Presumptive Bilirubin-Related Chlorodontia and Developmental Enamel Defects of the Primary Dentition in an Extremely Preterm Infant: A Case Report

Background: Chlorodontia is a rare condition characterized by intrinsic green discoloration of teeth. It is most often reported in association with bilirubin pigment deposition during teeth development, in cases of severe and/or prolonged neonatal hyperbilirubinemia. In extremely preterm infants, this condition may be complicated by other developmental enamel defects (DDE), such as hypoplasia or hypomineralization, linked to prematurity, systemic diseases, nutritional disturbances, and intensive care exposures. That overlap of enamel abnormalities can make diagnosis more difficult, necessitate a complex treatment plan, and increase the unpredictability of dental treatment efficacy. Case Presentation: This report presents the case of a child born at 25 weeks’ gestation with a birth weight of 910 g. Her neonatal course was complicated by, among others, recurrent episodes of hyperbilirubinemia, first neonatal (treated with phototherapy between the second and fifth day of life), and afterwards due to cholestasis from day 30 of life, with coexisting bacterial sepsis and metabolic disturbances. The available neonatal medical documentation indicated that total bilirubin level peak took place on the 40th day of life with levels approaching approximately 30 mg/dL, as well as levels of conjugated bilirubin being 19.0 mg/dL, but the exact peak values, duration, and bilirubin fractionation were not given in the patient’s discharge form. At 15 months of chronological age (11.5 months corrected age), she was referred for an assessment of abnormal morphology and green discoloration of the erupted primary incisors. Clinical examination revealed intrinsic green discoloration of the teeth, rough incisal edges and enamel breakdown on the incisal third. During follow-up, less intensity of the green pigmentation in the subsequent groups of erupted teeth was noticed. Despite excellent oral hygiene and adherence to a low-cariogenic diet, the primary first molars probably developed post-eruptive enamel loss with exposed dentin tissue. Minimally invasive management was introduced using atraumatic restorative treatment with glass-ionomer cement, combined with intensive preventive care. Conclusions: Despite the fact that, in the presented case, the diagnosis of presumptive bilirubin-related green pigmentation relies exclusively on the clinical picture and the complex neonatal medical history, it shows that, in extremely preterm infants, chlorodontia may coexist with hypomineralization or hypoplasia. This requires the introduction of dental treatment and prophylaxis, adjusted to the child’s age, to lower the risk of further complications of DDEs.