Final answer:
The reduced enamel epithelium is lost at the time a tooth erupts, allowing the enamel to emerge and become functional as the tooth breaks through the gum line. This occurs typically during middle childhood when permanent teeth are emerging and deciduous teeth are shed.
Step-by-step explanation:
The reduced enamel epithelium is lost when a tooth erupts and makes contact with the oral cavity. This specialized epithelium covers the developing tooth and plays a role in protecting the enamel organ. However, during eruption, the tissue disintegrates and is shed as the tooth breaks through the gum line, thereby making space for the enamel to emerge and become functional. Reduced enamel epithelium is responsible for forming the initial junction between the tooth and oral soft tissue; its loss allows for the establishment of the gingival epithelium.
In the context of dental development, the permanent teeth generally begin to emerge during middle childhood, with the first permanent molars typically appearing around the ages of 6 to 7. The deciduous, or baby teeth, are shed during this time to allow the eruption of permanent teeth. The reduced enamel epithelium is an essential part of this process, aiding in protecting the developing permanent tooth until it is ready to erupt and take over the function of the deciduous tooth.