tan1'3, MXZ Lau1, X Dai1, KJ Allen2'4, CJ Lodge (clodge@unimelb.edu.au)1'2
1.Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Carlton, Vic., Australia
2.Murdoch Childrens Research Institute and University of Melbourne Department of Paediatrics, Royal Children's Hospital, Parkville, Vic., Australia
3.NHMRC Centre of Research Excellence for Chronic Respiratory Disease, School of Medicine, University of Tasmania, Hobart, TAS, Australia 4.Institute of Inflammation and Repair, University of Manchester, UK
Keywords
Breastfeeding, Child, Dental caries, Meta-analysis, Systematic review
Correspondence
Caroline Lodge MBBS Grad Di Epi PhD, Allergy and Lung Health Unit (ALHU), Centre for Epidemiology and Biostatistics, School of Population & Global Health, Faculty of Medicine, Dentistry & Health Sciences, The University of Melbourne, Level 3, 207 Bouverie Street, Melbourne, Vic. 3010, Australia. Tel: +61 3 83440848 | Fax: +61 3 93495815 | Email: clodge@unimelb.edu.au
Received
18 May 2015; revised 10 June 2015; accepted 7 July 2015.
D0I:10.1111/apa.13118
ABSTRACT
Aim: To synthesise the current evidence for the associations between breastfeeding and dental caries, with respect to specific windows of early childhood caries risk. Methods: Systematic review, meta-analyses and narrative synthesis following searches of PubMed, CINAHL and EMBASE databases.
Results: Sixty-three papers included. Children exposed to longer versus shorter duration of breastfeeding up to age 12 months (more versus less breastfeeding), had a reduced risk of caries (OR 0.50; 95%CI 0.25, 0.99, I2 86.8%). Children breastfed >12 months had an increased risk of caries when compared with children breastfed <12 months (seven studies (OR 1.99; 1.35, 2.95, I2 69.3%). Amongst children breastfed >12 months, those fed nocturnally or more frequently had a further increased caries risk (five studies, OR 7.14; 3.14, 16.23, I2 77.1 %). There was a lack of studies on children aged >12 months simultaneously assessing caries risk in breastfed, bottle-fed and children not bottle or breastfed, alongside specific breastfeeding practices, consuming sweet drinks and foods, and oral hygiene practices limiting our ability to tease out the risks attributable to each. Conclusion: Breastfeeding in infancy may protect against dental caries. Further research needed to understand the increased risk of caries in children breastfed after 12 months.
INTRODUCTION
Dental caries (tooth decay) is a major public health problem affecting 60-90% of school-aged children (1), with increased prevalence in children from lower socio-economic groups (2). It is caused by multi-factorial and complex interactions between cariogenic bacteria in the mouth with dietary carbohydrates that produce acids and demineralise the teeth (2). The pain and infection caused by dental caries can be extremely distressing and can impact on quality of life and ability to function (3), lead to lost productivity and involve high health care costs (4) including general anaesthesia for treatment of severe cases. This accounts for one of the most common causes of child hospitalisation in industrialised countries (5) and is among the most common causes of avoidable child hospitalisations (6). Early loss of deciduous dentition can lead to ongoing dental problems in the permanent dentition.
The evidence concerning infant feeding as a risk factor for dental caries is inconsistent. Dental caries risk is related
to the carbohydrate content of breast milk or formula along with factors which determine the length of contact between breast milk or formula and the erupted dentition (i.e. frequency of feeding, and feeding practices which result in pooling of breast milk or formula around the teeth surfaces, such as feeding babies to sleep). The central determinant of caries risk, however, is the age of colonisation and levels of cariogenic bacteria (e.g. Streptococcus mutans) (7) in an infant's mouth. Earlier and denser oral colonization by cariogenic bacteria are related to increased caries risk (8). Breast milk, in contrast to formula, contains breast-specific
Abbreviations
95%CI, 95% Confidence Intervals; NOS, Newcastle Ottawa Scale; OR, Odds ratio; RCT, Randomized controlled trials; RR, Relative risk; WHO, World Health Organization.
Key notes
• Children exposed to more versus less breastfeeding up to 12 months had reduced risk of dental caries.
• Increased risk of dental caries in children breastfed >12 months, especially if frequent or nocturnal, may be due to unmeasured confounders including dietary sugars and oral hygiene practices.
• Research should simultaneously investigate breastfeeding practices including frequency and nocturnal routines, along with dietary and oral hygiene practices to more accurately determine specific risks.
©2015 The Authors. Acta P^diatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta P^diatrica 2015 104, pp. 62-84 This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium,
provided the original work is properly cited.
Lactobacilli and substances, including human casein and secretory IgA, which inhibit the growth and adhesion of cariogenic bacteria, particularly oral Streptococci (9,10). The risk of dental caries is also dependent on the presence of teeth and rises with increasing number of teeth. Risk also changes as the infant's diet starts to include foods and drinks other than breast milk or formula, depending on the carbohydrate content, acidity and consumption frequency of the introduced diet.
The important aspect of timing of tooth eruption for our systematic review is that the deciduous teeth most at risk of early childhood caries (eight upper and lower central and lateral incisors) start to erupt at 6 months and are fully erupted by 12 months. The next most vulnerable deciduous teeth (four upper and lower first molars) erupt between 13 and 19 months, the remainder are erupted by 33 months (11).
Current WHO breastfeeding guidelines recommend exclusive feeding for the first 6 months of life and complementary breastfeeding up to 2 years (12). Although the UNICEF calculated global prevalence of breastfeeding at 12 months from 62 countries is 74%, this figure hides the underlying heterogeneity between countries (13). As opposed to low income countries, the duration of total breastfeeding in high/middle income countries is shorter with only 21% of US mothers breastfeeding at 12 months (14) and similar rates in the UK (13), Canada (5) and Australia (15). National guidelines in high/middle income countries, where the risk of infant morbidity and mortality from gastrointestinal disease is relatively low, recommend breastfeeding for at least 12 months (16). Thus, investigating windows of exposure before and after 12 months of age is relevant to breastfeeding guidelines and practices as well as timing of tooth eruption.
The relationship between breastfeeding and dental caries has been systematically (17) and narratively reviewed (1820) with conflicting results between studies. There is controversy about what constitutes the best form of infant feeding to prevent dental caries and promote optimal dental health (21). Consequently no definitive optimal weaning times or breastfeeding practices have been determined to specifically address the risk of dental caries.
To summarise the current evidence for the association between breastfeeding and dental caries with specific reference to exposure windows and breastfeeding practices.
METHODS
Search strategy
We identified human English language studies through systematically searching electronic databases: PubMed Central, CINAHL and EMBASE from inception to the present. Our exposure of interest was breastfeeding as compared to formula or other feeding. Our outcome of
Table 1 Search terms used for the three databases electronically searched
[PUBMED]
#1 "Breast Feeding"[Mesh]
#2 "Milk, Human"[Mesh]
#3 Breast[All Fields] AND Feed*[All Fields]
#4 Breast-fe*[All Fields]
#5 Infant fe* [All Fields]
#6 Infant nutrition* [All Fields]
#7 #1 OR #2 OR #3 OR #4 OR #5 OR 6
#8 Dental caries (MeSH)
#9 Tooth decay
#10 "Early childhood caries"
#11 "Nursing bottle caries"
#12 #8 OR #9 OR #10 OR #11
#13 animals [mh] NOT humans [mh]
#14 #7 AND #12
#15 #14 NOT #13
[EMBASE]
#1 'breast feeding'/exp #2 'breast milk'/exp #3 Breast AND Feed* #4 Breast-fe* #5 Infant fe* #6 Infant nutrition*
#7 #1 OR #2 OR #3 OR #4 OR #5 OR 6
#8 'dental caries'/exp
#9 Tooth decay
#10 "Early childhood caries"
#11 "Nursing bottle caries"
#12 #8 OR #9 OR #10 OR #11
#13 [animals]/lim NOT [humans]/lim
#14 #7 AND #12
#15 #14 NOT #13
[CINAHL]
#1 "Breast Feeding" #2 "Milk, Human" #3 Breast AND Feed* #4 Breast-fe* #5 Infant fe* #6 Infant nutrition*
#7 S1 OR S2 OR S3 OR S4 OR S5 OR S6
#8 dental caries
#9 tooth decay
#10 early childhood caries
#11 nursing bottle caries
#12 S8 OR S9 ORS10 OR S11
#13 S7 AND S12
**For #13 limit to 'Human'
interest was the development of dental caries in deciduous or permanent teeth. An extensive list of search terms was used and is reported in Table 1.
We checked reference lists of all primary studies and review articles for additional references. The titles and abstracts were independently reviewed for initial inclusion by two researchers (RT and GB). Disagreement was resolved by discussion and if consensus could not be reached, a third author (CL) made the final decision.
Eligibility criteria
We included observational and experimental studies published in full text. We included children and adolescents from both general and high-risk populations (e.g. low socioeconomic communities). Dental caries as reported by appropriately qualified practitioner/researchers, a parent or through health records databases were included. We excluded participants who were born prematurely (<36 weeks gestation) because these infants are often fed by other sources and can have complicated medical interventions.
Assessment of quality and risk of bias
Two researchers (RT and GB) independently conducted a quality assessment of each study using the Newcastle-Ottawa Scale (NOS) (22). Study quality was graded on a scoring system (see Tables 2-5 for key criteria). Differences in assessment and grading were resolved by discussion with a third researcher (CL).
The assessment of risk of bias was guided by the GRADE system for rating the quality of the evidence of observational studies (23).
Literature review identified key confounders that should be controlled for in breastfeeding and dental caries studies: socio-economic status, age, mother's educational level,
number of teeth, and exposure to sugar in the diet (food or other liquid).
Data extraction
We extracted: study design; study country; age range of children; number of children; exposure and outcome definitions; how the outcome data were measured; effect estimates; confounders included in analysis; sub-group analysis; interactions; and findings.
Assessment for meta-analysis
Exposure and outcome definitions and effect estimates (odds ratios (OR), relative risks, prevalence ratios) with 95% Confidence Interval (95%CI) were abstracted where available for inclusion in a meta-analysis. Given the biological plausibility of the potential associations, we aimed to assess exposure to breastfeeding in two specific time windows: (i) Up to 12 months of age (upper and lower incisors present) and (ii) Beyond 12 months of age (other teeth erupting up to 33 months- increased risk of caries). As there were very few mothers who exclusively breastfed infants until 12 months or beyond, within these time windows we categorized studies into: (i) Never breastfed compared to any breastfeeding and (ii) More versus less breastfeeding. This category was created to include all
Table 2 Newcastle-Ottawa Quality Assessment score for Cohort studies nested in Randomized Controlled Trials
Selection of Outcome of Adequate
non- exposed Ascertainment interest not Assessment Adequate follow up
RCT Representativeness cohort of exposure present at start Comparability of outcome follow up time of cohorts Score/10
Feldens et al. (30) * * * * ** * * 8
Feldens et al. (27) * * * * ** * * 8
Table 3 Newcastle-Ottawa Scale Quality Assessment score for Cohort Studies
Selection of Outcome of Adequate
non-exposed Ascertainment interest not Assessment follow Adequate follow
Cohort studies Representativeness cohort of exposure present at start Comparability of outcome up time up of cohorts Score/10
Feldens et al. (25) * * * * ** ** * * 10
Chaffee et al. (26) * * * * * * * * 8
Hong et al. (31) * * * ** ** * 8
Kramer et al. (29) * * * * ** * * 8
Kramer et al. (28) * * * * ** * * 8
Ollila (38) * * * ** * * 7
Silver (32) * * * * * 5
Tada et al. (33) * * * * 5
Tanaka et al. (34) * * * ** ** * 8
Thitasomakul et al. (35) * * * * ** * 7
van Palenstein * * ** * * 6
Helderman et al. (36)
Yonezu et al. (37) * ** * * 5
Table 4 Newcastle-Ottawa Scale Quality Assessment score for Case-Control Studies
Adequate Representativeness Selection of Definition of Ascertainment Method of Nonresponse
Case control case definition of cases controls controls Comparability of exposure ascertainment rate Score/10
Bahuguna et al. (39) * * * * * 5
Matee et al. (40) * * * * 4
Roberts et al. (41) * * ** * 5
studies, which compared groups with relatively more (longer duration of breastfeeding) and relatively less breast milk exposure (shorter duration). To choose between multiple reported ORs for a single study we preferentially selected: estimates for exclusive breastfeeding or, if not available, any breastfeeding; then the longest duration compared with the shortest. If there were multiple ages of outcome within the particular group then we chose the oldest age reported.
