First premolar variations in number of roots, root canals and tooth length

Knowledge of external and internal morphology of the teeth is very important for members of all branches of dental practice. In conservative dentistry knowing external morphological characteristics of dental crowns is significantly because of tendency of certain tooth groups for decay and successful restoration in functional and aesthetic sense. Successful endodontic treatment is impossible without knowing the number and position of the root and root canals inside of them. The variability of the morphology of the human body includes teeth too. Internal morphology features can be analyzed in details only on extracted teeth. In this study, extracted first premolars were analyzed, fifty eight of upper jaw and sixty four of lower jaw. Statistical analysis showed that the average length of the upper first premolar is 21.05 mm and for lower 20.65mm. The upper first premolars usually have two roots. The most common number of channels in the upper first premolar is two. All observed lower first premolars have one root, and in most cases a single channel. The upper first premolar has a higher degree of variation of characters, from the bottom.