A knowledge of the types and frequency of x-ray abnormalities of the skull to be expected in the mentally retarded is of benefit to any physician who deals with this type of patient. We have had the opportunity to examine routine skull x-rays of a large number (1,669) of mentally defective patients, and the findings are reported in this paper.
Material and Methods
In 1949, it was decided at the Rosewood State Training School, Owings Mills, Md., that routine skull x-rays should be done on all patients admitted to this institution. This is a public institution for mentally defective patients, with a population of around 2,000. With a few exceptions, the skull x-rays were made between 1949 and 1957. A number of patients who were admitted before 1949, however, were called back for x-rays.X-rays of patients who died or who were discharged after 1954 had not been removed from