Diagnosis of the congenital form of syphilis is an important part of the palaeopathology of this disease. In theory, there are clear clinical signs to be found in the long bones and teeth, but it has rarely been possible to recognise the latter with a confidence in archaeological material, partly because the original descriptions of the dental deformities are sometimes contradictory and partly because it is nowadays difficult to find reference specimens in museums. This article describes two such specimens which have recently been rediscovered, and discusses the form of the dental defects which they show (Hutchinson's incisors, Moon's molars, and mulberry molars) in relation to the developmental sequence of the teeth.