Surface letter annotation

[GoogleCodeExporter]

Currently, we are using long names as labels for the surfaces of teeth. For 
example:

"Distal surface enamel of tooth"
"Occlusal surface enamel of tooth"

It would be helpful to shorten these labels to their commonly used letters:

mesial -> m
occlusal -> o
distal -> d
lingual -> l
labial/facial - f

We already do something similar to this in our use of the annotation "ADA 
Universal Tooth Number". Should create a similar annotation for surface letters?

- Bill

Original issue reported on code.google.com by [email protected] on 24 Mar 2015 at 1:47