The determination of measurements of teeth facilitates various procedures in dentistry. The purpose of this study was to evaluate the total length and the area of the non-extracted upper central incisors (UCI). Periapical radiographies of 42 UCI were placed over a lighted box. The outlines of the teeth and the pulp cavity were traced onto sheets and then measured using an image analyzer. The area of the upper left central incisor tooth (tooth 21) was statistically significantly larger in males than in females (p = 0.02). The total length of the right UCI was similar to that of the left one. This study demonstrates that computer-assisted morphometry is an important tool for the evaluation of the total length and areas of teeth and their pulp cavities. The significantly larger area of tooth 21 in males compared to females has anthropomorphic and clinical implications.