There are certain times when your dentist may recommend removing a tooth. A baby tooth could have contorted roots that prevent it from falling out, or your tooth could possibly be so decayed that the surrounding teeth are at risk and needs to be replaced by a dental bridge or implant. Orthodontic procedures, infection, or wisdom teeth could also require that a tooth is removed.
When your dentist determines a tooth needs to be removed, he could remove it during your regular checkup, or if more complicated could schedule another appointment for the procedure. Within your jawbone there are "tooth sockets", in these tooth sockets the rooth of your teeth are held in by ligaments. In order to extract a tooth, your dentist will expand the socket and seperate the tooth from the ligament that held it in place. The extraction process is generally very quick however, if you would like to discuss sedation please let you doctor know.
When a tooth is extracted, surrounding teeth can shift, causing issues with chewing or your jaw joint function. In order to avoid these complications your dentist may suggest replacing the extracted tooth.