Deciduous teeth Deciduous teeth Deciduous teeth, commonly known as milk teeth, baby teeth and temporary teeth, are the first set of teeth in the growth development of humans and other diphyodont mammals. They develop during the embryonic stage of development and erupt—that is, they become visible in the mouth—during infancy. They are usually lost and replaced by permanent teeth, but in the absence of permanent replacements, they can remain functional for many years. Primary teeth start to form during the embryo phase of human life. The development of primary teeth starts at the sixth week of tooth development as the dental lamina.
I Should Have Known Better solo) and thus draws a line under a significant period of their early music. The song's middle sixteen section features George Harrison's brand new Rickenbacker 360/12 12-string guitar. The mono and stereo versions have slightly different harmonica introductions. In the stereo version, the harmonica drops out briefly. Also, a noticeably clumsy and audible tape edit is heard during the second chorus between "You're gonna say you love me too, oh," and "And when I ask you to be mine." In the UK, "I Should Have Known Better" appeared on "A Hard Day's Night" and was released on 10 July 1964.