 Hello everybody. Welcome back. Let's talk about the different classes of occlusion. The perfect class, the ideal is normal occlusion, which is class one. But sometimes you're going to have class two and class three. There's also going to be two different types of class two, which you don't see in this chart. But sometimes if the anterior teeth are protruded forward or sometimes they can actually be protruded the other way. So backwards, but that's kind of getting into it a little bit deeper. They don't often talk about those different categories on the board exam, but I'm mentioning it just in case you do see that and you know that but I'll kind of summarize that later. So basically class one, that's the normal class of occlusion that is what we strive for. So we look at the first molar, you will look at the mesial buckle cusp of the first molar that should be into the groove of the first molar on the bottom. The easiest way of thinking about it that's easy for me to think about that was always easy for me to memorize. You might have learned it a different way in school but that I feel is the easiest way. But we have class two. So I'm not going to pay attention to this one yet. What about we have class two you guys. The easiest way to think about this one is to again look at the first molar on the top. It's going to be more mesial to the first molar on the bottom. That's it. If you want to get more specific, think the mesial buckle cusp is mesial to the first molar on the bottom. That's another way of looking at it too but it sounds the same doesn't it. So look at normal occlusion up here and then you have class two over here. So then what is class three oh and I should mention so if the first molar is going to be more mesial. That means that the maxillary teeth in turn are more mesial to the mandibular and the and the front teeth are probably going to be protruded. Class three. This is the opposite where the first molar on the top is completely distal to the first molar on the bottom. Sometimes it's not the length of the whole tooth. It could be a little bit. But just remember if that first molar on the top is distal to the first molar on the bottom. That is class three. This is when the mandible teeth are forward to the maxillary teeth and that obviously shouldn't happen. The ideal is when the maxillary teeth overlap the mandibular teeth. There's no protrusions. None of that. So I'm not going to touch on overbite and over jet. I'm going to save that for another video. I just wanted to talk about the different classes of occlusion in this one. But something else that I wanted to make note is sometimes and that's what they have up here. They have something called class one malocclusion. This is where the first molars are are properly able to fit together, but the anterior teeth are starting to protrude. So that is something to make note as well. But then what I mentioned at the beginning was class two malocclusion. Sometimes the anterior teeth can protrude, but then other times they can go the other way back so there's different types. If you're not sure you guys rule of thumb is just look at the first molars. Don't even worry about the canines, the anteriors for now just looks at the first molars to see which class of occlusion they are in. Class one is the normal and the ideal. I hope this helps you guys. Let me know if any questions and I'll see you guys in the next one.