Search results
Results from the WOW.Com Content Network
The dental follicle, also known as dental sac, is made up of mesenchymal cells and fibres surrounding the enamel organ and dental papilla of a developing tooth. [1] It is a vascular fibrous sac [2] containing the developing tooth and its odontogenic organ. The dental follicle (DF) differentiates into the periodontal ligament.
A condensation of ectomesenchymal cells called the dental sac or follicle surrounds the enamel organ and limits the dental papilla. Eventually, the enamel organ will produce enamel, the dental papilla will produce dentin and pulp, and the dental sac will produce all the supporting structures of a tooth, the periodontium. [1]
The sheath is also responsible for multiple or accessory roots (medial growth) and lateral or accessory canals in the root (break in epithelium). [3] It is controversial, but HERS may be involved in cementogenesis and the secreting of cementum, or that HERS-derived products might be related to enamel-related molecules, and that these proteins might initiate acellular cementum formation.
(1) The HERS, (2) epithelial rests of Malassez, (3) dental follicle, (4) cementoblasts, (5) periodontal ligament, (6) alveolar cells, (7) bone, (8) odontoblasts. In dentistry, the epithelial cell rests of Malassez (ERM) or epithelial rests of Malassez (pax epithelialis pediodontii) are part of the periodontal ligament cells around a tooth.
Tooth development begins at week 6 in utero, in the oral epithelium. The process is divided into three stages: Initiation; Morphogenesis and; Histogenesis [2]; At the end of week 7 i.u., localised proliferations of cells in the dental laminae form round and oval swellings known as tooth buds, which will eventually develop into mesenchymal cells and surround the enamel organ.
The dental follicle → The ectomesenchymal cells which are part of the fibrous sac that have been formed; The dental papilla → The ectomesenchymal cells which are lying deep to the enamel organ; The enamel organ → purely the epithelial component; The tissues which have been derived from each of the three components are:
These cells are star-shaped (hence stellate) and synthesize glycosaminoglycans. As glycosaminoglycans are produced, water is drawn in between the cells, stretching them apart. As they are moved further away from one another, the stellate reticular cells maintain contact with one another through desmosomes , resulting in their unique appearance.
It is thought that the central epithelial tissue of the cervical loop, the stellate reticulum, acts as a stem cell reservoir. In continuously growing teeth such as the rodent incisor the original structure of the cervical loop is maintained and no HERS forms. The stem cells provide the epithelial progeny to sustain the continuous growth.