Dental and Oral Investigation. Very often our cases, our treatment falls down really at the first hurdle. So it's really vital that we can do a very good dental examination.
So aims and objectives. So identify normal. And be aware also of the changes as our patients mature.
To understand the investigations that we would do. And how limited conscious examination is. How to do probing charting.
So, very much an essential part of any oral and dental assessment. How to do scoring for periodontal diseases. Choosing the investigations.
And particularly there, of course, thinking about our extra. So starting off with our canine dental formula, then we're looking at how these teeth are shaped for the function that they perform. So it's this morphology that matches the need.
We have our incisors for nibbling grooming, canines, catching and holding, and then the premolars together basically make a pair of scissors or pinking shears. And that's obviously for, for cutting food up into smaller chunks. So the main teeth section food are the carnassios.
However, in the maxilla, our carnassal is the 4th premolar, whereas in the mandible, the carnassal is the 1st molar. The molars in general are a flattened type of a tooth, so far more similar to many of our teeth, and therefore crushing and grinding. Obviously, with the exception of the first molar in the mandible, where we've got that again, cutting surface, particularly towards the meal, you might want to call rostral parts of the tooth.
So the cat, of course, has refined down this dentition. We've got the incisors, we've got the canines, but we have a fewer number of pre-molars and far fewer molars. And again, it's this contrast between our dog and an omnivore and a cat, which is very much an obligate carnivore.
In both cases, their teeth tend to erupt in around the same sort of timing. So between about 3 to 6 months, classically 4 to 5 months, then you'll see that your deciduous teeth are being replaced by the permanent. So the deciduous exfoliate, that's a normal programmed root resorption, leaving just this sort of cap of a crown which then can fall off quite easily.
Meanwhile, our permanent is developing and then starts to emerge into the mouth as part of our eruption as well. So similar timing and it's very good to do an adolescent check on particularly dogs at around 4 to 5 months because at that point our canines are typically emerged into the mouth and we can see where they're headed, which means that we can see whether we're likely to have issues or if our patient is going to get trauma, for example, to the palate from the mandibular canines. So we can see what's going to happen, but it's not yet happened.
So then we can think about early intervention. And trying to avoid the situation already being kind of embedded and having to rewind the clock for these cases. How many teeth do they have?
Well, owners are very interested in this sort of thing because they'll very often, when you've done extraction, say how many did you take out and how many are left. So just having it on the top of your head is useful. And for a dog, we're on 42, and for the cat, it's 30.
So have a look at our anatomy. So our dental tissues, really we can consider several things here. We've got the Portion of the tooth that you can see, of course, the crown, and we've got the root, and then we've got the tissues within there.
So, centrally we've got the pulp which lays down the dentting, so the walls of the tooth, and you can see that on the, the diagram to the side. So we sometimes call it the pulp dentin organ. So the pulp's laying down this dentin, of course, the tooth stays the same size, it's just that the walls become thicker and the space available for that pulp and the pulp cavity becomes narrower and narrower with age.
The other thing that happens is that the tip of the root forms. So prior to 12 months old, then we've got an opening at the end of that route. In fact, in a very young animal it would be very open, whereas 12 months, radiographically, we can see that that looks like it's blocked off most of the time, and by 18 months, typically we'd regard it as fully mature.
And when we've got a mature apex, then what we see is an apical delta. What that means is that you've got lots of tiny little holes in the end. So effectively it's like a little sieve.
And of course we've got to have blood vessels, lymph, nerves, etc. Going in and out of the pulp, and it's via these tiny little channels, so the apical delta forms. So, we've got our pulp in the centre, laying down the wall material.
We've got our enamel on the outermost part of the crown. It's the denser substance in the body, and it's basically like glass or ceramic. We of course have it in ourselves, but rather a thicker layer.
So in our patients that we see, they are lucky to have 0.5 millimetre thickness at the thickest point, whereas we would typically have about up to 4 times that. What it means, of course, is that if you chip your tooth as a cat or a dog, it's very likely you go full thickness through the enamel, and you're onto dentin below, which, as you'll see in a moment, is a porous substance.
So dense, yes, but porous as well. So we've got the central tissues and the tooth itself and the outer layer which we'll look at a bit more soon is the cementum and the outer coating of the root, and that is one of our periodontal tissues. So we also think about the teeth having a support structure, and that's 4 tissues which together combine and are often called the peridontium.
So looking at this pulp denting organ first. So we've got our little puppy there and you can see that we've got lots of deciduous teeth, long, spindly, fragile little teeth, and then looking very graphically at what lies beneath, we've got our developing permanent teeth. So the teeth.
