How To Number Supernumerary Teeth
This follows the "Universal/National" system that is commonly used in the U.S.
This system is identified as code set "JP" on dental claim forms and on HIPAA standard electronic dental claim transactions.
Simply put, 50 is added to the tooth number that is closest to the supernumerary tooth.
Simply put, the letter "S" is added to the tooth number that is closest to the supernumerary tooth.
Source: "Current Dental Terminology, CDT 2009 - 2010", American Dental Association
Further details can be found in the CDT manual.
See also ANSI/ADA/ISO Specification No. 3950 page.