Tooth apex and periodontium

The region at the tip of each root is the apex and is penetrated by an apical foramen. The foramen provides for passage of blood vessels and nerves into the pulp cavity.

The region at the tip of each root is the apex and is penetrated by an apical foramen. The foramen provides for passage of blood vessels and nerves into the pulp cavity.

Cellular cementum is found at the apical 1/3 of the tooth root. This type of cementum contains cementocytes within the mineralized cementum and is produced throughout life in response to force or trauma. Cementocytes reside within lacunae and have thin protoplasmic processes that occupy narrow tunnels called canaliculi.

Lamellae are thicker bands of hypocalcified, cellular cementum that indicate areas where force or trauma induced new cementum deposition or remodeling. Lamellae are found only in cellular cementum and are most prominent at the apex of the tooth root.

The periodontal ligament surrounds the root of the tooth and anchors it into the socket.

The apical principal fibers of the periodontal ligament connect the cellular cementum at the apex of the tooth to the alveolar bone proper.

Alveolar bone forms the tooth socket and is the anchorage site for the periodontal ligament. Along with the cementum and periodontal ligament, the alveolar bone functions to anchor the tooth into the socket.

Dentin is deposited throughout life by odontoblasts that reside in the pulp. Dentin makes up the bulk of the hard tissue of the tooth and is 70% mineralized.

This image was taken of a slide from the University of Michigan slide collection.