We performed meta-analysis if there were three or more studies in each time window and category of breastfeeding. Random effects meta-analyses were performed if the heterogeneity (I2) was >25%. Heterogeneity was considered to be high, and results unreliable if I2 values were >75%. We were unable to quantitatively assess for publication bias as no group contained more than 10 studies. Studies not meeting these criteria were qualitatively assessed.
Statistical analysis was performed using Stata IC 13 (StataCorp., LP Texas, USA).
RESULTS
Search results
Electronic literature search (2 October 2014) and manual search found 480 peer-reviewed scientific articles after duplicate papers were removed. Of these, 366 were excluded after abstract review for failing to meet the eligibility criteria. A large number of these papers were not related to breastfeeding or dental caries, were not in English or were not original research. Of the remaining 114 full text articles, 51 were excluded as: (i) they did not assess the relevant exposure (breastfeeding) and outcome (dental caries) or (ii) all feeding types were analysed together or (iii) data were duplicated in more than one paper or (iv) no analysis was reported or studies lacked control or comparator groups [Fig. 1 (24)]. In total 63 papers were included.
Characteristics of included studies
Although the 63 papers did not include randomised controlled trials (RCT) of breastfeeding, six cohort studies (25-30) were nested within RCTs of breastfeeding promotion interventions. There were eight additional cohort studies (31-38) and three case-control studies (39-41). The remaining 46 studies were cross-sectional in design (42-86). The studies were predominantly conducted in high and middle income countries with only eight studies from low income countries (87). All caries outcomes were
assessed by dental professionals through oral examination. Key characteristics are summarised in the Appendix.
Quality assessment
Tables 2 3, 4, and 5 detail the NOS score assigned to each included study. The cohort and cross-sectional studies that were embedded in RCTs of a range of breastfeeding promotion interventions (25-30) scored highly as the study designs overcame many sources of bias and reporting limitations that were apparent in the other cohort, case-control and cross-sectional studies. Other cohort studies were weakened by the method used to ascertain infant feeding practices (self-report) which subjected them to recall bias, recruitment of children through oral health services (selection bias), lack of reporting of the absence of caries at the commencement of the study (ascertainment bias), loss to follow -up and accounting for these participants (attrition bias), and lack of controlling for confounders. Case-control study designs were inherently subject to recall bias when ascertaining infant feeding practices. Furthermore, cases and controls were not representative of the broader population as they were recruited in settings where children were likely to have caries. Selection bias was also a problem as the selection of controls was not clearly described. Cross-sectional studies were the weakest but most common study design. The studies which scored <4 were classified as unsatisfactory due to major limitations in study design and reporting. Studies that scored 4 were classified as satisfactory, however, all of these studies lacked consideration of key confounders. In the higher quality studies (>5) there were limitations in how exposure was ascertained as many studies used self-report questionnaires (recall bias).
Meta-analysis
We meta-analysed the small number of studies which included statistical effect measures.
Breastfeeding up to 12 months of age
One prospective cohort (34) and four cross-sectional studies (48,52,59,70) reported odds ratios for the association between children who were exposed to more versus less breastfeeding up to 12 months (OR 0.50; 0.25-0.99, I2 86.8%) (Fig. 2). There were not enough studies to perform metaregression for formal investigation of this heterogeneity. There appeared to be differences, however, based on the comparison groups of the included studies. The two studies
Table 5 Newcastle-Ottawa Scale Quality Assessment score for Cross-sectional Studies
Selection of non- Ascertainment Assessment
Cross-sectional Representativeness exposed cohort of exposure Comparability of outcome Score/7
Alaluusua et al. (42) * * * 3
al-Dashti et al. (43) * * ** 4
Azevedo et al. (44) * * * ** 5
Campus et al. (45) * * ** * 5
Carino et al. (46) * ** 3
Dini (47) * * * * 4
Du et al. (48) * ** * 4
Dye et al. (49) * * ** ** 6
Folayan et al.(50) * * * 3
Folayan et al. (87) * * * 3
Forsman et al. (51) * * * 3
Hallett et al. (52) * * ** ** 6
Hallonsten et al. (53) * * * 3
Haq et al. (54) * * 2
Hardy (55) * 1
Harrison et al. (56) * * ** 4
Holt et al. (57) * * * 3
Hong et al. (58) * * ** * 5
lida et al. (59) * * * * * 5
Johansson et al. (60) * * * 3
Livny et al. (61) * * * 3
Majorana et al. (62) * * ** 4
Masumo et al. (63) * * * ** 5
Mattos-Graner et al. (64) * * ** 4
Nobile et al. (65) * * * 3
Nunes et al. (66) * ** ** 5
Perera et al. (67) * * * 3
Prakash et al. (68) * * * * 4
Prakasha Shrutha et al. (69) * * 2
Qadri et al. (70) * * * * 4
Retnakumari (71) * * * 3
Rosenblatt (72) * * * 3
Sankeshwari et al. (73) * * * 3
Santos (74) * * 2
Sayegh et al. (75) * * ** 4
Sayegh et al. (76) * * * ** 5
Serwint et al. (77) * * * 3
Slabsinskiene et al. (78) * * * 3
Songo et al. (79) * * 2
Tanaka, (80) * * ** * 5
Tiano et al. (81) * * * 3
Tyagi, (82) * 1
Vachirarojpisan et al. (83) * * * * * 5
Vazquez-Nava et al. (84) * * ** * 5
Wendt (85) * * * * 4
Yonezu et al. (86) * 1
which compared ever breastfeeding in the first 12 months with never breastfeeding (48,70), both showed a marked protective effect of breastfeeding on dental caries compared with other feeding. Whereas the three studies which compared a longer duration of breastfeeding in the first 12 months to a comparison group which included children who had had some exposure to breastfeeding did not (34,52,59). A meta-analysis on this three study subgroup found an OR of 0.92; 0.69-1.23, I2 0% (Fig. 3).
Breastfeeding after 12 months of age
Two cohort studies (33,34), one case control study (40) and four cross-sectional studies (52,65,75,78) reported odds ratios for the association between more or less breastfeeding after the age of 12 months and dental caries. The comparison groups for these studies included both those who had never been breastfed and those who had been breastfed for shorter durations. The pooled estimate was OR 1.99; 1.35-2.95, I2 69.3% (Fig. 4).
Records identified through database searching PubMed, Embase, CINAHL, Medline = 817
Additional records identified through other sources and hand searching = 10
Records after duplicates removed (n=347) = 480
Records screened = 480
Full text articles assessed for eligibility = 114
Articles included in synthesis = 63
Articles assessed for meta-analyses = Breastfeeding at 12 months: n=5 Breastfeeding beyond 12 months: n=6 Breastfeeding on demand or nocturnally: n=6
Title and abstract review - exclude n= 366
Not breastfeeding = 170
Not dental caries = 54
Not English = 30
Not research = 75
Pre-term babies = 3
Review papers = 32
Study protocols = 2
Full paper reviews - exclude BF not exposure or DC not outcome = 7 Breast & bottle feeding grouped together = 3 Data duplicated in other paper = 1 No analysis of BF and DC = 29 No control/comparator group = 12
Figure 1 PRISMA Flow diagram of review.
Only two studies (26,80) reported prevalence ratios so these could not be meta-analysed.
Nocturnal breastfeeding in those breastfed longer than 12 months
One cohort (36), one case-control (40) and three cross-sectional studies (67,84,86) reported odds ratios for the association between more versus less nocturnal breastfeeding and the risk of dental caries amongst the subgroup of children breastfed longer than 12 months. The pooled estimate was OR 7.14; 3.14-16.23, I2 77.1% (Fig. 5).
Narrative synthesis
The majority of studies (n = 46) were not included in the meta-analyses due to methodological differences in the measures of exposure and outcomes, or reporting of correlational analyses only.
Studies embedded in randomised controlled trials (RCTs)
It is not ethical to conduct randomized trials assigning participants to breastfeeding and non-breastfeeding groups in order to more definitively assess the association between breastfeeding and dental caries. However, a number of RCTs have been conducted that investigated the impact of breastfeeding promotion programmes (25-30). In a RCT of an intervention that provided monthly advice on healthy feeding practices over 12 months via home visits in Brazil
(25,27,30) the intervention group demonstrated a lower incidence of caries at 12 months (OR = 0.52, 0.27-0.97, p = 0.03) and 4 years (RR = 0.78, 0.65-0.93, p = 0.004). Investigating breastfeeding frequency at 12 months, the study also found a doubled risk of caries when feeding frequency was 3-6 times/day (RR = 2.04, 1.22-3.39, p = 0.000) and >7 times/day (RR = 1.97, 95%CI 1.452.68, p = 0.000) compared to 0-2 times/day. Analyses were adjusted for maternal schooling level, daily meals, bottle use for fruit juice/soft drinks, consumption of high density sugar and number of teeth. Another birth cohort study nested in an intervention conducted through maternal health centres in Brazil (26) found that, in adjusted regression models, as breastfeeding continued beyond 6 months the prevalence ratio of caries in breastfed children increased (compared to breastfeeding <6 months) but was only significant when still breastfeeding at >24 months: 6-11 months (PR = 1.45, 95% CI 0.83-2.53); 12-23 months (PR = 1.39, 95%CI 0.732.64); >24 months (PR = 1.85, 95%CI 1.11-3.08). A birth cohort study nested in a breastfeeding promotion intervention in Belarus found no significant difference in caries incidence or prevalence in the intervention group when children were aged 6.5 years (28,29).
Breastfed versus formula fed
Studies that examined ever versus never breastfed children reported a range of findings. Six cross-sectional studies
Study ID
Cohort study Tanaka (2013)
Cross-sectional study Du (2000) Hallett (2003) Iida (2007) Qadri (2012)
More vs Less Breastfeeding up to 12 months and risk of caries
Overall (I-squared = 86.8%, p = 0.000) NOTE: Weights are from random effects analysis
Ratio (95% CI)
0.67 (0.27, 1.65)
0.19 (0.08, 0.46) 1.00 (0.71, 1.41) 0.80 (0.42, 1.53) 0.27 (0.18, 0.41)
0.50 (0.25, 0.99)
Odds Ratio
Figure 2 More versus Less breastfeeding (including never breastfed) up to 12 months of age and the risk of dental caries
More vs Less Breastfeeding up to 12 months and the risk of caries
Study Odds %
ID Ratio (95% CI) Weight
Cohort study Tanaka
Cross-sectional study
Hallett
Overall (I-squared = 0.0%, p = 0.645)
NOTE: Weights are from random effects analysis
~~i— .05
~~i— .25
0.67 (0.27, 1.64) 10.47
1.00 (0.71, 1.41) 69.99
0.80 (0.42, 1.54) 19.53
0.92 (0.69, 1.23) 100.00
—I-T
1 1.5 2
Odds Ratio
Figure 3 More versus Less Breastfeeding (excluding never breastfed) up to 12 months of age and the risk of dental caries.
reported no significant difference in the prevalence of caries between the two groups (49,61,72-74,83); one cohort and one cross-sectional study reported significantly lower caries in breastfed children (32,57); one cross-sectional study found a lower adjusted caries risk in breastfed versus bottle-fed children (OR = 0.61, 95%CI 0.39-0.97, p = 0.038) (70); one cohort study reported higher caries increment in breastfed children between 12 to 18 months but the association disappeared in the multivariate analysis (35);
one cross-sectional study reported an increased risk of dental caries in ever breastfed children of borderline significance (p = 0.08) (77); and one cross-sectional study found a lower adjusted caries risk in breastfed versus bottle-fed children.
