What is a molar – and can it be a baby tooth?

A molar is a large back tooth with a broad chewing surface and several cusps. It breaks down food at the back of the mouth. Both primary and permanent dentitions contain molars. The first permanent molars erupt behind the primary molars rather than replacing a baby tooth in that position.

For training & practice ↓

Model molar chewing surface with cusps and natural grooves. — Simplified teaching illustration · not a patient case or treatment outcome

01 / 03

A broad chewing surface

Several cusps and the grooves between them form the chewing surface. This differs from the cutting edge of an incisor.

02 / 03

Back teeth are not all the same

Premolars are smaller back teeth; molars are larger ones. Permanent molars sit behind the premolars. Wisdom teeth are third molars.

03 / 03

Look carefully during tooth replacement

A first permanent molar may already be present while baby teeth remain in front. Primary molars are later replaced by premolars.

Watch the short explanation ↓

At a glance

What does it do?

It breaks down food using a broad chewing surface.

What matters in children?

Recognising and cleaning permanent molars even while baby teeth are still present.

How is an unusual chewing surface assessed?

By examination; a dark mark alone is not a diagnosis.

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

A broad chewing surface
Several cusps and the grooves between them form the chewing surface. This differs from the cutting edge of an incisor.
Back teeth are not all the same
Premolars are smaller back teeth; molars are larger ones. Permanent molars sit behind the premolars. Wisdom teeth are third molars.
Look carefully during tooth replacement
A first permanent molar may already be present while baby teeth remain in front. Primary molars are later replaced by premolars.

Often confused

Molar or premolar?

Both are back teeth. A premolar is a smaller back tooth and a molar a larger one. Primary molars are not simply smaller permanent molars.

Quick answers

How many roots does a molar have?

Usually several. Upper molars commonly have three roots and lower molars commonly have two. Variations occur, and the number of root canals is not automatically the same as the number of roots.

Is the first new back tooth a baby tooth?

A first permanent molar usually erupts behind the primary tooth row without a baby tooth falling out there. This is why it can be mistaken for a baby tooth.

Does a dark fissure mean decay?

Not necessarily. An examination is needed to distinguish staining from a carious change.

At the practice

For a personal conversation

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

Which back teeth are already permanent, and what matters when cleaning them?

A newly erupted back tooth or an unusual chewing surface is worth checking.

Have a back tooth checkedAppointment selection at Doctolib

Meet Dr. Niusha Barahmand Pour ↗

Learning layer for training & practiceUnderstand terminology and deepen knowledge

Cusp: A raised part of the chewing surface.
Fissure: A groove between cusps on a chewing surface.
Furcation: The area where the roots of a multi-rooted tooth divide.

Make the distinction

Both are back teeth. A premolar is a smaller back tooth and a molar a larger one. Primary molars are not simply smaller permanent molars.

Knowledge questionWhich statement describes a first permanent molar?

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

It replaces a central incisor
It erupts behind the primary molars
It is always a wisdom tooth

View answer

It erupts behind the primary molars

The first permanent molar extends the row behind the primary molars.

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.