Abstract
The aim of this study was to investigate the size, shape and position of the physiological foramen and the relationship between the age and gender to the location and size of the apical foramen of mandibular first premolars. One hundred and one extracted human mandibular first premolar teeth were examined; age and gender of the patients were recorded. Apices of teeth were examined stereomicroscopically for number, size and shape of apical foramina; frequency and deviation of accessory foramina from the apex and the relation with age and gender. Sixty-four of the premolars had one foramen and 23% had two. The distances from the foramina openings to the apices ranged from 0.07 to 2.18 mm. In younger range irregular shape was dominant (41%), whilst in older range, round shape was dominant (45%). The shape of the apical foramen changed with age and the distance from the foramen to the anatomical apex increased with age.