Embryology · Skeleton, muscles, limbs and skin

Teeth !

Embryonic structure

Each tooth comes from a dialogue between the lining of the mouth, which makes enamel, and neural crest cells, which make dentin and pulp.

Updated 2026-11-01

See it in 3D: Mandible · Maxillae · Upper right central incisor · Upper right first molar · Lower left central incisor · Gums (gingiva)

What it is

Teeth form through an interaction between the oral epithelium (ectoderm) and neural crest mesenchyme. From week 6 the dental lamina buds and passes through the bud, cap and bell stages. Enamel is the only ectodermal part; dentin, pulp, cementum and the periodontal ligament come from neural crest.

Key facts

Week 6: the basal layer of the oral epithelium forms a C-shaped dental lamina along each jaw.
Stages: bud → cap → bell.
Third month: buds of the permanent teeth appear, lingual to the milk teeth; they stay dormant until about age 6.
Eruption of the milk teeth (20): between 6 and 24 months of life.
The enamel knot is a signalling centre that shapes the crown.
HOX genes in the mesenchyme decide whether a tooth will be an incisor or a molar.

Structure

Enamel organ (ectoderm): inner dental epithelium, stellate reticulum and outer epithelium.
Ameloblasts (inner dental epithelium): lay down enamel.
Dental papilla (neural crest): odontoblasts that make dentin, then the pulp.
Dental sac (neural crest): cementoblasts (cementum) and periodontal ligament.
Epithelial root sheath: guides the shape of the root.

What it becomes

Enamel: the hardest layer, over the crown; ameloblasts disappear after eruption and enamel cannot be repaired.
Dentin: made by odontoblasts throughout the life of the tooth.
Cementum and periodontal ligament: anchor the root in its socket and cushion chewing.
Pulp: vessels and nerves inside the root canal.

Markers

RUNX2
EDA
PAX9
MSX1
BMP4
SHH

Clinical notes

Tetracyclines in pregnancy or early childhood stain the teeth permanently.
Cleidocranial dysplasia (RUNX2): extra teeth and late eruption of the permanent set.
Hypohidrotic ectodermal dysplasia: missing or peg-shaped teeth.
Natal teeth: present at birth, usually lower incisors with little enamel.
Amelogenesis imperfecta (enamel) and dentinogenesis imperfecta (dentin, sometimes with osteogenesis imperfecta).

Test yourself

Think of the answer, then tap the question to see it.

Which part of the tooth is of ectodermal origin?

The enamel, laid down by ameloblasts of the inner dental epithelium.

Which cells form dentin, and where do they come from?

Odontoblasts, which derive from the dental papilla, a neural crest mesenchyme.

In which week does the dental lamina appear?

Around week 6, as a C-shaped band of oral epithelium along each jaw.

Which antibiotic group is linked to permanent tooth staining?

The tetracyclines, which are deposited in teeth that are calcifying.

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See it in 3D

The structures of Durgical's 3D anatomy where it is found.

← All of embryology

Educational content on embryonic development; not a guide to prenatal diagnosis or to medicines in pregnancy and no substitute for a health professional's advice. No doses are given.

Sources: Cleidocranial dysplasia: MedlinePlus Genetics (MedlinePlus, US National Library of Medicine, 2026); Hypohidrotic ectodermal dysplasia: MedlinePlus Genetics (MedlinePlus, US National Library of Medicine, 2026); Langman's Medical Embryology, 13th ed., ch. 17: Head and Neck (Wolters Kluwer, 2015).

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Representative model, for educational purposes only.