Figure 4-1. - Stages in development of a tooth.
After the crown of the tooth has formed, the root begins to develop. Now the tooth begins to erupt (fig. 4-l), which is a movement of the tooth into its proper position in the mouth. For permanent teeth, it takes about 3 years from crown completion to the time the tooth emerges into the mouth. Figures 4-2 and 4-3 list the average emergence periods of primary and permanent teeth.
When primary teeth get ready to fall out and make way for the eruption of permanent teeth, they go through a process called exfoliation (shedding). The root of the primary tooth resorbs (looses structure) as the permanent tooth erupts from beneath. The primary teeth act as guides for the developing permanent teeth. The premature loss of primary teeth can have a serious impact on the eruption of permanent teeth and how they will be in position in the dental arch.
The Histology is the study of anatomy that deals with the minute structure, composition, and functions of tissues. Oral histology describes in detail the tissues of the teeth, periodontium, and the surrounding oral mucosa.Continue Reading