Figure 3

Micro-computed tomography horizontal plane at the physiological foramen level of the distal and palatal roots of a mandibular (a) and maxillary molar (b), respectively. In this plane the oval shape of the foramina can be clearly distinguished. The differences between the major and minor diameters of the foramina denote the demanding challenges to achieve a clinically ideal preparation of the foramen. max, maximum; min, minimum.