← All explanationsPremolar

Which tooth is a premolar, and how many roots does it have?

Premolars are the smaller posterior teeth between the canines and the molars. A complete permanent dentition usually has eight, two in each quarter of the mouth. Their chewing surfaces help break down food. Root number is not identical in every premolar.

For training & practice ↓

Anatomical educational model of a lower premolar with one root, gum and alveolar bone. — Lower premolar with one root · simplified model; individual anatomy varies

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Find it in the tooth row

Counting from the midline, premolars are the fourth and fifth teeth. They belong to the permanent dentition. There are no premolars in the primary dentition; primary molars occupy their future positions.

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Look at the shape

The crown has a chewing surface with cusps. Lower premolars usually have one root. Upper premolars, especially the first ones, may have one or more roots, and individual variations occur.

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Separate roots from canals

A root can contain one or more canals. Seeing one root therefore does not automatically mean there is only one root canal. Treatment relies on the individual anatomy assessed clinically.

Watch the short explanation ↓

At a glance

Who is this for?

Patients discussing findings and dental trainees learning tooth types.

How is the position identified?

As the fourth or fifth tooth from the midline in a permanent tooth row.

Which example will be shown?

An explicitly labelled lower premolar with one root; variations are explained separately.

Knowledge in motion

Explained in 36 seconds.

Three steps. No audio.
Each scene can also be selected manually.

Silent educational film with German on-screen text and simplified teaching images. Not a patient case or a promised treatment outcome. The full English explanation is available below.

Read the film text in English

Find it in the tooth row
Counting from the midline, premolars are the fourth and fifth teeth. They belong to the permanent dentition. There are no premolars in the primary dentition; primary molars occupy their future positions.
Look at the shape
The crown has a chewing surface with cusps. Lower premolars usually have one root. Upper premolars, especially the first ones, may have one or more roots, and individual variations occur.
Separate roots from canals
A root can contain one or more canals. Seeing one root therefore does not automatically mean there is only one root canal. Treatment relies on the individual anatomy assessed clinically.

Often confused

Premolar or molar?

Premolars are the smaller posterior teeth in front of the molars. Molars are the larger teeth further back. Size, chewing surfaces and root anatomy differ, with individual variation.

Quick answers

Is a premolar a baby tooth?

No. Premolars belong to the permanent tooth row. During tooth replacement they succeed the primary molars, while permanent molars erupt further back.

Does every premolar have two roots?

No. Many are single-rooted, particularly lower premolars. Upper first premolars show more varied root forms. Showing every premolar with two roots would be misleading.

Why does its exact shape matter?

Root canal treatment, extraction and other planning need to account for anatomy and possible variations. An educational graphic does not replace an individual examination.

At the practice

For a personal discussion

An editorially suggested question for a discussion with Dr med dent Niusha Barahmand Pour:

Which tooth does my finding refer to, and are there anatomical features that matter for the planned treatment?

Unsure which tooth your findings refer to? An appointment can clarify its position using the dental chart.

Discuss a dental findingAppointment selection at Doctolib

Meet Dr. Niusha Barahmand Pour ↗

Learning layer for training & practiceUnderstand terminology and deepen knowledge

Premolar: A small permanent posterior tooth at the fourth or fifth position from the midline.
Molar: A larger posterior tooth behind the premolars.
Root canal: An internal space inside a root; canal number need not equal root number.

Make the distinction

Premolars are the smaller posterior teeth in front of the molars. Molars are the larger teeth further back. Size, chewing surfaces and root anatomy differ, with individual variation.

Knowledge questionWhich statement is correct?

For learning, not for assessing personal symptoms. Your answer is not stored or sent.

All premolars have two roots.
One root can contain more than one canal.
The primary dentition contains eight premolars.

View answer

One root can contain more than one canal.

External root form and the internal canal system are different anatomical features.

Sources and context

Editorial research: 2026-11-02. General information, not an individual diagnosis or treatment recommendation. Teaching illustrations are simplified and do not depict a patient case.