But they're developing and really very little bone. So this is why, of course, if you fracture your tooth, as a pup, then you can get issues if you're taking that tooth out. You can cause issues to the developing permanent teeth, and if they break the jaw and you try and fix it, then you're very likely to get disruption, damage, compromise to those developing teeth.
Now when we look at an extracted tooth, you'll see that you've got your shiny smooth crown coated in enamel, and then there's a fairly clear line between that and a rough surfaced root. And that line, that demarcation is the cemento enamel junction. So cemento of the root meets the enamel of the cramp.
Got a little er additional picture here to the right of that, and there's a square being removed. I'm trying to show there is where we've removed enamel, and then underneath we would be down onto the denting. As our animal matures, our permanent tooth starts to emerge into the mouth, so you can see here there's larger canine.
And yet we still have our deciduous canine there with a long fragile root, and the emerging erupting permanent canine has very thin walls and a very big pulp and no tip to the root. So, whereas for our deciduous tooth, you can make out. The apex or the tip of the root here.
If we look at our permanent canine, we can see a very thin wall. And then it just stops. And if you look at the other side again down to the wall.
Follow it And it stops right there. And between those two walls, of course, it's all bulb. But you can see there's an open end.
There is no apex formed. There is no apical delta as yet. Further developments And we've now got a mature animal and You can see that we have.
An obvious end to the route. And we will have our apical delta there. We've got a narrow pulp cavity that we can see the centre of the tooth.
And then we've got thick dentalal walls. So a mature animal, probably about sort of 56 years old, this one. Now this is apical delta.
So, the apex of the tooth, and when we look at it under a scanning electron microscope, you can see that sieve-like nature, all those tiny little they, they are sort of like perforations, I don't want to call them tubules because that's something separate that we'll look at in a moment, but, you've got these tiny little er conduits so that we can have vessels going in and out of. Now, the reason they don't want to use the word tubules is if we take a tooth, and it could be root or it could be crown, but if we then take a transverse section. And we have a little look at that cut edge.
Then if we look down onto it, we get something that looks like, well, sort of a bull's eye with a pulp in the centre. And this is very stylized, of course. We've got our dental walls on the outside, but if we were to look in greater detail, what we'd see is actually there are tubules running from that pulp all the way through to the outer extremity of the dentin.
That might be under cementum or it might be of course in the crown under enamel. And what you have are tubules that run from pulp to the outer aspect, and within those tubules you have basically little nerve endings. So in other words, we've got potential for both sensitivity all the way out to the outermost point of the dentin, but also potentially we have a routine for bacteria, and particularly in a young animal, those walls of course will be quite thin.
And therefore, the tubules will be quite short and also relatively wide, so it's easy for the bacteria to get in. So, the second example is where we've got a layer of enamel on the outside, but same thing, both root and crown. If we were to remove a bit of that enamel and look down onto our dentin, again, scanning electron microscope, and you can see those dentinal tubules and, and how you could potentially get bacteria invading our tooth.
So, let's look at our support tissues, so supporting, sealing between the oral cavity and the body, protecting the soft tissues, again, when you're, you're eating food, particularly in the wild, then I'm still. It's rough and you don't want all your oral mucosa shredding, so it's going to be pretty tough around the tooth itself. So we've got these 4 tissues that make up this support structure and it suspends the tooth in each socket and We have alveola or socket bone.
Peridontal ligament fibres that suspend our tooth, so they are stretching between the bone and then also they go into the cementum so it's a little suspension, little shock absorbing fibres so that it takes the sort of the crunch out of chewing, if you will, . It's a more comfortable thing to do with these little shock caps or big fibres. So we've got our alveolar bone, our perdontal ligament fibres, the cementum we mentioned.
And then our final tissue, of course, is the gingiva. So specialised heavily keratinis oral mucosa. Something else just to note here is that we have our Sent to an Ad Junction right here.
And then you'll see that we have this zone of Attachment here. Epithelial attachment. OK, that basically is the seal.
Because, obviously, exterior to that, we've got a rural cavity and millions of bacteria and interior to that we're into soft tissues, bone, blood vessels, etc. There's also A little gap right here. That is the sulcus, so a natural gap between the free margin is this bit.
Of our gingiva and the tooth. And in a dog, you're usually looking at and also people actually a few millimetres or less. In a dog's canine tooth, you might be up to 4, maybe even 5 millimetres.
That might be normal. In a cat, far less, so generally speaking, you can't measure it 0 to 0.5 millimetre on their canine.
