Development of tooth is the complex process, involves formation of teeth from embryonic cells and starts growing slowly erupting into the mouth. For human to have a healthy oral environment, cementum, dentin, and the periodontium are the essentials that must develop during the stages of child tooth development.

Primary teeth of a baby will begin to form normally between the fifth and eighth weeks in utero and then permanent teeth will start to form during the twentieth week in utero. Moreover if teeth do not start developing at or near these times, then they will not develop at all. Significant amount of in-depth research has been carried out to determine the processes that primarily intiate development of tooth. It is accepted widely that there should be a factor within the tissues or the group of cells of the first branchial arch that is considered to be necessary for tooth development.

Tooth Bud

Tooth bud, otherwise called as tooth germ also is basically an aggregation of cells that forms the teeth. These aggregation of cells are derived from ectomesenchyme of neural crest and also derived from the ectoderm of first branchial arch.

This tooth bud is primarily organized into three organs. They are as

o Enamel Organ

o Dental Papilla

o Dental Follicle

Enamel organ is composed of inner enamel epithelium, outer enamel epithelium and stratum intermedium. All these cells gives rise to ameloblasts that normally produces reduced enamel epithelium and enamel. The location where the inner enamel epithelium and outer enamel epithelium join is called to be as cervical loop.

Growth of this cervical loop cells into the tissues forms hertwig’s epithelial rooth sheath, this sheath determines the root shape of the tooth.

Dental papilla normally has some cells that finally grows into odontoblasts which are dentin forming cells. To this the junction between the inner enamel epithelium and the dental papilla determines the tooth’s crown shape. Tooth pulp is formed as the result of mesenchymal cells which is present within dental papilla.

Another tooth bud organ is the Dental follicle which gives rise to three vital entities.
They are as osteoblasts, cementoblasts and fibroblasts. Tooth cementum is formed by the cementoblasts, osteoblasts give rise to a special bone called as alveolar bone around the teeth root. Last entity called fibroblast develops periodontal ligaments that connects alveolar bone to the teeth through cementum

Tooth Bud Development Stages

Child tooth development is divided into 4 major stages. They are as follows

o The Bud Stage

o The Cap Stage

o The Bell Stage

o The Crown Stage or Maturation Stage

Bud Stage

Bud stage is characterized by the tooth bud appearing without a clear arrangement of cells. This Bud Stage technically starts the epithelial ells proliferate into the jaw ectomesenchyme.

Cap Stage

Cap stage is the second stage in tooth bud development. During this Cap stage the first signs of the proper arrangement of cells in tooth bud occurs. Group of ectomesenchymal cells stops its production of other extracellular substances which generally results in aggregation of dental papilla cells. Here at this stage the tooth bud starts to grow around the ectomesenchymal aggregation taking cap appearance and becomes enamel dental organ. Enamel organ eventually produces enamel, and then the dental papilla produces pulp and dentin, finally the dental follicle produces the supporting tooth structure.

Bell Stage

Bell stage is generally known for the morphodifferentiation and histodifferentiation that takes place. During this stage the dental organ is bell shaped, the majority of its cells are called as stellate reticulam, this is because of their shape appear like a star. Other structures that appear in the tooth development in this stage are enamel cords, enamel knots, and enamel niche.

Crown Stage

During this next stage of tooth development hard tissues including dentin and enamel develops, this stage is called the maturation or the crown stage. Important cellular changes takes place at this time.

The development stage of tooth is an attempt to categorize major changes that takes place along the continuum at the same time it is difficult to make any kind of decision like what stage must be assigned to a particular developing of tooth. This child tooth development research is further complicated by the varying histologic sections and appearance of the developing tooth which can often appear to be in different stages.

By: Anant Kumar

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