Ó 2013 Eur J Oral Sci
Eur J Oral Sci 2014; 122: 7–14 DOI: 10.1111/eos.12094 Printed in Singapore. All rights reserved
European Journal of Oral Sciences
Review
Developmental enamel defects in children born preterm: a systematic review
Pernille E. Jacobsen1, Dorte Haubek1, Tine B. Henriksen2, John R. Østergaard3, Sven Poulsen1 1
Section of Pediatric Dentistry, Department of Dentistry, Health, Aarhus University, Aarhus; 2 Perinatal Epidemiology Research Unit, Department of Pediatrics, Aarhus Universty Hospital, Aarhus; 3Center for Rare Diseases, Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark
Jacobsen PE, Haubek D, Henriksen TB, Østergaard JR, Poulsen S. Developmental enamel defects in children born preterm: a systematic review. Eur J Oral Sci 2014; 122: 7–14. © 2013 Eur J Oral Sci The purpose of this review was to evaluate the association between developmental enamel defects and children born preterm. An identical search was performed in PubMed and Embase and was limited to human studies and studies written in English, German, Danish, Swedish, or Norwegian. Reviews, case studies, and case series were excluded. A total of 283 articles were identified. Twenty-three publications, of which 19 were follow-up studies, two were case–control studies, and two were crosssectional surveys, were enrolled in the review. The majority of the studies (n = 17) dealt with enamel hypoplasia of the primary teeth. Thirteen studies reported an association between preterm birth and enamel hypoplasia, and, in addition, few studies reported an increased risk of enamel opacities in the primary teeth, in children with a birth weight 2000 g GA > 37 > 42 wk
Exposed 40 children, 5–10 yr
Exposed GA < 37 wk
Unexposed 40 children, 5–10 yr
Unexposed GA > 37 wk
Exposed 62 VPT children, 9–12 yr 20 EPT children, 9–12 yr
Exposed VPT: 29 < GA < 32 wk
Unexposed 82 children 9–12 yr
Findings (prevalence)
EPT: 24 < GA < 28 wk Unexposed GA > 37
Exposed 40 VPT children,12–16 yr + dental records at age 9
Exposed GA < 29 wk
Unexposed 40 children,12–16 yr + dental records at age 9
Unexposed GA > 37 wk
Weerheijm criteria MIH Modified DDE-index for all permanent teeth Demarcated opacities, diffuse opacities and hypoplasia
Modified DDE-index Primary dentition Opacities Permanent dentition Opacities and hypoplasia
*A combined count of opacities and hypoplasia. BW, birth weight; DDE-index, Developmental Defects Enamel-index; EPT, extremely preterm; GA, gestational age; LBW, low birth weight; MIH, molar incisor hypomineralization; NS, not significant at the significance level chosen; VLBW, very low birth weight; VPT, very preterm.
12
Jacobsen et al.
permanent incisors and first permanent molars in verylow birth-weight children. Finally, a case–control study (37) and a crosssectional study (26) qualified for entering the review according to the criteria described above. LUNARDELLI et al. (37) reported around twice the risk (OR = 2.6; 95% CI = 1.0–6.4) of enamel defects in the primary teeth in low birth-weight children. In a study on the permanent teeth, Arrow (26) reported similar results (OR = 2.11; 95% CI = 1.03–4.31) on the risk of enamel defects in the permanent first molars.
Discussion The systematic evaluation of the publications included in the present review indicates an association between preterm birth and developmental enamel defects in the primary dentition, whereas the evidence for an association with developmental defects in the permanent dentition is weaker. Considerable methodological differences were found between the studies with respect to, e.g. design, choice of outcome, study size, diagnostic criteria and analytic approach. Furthermore, the consideration of potential confounders in the studies varied extensively. This made it difficult to compare the results of one study with those of another. Analyses varied from simple analysis of 2 9 2 tables to multivariate analyses with over 30 explanatory variables. Because of this heterogeneity between studies, common to observational studies, a meta-analysis is not recommended (41). Instead, we validated the studies based on criteria for selection, comparability, and outcome measurements according to the NOS (Tables 1, 2). The fact that only 10 of 23 studies were categorized as high quality confirms the need for further well-designed studies. The most common design was the follow-up design, with collection of information from medical or hospital records, which makes it possible to secure adequate power and, to some extent, to control for confounders and reduce potential bias from differential recall. Some studies have relied on parental recall of gestational age and are therefore less reliable and have potentially biased exposure information, which may decrease the validity of these studies. There is a risk of selection bias if only children who enter a specific postnatal follow-up program are examined. It is therefore very important to describe the criteria for entry into the follow-up program and reasons for non-participation in order to be able to interpret the results. Only three out of the original 23 studies in the present review provided such a description (21, 22, 26). Furthermore, only four studies (21, 26, 34, 37) were blinded. In unblinded assessment of dental diseases, information bias may hamper the validity. The majority of the studies, categorized as high quality, have been conducted within the latest 5 yr (2009–2012). This indicates increased awareness of the importance of studies with high validity in both the researcher groups as well as among publishers. Still, when comparing the results from high-quality studies,
the results are inconclusive in relation to enamel defects in the permanent teeth, whereas they all found a significant increase of hypoplasia or enamel defects in the primary teeth. The treatment and care of premature children has improved considerably during the last 20–30 yr, resulting in improved survival and health. The specialized neonatal care units are now capable of ensuring the survival of children with extremely-low birth weight. Accordingly, the extent of the medical treatment has evolved. Our knowledge of medical interaction with dental development is limited, but it could influence the risk of developmental defects, even in the permanent dentition, and therefore should be taken into consideration. Thus, preterm or low birth-weight children from earlier studies may not be comparable with those from more recent studies. Also, we found definitions of prematurity of children enrolled in the studies that varied from birth weight