Breastfeeding duration
Three of four cohort studies found that breastfeeding beyond 12 months was correlated or associated with increased caries
Breastfeeding beyond 12 months and risk of caries
Study ID
Cohort study
Tanaka(2013)[=18 mth]
Tada (1999) [=18 mth]
Case-Control
Matee (1994) [1yr vs 3yr]
Cross-sectional study Hallett (2003) [>13mth] Nobile (2014) [= 20mth] Sayegh (2002) [>18mth] Slabsinskiene (2010) [>13mth]
Overall (I-squared = 69.3%, p = 0.003) NOTE: Weights are from random effects analysis
Odds Ratio (95% CI)
2.47 (0.94, 6.51) 6.65 (2.90, 15.25)
2.40 (0.67, 8.65)
1.50 (0.94, 2.40) 1.26 (1.01,1.57) 1.50 (1.09, 2.07) 10.00 (1.28, 78.12)
1.99 (1.35, 2.95)
Odds Ratio
Figure 4 Breastfeeding beyond 12 months and the risk of dental caries.
Study ID
Nocturnal breastfeeding beyond 12 months and risk of dental caries
Odds Ratio (95% CI)
Cohort study van Palenstein (2006)
Case-Control Matee (1994)
Cross-sectional study Perera (2014) Vazquez-Nava (2008) Yonezu (2007)
Overall (I-squared = 77.1%, p = 0.002)
NOTE: Weights are from random effect ~T
> 35.00 (6.29, 194.87)
•> 17.80 (6.30, 50.30)
2.54 (1.29, 5.01) 3.60 (2.51, 5.16) 10.66 (2.23, 50.96)
7.14 (3.14, 16.23)
~l-1—T
10 15 20
Odds Ratio
Figure 5 More versus Less nocturnal breastfeeding and the risk of dental caries in those breastfed longer than 12 months.
prevalence compared with shorter durations of breastfeeding. Chaffee et al. (26) found that the adjusted prevalence ratio of caries in children breastfed >24 months was 2.1 (95%CI 1.5-3.25) compared to children breastfed <6 months. Yonezu et al. (37) found significantly more caries in children breastfed >18 months than those weaned <18 months. Feldens et al. (25) found the risk of caries
rose in children breastfed beyond 12 months. Ollila et al.'s (38) survival analysis found no difference between children breastfed >12 months and those not. Cross-sectional studies reported variable findings: increased caries prevalence in children breastfed longer than those breastfed for shorter times (44,45,53,54,63,65,71,75,78,81,85); and no difference in caries prevalence between duration groups (66,82).
The few studies that controlled for confounding factors found decreased caries risk with shorter breastfeeding duration (6-12 months) compared to longer duration (>13 months) (26,34,45,76,80) and increased risk of caries if breastfed <6 months (31,48).
Breastfeeding on demand and nocturnally
In addition to the meta-analysed studies, a number of cross-sectional studies reported significant correlations between infants/children breastfed during the night (44,67), on demand (68) or sleeping with a nipple in the mouth (60,71,76) and increased prevalence of dental caries. One cohort study found an increased adjusted risk of dental caries with increased daily breastfeeding frequency including nocturnal feeding (25).
DISCUSSION
Qualitative assessment of studies investigating breastfeeding up to 12 months of age suggested that children who were exposed to more breastfeeding (longer duration) compared to less or no breastfeeding were protected from dental caries. Meta-analysis of five studies also found reduced risk of dental caries in children breastfed more versus less up to 12 months, however, the heterogeneity between studies was too high to make the estimate reliable. In contrast, children who were breastfed beyond 12 months had an increased prevalence of dental caries. Amongst those who continued to be breastfed after 12 months, there was a further increased risk of caries in children who were breastfed nocturnally.
Three elements are essential for dental caries to occur: a tooth, cariogenic bacteria (e.g. Streptococcus mutans) and substrate for the bacteria (sugar) (2). The risk of developing dental caries changes as factors associated with each element change. The first tooth usually erupts in an infant's mouth between 6 and 12 months of age. As each tooth erupts the risk of developing dental caries increases, hence age and number of teeth increases risk. Cariogenic bacteria are transmitted to the child via close contact with the mother's saliva (88) but their levels and cariogenicity vary between individuals (2) depending on maternal bacterial levels, maternal caries prevalence, oral hygiene practices and exposure to dietary sugars (21). Breast milk is known to contain immunomodulatory factors along with a rich microbiome which is responsible for establishing normal intestinal flora (89). Initial protection from dental caries may be mediated through establishment of a healthy oral microbiome in infants through exposure to breastfeeding and contact with skin and breast milk microbiomes. Additionally, the child's oral microbiome changes over time with the emergence of new teeth. The essential substrates for cariogenic bacteria are simple carbohydrates (sugars) which can be in a range of forms (e.g. lactose, sucrose, glucose). The longer these sugars are in contact with teeth, the higher the risk of dental caries. The amount of carbohydrate (cariogenicity) contained in the different milks and formulas may also help to explain the different
results we found before and after 12 months of age. The cariogenicity of human breast milk has not been extensively examined under in vivo conditions, however animal studies suggest that at high frequency exposures, human breast milk has greater cariogenicity compared to bovine milk but less than infant formula (90,91). Relative cariogenicity of breast milk will also depend on the comparison group. Below 12 months it is usual to feed infants either breast milk or formula which have around the same carbohydrate content. After 12 months, however, children in high income countries are often weaned onto cow's milk which has half the carbohydrate content of human milk. However, each element is subject to modification by risk factors such as socio-economic status, maternal educational level, maternal oral health, maternal smoking status, position in birth order, sugars in diet, oral hygiene and exposure to fluoride (2).
Breastfeeding duration, frequency of breastfeeding and nocturnal breastfeeding during sleep are most often analysed as separate breastfeeding behaviours, however they are inter-related. Nocturnal breastfeeding is often used to comfort an infant or child who may then fall asleep with the nipple in their mouth. In this position, the tongue fills the mouth and holds the breast milk against the surfaces of the teeth, thereby prolonging the exposure of the substrate to the cariogenic bacteria that are attached to the teeth surfaces and hence increasing the risk of dental caries. It is possible that children breastfed beyond 12 months are also engaging in nocturnal breastfeeding but the modification of dental caries risk by infant feeding practices has not been examined in depth in any of the studies included in this review. In addition, children >12 months are no longer being exclusively breast or bottle fed and the diet is expanding to include other fluids and solids. It has been reported that children who are breastfed for longer durations also have more frequent cariogenic food intakes (25,53,58). Oral hygiene practices to remove bacterial plaque are important as more teeth erupt to reduce the risk of dental caries. Only a few studies included in this review controlled for key confounding factors and this may have resulted in an over-estimation of the role of prolonged, frequent and nocturnal breastfeeding in the development of dental caries. Until the dietary and oral hygiene details of these children are controlled for we cannot be certain whether prolonged, frequent or nocturnal breastfeeding can be principally associated with early childhood caries.
This is the first systematic review of breastfeeding and dental caries that includes critical exposure windows, limited meta-analyses and a range of study types. We provide quantitative evidence that is suggestive of the potentially protective effects of breastfeeding from dental caries up to 12 months, but higher risk of dental caries in children breastfed beyond 12 months, frequently, and/or nocturnally. However, there is high heterogeneity between the studies included in the meta-analyses (possibly due to differing comparison groups) and lack of controlling for key confounders (e.g. other foods/drinks in the diet, oral
hygiene, maternal oral health status) which limits the reliability of the results.
CONCLUSION
Breastfeeding up to 12 months of age is not associated with an increased risk of dental caries and in fact may offer some protection compared with formula. However, children breastfed beyond 12 months, a time during which all deciduous teeth erupt, had an increased risk of dental caries. This may be due to other factors which are linked with prolonged breastfeeding including nocturnal feeding during sleep, cariogenic foods/drinks in the diet, or inadequate oral hygiene practices. Further research with careful control of pertinent confounding factors is needed to elucidate this issue and better inform infant feeding guidelines. As per recommendations from previous reviews (17,19), the introduction of food sources to infants should be low in simple carbohydrates (sugars) and oral hygiene practices should start with the eruption of the first tooth so that bacterial plaque is removed from tooth surfaces to reduce the risk of dental caries.
CONFLICT OF INTEREST STATEMENT
Preparation of the manuscript was assisted by funding from the WHO, which had no part in determining the outcomes or presentation of findings. None of the authors has any conflicts of interest to declare.
References
1. Petersen PE. The World Oral Health Report. In: World Health Organisation, editor Continuous improvement of oral health in the 21st century - the approach of the WHO Global Oral Health Programme. Geneva: World Health Organisation, 2003.
2. Selwitz RH, Ismail AI, Pitts NB. Dental caries. Lancet 2007; 369: 51-9.
3. Sheiham A. Dental caries affects body weight, growth and quality of life in pre-school children. Br Dent J 2006; 201: 625-6.
4. Casamassimo PS, Thikkurissy S, Edelstein BL, Maiorini E. Beyond the dmft: the human and economic cost of early childhood caries. J Am Dent Assoc 2009; 140: 650-7.
5. Gionet L. Breastfeeding trends in Canada. Health at a Glance. Canada: Statistics Canada Catalogue no. 82-624-X, 2013.
6. Madan C, Kruger E, Perera I, Tennant M. Trends in demand for general anaesthetic care for paediatric caries in Western Australia: geographic and socio-economic modelling of service utilisation. Int Dent J 2010; 60: 190-6.
7. Takahashi N, Nyvad B. The role of bacteria in the caries process: ecological perspectives. J Dent Res 2011; 90: 294-303.
8. Tanzer J, Livingston J, Thompson A. The microbiology of primary dental caries in humans. J Dent Educ 2001; 65: 1028-37.
9. Danielsson Niemi L, Hernell O, Johansson I. Human milk compounds inhibiting adhesion of mutans streptococci to host ligand-coated hydroxyapatite in vitro. Caries Res 2009; 43: 171 -8.
10. Holgerson PL, Vestman NR, Claesson R, Ohman C, Domellof M, Tanner AC, et al. Oral microbial profile discriminates
breast-fed from formula-fed infants. J Pediatr Gastroenterol Nutr 2013; 56: 127-36.
11. The American Dental Association. Tooth eruption: the primary teeth. J Am Dent Assoc 2005; 136: 1619.
12. World Health Organization. Infant and young child feeding. Fact Sheet No 342. Available at: http:// www.who.int/mediacentre/factsheets/fs342/en/February 2004. (accessed on 10th April 2015).
13. unicef GLOBAL DATABASES. Infant and young child feeding. In: data.unicef.org, editor. Available at: http://data.unicef.org/nutrition/iycf. (accessed on April 30, 2015) October 2014.
