Congenital syphilis or mercury treatment: dental alterations in a twelfth- or thirteenth-century child from Medinaceli, Soria, Spain.

Syphilis, together with its variant congenital syphilis, is a disease caused by subsp. . This paper documents possible new skeletal evidence for congenital syphilis from the Medieval Era (twelfth and thirteenth centuries CE) burial site of Medinaceli in the Province of Soria in North-Central Spain. What is involved is dental alteration due to congenital syphilis, mercury treatment, or a combination of both. This study focuses on the hypoplastic dental changes observed in a child approximately eight years of age. Only a fragmented skull with left maxilla and the left side of the mandible were preserved. Macroscopic analysis, X-rays, computerized tomography (CT) and mercury detection analysis by inductively coupled plasma mass spectrometry (ICP-MS) techniques were used to observe dental abnormalities. In addition to extensive caries in the upper second deciduous molar, pulpo-alveolar lesions and facial alterations were observed. The absence of the rest of the skeleton tends to make a diagnosis of congenital syphilis difficult. However, the dental stigmata observed do permit a reasonable diagnosis.