Eur J Oral Sci 2014; 122: 7–14 DOI: 10.1111/eos.12094 Printed in Singapore. All rights reserved
European Journal of Oral Sciences
Review
Developmental enamel defects in children born preterm: a systematic review
Pernille E. Jacobsen1, Dorte Haubek1, Tine B. Henriksen2, John R. Østergaard3, Sven Poulsen1 1
Section of Pediatric Dentistry, Department of Dentistry, Health, Aarhus University, Aarhus; 2 Perinatal Epidemiology Research Unit, Department of Pediatrics, Aarhus Universty Hospital, Aarhus; 3Center for Rare Diseases, Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark
Jacobsen PE, Haubek D, Henriksen TB, Østergaard JR, Poulsen S. Developmental enamel defects in children born preterm: a systematic review. Eur J Oral Sci 2014; 122: 7–14. © 2013 Eur J Oral Sci The purpose of this review was to evaluate the association between developmental enamel defects and children born preterm. An identical search was performed in PubMed and Embase and was limited to human studies and studies written in English, German, Danish, Swedish, or Norwegian. Reviews, case studies, and case series were excluded. A total of 283 articles were identified. Twenty-three publications, of which 19 were follow-up studies, two were case–control studies, and two were crosssectional surveys, were enrolled in the review. The majority of the studies (n = 17) dealt with enamel hypoplasia of the primary teeth. Thirteen studies reported an association between preterm birth and enamel hypoplasia, and, in addition, few studies reported an increased risk of enamel opacities in the primary teeth, in children with a birth weight 2000 g GA > 37 > 42 wk
Exposed 40 children, 5–10 yr
Exposed GA < 37 wk
Unexposed 40 children, 5–10 yr
Unexposed GA > 37 wk
Exposed 62 VPT children, 9–12 yr 20 EPT children, 9–12 yr
Exposed VPT: 29 < GA < 32 wk
Unexposed 82 children 9–12 yr
Findings (prevalence)
EPT: 24 < GA < 28 wk Unexposed GA > 37
Exposed 40 VPT children,12–16 yr + dental records at age 9
Exposed GA < 29 wk
Unexposed 40 children,12–16 yr + dental records at age 9
Unexposed GA > 37 wk
Weerheijm criteria MIH Modified DDE-index for all permanent teeth Demarcated opacities, diffuse opacities and hypoplasia
Modified DDE-index Primary dentition Opacities Permanent dentition Opacities and hypoplasia
*A combined count of opacities and hypoplasia. BW, birth weight; DDE-index, Developmental Defects Enamel-index; EPT, extremely preterm; GA, gestational age; LBW, low birth weight; MIH, molar incisor hypomineralization; NS, not significant at the significance level chosen; VLBW, very low birth weight; VPT, very preterm.
12
Jacobsen et al.
permanent incisors and first permanent molars in verylow birth-weight children. Finally, a case–control study (37) and a crosssectional study (26) qualified for entering the review according to the criteria described above. LUNARDELLI et al. (37) reported around twice the risk (OR = 2.6; 95% CI = 1.0–6.4) of enamel defects in the primary teeth in low birth-weight children. In a study on the permanent teeth, Arrow (26) reported similar results (OR = 2.11; 95% CI = 1.03–4.31) on the risk of enamel defects in the permanent first molars.
Discussion The systematic evaluation of the publications included in the present review indicates an association between preterm birth and developmental enamel defects in the primary dentition, whereas the evidence for an association with developmental defects in the permanent dentition is weaker. Considerable methodological differences were found between the studies with respect to, e.g. design, choice of outcome, study size, diagnostic criteria and analytic approach. Furthermore, the consideration of potential confounders in the studies varied extensively. This made it difficult to compare the results of one study with those of another. Analyses varied from simple analysis of 2 9 2 tables to multivariate analyses with over 30 explanatory variables. Because of this heterogeneity between studies, common to observational studies, a meta-analysis is not recommended (41). Instead, we validated the studies based on criteria for selection, comparability, and outcome measurements according to the NOS (Tables 1, 2). The fact that only 10 of 23 studies were categorized as high quality confirms the need for further well-designed studies. The most common design was the follow-up design, with collection of information from medical or hospital records, which makes it possible to secure adequate power and, to some extent, to control for confounders and reduce potential bias from differential recall. Some studies have relied on parental recall of gestational age and are therefore less reliable and have potentially biased exposure information, which may decrease the validity of these studies. There is a risk of selection bias if only children who enter a specific postnatal follow-up program are examined. It is therefore very important to describe the criteria for entry into the follow-up program and reasons for non-participation in order to be able to interpret the results. Only three out of the original 23 studies in the present review provided such a description (21, 22, 26). Furthermore, only four studies (21, 26, 34, 37) were blinded. In unblinded assessment of dental diseases, information bias may hamper the validity. The majority of the studies, categorized as high quality, have been conducted within the latest 5 yr (2009–2012). This indicates increased awareness of the importance of studies with high validity in both the researcher groups as well as among publishers. Still, when comparing the results from high-quality studies,
the results are inconclusive in relation to enamel defects in the permanent teeth, whereas they all found a significant increase of hypoplasia or enamel defects in the primary teeth. The treatment and care of premature children has improved considerably during the last 20–30 yr, resulting in improved survival and health. The specialized neonatal care units are now capable of ensuring the survival of children with extremely-low birth weight. Accordingly, the extent of the medical treatment has evolved. Our knowledge of medical interaction with dental development is limited, but it could influence the risk of developmental defects, even in the permanent dentition, and therefore should be taken into consideration. Thus, preterm or low birth-weight children from earlier studies may not be comparable with those from more recent studies. Also, we found definitions of prematurity of children enrolled in the studies that varied from birth weight
