Periodontal Ligament: fibrous tooth to periodontium ligament

Periodontal Ligament: fibrous tooth to periodontium ligament

Periodontal ligament is the soft, richly vascular and cellular connective tissue which surrounds the roots of teeth and joins the root cementum with the socket wall.

It is estimated that the periodontal ligament is nearly 70% water. It is also thought to have a significant impact on the strength of the tooth and its ability to withstand high levels of stress. The completeness and vitality of the periodontal ligament are critical components of a functional tooth.

In most cases, the periodontal ligament ranges from about 0.15 to 0.38mm wide. The thinnest part of the periodontal ligament is located in the middle third of the root. The periodontal ligament’s width reduces over time as the patient ages.

The periodontal ligament (desmodontium) is a fibrous joint (syndesmosis) that suspends the root of each tooth in its alveolar bone socket.

The periodontal ligament fibers are anchored in auch a way that each tooth is capable of small movements in its alveolar socket. The periodontal ligament holds the teeth in sprung suspension, within the socket.

Periodontal ligament is composed of soft complex vascular and highly cellular connective tissue that surrounds the tooth roots and connects to the inner wall of the alveolar bone.

Collagen fibers of the periodontal ligament, or Sharpey fibers, are woven into the cementum of the tooth on the one hand, and into the periosteum and the substance of the alveolar bone on the other.

Narrow space - the periodontal space (RP) separates the roots of the teeth from the alveolar bone. This space is crossed by strong collagen fibers of the periodontal ligament and a number of preelastic, or oxytalan, fibers.

In addition, this space contains a certain amount of loose connective tissue, in which the lymphatic and blood vessels (CS) are located, and nerve fibers go from the alveolar bone through its openings.

Periodontal ligament supplies nutrients to the cementum , bone, and gingiva by way of blood vessels and provides lymphatic drainage. Rich vascular plexus at apex & in the cervical part of the ligament.

The principal function of the periodontal ligament is to connect the tooth to the jaw, which it must do in such a way that the tooth will withstand the considerable forces of mastication.

This requirement is met by the masses of collagen fiber bundles that span the distance between the bone and the tooth and by ground substance between them.

At one extremity the fibers of the periodontal ligament are embedded in bone; at the other extremity the collagen fiber bundles are embedded in cementum. Each collagen fiber bundle is much like a spliced rope in which individual strands can be remodeled continually without the overall fiber losing its architecture and function. In this way the collagen fiber bundles can adapt to the stresses placed on them.

The periodontal ligament has another important function, a sensory one. Tooth enamel is an inert tissue and therefore insensitive, yet the moment teeth come into contact with each other, we know it. Part of this sense of discrimination is provided by sensory receptors within the periodontal ligament.

The periodontal ligament has been proposed as a niche of neural crest stem cells (Coura et al., 2008). In 2004, Seo and colleagues successfully isolated multipotent stem cells from periodontal ligament of human third molars and proved that they have multilineage differentiation capacity.

Periodontal ligament provides the most efficient proprioceptive mechanism. The nerves there transmit proprioceptive information via the periodontal ligaments, enabling the teeth to use the periodontal ligaments to adapt to the prevailing forces and to reposition themselves to a limited extent.

Fusion of alveolar bone and cementum with obliteration of the periodontal ligament is termed Ankylosis.


References

Den Tim


Practicing Dentistry for 20 years