14. Li R, Fein SB, Chen J, Grummer-Strawn LM. Why mothers stop breastfeeding: mothers' self-reported reasons for stopping during the first year. Pediatrics 2008; 122: (Suppl 2): S69-76.
15. Australian Institute of Health and Welfare. 2010 Australian national infant feeding survey: indicator results. Canberra, Australia: AIHW, 2011.
16. Department of Health. Breastfeeding. Available at: http:// www.health.gov.au/breastfeeding: Australian Government Department of Health. (accessed on 11th April 2015).
17. Valaitis R, Hesch R, Passarelli C, Sheehan D, Sinton J. A systematic review of the relationship between breastfeeding and early childhood caries. Can J Public Health 2000; 91:411-7.
18. Salone LR, Vann WF, Dee DL. Breastfeeding: an overview of oral and general health benefits. J Am Dent Assoc 2013; 144: 143-51.
19. White V. Breastfeeding and the risk of early childhood caries. Evid Based Dent 2008; 9: 86-8.
20. Ribeiro NM, Ribeiro MA. Breastfeeding and early childhood caries: a critical review. J Pediatr 2004; 80: S199-210.
21. Leong PM, Gussy MG, Barrow SY, de Silva-Sanigorski A, Waters E. A systematic review of risk factors during first year of life for early childhood caries. Int J Paediatr Dent 2013; 23: 235-50.
22. Wells G, Shea B, O'Connell D, Peterson J, Welch V, Losos M, et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. http:// www.ohri.ca/programs/clinical_epidemiology/oxford.asp. (accessed on 30th November 2014).
23. Guyatt GH, Oxman AD, Vist G, Kunz R, Brozek J, Alonso-Coello P, et al. GRADE guidelines: 4. Rating the quality of evidence—study limitations (risk of bias). J Clin Epidemiol 2011; 64: 407-15.
24. PRISMA. PRISMA Statement - preferred reporting items for systematic reviews and meta-analyses. www.prisma-statement.org/. Accessed 30th November 2014
25. Feldens CA, Giugliani ERJ, Vigo A, Vitolo MR. Early feeding practices and severe early childhood caries in four-year-old children from southern Brazil: a birth cohort study. Caries Res 2010; 44: 445-52.
26. Chaffee BW, Feldens CA, Vitolo MR. Association of long-duration breastfeeding and dental caries estimated with marginal structural models. Ann Epidemiol 2014; 24: 448-54.
27. Feldens CA, Giugliani ER, Duncan BB, Drachler Mde L, Vitolo MR. Long-term effectiveness of a nutritional program in reducing early childhood caries: a randomized trial. Community Dent Oral Epidemiol 2010; 38: 324-32.
28. Kramer MS, Matush L, Bogdanovich N, Aboud F, Mazer B, Fombonne E, et al. Health and development outcomes in 6.5-y-old children breastfed exclusively for 3 or 6 mo. Am J Clin Nutr 2009; 90: 1070-4.
29. Kramer MS, Vanilovich I, Matush L, Bogdanovich N, Zhang X, Shishko G, et al. The effect of prolonged and exclusive breastfeeding on dental caries in early school-age children. Caries Res 2007; 41: 484-8.
30. Feldens CA, Vitolo MR, Drachler Mde L. A randomized trial of the effectiveness of home visits in preventing early childhood caries. Community Dent Oral Epidemiol 2007; 35: 215-23.
31. Hong L, Levy SM, Warren JJ, Broffitt B. Infant breast-feeding and childhood caries: a nine-year study. Pediatr Dent 2014; 36: 342-7.
32. Silver DH. A longitudinal study of infant feeding practice, diet and caries, related to social class in children aged 3 and 810 years. Br Dent J 1987; 163: 296-300.
33. Tada A, Ando Y, Hanada N. Caries risk factors among three-year old children in Chiba, Japan. Asia Pac J Public Health 1999; 11: 109-12.
34. Tanaka K, Miyake Y, Sasaki S, Hirota Y. Infant feeding practices and risk of dental caries in Japan: the Osaka Maternal and Child Health Study. Pediatr Dent 2013; 35: 267-71.
35. Thitasomakul S, Piwat S, Thearmontree A, Chankanka O, Pithpornchaiyakul W, Madyusoh S. Risks for early childhood caries analyzed by negative binomial models. J Dent Res 2009; 88: 137-41.
36. van Palenstein Helderman WH, Soe W, van't Hof MA. Risk factors of early childhood caries in a Southeast Asian population. J Dent Res 2006; 85: 85-8.
37. Yonezu T, Ushida N, Yakushiji M. Longitudinal study of prolonged breast- or bottle-feeding on dental caries in Japanese children. Bull Tokyo Dent Coll 2006; 47: 157-60.
38. Ollila P, Larmas M. A seven-year survival analysis of caries onset in primary second molars and permanent first molars in different caries risk groups determined at age two years. Acta Odontol Scand 2007; 65: 29-35.
39. Bahuguna R, Younis Khan S, Jain A. Influence of feeding practices on dental caries. A case-control study. Eur J Paediatr Dent 2013; 14: 55-8.
40. Matee M, van't Hof M, Maselle S, Mikx F, van Palenstein Helderman W. Nursing caries, linear hypoplasia, and nursing and weaning habits in Tanzanian infants. Community Dent Oral Epidemiol 1994; 22: 289-93.
41. Roberts GJ, Cleaton-Jones PE, Fatti LP, Richardson BD, Sinwel RE, Hargreaves JA, et al. Patterns of breast and bottle feeding and their association with dental caries in 1- to 4-year-old South African children. 2. A case control study of children with nursing caries. Community Dent Health 1994; 11: 38-41.
42. Alaluusua S, Myllarniemi S, Kallio M, Salmenpera L, Tainio VM. Prevalence of caries and salivary levels of mutans streptococci in 5-year-old children in relation to duration of breast feeding. Scand J Dent Res 1990; 98: 193-6.
43. al-Dashti AA, Williams SA, Curzon ME. Breast feeding, bottle feeding and dental caries in Kuwait, a country with low-fluoride levels in the water supply. Community Dent Health 1995; 12: 42-7.
44. Azevedo TD, Bezerra AC, de Toledo OA. Feeding habits and severe early childhood caries in Brazilian preschool children. Pediatr Dent 2005; 27: 28-33.
45. Campus G, Solinas G, Strohmenger L, Cagetti MG, Senna A, Minelli L, et al. National pathfinder survey on children's oral health in Italy: pattern and severity of caries disease in 4-year-olds. Caries Res 2009; 43: 155-62.
46. Carino KMG, Shinada K, Kawaguchi Y. Early childhood caries in northern Philippines. Community Dent Oral Epidemiol 2003; 31: 81-9.
47. Dini EL, Holt RD, Bedi R. Caries and its association with infant feeding and oral health-related behaviours in 3-4-year-old Brazilian children. Community Dent Oral Epidemiol 2000; 28: 241-8.
48. Du M, Bian Z, Guo L, Holt R, Champion J, Bedi R. Caries patterns and their relationship to infant feeding and socio-
economic status in 2-4-year-old Chinese children. Int Dent J 2000; 50: 385-9.
49. Dye BA, Shenkin JD, Ogden CL, Marshall TA, Levy SM, Kanellis MJ. The relationship between healthful
eating practices and dental caries in children aged 2-5 years in the United States, 1988-1994. J Am Dent Assoc 2004; 135: 5566.
50. Folayan MO, Sowole CA, Owotade FJ, Sote E. Impact of infant feeding practices on caries experience of preschool children. J Clin Pediatr Dent 2010; 34: 297-301.
51. Forsman B, Ericsson Y. Breastfeeding, formula feeding and dental health in low-fluoride districts in Sweden. Community Dent Oral Epidemiol 1974; 2: 1-6.
52. Hallett KB, O'Rourke PK. Social and behavioural determinants of early childhood caries. Aust Dent J 2003; 48: 27-33.
53. Hallonsten AL, Wendt LK, Mejare I, Birkhed D, Hakansson C, Lindvall AM, et al. Dental caries and prolonged breast-feeding in 18-month-old Swedish children. Int J Paediatr Dent 1995; 5: 149-55.
54. Haq ME, Begum K, Muttalib MA, Shahidullah M. Prevalence of caries in urban children and its relation to feeding pattern. Bangladesh Med Res Counc Bull 1985; 11: 55-63.
55. Hardy NR. The effect of breast feeding in infancy on the D.M.F. ratio of deciduous canine and molar teeth in children below seven years of age. Apex 1978; 10: 7-8.
56. Harrison R, Wong T, Ewan C, Contreras B, Phung Y. Feeding practices and dental caries in an urban Canadian population of Vietnamese preschool children. ASDC J Dent Child 1997; 64: 112-7.
57. Holt RD, Joels D, Winter GB. Caries in pre-school children. The Camden study. Br Dent J 1982; 153: 107-9.
58. Hong CHL, Bagramian RA, Hashim Nainar SM, Straffon LH, Shen L, Hsu C-YS. High caries prevalence and risk factors among young preschool children in an urban community with water fluoridation. Int J Pediatr Dent 2014; 24: 32-42.
59. Iida H, Auinger P, Billings RJ, Weitzman M. Association between infant breastfeeding and early childhood caries in the United States. Pediatrics 2007; 120: e944-52.
60. Johansson I, Holgerson PL, Kressin NR, Nunn ME, Tanner AC. Snacking habits and caries in young children. Caries Res 2010; 44: 421-30.
61. Livny A, Assali R, Sgan-Cohen HD. Early Childhood Caries among a Bedouin community residing in the eastern outskirts of Jerusalem. BMC Public Health 2007; 7: 167.
62. Majorana A, Cagetti MG, Bardellini E, Amadori F, Conti G, Strohmenger L, et al. Feeding and smoking habits as cumulative risk factors for early childhood caries in toddlers, after adjustment for several behavioral determinants: a retrospective study. BMC Pediatr 2014; 14: 1471-2431.
63. Masumo R, Bardsen A, Mashoto K, Astrom AN. Prevalence and socio-behavioral influence of early childhood caries, ECC, and feeding habits among 6-36 months old children in Uganda and Tanzania. BMC Oral Health 2012; 12: 14726831.
64. Mattos-Graner RO, Zelante F, Line R, Mayer MPA. Association between caries prevalence and clinical, microbiological and dietary variables in 1.0 to 2.5-year-old Brazilian children. Caries Res 1998; 32: 319-23.
65. Nobile CG, Fortunata L, Bianco A, Pileggi C, Pavia M. Pattern and severity of early childhood caries in Southern Italy: a preschool-based cross-sectional study. BMC Public Health 2014; 14: 1471-2458.
66. Nunes AMM, Alves CMC, Araujo F, Ortiz TML, Ribeiro MRC, Silva AAMD, et al. Association between prolonged breastfeeding and early childhood caries: a hierarchical approach. Community Dent Oral Epidemiol 2012; 40: 542-9.
67. Perera PJ, Fernando MP, Warnakulasooriya TD, Ranathunga N. Effect of feeding practices on dental caries among preschool children: a hospital based analytical cross sectional study. Asia Pac J Clin Nutr 2014; 23: 272-7.
68. Prakash P, Subramaniam P, Durgesh BH, Konde S. Prevalence of early childhood caries and associated risk factors in preschool children of urban Bangalore, India: a cross-sectional study. Eur J Dent 2012; 6: 141-52.
69. Prakasha Shrutha S, Vinit GB, Giri KY, Alam S. Feeding practices and early childhood caries: a cross-sectional study of preschool children in kanpur district, India. ISRN Dent 2013; 5: 275193. doi: 10.1155/2013/275193. eCollection 2013.
