Professional lingo can be confusing to the non professional. I cannot understand lawyer talk. I have signed so many contracts and loan that I do not understand at all. Dental talk can be confusing also, but at least there are only 20 primary teeth and 32 secondary (adult) teeth. It took a long time at Columbia University School of Dental and Oral Surgery for me to learn dental lingo, two years actually. The tooth identification system used in the United States of America uses letters for the twenty primary and thirty two secondary teeth, stating in the upper right back with A and 1 respectively. Tooth #1 is an upper right wisdom tooth or third molar. Tooth #3 is identified in this schematic. Tooth #3 is the upper right first molar, a very key and important tooth. Our first molars typically erupt at the age of 6, the very first secondary tooth to enter our oral cavity. It usually has the most complicated root system and is usually the first tooth lost due to periodontal disease.