Consider the following examples of two different types of statistical investigations. Example 1 Radio rating services sometimes collect data on listenership by asking participants to record the date, time, and station each time they listen to the radio.
Popular types of invisible braces include ceramic brackets, inside braces and clear aligners. Ceramic braces are just like metal braces, except that they use tooth-colored brackets (and sometimes tooth-colored wires) rather than metal to straighten teeth.
Dental braces are one way to fix misaligned teeth (although they are very visible which many patients do not like the idea of) and a newer treatment method which is become very popular is called Invisalign (which are almost invisible braces).