What is an odontogram?

Answer 1

An odontogram is a chart dentists use to document a patient's existing dental restorations and also to record planned dental restorations and treatment. The odontogram may be a drawing that closely approximates the appearance of actual teeth, or may be stylized and highly abstracted. The teeth are numbered on odontograms according to two major systems--the Universal System used primarily in the U.S., and the F.D.I. (Federation Dentaire Internationale) System used widely in Europe.

The Universal System begins numbering the adult teeth with the upper right third molar being tooth #1. The upper teeth are numbered consecutively around the arch to the upper left third molar, which is tooth #16. Then the numbering drops down to the lower arch and continues with the lower left third molar being #17 and continues, consecutively again, back around to the lower right third molar being tooth #32. The deciduous (baby) teeth are "numbered" with letters, starting with the upper right second deciduous molar being #A and continuing similarly to the adult teeth until we reach the lower right deciduous second molar, which is #T (humans normally have 20 deciduous teeth and 32 permanent teeth.)

The F.D.I. system uses a quadrant system of notation where we begin with the central incisors being teeth #x1 and count back to the third molars, which are teeth #x8. The number "x" indicates which quadrant the tooth is in--1 for the upper right quadrant, 2 for the upper left, 3 for the lower left and 4 for the lower right. Deciduous teeth are numbered by indicating quadrants 5,6,7, and 8, along with the individual tooth number.

So, in the Universal System, the adult upper right central incisor would be tooth #8, and the upper right deciduous central incisor would be tooth #E. In F.D.I. notation these same teeth would be #11 and #51.

There are many other tooth numbering systems still in use besides Universal and F.D.I.--in particular the Palmer System is often used by childrens dentists and orthodontists.

Similarly, there are many, many styles of odontograms in use. The individual dentist will choose the odontogram s/he is most comfortable with and which best suits his or her needs.

Choice of odontogram and numbering system can be an important issue in forensic dentistry (forensic odontolgy), where dental records are used to identify an unidentifed deceased person. A forensic dentist may receive dental charts and odontograms from a dentist using nonstandard numbering or an unusual type of odontogram, and proper interpretation of these records becomes very difficult.