70. Qadri G, Nourallah A, Splieth CH. Early childhood caries and feeding practices in kindergarten children. Quintessence Int 2012; 43: 503-10.
71. Retnakumari N, Cyriac G. Childhood caries as influenced by maternal and child characteristics in pre-school children of Kerala - an epidemiological study. Contemp Clin Dent 2012; 3: 2-8.
72. Rosenblatt A, Zarzar P. Breast-feeding and early childhood caries: an assessment among Brazilian infants. Int J Pediatr Dent 2004; 14: 439-45.
73. Sankeshwari RM, Ankola AV, Tangade PS, Hebbal MI. Feeding habits and oral hygiene practices as determinants of early childhood caries in 3- to 5-year-old children of Belgaum City, India. Oral Health Prev Dent 2012; 10: 283-90.
74. Santos AP, Soviero VM. Caries prevalence and risk factors among children aged 0 to 36 months. Pesqui Odontol Bras 2002; 16: 203-8.
75. Sayegh A, Dini EL, Holt RD, Bedi R. Caries prevalence and patterns and their relationship to social class, infant feeding and oral hygiene in 4-5-year-old children in Amman, Jordan. Community Dent Health 2002; 19: 144-51.
76. Sayegh A, Dini EL, Holt RD, Bedi R. Oral health, sociodemographic factors, dietary and oral hygiene practices in Jordanian children. J Dent 2005; 33: 379-88.
77. Serwint JR, Mungo R, Negrete VF, Duggan AK, Korsch BM. Child-rearing practices and nursing caries. Pediatrics 1993; 92: 233-7.
78. Slabsinskiene E, Milciuviene S, Narbutaite J, Vasiliauskiene I, Andruskeviciene V, Bendoraitiene EA, et al. Severe early childhood caries and behavioral risk factors among 3-year-old children in Lithuania. Medicina (Kaunas) 2010; 46: 135-41.
79. Songo BF, Declerck D, Vinckier F, Mbuyi MD, Pilipili CM, Kayembe KP. Caries experience and related factors in 4-
6 year-olds attending dental clinics in Kinshasa, DR of Congo. Community Dent Health 2013; 30: 257-62.
80. Tanaka K, Miyake Y. Association between breastfeeding and dental caries in Japanese children. J Epidemiol 2012; 22: 72-7.
81. Tiano AV, Moimaz SA, Saliba O, Saliba NA. Dental caries prevalence in children up to 36 months of age attending daycare centers in municipalities with different water fluoride content. JAppl Oral Sci 2009; 17: 39-44.
82. Tyagi R. The prevalence of nursing caries in Davangere preschool children and its relationship with feeding practices and socioeconomic status of the family. J Indian Soc Pedod Prev Dent 2008; 26: 153-7.
83. Vachirarojpisan T, Shinada K, Kawaguchi Y, Laungwechakan P, Somkote T, Detsomboonrat P. Early childhood caries in children aged 6-19 months. Community Dent Oral Epidemiol 2004; 32: 133-42.
84. Vazquez-Nava F, Vazquez RE, Saldivar GA, Beltran GF, Almeida AV, Vazquez RC. Allergic rhinitis, feeding and oral habits, toothbrushing and socioeconomic status. Effects on development of dental caries in primary dentition. Caries Res 2008; 42: 141-7.
85. Wendt LK, Birkhed D. Dietary habits related to caries development and immigrant status in infants and toddlers living in Sweden. Acta Odontol Scand 1995; 53: 339-44.
86. Yonezu T, Yotsuya K, Yakushiji M. Characteristics of breastfed children with nursing caries. Bull Tokyo Dent Coll 2007; 47: 161-5.
87. The World Bank. Available at: http://www.worldbank.org/. http://www.worldbank.org/. (accessed on 20th Feb 2015).
88. Vadiakas G. Case definition, aetiology and risk assessment of early childhood caries (ECC): a revisited review. Eur Arch Paediatr Dent 2008; 9: 114-25.
89. Kerr CA, Grice DM, Tran CD, Bauer DC, Li D, Hendry P, et al. Early life events influence whole-of-life metabolic health via gut microflora and gut permeability. Crit Rev Microbiol. 2015; 2015: 326-40.
90. Peres RC, Coppi LC, Volpato MC, Groppo FC, Cury JA, Rosalen PL. Cariogenic potential of cows', human and infant formula milks and effect of fluoride supplementation. Br J Nutr 2009; 101: 376-82.
91. Bowen WH, Lawrence RA. Comparison of the cariogenicity of cola, honey, cow milk, human milk, and sucrose. Pediatrics 2005; 116: 921-6.
APPENDIX Study characteristics and summary of NOS QA
References [NOS QA Type of study/brief Sample size (gender
score] description Study population/Country °/o given if reported)
Randomised controlled trial (RCT) Feldens et al. (30) [8* Good]
Feldens et al. (27) [8* Good]
RCT of an intervention that provided monthly advice on healthy feeding practices (exclusive breastfeeding up to 6 months. >6 months encouraged to continue breastfeeding and introduce foods) up to 12 months via home visits
As for Feldens et al. (2007)
Mothers who gave birth in public health system; Sao Leopoldi, Brazil; October 2001 - June 2002
Mothers who gave birth in public health system; Sao Leopoldi, Brazil; October 2001 - June 2002
N = 500 Intervention n = 200 Control n = 300
N = 340 Boys =195 (57.4%) Intervention n = 141 Control n = 199
Cohort
Chaffee et al. (26) [8* Good]
Birth cohort study nested in a cluster RCT of an intervention in maternal health centres, 2008-2011
Birth to 38 months years; Porto Alegre, Brazil; Low income families
715 pregnant women
Feldens et al., (25) [10* Very good]
Birth cohort study (nested in an RCT of an intervention in a birth cohort)
Cohort of children aged 4 years; Sao Leopoldo, Brazil
340 children (baseline = 500); Boys =195 (57.4%)
Hong et al. (31) [8* Good]
Longitudinal birth cohort Iowa, USA study
N = 509
Questionnaires: 3-6 months from birth Dental exams: 5 years and 9 years
Exposure definition
Outcome definition and age
Exposure estimate (95% CI)
Other variables included in the models as confounders
Interactions
(Q Q Q.
Intervention group received advice at home
Age 12 months Early Childhood Caries (ECC) -decayed surfaces >1 in any primary tooth (decay)
Intervention group risk of caries: OR = 0.52 (0.27-0.97) p = 0.03 cf control group
Number of teeth
Intervention group received advice at home
Age 4 years
1. ECC -dmfs >1 in any primary tooth (decay)
2. Severe-ECC (S-ECC) - dmfs >5 or one or more cavitated, missing, filled smooth surface of anterior teeth.
3. Affected teeth (decayed or cavitated) - dmft
Ref group = control with RR = 1.0 None reported
ECC: Interv RR = 0.78 (0.65-0.93)
p = 0.004
NNT = 7 (4-20)
S-ECC: Interv RR = 0.68 (0.5-
0.92) p = 0.01
NNT = 8 (5-30)
Affected teeth: Mean
Interv = 3.25 (4.25) cf
Control = 4.15 (4.57) p = 0.023
Breastfeeding duration: <6 months 6-11 months 12-23 months 24 months+
Breastfeeding: Frequency
Breastfeeding duration <6 months >6 months
Dental status evaluated at 38 months
Severe-ECC - 1 or more affected maxillary teeth or 4 or more decayed, missing due to caries or filled tooth surfaces (dmfs >4)
Age 4 years Severe ECC
>1 cavitated, missing or filled smooth surfaces in primary maxillary anterior teeth, or dmfs values >5
Age 5 years and 9 years Dental caries in:
(a) All primary teeth
(b) 2nd deciduous molars (e)
Fully adjusted regression models Breastfeeding at stages and S-ECC: Prevalence ratio <6 = 1
6-11 = 1.45 (0.83-2.53) 12-23 = 1.39 (0.73-2.64) >24 = 1.85 (1.1 1-3.08)
Adjusted model: RR of S-ECC associated with daily breastfeeding frequency at 12 months: 0-2 RR = 1.0
3-6 RR = 2.04 (1.22-3.39) >7 RR = 1.97 (1.45-2.68) p = 0.000 Tooth level: Caries in (e) at 5 years Mean dfs
BF <6 months = 0.55 BF >6 months = 0.33 p = 0.02
Person level: caries in (e) at 5 years Breastfeeding <6 months OR = 15.58 [no 95% CI reported] (p = 0.005)
Maternal age; Education; Parity; Pre-pregnancy BM1; Smoking status; Social class; Child age; gender; Time varying bottle use; Feeding habits; Length-for-age z scores
Maternal schooling; Daily meals and snacks; Bottle use for fruit juice/soft drinks at 12 months; High density sugar at 12 months; Teeth at 12 months
Gender, hypoplasia, parental education level, family income level, gestational weeks, birth weight, age at time of dental exam, average daily fluoride intake (mg), home tap water fluoride level(ppm), average daily soda pop intake, daily tooth-brushing frequency
High frequency day time breastfeeding Long duration, high frequency
Appendix (Continued) References [NOS QA score] Type of study/brief description Study population/Country Sample size (gender °/o given if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) Other variables included in the models as confounders Interactions
Kramer et al. (29) Prospective cohort study Children aged 6.5 years Total n = 13,883 Experimental vs control Age 6.5 years The experimental intervention had None reported
[8* Good] nested in RCT of BF Belarus Experimental n = 7108 groups Dental caries no significant effect on the DMFT/
promotion intervention Control n = 6781 DMFT/dmft dmft numbers or proportions (both
(PRO BIT) all teeth and incisors only)
Kramer et al. (28) Prospective cohort study Children aged 6.5 years Exclusive BF at 3 months: Children aged 6.5 years No significant difference in dmft in None reported
[8* Good] nested in RCT of BF Belarus EBF3 n = 2862 Dental caries EBF3 and EBF6 groups
promotion intervention Exclusive BF at 6 months dmft
(PRO BIT) EBF6 n = 621
Ollila and Larmas (38) Cohort study 11 day care centres N = 183 (baseline) Breastfeeding Baseline 2.5 years Prolonged breastfeeding (> None reported
[7* Good] Time points: Oulu, Finland N = 175 (follow up) <12 months Follow up 9.6 years 12 months) had no effect on caries
Baseline = mean age > 12 months Restoration due to caries in a onset in terms of survival estimates
2.5 years (0.7- primary 2nd molar and first in either the deciduous molars or
4.3 years) permanent molar on upper permanent molars.
