See also: The challenges confronting any new biometric modality
I suspect that any definable aspect of the human anatomy could be used as a biometric identifier — in instances where teeth are all that is known about an individual, they are used for high confidence identification — I'm afraid that, for the foreseeable future, the cards are stacked against any new biometric modality catching on in any big way.more at the link
The reasons for this are both scientific (research based) and economic (market based).
On the science side, a good biometric modality must be: unique, durable, and easily measurable. If any of these are missing, widespread use for ID management isn't in the cards. If something is unique and durable but isn't easily measurable, it can still be useful but it isn't going to become ubiquitous in automated (or semi-automated) technology. Teeth and DNA fit this model. Teeth have been used to determine the identity of dead bodies with a high degree of certainty for a long time, but we aren't going to be biting any sensors to get into our computers any time soon — or ever. Likewise with DNA.
There is also the challenge of proving that a modality is in fact unique, durable and easily measurable which requires a whole lot of experimental data and (especially regarding uniqueness) a healthy dose of statistical analysis.
