Deciduous teeth first teeth seen in the mouth are the mandibular centrals and the last are the maxillary second molars. The primary teeth are made up of central incisors, lateral incisors, canines, first molars, and secondary molars; there is one in each quadrant, making a total of four of each tooth. All of these are gradually replaced with a permanent counterpart except for the primary first and second molars; they are replaced by premolars. The replacement of primary teeth begins around age six, when the permanent teeth start to appear in the mouth, resulting in mixed dentition. The erupting permanent teeth cause
U Should've Known Better April 2004, and features rapper Young Buck appears in the video as her love interest. The video follows the single's topic of a misunderstandings in a relationship, showing Monica as the girlfriend, with the boyfriend held in a Mexico hold-prison. With Monica getting help from a guy friend, her boyfriend's best friend sees them and thinks otherwise. Monica drives through the desert of Mexico to get him out of prison. The video ends with Monica and her boyfriend hugging at the end and going home together. The "U Should've Known Better" video premiered worldwide in May 2004 at the end