Dentition mammals the infants have a set of teeth that fall out and are replaced by adult teeth. These are called deciduous teeth, primary teeth, baby teeth or milk teeth. Animals that have two sets of teeth, one followed by the other, are said to be diphyodont. Normally the dental formula for milk teeth is the same as for adult teeth except that the molars are missing. Because mammal teeth are specialised for different functions, many mammal groups have lost teeth not needed in their adaptation. Tooth form has also undergone evolutionary modification as a result of natural selection for specialised
U Should've Known Better successful on "Billboard"´s component charts. It reached number 6 on the Hot R&B/Hip-Hop Singles & Tracks—Monica's tenth non-consecutive top ten entry on that particular chart—as well as the top ten on the Hot R&B/Hip-Hop Airplay and the top twenty on the Hot 100 Airplay chart. It also appeared on the Rhythmic Top 40 at number 20. The song was ranked 72nd on the Hot R&B/Hip-Hop Singles 2004 year-end chart. The music video for "U Should've Known Better" was shot by director Benny Boom, and produced by Joyce Washington for FM Rocks. It was filmed in various locations throughout Mexico, in