this is a quick video guide to identification and orientation of the adult technician here I've got some models of teeth oversized in front of me that are both the upper arch here and the lower arch opened out together so we're looking at the patient's right hand side this is their lower right and this is their upper right but laid out on the table so we can see I'm going to take you through the orientation of the teeth one by one and give you the identifying features of each tooth so if given the tooth in isolation you stand a chance of identifying which one it is and which way round it goes before we start or just clarify some terms in the description of the teeth I'm going to refer to the teeth by number one two three four five six seven eight but also by name so one and two of the upper and lower arches are incisors the threes are the canines the fours and fives are premolars and the 6 7 and 8 are molars the direction of the teeth in the mouth we refer to the term says buckle which is the cheek side and if I take a tooth out the arch we can explain this so if it's on the cheek side of the mouth it's the buckle if it's on the inner side which is palatal or on the lower lingual because it's next to the tongue the front or towards the front of the head is the mesial so that's this side and towards the back on towards the back of the head is distal so let's first look at the anterior teeth and the anterior teeth are described as the teeth of the incisors and the canines so from here forwards let's identify the anterior teeth we look at the upper incisors first so here they are in isolation and you can see that they the 1 and the 2 or the incisor and the lateral incisor are both fairly similar in shape and in fact in in isolation is hard to tell without the size relative one to the other which one might be which to orientate the teeth the simple thing to look for is the mesial corner and that is usually sharp on the upper incisors so let's just identify this on both teeth so on the main in size that this is the sharper corner this one's more rounded on the lateral this is the sharper corner leading to a more rounded surface and a good comparison is your feet if you look at your shoes the sharper surface is usually on the inside and it's the same in the mouth so if you're looking at a size like this look for the sharper surface here you can also look for the cingulum cusps here to make sure that you're not accidentally looking at a canine let's put them back in the arch and compared to the lower incisors the lower incisor is a little bit trickier because they vary they're not both the same shape the lower one does follow the rule of the upper in that it has a sharper medial corner here and they rounded distal corner here but the two does not in fact it's identifying shape is it's more fan-shaped compared to the asymmetrical shape of the one so if you're looking at a lower incisor and it's quite even and fan-shaped it's probably a two if you're looking at it and you can see some asymmetry that relates to a square mesial edge it's probably a one you can look at the teeth from the occlusal to look at the twist in the occlusal surface in order to help your own take them into the arch a little better as well moving on to the canines and I take them both from the arch for comparison they are relatively easy to identify orientation wise and also whether they're upper or lower the other canine is quite a wide tooth in this case and the lower canine is much more slender if you have them to compare it's quite an easy distinction to make orientation is also relatively simple if the canines are not heavily worn look for the shorter surface from the point to be the mesial so in this case the mesial surface of the tooth here to put it into the upper right arch and this is the shorter side from the point puts it here for the lower it's exactly the same rule look for shorter surface and then the point and then the longer distal surface allows you to orientate it into the arch a final distinction distinguishing feature is there's no singular as the Plato or lingual side of the Kanan is often used as a ramp for taking canine guidance in occlusion there would be no cusps here otherwise you get a rather nasty bump as you move two teeth we now move on to the upper premolars and if I pull them out you'll notice that on quick examination they look extremely similar the identifying feature of an upper promoter over a lower is that the cusps sizes are relatively similar between the buckle and the palatal so if I turn the teeth you will see they are fairly even the lowers the buccal is much larger than the linker as you'll see in a minute in order to identify the 4 from the 5 look for the canine fossa which is this groove here which I can emphasize against the background this is so that it can fit tightly in with the canine like this the canine fossa means hole for the canine so let's place these back in the arch and show you the lovers the lower premolars in comparison vary in shape and are easy to identify once you have them identified as lowers so the 4 is canine shaped as you classically Erikson except from the the uppers but the difference in cusps sizes is quite pronounced here we go for the lower 5 you may think that the tooth has three cusps one two three but it's bifurcated by this groove here in order to make it look like it has three cusps so it's very easy to identify lower 5 because if you think it's got three cusps you're probably holding a lower 5 the disparity between the custom makes it very difficult to not identify the buckle as that will be larger replacing these are moving now on to the molars now the upper molars when looked at together do look to be fairly similar in shape although you'll see that there's a graduation in size at the six is larger than the seven which is larger than the eight in isolation it's a bit hard to identify six to seven usually but there are some features so let's pull the six out and identify on its own it has four cusps as do all upper molars one two three four in this case there was a little cusp here called the cusp of care of belly but don't rely on that as it's not on all upper molars not everybody has it when it does occur always occurs on the mesial palatal cusp for identification and orientation of the tooth what to aim for is this cusp here have a look at this one the distal palatal cusp it's the one that looks like it's hanging on the back and not part of the main tooth and if you orientate it so that is the distal palatal of the tooth so you can say right in my arch how I'm going to rotate this well let's put it distally and then let's put it politely that means the tooth must go this way round and it should fit into the arch so if you've got a cuspid keira belly you've almost certainly got six in your hand if not you'll have to go on size and also the tooth attends me a bit square and then the seven because it has a slightly larger shape moving on to the seven same as the six four cusps again one two three four and again the distal palatal cusp seems to be hanging on the back so orientate the tooth with that there distal palatal II and you'll be okay for the eight sometimes more foot morphology wise anything can go because things get a bit squashed back here but again it's got four cusps although a little harder to identify one two three and again this cusp here which almost looks like a feature of one of the others but that's it in order to orientate it again try and put the distal palatal cusp in its place but you might find that it's a little bit harder if you have the roots of the tooth it's it's much more easy to identifies the roots or often heavily curved distally so it makes identification or tooth much easier so let's put those back in the arch and look at the lower molars as distinguishing between those is even more difficult let's bring them up and you can see on first glance they look quite similar but we will notice straightaway that the lower six apart from being the largest tooth in area in the mouth also is the only one with five cusps one two three four five if you orientate the teeth at the the fatter wider aimed is meesal II and the three cusps Arbuckle II you've got it around the right way so put the three cusps Buckley and make sure that the thicker end of the tooth is towards the mesial and you're okay there is another trick as well which is to turn the tooth over and you can see that has quite pronounced can't with the buccal being quite bulbous and the lingual being a straighter side now the reason that these you've got this straight decide here is when you put the teeth all together you get a groove which is where the tongue sits like this so my hand is now the tongue and you can see how it works if I have the tooth around the wrong way you can't use that feature and it looks wrong so make sure that the tongue can fit into that groove and you've probably got that lower mole around the right way the seven in the eight are both four cusps teeth but they are very different to the upper molars in the fact that the four cusps are very evenly distributed almost like a cross or currant bun when you look at the tooth in form one two three four and a here one two three four if I turn the teeth so that we're looking distally you can see the can't in both teeth so that the tongue space is here so that allows us to orientate them but distinguishing between the seven and the eight is very difficult and you will need to rely on looking at the relative size difference because the age will be smaller or looking for these squeeze in the tooth to be more pronounced so if there's a trickiest teeth jewelry and tight in the mouth it's probably these two together if you're given them in this form so hopefully that is a short overview to identifying and orientating the teeth in the adult dentition