Abstract
This paper reported that green pigmented deciduous teeth caused by hyperbilirubinemia could undergo light yellowish discoloration after a long period of time, and the bilirubin even in such yellowish teeth could be demonstrated with the light absorption analysis.
A one-year-old male with green pigmented lower deciduous central incisors was referred to Chiba Children's Hospital. At the first examination, a green and yellowish area was seen in the cervical 4/5part of the crown. Shortly after birth, extensive cephalohematoma as well as disseminated intravascular coagulation occurred followed by hyperbilirubinemia,20-59.6 mg/dl on the plasma bilirubin level. Based on oral findings and his history, clinical diagnosis of bilirubin-pigmented teeth caused by hyperbilirubinemia was made. Because of no visible symptoms other than the pigmentation, the teeth were clinically followed up without any treatment. Until 3 years and 5 months of age, the green pigmentation had gradually discolored to light brown and consequently to light yellow by the age of 5years.
The light yellowish deciduous teeth which shed naturally were examined and the following results were obtained.
1) With the ground section of the teeth, the pigmented band probably caused by bilirubin deposit was seen in the dentine using light microscopy.
2) Fluorescence was observed in the pigmented band by means of irradiation of 546 nm wave length light.
3) With spectrophotometric analysis (after SHIBATA, T. et al.1996), chemically extracted samples from pigmented teeth showed maximum absorption spectra at 450 nm wave length light, and after diazo reaction of the sample, they shifted from 450 to 540 nm. The absorption spectrum of the pigmented tooth samples closely paralleled that of normal ones to which bilirubin standard was added, with the former more enhanced than the latter.
Based on these findings, the presence of bilirubin was demonstrated even in light yellowish pigmented teeth. Pigmentation of teeth induced by hyperbilirubinemia was also found to pass over into various color stages, such as from green to light brown or light yellow.
