The basal area of posterior tooth crown components: The assessment of within tooth variations of premolars and molars

This paper presents the basic hypotheses and methods for describing the basal area, the projected relative plane surface areas of molar and premolar crown components. Basically these methods utilize definable anatomical landmarks which are projected from the occlusal surface of the posterior teeth to the occlusal plane. The relative plane surface area, a projection of the basal surface area, can be described by a series of vectors which outline each crown component as a polygon. The description of the dentition in this way is essential to a variety of experimental designs, i.e., the analysis of the range of variation of occulsion, the measuring and expression of shape and the description of the “within tooth” variations in size and position of each crown component.