Dentinoenamel junction

The interface between the enamel and dentin in a tooth

Dentinoenamel junction

200px
Cross-section of a tooth showing the dentinoenamel junction
Latin	junctio dentinoenamelis
System	Teeth

The dentinoenamel junction (DEJ) is the boundary between the enamel and dentin layers of a tooth. It is a critical interface in tooth anatomy, playing a significant role in the structural integrity and function of teeth.

Structure

The dentinoenamel junction is a scalloped interface, which increases the surface area for the attachment of enamel to dentin. This scalloped pattern is more pronounced in the coronal region of the tooth, where the forces of mastication are greatest. The DEJ is formed during tooth development when the ameloblasts (enamel-forming cells) and odontoblasts (dentin-forming cells) interact.

Function

The primary function of the DEJ is to provide a strong bond between the enamel and dentin, which is essential for the tooth's ability to withstand the forces of chewing. The DEJ also acts as a barrier to prevent the propagation of cracks from the enamel into the dentin, thereby protecting the pulp chamber from potential damage.

Development

The formation of the DEJ occurs during the tooth development process. It begins with the differentiation of odontoblasts from the dental papilla, which start to lay down the dentin matrix. Subsequently, ameloblasts differentiate from the inner enamel epithelium and begin to secrete enamel matrix. The interaction between these two cell types at the DEJ is crucial for the proper formation of both enamel and dentin.

Clinical significance

The integrity of the DEJ is vital for the overall health of the tooth. Any disruption or weakening of this junction can lead to dental problems such as dental caries or tooth fracture. Understanding the properties of the DEJ is important for the development of dental restorative materials and techniques.

Also see

• Enamel
• Dentin
• Tooth development
• Dental caries
• Tooth anatomy