Follow up 7 years right and lower left (teeth id
later = mean age numbers: 55 and 75; 16 and
9.6 years (3.1- 36)
12.7 years)
Survival analysis
Silver, (32) Longitudinal cohort study Town north of London 3 years olds n = 161 Questionnaire at age 3: 3 years & 8-10 years Babies that were breast fed only had None reported
[5* Satisfl Baseline 3 years (1973) Boys = 84 (52%) Breast fed Dental caries significantly lower dmft cf children
Follow up 8-10 years 8-10 years olds Bottle fed dmft bottle fed, especially those with
(1979) Kendall's Tau n = 161 (unsweetened/ sweetened bottle content.
instead of X2 Boys = 85 (53%) sweetened) p < 0.01
Tada et al. (33) Cohort Infants N = 392 Breast feeding (yes/no) 18 months & 3 years Breast feeding at 18 months of age None reported
[5* Satisfl Examination at Chiba city, Japan Boys = 215 (54.8%) Dental caries significantly associated with caries
18 months and 3 years dmft increment increase in caries in
of age - increment All upper anterior teeth OR = 6.65
change was analysed. Upper anterior (2.89-15.2, p = <0.05)
Tanaka et al. (34) Prospective cohort study Pregnant women and their N = 315 Breast feeding duration: Aged 41-50 months Adjusted OR Adjusted for: Maternal age
[8* Good] 5 surveys at baseline, 2- infants <6 months; 6- Dental caries dft (missing Risk of breastfeeding duration and at baseline; Maternal
9 months, 16- Neyagawa City, Japan 11 months; 12- teeth excluded) ECC: smoking during
24 months, 29- 17 months; Moderate ECC = 1-4 teeth <6 months OR = 1 pregnancy; Family
39 months, 41- >18 months with caries not involving 6-11 months OR = 0.67 (0.27- income; Parental
49 months. maxillary anterior teeth 1.62) education level; Child's
Dental exam at 41- Severe ECC = >1 caries in 12-17 months OR = 1.09 (0.45- gender; Birth weight; Age
50 months maxillary anterior teeth or >5 2.71) at first tooth eruption;
caries in all teeth >18 months OR = 2.47 (0.95- Tooth brushing
6.59) frequency at 4th and 5th
Quadratic trend p < 0.05 surveys; Use of fluoride;
Statistical significance was lost Regular dental check-
when comparing risk for M-ECC ups; Household smoking
with caries free and S-ECC and at 5th survey; Age at oral
caries free - but the trend was examination
towards positive associations with
increased BF duration
m S-a' (Q Q Q.
Appendix (Continued) References [NOS QA score] Type of study/brief description Study population/Country Sample size (gender °/o given if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) Other variables included in the models as confounders Interactions
Thitasomakul et al. (35) Longitudinal observational All women in district who gave N = 495 Type of milk feeding: Age 9-12 months & 12- Bivariate analysis: crude caries None reported
[7* Good] community based study birth November 2000 to Boys = 254 (51.3%) Breast feeding 18 months increment between 9-12 months
- birth cohort. October 2001 Bottle feeding Dental caries and 12-18 months was
Followed up at 9,12 and Thepa district Thailand Mixed breast- and bottle Crude caries significantly higher among children
18 months feeding increment = from 9- who were breast fed cf bottle fed or
12 months and 12- mixed feeding.
18 months Negative binomial analysis - no
Incidence density = tooth association between increased
surface developing caries; incident density and breastfeeding
Incidence density ratio = ratio reported.
of incidence density of those
exposed to those not exposed
to the particular independent
variable concerned.
van Palenstein Helderman Retrospective cohort Children aged 25-30 months - N = 163 breastfed Breastfeeding: Children aged 25-30 months Significant associations: None reported
et al. (36) recruited through children (children Total number Dental caries >2 nocturnal breast feedings and
[6* Satisfl immunization records at excluded who Of feeds (low/high) ECC - presence of caries in >1 ECC OR = 35 (p < 0.0001)
health centres consumed 'jaggery; and Total exposure time to tooth >15 min feeding per night
Daik-U, Burma those who were bottle breastfeeding (low/high) OR = 100 (p < 0.0002)
fed and breastfed from Median value sets low/
5 months) high
Prolonged breastfeeding
beyond 12 months age
Yonezu et al. (37) Prospective cohort Infants attending preventive N = 922 at 18 months Prolonged breastfeeding Aged 18 months, 24 months Mean dft of children being breastfed None reported
[5* Satisfl Control sample = 205 dental care programs at public N = 742 at 24 months or bottle feeding at and 36 months at 18 months (0.36) was
children weaned off health centres N = 910 at 36 months 18 months Dental caries dft significantly higher than the control
breast or bottle feeding Japan N = 592 followed group (0.06) p < 0.05
<18 months longitudinally Mean dft of children being
breastfed at 24 months (0.51) was
significantly higher than the control
group (0.11) p < 0.05
Cose control
Bahuguna et al. (39) Case control Outpatient department of Case n = 400 Breast feeding duration Children aged 1-18 years Significantly higher proportion of None reported
[5* Satisfl Cases had caries paedodontics and preventive Control n = 400 <6 months Dental caries case subjects were breastfed for
Control were caries free dental clinic > 6 months DMFT/deft longer than 6 months compared to
Lucknow, India Bottle feeding (no detail control (p < 0.001)
reported) Significantly higher proportion of
cases had been bottle fed
(p = 0.017)
Matee et al. (40) Case control Children aged ]-4 years Case n = 116 Breastfeeding duration Case mean age = 1.6 years Duration of breastfeeding (1 yearvs None reported
[4* Unsatisf] Cases = rampant caries attending maternal and child Control n = 243 Night feeding (duration Control mean 3 years) OR = 2.4 (0.7-9.1)
Controls = no caries health centres in 9 out of 25 of nipple in the mouth: age = 2.1 years p = 0.18
regions in Tanzania 0 h, y2 h, 1 h, >1 h) Dental caries Night breast feeding habits
Bottle feeding and Rampant caries (>2 caries OR = 17.8 (6.3-50.3) p < 0.0001
content in bottle lesions in maxillary incisors) Linear hypoplasia OR = 15.6 (8.0-
30.5) p = <0.0001
Roberts et al., (41) Case control 1 -4 year old children Case n = 109 Breast feeding frequency Aged 1 -4 years Dental caries No significant association between None reported
[5* Satisfl Cases = caries South Africa Control n = 109 Breast feeding duration dmft frequency and duration of breast
Controls = caries free Bottle feeding dmfs feeding and dental caries
prevalence
S-«s Q 3 Q.
—I zr
Appendix (Continued) References [NOS QA score] Type of study/brief description Study population/Country Sample size (gender % given if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) Other variables included in the models as confounders Interactions
Cross-sectional
Alaluusua et al. (42) Cross-sectional Children aged 5 who N = 144 Duration of exclusive Aged 5 years Distribution of dmfs among children None reported
[3* Unsatisf] participated in a longitudinal Boys = 59 (41 %) breastfeeding: Dental caries with longer or shorter duration of
nutrition and health study that <2 months dmfs breastfeeding was equal
promoted breast feeding up <2-6 months
to 12 months; Finland >6-9 months
>9-12 months
>12 months
al-Dashti et al., (43) Cross-sectional Children aged 18-48 months N = 227 Infant feeding practices Aged 18-48 months Children breast fed at birth None reported
[4* Satisf] bom and continuously Boys =101 (44.5%) Breast fed Dental caries - no detail significantly more likely to be caries-
resident in Kuwait. Bottle fed provided re how this is free than those breast and bottle
Recruited through hospital Breast and bottle fed assessed fed or bottle fed only
and health centre
Azevedo et al. (44) Cross-sectional Preschool children; age 36- N = 369 Infant feeding practices Age 36-71 months Breastfeeding during night None included as None
[5* Good] 71 months; Brazil public Boys = 188 (51%) including patterns and S-ECC - >1 dmfs in primary time = 265 (72%) - statistically confounders
health centres duration of bottle maxillary anterior teeth associated with SECC (p = 0.02);
feeding and Breastfeeding after 12 months of
breastfeeding age = 70% of SECC children and
50% of non-SECC children -
significant association b/w
breastfeeding children >12 months
and presence of SECC (p = 0.004)
Campus et al. (45) National cross-sectional 4 years old children, Italy N = 5538 (aged 47.2 monthDuration of breastfeeding Age 4 years Children BFfor>13 months had Gender; Parent nationality;
[5* Good] survey; March 2004- +/- 3.5 months) (<13 months or Dental caries dmfs significantly higher dmfs than those Parent education; Pre-
April 2005 Boys = 2518 (45.5%) >13 months) BF <13 months (p < 0.05) term births; Age of tooth
Association between prolonged BF eruption; Tooth brushing
and dental caries only seen in habits; Disease or
bivariate analysis and no conclusion medication during
about harmful consequences can pregnancy
be drawn from multivariate
modelling
Cariño et al. (46) Cross sectional survey; Children aged 2-6 years; n = 452 Feeding Aged 2-6 years Bivariate analysis Child's primary caregiver;
[3* Unsatisf] October - November Northern Philipines - 3 areas Aged 3-6 years Breastfed only Dental caries No significant difference in Feeding practices;
1999 in 2 regions Stratified 3-A and 5- Mixed breastfed and ECC associations between Toothbrushing; Snaeking
6 years bottle fed dmft breastfeeding bottle feeding and frequency; Type of
Bottle fed only weaning age and ECC snacks eaten; Last dental
No answer visit; Reason for last visit
Weaning age
<2 years old
>2 years
Still breast or bottle
feeding
No answer
Dini et al. (47) Cross-sectional survey; Children enrolled in municipal N = 245 Breast feeding and/or Aged 3-4 years Statistically significant: None reported
[4* Satisf] 1998 nurseries; 3-4 years; Boys =137 (56%) bottle feeding Dental caries dmfs or dmft Caries in molars and incisors and
Araraquara, Sao Paolo, Brazil Duration of children who were never breast fed
breastfeeding: or those who were breast fed
Never beyond 24 months age OR = 3.1
<24 months (1.1-8.4) p = 0.03
>24 months
m S-a' ÍQ
Q 3 Q.
Appendix (Continued) Type of study/brief References [NOS QA score] description Study population/Country Sample size (gender % given if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) Other variables included in the models as confounders Interactions
Du et al. (48) Cross sectional survey Children in kindergartens; N = 426 Infant feeding - breast Aged 24^17 months; Mean Bottle fed only children had Stepwise logistic
[4* Satisf] urban Hanchuan, China Boys = 250 (59%) and /or bottle age = 40 months statistically significant higher regression: Gender
Duration of breast Dental caries (dmfs or dmft) prevalence of incisor caries (male/female); Age
feeding Rampant caries = 2 or more (p < 0.05) and rampant caries (24-35 months /36-
teeth with caries affecting (p < 0.01) cf with partially or fully 47 months); Education
palatal and /or labial surfaces breast fed children. (low/high); Income
of primary incisors Children who had been wholly (low/high); Feeding
bottle fed had higher risk of caries (bottle/breast)
cf children partially or wholly
breastfed:
rampant caries OR = 5.27 (2.16-
12.89) p = 0.003
incisor caries OR = 2.38 (1.03-
4.76) p = 0.042
Dye et al. (49) Cross sectional National Children aged 2-5 years; N = 4236 History of breast feeding - Aged 2-5 years In models adjusted for poverty, Poverty Poverty and
[6* Very good] Health and Nutrition USA Boys = 2081 (49.1%) yes or no Dental caries - decayed or education and race/ethnicity the Education of parent educational
Examination Survey III - filled primary dental surfaces findings indicate that there is no Race/ethnicity attainment
1988-1994 (dfs) relationship between caries and a
history of ever breastfeeding
Folayan et al. (50) Cross-sectional Children aged 6-71 months; N = 396 -Exclusive breastfeeding Aged 6-71 months Significant predictors of dmft: None reported
[3* Unsatisf] 3 randomly selected LGAs in Boys = 217 (54.8%) Almost exclusive: breast dmft Duration of breastfeeding
Lagos State, Nigeria milk with water Rampant caries = caries (p = 0.002) & form of
supplement affecting 1 or more maxillary breastfeeding [exclusive
Partial/mixed incisors with or without breastfeeding] (p = 0.03)
breastfeeding involvement of primary molars No significant association b/w form
Caries = caries affecting of breast feeding and rampant
tooth/teeth exclusive of caries or caries.
maxillary anterior tooth/teeth No sig association b/w duration of
No caries breastfeeding and caries or no
caries - however significant
association between duration of
breastfeeding and rampant caries
(p = 0.02)
Folayan et al. (87) Cross-sectional Children attending the Child N = 205 Duration of breastfeeding Aged 1 -16 years No association found between None reported
[3* Un satisf] Dental Health Clinic of 2 Boys = 108 (52.7%) Breastfeeding on Rampant caries rampant caries, duration of breast
hospitals in Nigeria 1-5 years n = 91 demand or leaving the feeding (p = 0.13), form of
6-10 years n = 88 nipple in mouth breastfeeding (p = 0.84) or
11-16 years n = 26 overnight during night duration of bottle feeding
feeding. (p = 0.07) in children aged 1-
Duration of bottle 5 years
feeding
Forsman et al. (51) Cross-sectional study; 2 (1) Vaxjo, Sweden; Vaxjo -Exclusive breastfeeding Aged 4 years Results reported in frequencies and None reported
[3* Un satisf] sites Children born 1962 and n = 726 for first 5 months (B) Dental caries t-tests
1963; Gothenburg n = 115 -Exclusive water diluted defs and deft No significant differences in caries
Data on infant feeding infant dry milk formula between the B and F groups in both
extracted from records in for first 5 months of life sites.
