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I, Glenn Bowie, used teeth mentioned above in teaching a geology class to elementary school children in 2005. During March 2009, I read online texts and examined images in websites devoted to equus occidentalis paleogeology, to equine dentistry, and veterinary science.
An Intel Model CS430 webcam was used on March 30 to obtain seven images of upper left pm2.
      
On March 31, an Intel Play QX3 microscope backed by modern qx3plus software was used at magnifications 10, 60, and 200X. I focussed on material attached to a root. One patch is clearly jawbone remnant. The other consists of fibres and particles of silica. The horse was digesting windblown sand or loess when he perished.
He became extinct at the close of the most recent Ice Age.
  
In order to show how well the three premolars can be fitted together, let me use putty to separate them, and then remove the spaceing material.
 
 
 
 
 
It is time to look more carefully at the three upper left molars. The focus will be on m1. 
Until this point, I have refrained from using language to describe teeth details. I was trained in engineering and earth sciences. I am completely dumb about biological sciences.
However, I must be willing to accept the fact that I am going to be wrong at times. My online geology class has an image in which grains of loess are clearly evident. The following image looks down at a particular part of the crown of molar m1 where some rounded silica sand grains can be seen amongst other material. They are loess.
Think of the crown of m1 as being approximately 2.5 cm square. Imagine m1 as being in your own upper left jaw. The foreground face of m1 is shown in the next image. The right side can be felt by your tongue. Your left cheek can feel the left tooth edge. Examine the foreground valley. The crown edge is sharp. It can scratch my left thumbnail. If I hold a dentists' pick rather than m1 in my right hand, I can see by scratching the nail that the tooth sharp enamel edge and the pick have Mohs hardness 6. The material surounding cusps in the crown is dentin, or dentine. When the pick is used as shown the dentin is seen to be relatively soft, perhaps due to decomposition. A root image follows. The cement, or cementum, hardness is comparable to enamel hardness.
The following five images show root region details. I would like to discuss them with you.
We are at the rostral corner of the crown's lingual edge.
They are indistinct, but there are sharp promontories along the lingual edge. Are they hooks?
The caudal corner is rounded and has a facet.
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