The Twin Clinical Method (Gedda, 1963) has been applied to the study of dental pathology. Four cases of MZ female twin pairs have been studied, concordantly affected by dental agenesis (case I), mirror-imaging dental agenesis (case II), diastema (case III), and dental caries and enamel dystrophy (case IV). The test has also been applied, and for the first time, to a set of MZ female triplets, concordantly affected by dental caries and malposition.
In all the above cases, the test has permitted to reject hypothesis of a concordance being due to chance, while postulating the existence of a causality.
The latter is ascribed to the common heredity characterizing MZ cotwins.