ROENTGENOGRAPHIC STUDIES OF TISSUES INVOLVED IN CHRONIC MOUTH INFECTIONS

In a paper 1 presented before this section at the New York meeting last year there was included a tabulation covering a critical examination of 3,000 roentgenographic films of the teeth and adjacent bone of the mouths of 300 adults. During the past year these studies have been continued with results that very closely parallel the previous figures. The present tabulation, which includes that of last year, covers 600 roentgenographic mouth examinations, for each of which ten small films were made—a total of 6,000 films. 2 The object of this study is primarily to determine as nearly as possible the average percentage of chronic mouth infections, which are of two types: (1) those that begin with inflammations of the gingivae and progress along the side of the root toward the apex, destroying the peridental membrane and adjacent alveolar process—chronic suppurative pericementitis; (2) those which, subsequent to the death of the