Table 4 Classification of developmental defects of enamel using the preterm developmental defects of enamel (PDDE) index.

Qualitative defects: Opacities with abnormal color shades

M score

Normal color and opacity

0

White opacity defect

1

Yellow defect

2

Yellow–brown defect

3

Quantitative defects: Structural defect associated with enamel hypoplasia

P score

Normal tooth morphology

0

Dental structural defects confined to enamel

1

Dental structural defects that affect both enamel and dentin

2