You might get up to a millimetre. So if we measure those and put them on our chart, well, don't put them on your chart because that would be normal. But if we've got a deviation from that, if we're going 7 millimetres, 8 millimetres, etc.
5 millimetres, then we need to write that down because either our gingiva is growing up and over the tooth. We get swelling with gingivitis, but we're really talking here about something like hyperplasia. Or we've got loss of attachment, in other words, we've got a pocket.
Or we could have a combination of both, of course. So we talk about the teeth, the mouth in a slightly different way to the rest of the body. So we've basically got the skull made up of four quadrants, upper and lower and a right and left of each.
And there are of course all sorts of different structures and anatomy that we need to bear in mind in each so nasal cavity, infraorbital foramen, mental, foramine, that kind of thing. And within each quadrant we have our teeth. So the way that they are labelled is with a 3 digit number.
It's called a modified Trident system. And the first number of those 3 tells us. Whereabouts we are, which quadrant are we in?
And it starts with the number 1, which would be right upper. We go across to the 2s, left upper, straight down to the left lower, starts with a 3, and then across the face back to the right again, and a 4 would be our right, lower, or right mandibular. So we know what quadrant we're in, and then the 2nd and 3rd numbers are going to identify the tooth.
And we have to have 3 digits because of the number of teeth that a dog can have. But we basically start with our first incisor, assuming it's there, and work our way back. Now if there's extra teeth, supernumerary teeth, we don't change the numbering.
We try and work out which tooth it is supernumerary to, and then we, we call it SN or supernumerary. So it might be, you know, if you've got an extra 206, OK, we've got 206 SN. If we're missing a tooth, it might be missing, might have been extracted, etc.
Again, no renumbering, we just tend to denote which one is missing by circling the number on a dental chart. Once we've identified our tooth, we can also further then identify areas on a tooth. So, the first thing to consider is medial and distal.
So, Mesial is referring to the proximity on a particular tooth to the central midline. So we've got a midline, of course, a synthesis that runs into the er the mandible, but also the maxilla there. But we are only bothered.
About this most. Rostral aspect of it, so that midline. Therefore, if we were to look at, let's look at tooth 102, so we're in the right of a quadrant.
And the second premos were here. OK. So we're on that tooth, and the closer part of that tooth to that central midline, that's rostral, is the medial aspect of the tooth, so that's right.
Here, so that would be me. The aspect of the tooth which is furthest away from that is the Distal. And of course that works as we go further cord in the mouse.
If you look at our other photograph, for example, on the carnassio, we have Mel. And we have Distal because it's all about that. Central.
Midline, right here. OK, so easy on this still. Then, if we think about premolars and molars, then they are next to the cheeks, and in the cheeks we have albuxinator muscles.
So the outer or lateral aspect of, say, our maxillary caratal, you might want to call it the lateral aspect, but it's actually called the buckle. Surface of the tooth. So again, for example, here on our carnasal.
This is all buckle. If we are looking at canines and incisors, they are next to the lips. So, in other words, the labia.
So that's the labial surface. So again, I've got a labial surface right here. In terms of our mandibular teeth, if we think about going inside now, so what you might want to call medial aspect, well, it's next to the tongue, so we call that the lingual surface.
In the maxilla, of course, it will be next to the palette, so that'll be the palatal surface. And again, if we look at our photo there to the left of the skull, then if we just take this second pre-molar, so we're on 106 here. This is a vital surface.
And then occlusal, finally, is the biting edges, so. Here, with our premolars, we've got these occlusal surfaces, the surfaces that meet together, relate together. OK, and that could be mandibular, as you've seen, and here, maxillary as well.
OK. Then, what we can do is combine. So, for example, if I wanted to tell you about a hairline crack on my left upper canine, I would be talking about 204, that would identify the tooth.
And then if I said, yep, there's a hairline crack on the distal labial aspect, you'd think, OK, labial distal, so I'm looking for something maybe. Around here. OK, so again, it's just a way of describing where something is on a tooth.
OK. Now, in terms of investigation, we start off conscious and work our way to anaesthetized. The conscious element is limited.
So, of course, what we do want to do is get a good history, make sure that we're not just thinking about teeth or mouths, that we're getting a history of the whole animal. What's its heart like? Have there been any previous anaesthetics that were an issue, etc.
Etc. Then we want to try and do our normal full conscious examination. Again, bearing in mind the animal's nature and the limitations of that, but .
