The minimal width of the periodontal space

Radiographs of horizontal serial sections of dentate human mandible disclose a picture of the periodontal space, the bony margin of which is highly irregular. The minimal width of this space was measured at four points roughly 90 degrees apart and the average minimal width obtained. It is suggested that the usual clinical radiographic picture of the periodontal space of a particular tooth or teeth is such that a judgment of the width of the space cannot be made with any certainty.