Ameloblast Ameloblast Ameloblasts are cells present only during tooth development that deposit tooth enamel, which is the hard outermost layer of the tooth forming the surface of the crown. Each ameloblast is a columnar cell approximately 4 micrometers in diameter, 40 micrometers in length and is hexagonal in cross section. The secretory end of the ameloblast ends in a six-sided pyramid-like projection known as the Tomes' process. The angulation of the Tomes' process is significant in the orientation of enamel rods, the basic unit of tooth enamel.Distal terminal bars are junctional complexes that separate the Tomes' processes from ameloblast proper. Ameloblasts
Human tooth mixed stage. The mixed stage lasts until the last primary tooth is lost and the remaining permanent teeth erupt into the mouth. There have been many theories about the cause of tooth eruption. One theory proposes that the developing root of a tooth pushes it into the mouth. Another, known as the cushioned hammock theory, resulted from microscopic study of teeth, which was thought to show a ligament around the root. It was later discovered that the "ligament" was merely an artifact created in the process of preparing the slide. Currently, the most widely held belief is that the periodontal