Human tooth development inner enamel epithelium) What follows is part of the initial 'enamel organ', the center of which is made up of stellate reticulum cells that serve to protect the enamel organ. This is all encased by the OEE layer. Other events occur during the bell stage. The dental lamina disintegrates, leaving the developing teeth completely separated from the epithelium of the oral cavity; the two will not join again until the final eruption of the tooth into the mouth. The crown of the tooth, which is influenced by the shape of the inner enamel epithelium, also takes shape during this stage.
Human tooth discoloration may occur with alkaptonuria and rarely with Parkinson's disease. Erythroblastosis fetalis and biliary atresia are diseases which may cause teeth to appear green from the deposition of biliverdin. Also, trauma may change a tooth to a pink, yellow, or dark gray color. Pink and red discolorations are also associated in patients with lepromatous leprosy. Some medications, such as tetracycline antibiotics, may become incorporated into the structure of a tooth, causing intrinsic staining of the teeth. Tooth eruption may be altered by some environmental factors. When eruption is prematurely stopped, the tooth is said to be impacted. The most common