Children's Welfare Centre, (F)
(2) Gothenburg, Sweden
Children born in 1964
Questionnaire
(Q Q 3 Q.
Appendix (Continued) References [NOS QA score] Type of study/brief description Study population/Country Sample size (gender % given if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) Other variables included in the models as confounders Interactions
Hallett et al. (52) Cross-sectional; Preschool s; N = 2515 Duration of breastfeeding: Aged 4-5 years Multivariate analysis Sleep with bottle (y/n);
[6* Very good] Self administered North Brisbane, Australia Boys = 1307 (52%) None; <3 months; 3- ECC- dmfs and dmft > 1 Ref = no breastfeeding Sip from bottle (y/n);
questionnaire 6 months; 7- <3 months OR = 1.0 (0.7-1.3) Ethnicity; Family income
12 months; (P = 0.9)
>13 months 3-6 months OR = 0.7 (0.5-1.0)
(p = 0.05)
7-12 months OR = 1.0 (0.7-1.4)
(P = 0.9)
>13 months OR = 1.5 (0.9-2.3)
(p = 0.09)
Hallonsten et al. (53) Cross-sectional survey; Child welfare centres (n = 48 N = 200 Breastfeeding Aged 18 months No significant difference in defs of None reported
[3* Unsatisf] 1981-1982 centres); 3 counties in Duration of Dental caries children with caries being breastfed
Comparative study of 4 Sweden breastfeeding defs and children with caries not being
groups (± breastfeed in g breastfed
and ± dental caries) No analysis of association between
defs and breastfeeding duration
Haq et al. (54) Cross-sectional Recruited from hospitals, N = 530 Feeding: Aged 5 months - 6 years No significant difference in caries Sweet drink intake
[2* Unsatisf] private dental clinics and Breast fed Dental caries between those breast fed, bottle analysed with each
public dental clinic, Dhaka, Bottle fed dmft fed or mixed fed. exposure
Bangladesh Mixed fed Longer duration of feeding (either
Breastfeeding duration: breast, bottle or mixed fed)
6 months - 1 year significantly associated with
1-2 years prevalence of caries.
2-3 years
Hardy (55) Cross-sectional Village communities in Greece N = 225 Breast fed Aged 2-6 years No significant difference in caries None reported
[1* Unsatisf] Wholly breast fed = 159 Bottle fed Dental caries dmft between the two groups.
Wholly bottle fed = 66
Harrison et al. (56) Cross-sectional Vietnamese migrants; N = 60 Breastfed Mean age Correlational statistics. None reported
[4* Satisfl Vancouver, Canada Boys = 31 (52%) Breastfeeding duration 32.4 months ±21.3 No association between dental
Dental caries - defs caries and nursing caries and
Nursing caries (>2 maxillary breastfeeding.
teeth have decay)
Holt et al. (57) Cross-sectional Maternal and child welfare N = 555 Breast feeding Aged 12 - 60 months A significantly higher proportion of None reported
[3* Unsatisf] centres in Camden and Boys = 275 (49.5%) No breastfeeding for Caries - visible cavity involving children wholly breastfed (95%)
Islington Health Authority, >2 weeks = Wholly dentine were caries free compared with the
London, UK bottle fed Rampant caries - labial or proportion of children wholly bottle
palatal carious lesions fed (82%) (p <0.01)
involving >2 maxillary incisor
Hong et al. (58) Cross-sectional Singapore 190 children Breast feeding Mean Presence of dental decay: Child racial group,
[5* Good] Boys = 98 (51.6%) till 10 months; age = 36.3 months ± 6.9 Adjusted frequency of sweets,
Chinese = 60% > 10 months Dental caries Breastfeed <10 months (ref) importance of baby
Malay = 32% dmfs/dmft breastfeed >10 months: RR = not teeth, plaque on teeth
Other = 7% significant [Results not shown]
Risk for decayed and filled teeth
Adjusted
Breastfeed <10 months (ref)
breastfeed > 10 months: mean
ratio =1.85 (1.12-3.05)
p = 0.016
Risk for decayed and filled surfaces
—I zr
m S-a' «s Q 3 Q.
Appendix (Continued) References [NOS QA score] Type of study/brief description Study population/Country Sample size (gender % given if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) Other variables included in the models as confounders Interactions
Adjusted
Breastfeed <10 months (ref)
breastfeed > 10 months: mean
ratio = 2.32 (1.44-3.70)
p = 0.001
lida et al. (59) Cross-sectional Children aged 2-5 years N = 1576 History of BF = ever BF; Aged 2-5 years ECC - Adjusted Birth weight; Age; Gender; Race/ethnicity
[5* Good] National Health and USA Boys = 793 (50.3%) Overall BF Dental caries Hx of BF: aOR = 0.97 (0.63-1.49) Race/ethnicity; Poverty Poverty status
Nutrition Examination duration = age when ECC = presence of any dfs on p = 0.89 status; Maternal age at
Survey child completely stopped any primary tooth S-ECC - Adjusted child's birth; Maternal
BF or being fed breast S-ECC = presence of any dfs Hx of BF: aOR = 0.83 (0.49-1.40) history of smoking during
milk; Exclusive BF on any maxillary incisor p = 0.47 pregnancy; History of
duration = Age when No statistically significant hospital admission; Time
child was first fed associations between of exclusive since last dental visit
something other than breastfeeding duration or full
breast milk or water; Full breastfeeding duration
BF duration = Age when
child was first fed
formula, milk or solid
foods on a daily basis
Johansson et al. (60) Cross-sectional Preschool children presenting N = 1206 Breastfeeding continues Aged 6 months - 5 years Children breast fed when sleeping None reported
[3* Unsatisf] for well children visits at Boys = 622 (51.6%) after falling asleep Dental caries had significantly higher deft (1.48)
paediatric clinic in Boston deft cf children who were not (0.61)
Medical Centre, USA p = 0.0003
Those bottle fed in bed or at nap
time did not have a significantly
higher deft (0.53) those who did
not (0.64) p = 0.233
Livny et al. (61) Cross-sectional Children in Jahalin Bedouin N = 102 Breastfeeding only Aged 12-36 months No significant associations between None reported
[3* Unsatisf] community, Jerusalem Boys = 56 (54.9%) Breastfeeding and bottle Dental caries dmft feeding practices and caries/no
feeding caries
Majorana et al. (62) Cross-sectional Children aged 24—30 months N = 2450 Exclusive breastfeeding Aged 24—30 months Moderate and high caries was not None reported
[4* Satisfl Questionnaire Brescia, Italy Males = 1181 (49.3%) Moderate-high mixed Caries - dmfs observed in subjects exclusively
feeding (58-99% breast ICDAS score for severity breast fed, whereas high caries
milk) severity level was predominant in
Low mixed feeding (1- children fed with formula
57% breast milk) OR = 6.75 (6.00-7.58) p < 0.01
Masumo et al. (63) Cross-sectional Manyara (high fluoride rural Child-caretaker pairs Current breastfeeding Aged 6-36 months Breast feeding status was not Age; Plaque score;
[5* Good] area) and Kampala (low Manyara n = 1221 (yes/no) Dental caries significantly associated with ECC in Enamel hypoplasia;
fluoride urban area), Uganda Boys = 616 (50.5%) Breastfeeding duration ECC = dmft multiple variable models Teeth present; Sugar
Kampala n = 816 Decayed (dt) - cavitated Manyara: consumption; Number
Boys = 414 (50.7%) dt = absent or present Currently breastfeeding a OR = 0.8 of teeth present
(0.30-2.17) p = NS
Kampala
Currently breastfeeding a OR = 1.4
(0.70-2.79) p = NS
Significantly higher prevalence of
caries in children breast fed 25-
36 months compared to those
breastfed 6-12 or 13-24 months
S-a' (Q Q 3 Q.
Appendix (Continued) References [NOS QA score] Type of study/brief description Study population/Country Sample size (gender % given if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) Other variables included in the models as confounders Interactions
Mattos-Graner et al. (64) Cross sectional Children attending 9 public N = 142 Duration of breastfeeding Aged 1-2.5 years Children never breastfed or breastfed None reported
[4* Satisfl school nurseries, (0-3 months; 3- Dental caries to 3 months exhibited higher caries
Sao Paolo, Brazil 31 months); ds (no missing or filled teeth prevalence than children breastfed
Frequency of breast were found) for longer period (X2 = 4.11,
feeding p < 0.05)
Nobile et al. (65) Cross-sectional Children in kindergartens in N = 515 Occurrence and duration Aged 36-71 months Prevalence of ECC significantly Potential confounders
[3* Unsatisf] Southern Italy Boys = 262 (51 %) of breast feeding: History Dental caries increased with duration of breast included in the models
(yes/no); duration (<4; ECC: >1 decayed, missing of feeding OR = 1.26 (1.01-1.57) but these are not
5-10; 11-19; filled teeth (dmft) p = 0.039 specified.
>20 months) S-ECC: In children Prevalence of S-ECC significantly Possibly: Dental visit in
Bottle feeding - sleep <3 years = any sign of increased with breastfeeding previous year; Age;
with sweetened bottle or smooth surface caries; in OR = 2.06 (1.13-3.76) p = 0.019 Mother's education level;
pacifier children aged aged 3- Start using cup; Sleep
5 years = 1 or more with bottle or pacifier;
cavitated, missing or filled Start toothb rushing;
smooth surfaces in primary Maternal age at delivery;
maxillary anterior teeth; or Mother's age
dmft >4 at age 3; dmft >5 at
age 4; dmft >6 at age 5
Nunes et al. (66) Cross-sectional Preschool children; Low income N = 241 Non-exposed = those Aged 18 - 42 months Prolonged breastfeeding not Child age; Nocturnal bottle
[5* Good] families; Non exposed n = 192 breast fed for Mean age = 34.5 months associated with ECC in this model. feeding with infant
Sao Luis, Brazil Exposed n = 49 <12 months Dental caries [Data not shown] formula; Daily sucrose
Exposed = those still ECC, dmft consumption between
breastfeeding at time of main meals
examination
Perera et al. (67) Cross-sectional Children aged <60 months in a N = 285 Exclusive breastfeeding- Aged <60 months No significant difference in the deft None reported
[3* Unsatisf] pediatric ward of a teaching Boys = 138 (48.4%) breast milk up to Dental caries of children exclusively breast fed
Hospital; Sri Lanka 6 months deft and those not exclusively breastfed
Overnight feeding (bottle p = 0.28
or breast) Children fed overnight with breast
milk had caries prevalence of
51.4% cf children not fed overnight
(29%) OR = 2.54 (1.29-5.01)
along with higher mean deft
p = 0.001
Prakash et al. (68) Cross-sectional Playschools and private N = 1500 On-demand breastfeeding Age 8-48 months On demand breastfeeding and None reported
[4* Satisfl hospitals (not defined) Dental caries presence of caries X2 = 17.71
Children aged 8-48 months p = 0.001
Urban Bangalore, India
Prakasha Shrutha et al. (69) Cross-sectional Children aged 3-5 years - Play N = 2000 Breastfeeding frequency Age 3-5 years Prevalence of dental caries showed None reported
[2* Unsatisf] homes/preschools in Kanpur Boys = 974 (48.7%) 5 times Dental caries inverse relationship with frequency
District, India 5-10 times dmft of breastfeeding but not significant
>10 times Caries prevalence increased with
Duration of duration of breastfeeding and
breastfeeding p < 0.05
<6 months Caries prevalence higher in children
6 months-1 year who were introduced to the bottle
1-1.5 years around 2 years of age p < 0.001
1.5-2 years
Age bottle feeding
introduced
<6 months
6 months-1 year
1-2 years
Not introduced
—I zr
m S-a' «s Q 3 Q.
