thumb|left|upright|The Universal Numbering System for adult human teeth, used in the USA. The view is from a dental practitioner's perspective, meaning tooth 1 is the upper right rear (third) molar. Most countries use the FDI numbering system.
thumb|left|upright|The Universal Numbering System for adult human teeth, used in the USA. The view is from a dental practitioner's perspective meaning tooth 1 is the upper right rear (third) mol,ar. Most countries use the FDI numbering system.