This roentgenologic study of pneumatization of the mastoid and of changes observed associated with suppuration of the middle ear was presented by Dr. Bröste as a thesis for the degree of Doctor of Medicine at the University of Copenhagen. One hundred and thirty-four patients were examined along with their clinical histories. It was hoped that such an associated examination would correlate diseases of the middle ear with the changes in the mastoid.
His basic hypothesis was that the degree of mastoid pneumatization is dependent on the vitality of the epithelium of the tympanic cavity and, therefore, that the anatomic development of the mastoid is to be considered as a function of the character of the mucous membrane of the middle ear and that diseases in the middle ear and in the mastoid might therefore be expected to show a correlation. He accepts Wittmaack's classification of three chief variants in the