A distinctive feature of the lower premolars is the 'inclination of the crown in the lingual direction.
Lower first premolar
It is the smallest premolar in the oral cavity. It belongs to the pillars of class II according to Voldrich.
The cusps are divided by an edge into a shorter, higher mesial part and a longer, higher distal part. The buccal tubercle is very sharp and points in a lingual direction. The lingual bump, on the other hand, is smaller and much lower.
There is only one root, oval or circular in shape.
The root canal is only one in 75 % of the cases and is oval in shape.
The pulp cavity is cylindrical and extends into the two corners of the pulp, the larger buccal and the smaller lingual.
Second lower premolar
It is generally the largest of all premolars. Its masticatory surface differs from the others in that it can exist in several forms (two-pronged, three-pronged and multi-pronged). It is a Voldrich class II pillar.
- SVOBODA, Otto. Dental propaedeutics : Textbook for medical schools. 1. edition. Avicenum, 1984. 392 pp.