Appendix (Continued) Type of study/brief Sample size (gender % given Other variables included in
References [NOS QA score] description Study population/Country if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) the models as confounders Interactions
Qadri et al. (70) Cross-sectional survey Children aged 3-5 years N = 400 Feeding practices during Aged 3-5 years Logistic regression: Models are adjusted but
[4* Satisfl 20 kindergartens in Syria Boys =191 (47.8%) infancy: predominately breastfed vs bottle fed. Dental caries dmft ECC Fully adjusted dietary practices (bottle vs breastfeeding) and (1) dmft OR = 0.61 (0.39-0.97) p = 0.038 (2) ECC OR = 0.27 (0.18-0.41) p < 0.001 Age was only significant factor associated with dmft and ECC confounders included are not reported (possibly age, gender and dietary practices are the covariates).
Retnakumari et al. (71) Cross-sectional Children attending N = 350 Duration of breastfeeding: Aged 12-36 months Significant association between None reported
[3* Unsatisf] immunisation clinic, day care centres - aged 12-36 months Kerala, India Male =171 (48.9%) Night feeding only Present now <1 year 1-2 years >2 years Falling asleep with nipple in the mouth Dental caries defs caries severity and duration of breastfeeding (analysis not shown) Severity of decay higher in children who fell asleep with nipple in the mouth (OR 2.92, p < 0.05) [95% CI not reported]
Rosenblatt et al. (72) Cross-sectional Pediatric clinic -two public N = 468 Feeding practices: Aged 12-36 months No significant association between None reported
[3* Unsatisf] maternity hospitals Recife, Brazil Boys = 222 (47.4%) Breast feeding Breast feeding + baby bottle sugared milk Baby bottle sugared milk Cup+ sugared milk Dental caries deft type of feeding and presence of caries
Sankeshwari, (73) Cross-sectional Children aged 3-5 years; 20 N = 1250 Breastfeeding: history, Aged 3-5 years Significant [unadjusted] associations None reported
[3* Unsatisf] preschool s in Bel gaum, India Boys = 663 (59.4%) duration, timing, frequency Bottle feeding: history, duration, timing frequency, contents Dental caries - dmft (ECC) (X2) between lower prevalence of ECC and history of breastfeeding (yes/no: p = 0.02), duration of breastfeeding (6-24 months/ <6 months or >24 months: p = 0.001).
Santos, (74) Cross-sectional Outpatients of the Pediatric N = 80 Breastfeeding Aged up to 36 months No significant associations were None reported
[2* Unsatisf] University Hospital, Brazil Boys = 45 (56.3%) Dental caries found between the prevalence of caries and nocturnal bottle- and breast-feeding.
Sayegh et al. (75) Cross-sectional Kindergartens in Amman, N = 1140 Infant feeding practice: Aged 4-5 years Breast feeding duration >18 months Characteristics included in
[4* Satisfl Jordan Boys = 582 (51.1 %) Breastfeeding Bottle feeding Both Duration Frequency (on demand) Dental caries Dmft Incisors; incisors and canines; molars; incisors, canines and molars or never (grouped together) - OR caries in any teeth = 1.5 (95% CI 1.1-2.1) p < 0.05 Breast feeding on demand cf not breast feeding on demand OR caries in any teeth = 1.8 (95% CI 1.3-2.5) p < 0.05 stepwise regression: Age; Social class; Sleep with mother; Bottle feeding time; Use of comforter; Confectionery at bed or night time
Sayegh et al. (76) Cross-sectional Kindergartens in Amman, N = 1075 Breastfeeding/ Bottle Aged 4-5 years Caries: Breastfeeding 18 months vs Characteristics included in
[5* Good] Jordan Boys = 553 (51.4%) feeding duration: <6-18 months >18 months Breastfeeding/ Bottle feeding frequency: Never; Not on demand; On demand Dental caries dmft Caries = dmft >1 Severe caries = dmft >4 never - not significant [data not shown] Severe caries: Breast feeding > 18 months vs never breastfeeding OR = 2.3 (95% CI 1.1-4.8) the stepwise multiple logistic regression model: Dental plaque; Sleeping beside mother; Use of comforters; Confectionery; Ma rma 1 a de/j a m/h oney/ halawi at breakfast or dinner
S-a' (Q Q 3 Q.
Appendix (Continued) References [NOS QA score] Type of study/brief description Study population/Country Sample size (gender % given if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) Other variables included in the models as confounders Interactions
Serwint et al. (77) Cross-sectional Hospital based pediatric clinic, N=110 Ever breast fed Aged 18-36 months Ever breast fed and caries OR = 2.9 Controlled for familial
[3* Unsatisf] California, USA Boys = 55 (50%) Bottle feeding was Dental caries: (95% CI 0.9-9.9) p = 0.08 - characteristics: Maternal
primary interest Caries borderline significance. cavities; Mother aims to
Non-caries keep teeth by age 65;
Child drank fluoride
water; fluoride
supplements; Brush
child's teeth
Slabsinskiene et al. (78) Cross-sectional Kindergartens in 10 counties in n = 80 Duration of breast Aged 2.5-3.5 years In children who breastfed beyond None reported
[3* Unsatisf] Subset questionnaire Lithuania feeding: Dental caries 13 months the risk of developing
Children with no caries <12 months dmft/dmfs S-ECC was high OR = 10.0 (95%
n = 40 Children with S- >13 months No caries CI 1.28-78.12)
ECC n = 40 S-ECC
Songo et al. (79) Cross-sectional Dental units of five hospitals or N = 158 Breast feeding: Aged 4-6 years Children being exclusively breast fed None reported
[2* Unsatisf] private clinics in Kinshasa, Boys = 79 (50%) Exclusive Dental caries - dmft or have both bottle and breast
Democratic Republic of Mixed with bottle presented with lower caries levels
Congo Bottle feeding only OR = 0.16 (95% CI 0.04-0.66)
Tanaka et al. (80) Cross-sectional Public health centre N = 2056 Breastfeeding duration Aged 3 years Adjusted Prevalence Ratios (95% CI) Adjusted for: gender;
[5* Good] Fukuoka City, Japan Boys = 1087 (52.9%) regardless of exclusivity: Dental caries Breastfeeding duration (months) Tooth brushing
<6 months dmft >1 <6 PR = 1 frequency; Use of
6-11 months 6-11 PR = 0.79 (0.6-1.05) Fluoride; Regular dental
12-17 months 12-17 PR 0.86 (0.66-1.13) check-ups; Between
>18 months >78 PR 1.66 (1.33-2.06) meal snack frequency;
Breastfeeding for 18 months or Maternal smoking during
longer significantly associated with pregnancy; Exposure to
higher prevalence of dental caries environmental tobacco
smoke at home; Parental
education levels
Tiano et al. (81) Cross-sectional Public day care centres in 2 N = 68 Breast feeding duration Aged 18-36 months CCL prevalence is significantly Not reported
[3* Unsatisf] municipalities in Brazil <12 months Dental caries associated with duration of
13 months + CCL = cavitated carious breastfeeding (p = 0.02)
lesions ECC prevalence is not associated
ECC = any stage of carious with duration of breastfeeding
lesion
Tyagi (82) Cross-sectional Kindergartens in Davangere, N = 813 Duration of breast Aged 2-6 years Mean dfs increases with duration of Not reported
[1 * Unsatisf] Karnataka, India Boys = 395 (48.6%) feeding: Dental caries breast feeding but not statistically
3-9 months dfs significant
10-12 months
13-24 months
25^12 months
Vachirarojpisan et al. (83) Cross-sectional Health centres, U-Thon District N = 520 Method of feeding: Aged 6-19 months Bivariate analysis of 15-19 month Multivariate models
[5* Good] in Suphan Buri Province, Boys = 272 (52.3%) Breast feeding Dental caries group: controlled for: Age;
Thailand Bottle feeding or mixed dmfs; dmft Significant association between Number of teeth present
feeding Intensity of ECC (l-ECC) = breastfeeding and l-ECC
ratio of affected teeth (non (p = 0.018). Significant association
cavitated + cavitated): erupted lost in multivariate models that
teeth include all age groups.
Vazquez-Nava et al. (84) Cross-sectional study Children aged 4-5 years who N = 1 160 Breast feeding Aged 4-5 years Significant association between Not reported
[5* Good] within prospective cohort had been longitudinally Boys = 585 (50.2%) Breast feeding Dental caries (assessed from breastfeeding beyond 12 months
study studied since 4 months of >12 months & at night 2 years of age) & at night and dental caries
2005 age. Bottle feeding deft and defs OR = 3.6 (2.51-5.16) p < 0.001
Not reported
m S-a' «s Q 3 Q.
Appendix (Continued) Type of study/brief Sample size (gender % given Other variables included in
References [NOS QA score] description Study population/Country if reported) Exposure definition Outcome definition and age Exposure estimate (95% CI) the models as confounders Interactions
Wendt & Birkhed (85) Cross-sectional study Preschool children in Baseline n = 671 Breast feeding: Examined at 1 year, 2 years Significantly more children with
[4* Satisfl within prospective Jonkoping, Sweden - 1 year n = 632 <2 months and 3 years of age caries than without caries at the age
longitudinal study comparison of Swedish 1 year caries free Still breast fed Dental caries of 3 had either been breast fed for
3 time points: 1 year, children and immigrant n = 629 dmfs <2 months or >12 months
2 years, 3 years children 2 years n = 298 2 years caries free n = 276 3 years n = 270 3 years caries free n = 210
Yonezu et al. (86) Cross-sectional Infants attending preventive N = 105 Bed time breast feeding Aged 18 months Odds of caries at 24 months was None reported
[1* Unsatisf] dental care programs at public health centres. Children have been or are being breastfed Dental caries dft significantly higher OR = 10.66 (2.23-50.96) for bedtime breast fed children than children not breast fed at bed time (p < 0.05)
ECC = Early childhood caries; S-ECC = Severe early childhood caries; dmfs/t = decayed, missing, filled and extracted deciduous surfaces/teeth; defs/t = decayed, extracted due to caries, filled deciduous surfaces/ teeth; DMFT = Decayed, Missing, Filled and Extracted permanent surfaces/teeth; ICDAS = International Caries Detection and Assessment System (Reference: ICDAS Foundation. What is ICDAS?. https:// www.icdas.org/what-is-icdas, 9 March 2015).
