Hypoplasia-associated severe early childhood caries--a proposed definition

Abstract

We propose a new classification of severe early childhood caries (S-ECC): hypoplasia-associated severe early childhood caries (HAS-ECC). This form of caries affects mostly young children living at or below poverty, characterized by structurally damaged primary teeth that are particularly vulnerable to dental caries. These predisposing developmental dental defects are mainly permutations of enamel hypoplasia (EHP). Anthropologists and dental researchers consider EHP an indicator for infant and maternal stresses including malnutrition, a variety of illnesses, and adverse birthing conditions. Differentiation of HAS-ECC from other forms of early childhood caries is warranted because of its distinct etiology, clinical presentation, and eventual management. Defining HAS-ECC has important clinical implications: Therapies that control or prevent other types of caries are likely to be less effective with HAS-ECC because the structural integrity of the teeth is compromised prior to their emergence into the oral cavity. By the time these children present to the dentist, the treatment options often become limited to surgical management under general anesthesia. To prevent HAS-ECC, dentists must partner with other health providers to develop interventions that begin with pregnant mothers, with the aim of eliminating or ameliorating the covariates accompanying poverty, including better pre- and post-natal care and nutrition.

Figure 1.

Pre- and post-natal developmental formation of the primary dentition. (A) Drawings from the recent histological study by AlQahtani and co-workers (AlQahtani et al., 2010). (B) The average developmental stage of the primary maxillary anteriors at birth (redrawn by permission of the authors). (C) Clinical representation of EHP that occurred around birth. Note the downward curve or “frown” coincidental to the stage of individual tooth development at time of insult. The child was malnourished but did not have access to refined sugar.

Figure 2.

Macroscopic and microscopic views of an incisor with HAS-ECC. (A) An extracted central incisor from a four-year-old child. A faint band of EHP including the mesial surface presents a large caries lesion. (B) Cross-section of the same incisor and imaged with polarized light microscopy. Note the pronounced neonatal line in both enamel and dentin with overlying evidence of insult occurring close to the birth of the infant. Also present is perturbed enamel structure in the region of the opaque band appearing clinically in (A). (C) Backscattered electron imaging in the scanning electron microscope (BSE-SEM) over the region of hypoplastic enamel reveals significant demineralization (color-coded orange, yellow, green, and blue, with decreasing density in enamel at left). (D) SEM images of the surface of enamel overlying the area of opacity and clear areas of disruption to surface integrity promoting retentive niches for cariogenic bacteria. (E) SEM images of other sites on the surface of the tooth display irregularities as well.

Figure 3.

The clinical presentations from preschool children with various degrees of caries and/or EHP of HAS-ECC. Panel A shows EHP on multiple primary teeth without active caries that we propose to define as HAS-ECC, stage 0. Panel B shows primary teeth with EHP and a minor to moderate degree of caries that we propose to define as HAS-ECC, stage 1. Panel C shows primary teeth with EHP and severe caries which we propose to define as HAS-ECC, stage 2. These preschool children were from impoverished families, mainly from China, with a documented history of malnutrition (Li et al., 1995). Almost all of them were colonized with moderate to high levels of mutans streptococci (Li et al., 1994).

Figure 4.

Model of the sequence of events leading to HAS-ECC (see text). MS, mutans streptococci.