Hereditary Ectodermal Dysplasia (Congenital Ectodermal Defect)

I wish to report two cases of patients who present unusual types of multiple congenital anomalies, the tissues affected in both cases having developed principally from embryonic ectoderm. Descriptions of similar patients are not lacking in the dental and medical literature, but the condition has not been specifically called to the attention of pediatricians. In the patients whose cases are to be reported in this paper the paucity of scalp hair, eyebrows and eyelashes, the prominence of the brow and the defects in the development of the teeth were so strikingly similar that one would not hesitate in supposing the cause of the anomalies, however obscure, to be the same in both children. And yet, in race and in several most important clinical respects they differed markedly. These will be discussed in detail. REPORT OF CASES Case1.—History.—H. C., a Jewish boy, aged 14, had been seen from