premolaar

Premolaar is the Dutch term for the premolar, a tooth located between the canine and the molars in the permanent dentition. In humans, there are eight premolars: two on each side of the upper and lower jaws, consisting of the first and second premolars in each quadrant. They are sometimes called bicuspids because they typically have two cusps.

Anatomy and variation: Maxillary premolars usually have two cusps (buccal and palatal/lingual) and commonly two roots, though single-root forms occur. Mandibular premolars are more variable in root anatomy, often single-rooted, and can have two or three cusps, especially the second premolar. Crown size and cusp patterns vary among individuals, and some premolars exhibit additional or reduced cusps or unusual groove configurations.

Development and eruption: Premolars develop after the canines and typically replace the primary second molars in the dental arch. Eruption timing is variable but commonly places first premolars around ages 10–11 and second premolars around 11–12 years of age. The exact sequence can differ between individuals and jaws.

Function and occlusion: Premolars assist in chewing by tearing and grinding food, help maintain vertical dimension of the face, and contribute to efficient occlusal contacts. They play a role in guiding occlusion during jaw movements and in distributing biting forces.

Clinical relevance: Premolars are frequently involved in orthodontic treatment planning, including decisions about extractions to relieve crowding or adjust bite. They are common sites for caries and endodontic treatment due to their groove patterns and fissures. Variations such as agenesis (missing premolars), supernumerary premolars, and atypical cusp formations can influence diagnosis and treatment.