Human Anatomy
- Maxillary first premolar
- Maxillary second premolar
- Mandibular first premolar
- Mandibular second premolar
- Premolar teeth are permanent teeth distal to the canines, preceded by deciduous molars.

Morphology
- Premolars have one large buccal cusp, especially in the mandibular first premolar.
- The lower second premolar usually has two lingual cusps.
- The lower premolars and the upper second premolar usually have one root.
- The upper first premolar usually has two roots, but can have just one or three roots.
- Premolars are referred to as bicuspid, with a buccal and a palatal/lingual cusp separated by a mesiodistal occlusal fissure.

Maxillary Premolars
- Maxillary First Premolar:
- Crown appears ovoid, wider buccally than palatally.
- Similar to adjacent canine from a buccal view.
- Roots: Two roots buccal and palatal, sometimes only one root.
- Maxillary Second Premolar:
- Similar to maxillary first premolar, but with rounder mesio-buccal and disto-buccal corners.
- Two cusps are smaller and more equal in size.
- Shorter occlusal fissure.
- Usually one root.

Mandibular Premolars
- Mandibular First Premolar:
- Smallest premolar out of all four.
- Dominant buccal cusp and a very small lingual cusp.
- Two-thirds of the buccal surface can be seen from the occlusal aspect.
- Single conical root with an oval/round cross-section, grooved longitudinally mesially and distally.

Orthodontics and Other Mammals
- Orthodontics:
- Four first premolars are the most commonly removed teeth in orthodontic treatment.
- Removal of only the maxillary first premolars is the second likeliest option.
- Premolar extraction therapy was initially contested in the orthodontic field.
- Patient reports of health consequences due to extraction/retraction have sparked debate.
- More orthodontists are now avoiding extraction therapy, with a current official rate of 25%.
- Other Mammals:
- Primitive placental mammals have four premolars per quadrant, but the most mesial two have been lost in catarrhines.
- Paleontologists refer to human premolars as Pm3 and Pm4.
- Weiss and Mann (1985) and Warwick and Williams (1973) provide further information on premolars in mammals.
- Standring (2015) discusses the anatomical basis of premolars in humans.
- Kimura et al. (2009) identify a genetic determinant of shovel-shaped incisors in humans.