[Medicolegal identification : teeth and blood groups (author's transl)].
The absorption-elution technique may be used to give adequate grouping in 85% of cases of ABO groups from dental tissue, the results being specific for amounts of 20 to 100 mg of fine powder. ABO antigens are better preserved in the tooth itself, dried, but also to a lesser extent (83% of positive results) in Bouin's fluid whilst formol destroys the ABO antigens of the tooth. Antigenic substances are progressively broken down in relation to the duration and method of preservation. These parameters must therefore be borne in mind for the group O (false "O"). The dental pulp has the same ABO specificities as the tooth and dry or moist preservation better preserves the characteristics. By contrast, areas of caries or damaged teeth result in a high number of errors due to foreign antigens borne by bacteria. With the identification factors which may be provided by study of the odontogram and dental are by Gustafson's method on the one hand, and studies of blood group using powdered tooth or even old dental pulp, the expert may make a medicolegal identification in more than 90% of cases.