[Aplasia of the premolars as a leading symptom of ectodermal dysplasia].

The primary symptom in the tooth system, a tendency toward aplasia of the bicuspid teeth in both dentition periods, was reported for an ectodermal syndrome which has seldom been described. In agreement with the observation by BOOK (1950), we also observed excessive perspiration (hyperhidrosis) and premature graying of the scalp hair (canities prematura). The syndrome, which is limited to ectodermal disturbances, is a dominant trait, the incidence of which is apparently higher in Northern European countries. Trigeminal neuralgias seem to appear in conjunction with this genetic disturbance. Compared with other partial anodontic and oligodontic syndromes, it is striking that no other groups of teeth are affected; the bicuspid teeth however show signs of aplasia, hypoplasia, structural disturbances (discoloration), and premature loss of even the deciduous teeth.