Abstract
In order to get effective guides for the identification of the rightness or leftness of the tooth and also for the plaster sculpture, the crowns of right mandibular central incisor, lateral incisor and canine were transversally separated into 12 even sections, and the outline of each section crossing at the right angle to the teeth axis and the outline by incisal aspect were recorded with the Contracer. The curve symbols were observed anglewise by the outline thus recorded, and the areas forming the curve symbol were also examined to get the following results:
1. No curve symbole was seen in the mandibular central incisor and lateral incisor by the outline by incisal aspect, but in the mandibular canine the curve symbol was apparently observed.
2. Regarding the curve symbols of each of the outlines of 12 sections of the crown, the curve symbol was observed at the area of 1/4 from the incisal side of the mandibular central incisor, at the area of 2/3 from the incisal side the mandibular lateral incisor and at the area of 3/4 from the cusp apex of the mandibular canine.
