Dental evidences of treatment with mercury: a probable case from 16th century Sardinia

Archaeological excavation carried out in the cemetery of Alghero, referable to the plague outbreak of the 1582-1583 AD, brought to light the skeletal remains of a child aged 4-5 years with dental anomalies. Several deciduous and erupted and unerupted permanent teeth are preserved, even if they were found isolated as the maxilla and the mandible are not preserved. The deciduous dentition appear to be normal. As for the permanent dentition, notable pathological changes were observed. Left and right upper central incisors display two transverse encircling furrows that divide the crown into thirds; the mid-part of the crown is pitted on the labial aspect. The upper canines resemble fangs by their decreased tips with thin and tapered enamel. The permanent first molars are marked by a sharp circumferential groove at mid-crown level; the crown surface is finely pitted with honeycomb appereance. The permanent teeth are patchily colored from yellow to brown. Some alterations affect also the post-cranial bones; a diffuse periostitis is evident on the diaphyseal surface of right humerus, radius and ulna and left radius and ulna as well as on the diaphyseal surface of the tibiae. The dental anomalies observed in this child suggest a disturbance of enamel development during the perinatal period and early infancy. These changes suggest that therapy with mercury may have disrupted enamel development, producing specific enamel deformities. An underlying diagnosis of congenital syphilis can be supposed, even if typical enamel defect are absent.