Alpaca teeth are actually only on their bottom jaw. On top they have a hard pad where they mash their hay up against.
I was not able to get a good picture of this myself but found several pictures on-line that give a good visual of what I am talking about:
This picture shows the alpacas mouth, with nice trimmed teeth. The teeth come out of the alpaca's bottom jaw, and there is a pink/grey pad for the top jaw. They rip off hay there, and then mash the hay in the back of their mouth.
I found that picture on a wonderful blog with a post about trimming teeth - you can find that here. It's a great write up.
Here's another picture I found:
In that picture (link to where I found that picture) the people are holding the alpaca's lips back, the teeth come out of the alpacas lower jaw, with a black/pink pad on the top jaw. Further back, the blue and green arrows point to fighting teeth. Typically only males have fighting teeth (though sometimes females will have them also) and they are for exactly what you'd think - fighting. Out on the range in their native lands of South America where alpacas roam (not kept inside fences like they are in the United States), males will fight for hierarchy and left to their own defenses, males use their fighting teeth to try to castrate each other. Boys!?! Right :) Well, it is survival of the fittest out there. Here on our farm we trim back fighting teeth so there is no on farm castration (at least not by the alpacas). They do wrestle and fight some but without fighting teeth to cause damage. We also house our boys some distance from the females (just the smell and sight of females will cause males to fight more - fight over who can get to those pretty girls first).
This is our alpaca dentistry kit:
This is an alpaca tooth-o-matic (I don't sell them but you can do a quick google search if you'd like to purchase one). Like all tools it can be used incorrectly and cause serious problems. While alpaca teeth can grow long, it also can happen that people trim their teeth too low and open up their pulp cavity which could result in their losing their teeth. As with any tool, it is essential that it is used correctly. At first we were scared of the tooth-o-matic due to hearing some horror stories. We started out using a dremel instead. However, I have problems with my joints and J has back issues, the shear mechanics of holding an adult alpaca still long enough to dremel was not possible for us. We decided for our alpaca's health and our own safety we needed the tooth-o-matic.
The tooth-o-matic works by putting the light orange part (far right) into the alpaca's mouth, then turn on the rotating circular saw, zip in and out and it cuts off the top of the teeth in seconds. I can hold them for seconds :)
For the little ones and even older alpacas who only need a little trim we do use a dremel:
We decide which tool to use based on what the alpaca's needs are, and what we can manage the easiest in order to get them what they need.
Some alpaca farmers choose to trim teeth with OB wire. We haven't chosen to do it this way because it also takes some time which leaves me holding an alpaca still longer than I really can. It is a safe and effective way to do it.
Here is a video that shows using an OB wire then a dremel: link to video.
Here is using a dremel: link to video.
And here they are finishing up shearing then do a quick cut with the Tooth-o-matic: link to video.
We don't do it exactly like that, we actually have the alpaca strapped down for shearing and keep them with their head on the ground while using the tooth-o-matic or dremel. However, this gives the idea of what it's like. And you can see how the tooth-o-matic is so much quicker than the other methods.