← All explanationsTooth gemination

Can one developing tooth produce a double crown?

In tooth gemination, one developing tooth attempts to divide. This may produce a broad crown that appears split. The tooth count is often normal when the double crown is counted as one, but further findings are needed to distinguish fusion.

For training & practice ↓

Teaching model of a broad, notched incisor crown above a single root. — Possible form of gemination. The notch is developmental; internal anatomy is not depicted.

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One origin, divided shape

The change forms before eruption. A visible notch does not mean a finished tooth is currently breaking apart.

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Assess internal form

Crown, root and canal anatomy are assessed together where necessary. A teaching image shows only one possible variant.

03 / 03

Cleaning and space

A groove or broad crown can affect cleaning or space. Treatment depends on its actual consequences.

Read the full explanation

One origin, divided shape
The change forms before eruption. A visible notch does not mean a finished tooth is currently breaking apart.
Assess internal form
Crown, root and canal anatomy are assessed together where necessary. A teaching image shows only one possible variant.
Cleaning and space
A groove or broad crown can affect cleaning or space. Treatment depends on its actual consequences.

Notes on the teaching images

Possible form of gemination. The notch is developmental; internal anatomy is not depicted.

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Watch the short explanation ↓

At a glance

Timing?

During tooth development.

Tooth count?

Often normal, but not a stand-alone diagnostic test.

Planning?

Consider grooves, space and internal anatomy.

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 as text.

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Often confused

Gemination versus fusion

Gemination starts with one developing tooth; fusion with two. The double-crown appearance alone does not reliably distinguish them.

Quick answers

Can a photograph reliably show gemination?

No. Fusion and other variations may look similar.

Must the double tooth be separated?

Not automatically. Internal anatomy and potential harm must be considered before intervention.

Can it affect a primary tooth?

Yes. Eruption and the permanent successor are also considered.

At the practice

For a personal discussion

Editorially suggested question to discuss with Dr Niusha Barahmand Pour:

Which variation is present, and how does it affect care and eruption?

An unusually divided crown can be assessed to determine whether cleaning advice or further measures would help.

Have a double crown assessedAppointment selection at Doctolib

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Learning layer for training & practiceUnderstand terminology and deepen knowledge

Gemination: Attempted division of one developing tooth.
Tooth germ: The early developing structure of a tooth.
Crown notch: An indentation found in some double crowns.

Make the distinction

Gemination starts with one developing tooth; fusion with two. The double-crown appearance alone does not reliably distinguish them.

Knowledge questionWhich statement fits gemination?

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

One tooth germ attempts to divide.
Two finished teeth stick together while eating.
It is always a recent fracture.

View answer

One tooth germ attempts to divide.

The variation develops during tooth formation.

Sources and context

Editorial research: 2026-11-06. General information, not an individual diagnosis or treatment recommendation. Teaching illustrations are simplified and do not depict a patient case.