all right let's move on to the periodontal ligament fibers so to recap there are four tissues that make up the periodontium or four things that surround the toot we looked at the gums which is the the gingiva we looked at let's scroll up so you can see what we looked at so we looked at the junk with the gums now what we're going to look at is the paired onto ligament fibers which is the black line that you see surrounding the tooth also then look at the cementum and then the bone those are the four tissues that make up the periodontitis those are the four things that surround the toot and the four things that we really need to concentrate on that's going to make up our whole period of course so when we're looking at a picture of a cheat we see that um here's a toot and we can see these black lines that are over here the black lines are your periodontal ligament fibers and for this class and for this lecture i just want you to know um what it looks like and so i'm going to zoom in to this area over here and when you zoom in over here you'll notice that on one side the paired onto ligament fiber is attached to the cementum which is over here and on the other side it's attached to the bone which is over here so the periodontal ligament fibers are just lines like this this kind of connective tissue lines that attach to the root on one side or the cementum should be more precise on one side and the bone on the other side now what i want you guys to know is that the end okay so the endings of the periodontal ligament fibers they have a fancy name and that fancy name is called sharpies okay so that's just the name of the ending of the or the very end of the periodontal ligament fibers they're known as sharpies fibers okay let's talk about the cementum so this momentum is maybe i'll try it over here so here we have here we have a root and the cementum basically covers the entire root okay so the cementum covers the entire roots if i have to color in the entire root that brown color that we're looking at is the cementum it's kind of like a hard layer it's um attached to the dentin but it's softer than the dentin or enamel so remember we have the enamel and then on the inside of the enamel we have dentin um so it's attached to the dentin is you know um sticking to the dentin that's very soft and if you remember so if we look at the dentin so we have the in we have the enamel okay and then we have the root and then we have a dentin which is in between and so what i want you guys to know is that the thyroid is a dentin the dentin has tubules okay so this is and it's got lots of holes and what this mention does let's see if i can draw the cementum here the cementum kind of covers the entire dentinal tubules what covers those those holes that are in the dentin and what's really cool about that is that if the holes or the tubules was not covered by cementum you would feel a lot of sensitivity so it's so great to have cementum there because the cementum covers the tubules so that you don't feel sensitivity okay so cement is really cool um you know when we're when we're deep riding we don't want to aggressively take off the cementum because it can expose these tubules it can expose these holes in the dentin and that would make us feel more sensitive so the cementum seals off recovers the dentinal tubules so we don't feel sensitivity another thing about cementum is that it becomes thicker with age so you know if you're grinding and clenching a lot you'll notice that people have um i should change the color here that people would have a lot pepsi mentioned as they grow older and we'll discuss that more later on but as they grow older you're going to notice that people have a lot more cementum at the bottom so as you get older with age the cementum does get thicker okay we'll talk about the bone now so the bone is another part that is around the tooth right another tissue that surrounds the tooth so this is your bone over here that's around institute some words that i want you guys to know is your alveolar brown proper also known as your crib reform plate so it's basically the way to describe it is if you look at this picture over here do you see that this area has no toot and there is um let's see if i can color it in so this shaded area over here that i'm shading in i don't know if i like that actually see if i can undo that okay but basically the shaded area that we're looking at over here this is your alveolar bone proper it's a layer that's like lining the socket the socket is the area where the tooth is missing and so the inside part that we're looking at so the inside bone that we're looking at inside the socket that is known as your alveolar bone proper and i have a different picture later on that i'll show you the alveolar bone proper is that outline of the socket the outline of that hole that hole and the alveolus so this word over here is the entire socket so that hole or the gap or like the air that we're seeing inside this area over here that is your alveolus so wherever there's no tooth what we're looking at is your alveolus and the bone that is outlining that socket that bone that the inner bone is known as your alveolar bone proper javiola bone proper is the outline of the inside and the gap that we're looking at is known as for alveolus and then we have something called cortical bone and catalyst bone and so cortical bone also known as compact bone is the bone that forms the outer wall so here's your cortical bone let's see if i can outline this better so this over here is the cortical bone the outline of this is your cortical bone so it's the outside is your cortical bone cortical bone kind of like your outside um we can see it over here cortical bone is on the outside so this is yours so this picture over here is taken from like this over here okay and i've just kind of reversed it or mirror imaged it and attempted to draw it out my apologies for the horrible drawing but that is your cortical bone over here we also have an outline over here that's cortical hard bone okay cortical is like heart and then cancellous bone is the inside part and it's the spongy bone you can see it has holes in it that's kind of spongy um if you look at the x-ray this on the inside so this part over here you can see it's more softer that is your spongy cancellous bone there's a cancellous bonus over here cortical bone is hard bone that's on the outside cancellous bone is on the inside usually found in the interproximal area as well interproximal means insurance in between proximon is kind of think of the in between t so interproximal area are areas that are in between teeth also what i want you guys to know is that this these gaps that we're looking at here so here we have a tooth missing here we have another tooth missing that if you're looking at the outline so the black outline that you see over here that is your alveolar bone proper so it's the outline okay when we're looking at it from you know looking at it directly the outline that we're looking at the black outline that we're looking at is your alveolar bone proper and the space the hollow space is your alveolus okay so the outline is your alveolar bone proper but the space is the alveolus last thing i want you guys to know is something called a periosteum so if you're looking at the gum so let's say i'm looking at this picture over here the pink thing that we're looking at the gum that we're looking at is known as your epithelial tissue so epithelial tissue is your outside tissue okay so that's what i've kind of drawn over here so the outside is your epithelial tissue and then we have layers so imagine underneath the epithelial tissue we have another tissue that is your connective tissue i think i drew this somewhere above here so this pink thing is your epithelial tissue then we have your connective tissue okay which is underneath the epithelial tissue underneath the gums is your connective tissue and then yes we do have the bone but there is one layer that is just above the bone so let's look at this picture again we have your epithelial tissue that's your gums underneath that we have your connective tissue and connective tissue is where all your blood supply is and we'll look at that later on and then we have a thin layer maybe nothing but we have a layer that's called periosteum so remember the word peri means around and osteum i want you to think of bone so it's a layer that's around the bone and the periosteum is right here and then we have the bone underneath if you look over here we have the bone that's over here and so there's actually a periosteum layer that's right on top of the bone that's covering the bone so these are the four layers we see in the mouth um and i want you guys to know those layers and we'll talk more about it as we move on but we have the epithelial tissue which is your outside layer then if you you know if you cut through you would cut through your connective tissue then you would cut through the periosteum and then you would see the bone so this kind of layers that we're cutting through to access the bone for example so these are just different terms that we might see throughout the course and i thought this is a great introduction to understand the different tissues that make up the periodontium and some words that you will see as we progress through the peria course