The last thing that I look at when I'm assessing my patients is the mouth. So start off just generally looking at how the animal comes in through the door, how friendly it is, is obviously an aspect, how amenable, and then we're thinking, OK, let's have a listen to this chest. Let's feel the pulses, look at the colour capillary.
Fill abdominal palpation, feeling for the lymph nodes, and then we're on to the neck, thyroid area as well, working towards the head. So our neck examination, our facial examination, looking for any asymmetry swelling, tenderness, tracts and, and discharge. Muscle wastage, anything like that.
And then finally we get to our oral cavity and then our teeth. So of course if you're getting a growl at the starts, then you're not going to push you look too far. The truth is we need an animal to sleep to get a proper detailed oral examination anyway.
So if you didn't manage that much conscious, it's not the end of the world. We do want to try and get any preoperative testing done, so typically that would be our blood testing, our biochemistry, electrolytes, PCV, that kind of thing, safety thing a lot of the time, but also if you've got, suspicions about this animal's health. And that might be just various things that you pick up, but it may also be that the oral cavity is faring rather badly given this animal's age, and therefore it could well be that we've got some sort of systemic compromise that's contributory to that.
So, blood testing and then of course in cats, we often start thinking about viral testing where again we've got suspicion. Once our animals asleep, then we're looking at oral examination, probing and charting. Then our X-rays and biopsies were relevant.
So this conscious examination, do what you can safely, and one of the things if you can do that's really useful is to look at the occlusion, which is of course what's happening here. So the relationship of the jaws and the teeth within them, and we want to have a little look at how the incisors meet the canines and the premolars, and this is a good example. This photo is showing you a normal orthoocclusion where our maxillary is a little longer and broader than our mandible.
And therefore our maxillary incisors sit slightly further forward. The mandibulars rest on the inside of the palatal aspect of the maxillary incisors. The canines sweep past each other with our mandibular canine sitting in a little diastoma between the third incisor and the maxillary canine.
So that creates us a canine interdigitation and combined with the incisors. And this scissor bit, then we get our dental interlocked and it's almost acting like its own retentive brace, and if we get that right, the animal gets that right, then as the head grows and the face grows, then hopefully everything will be held in synchrony and we'll go from deciduous teeth to permanent and all will be good. But of course if it's wrong.
Then that goes out and what can end up happening is we get a different kind of brace formed, which is a problematic one that's holding things in the wrong position and can make things quite difficult to escape from and get back to normality. The premolars would typically do this pinking shear effect. So you can see how we get this zigzag, and then in theory.
The gaps between the teeth are pretty. Even, and that's telling you that there's a nice balanced relationship between the length of the maxilla and the mandibles. So, our intraoral view, we can get a general view, we can get our occlusion, hopefully, gently closing the mouth, nice and slow so they don't bite their own tongue.
Look from the left, look from the right, lifting the lips and cheeks, and look rostrally and then you, you're good to go. We can't always do that. We know that not every animal's going to be amenable.
So, if we see an abnormality, it could be the broken tooth, it could be a tract, it could be a swelling, or maybe we can't look properly in this animal's mouth. So an example would be our police dogs that we tend to get. And instead what you have is a high index of suspicion.
Maybe an owner saw something, but maybe they're just behaving oddly, of course. Again, the police dogs we're thinking about them talking how they're not performing the same way. They're not applying the same pressure to the arm, that kind of thing.
So it can be just one thing that enables this animal, creates its ticket to. General examination, sorry, general anaesthetic and examination, that is of a detailed nature under that anaesthetic. So once our animal is asleep, we've got our extraoral views that again might be the first chance really that we get to go around the face with a an aggressive dog.
And then intraoral, we want a general oral view and you start off here at induction, so that might be a first chance to look before the ET tube is down in those situations, this is the moment to have a look at the occlusion. So, as long as your animal's deep enough, ideally pre-oxygenated as well. Tuck the tongue right the way back in the oropharynx, gently closing the mouth, making sure again that you're not biting the tongue for the animal.
And have a look at that occlusion left, right, rostral. Then turn back as quickly as possible, get the tube down, but have a look at what you're going past with that ET tube. So what about the tonsils?
Are they in the crips? Any abnormalities? Have we got any changes to the base of the tongue?
What about the epiglottis, the erytioids? Just be observant of things as you go. Once we're intubated, getting settled, this is the point at which I do a chlorhexidine prep.
Now, in truth, really what I'm doing is a soft tissue check. But the chlorhexidine makes it a nice place for you to work and for your patient, so I dribble it around all the soft tissues, lining of lips, cheeks, the palate, of course, tongue, surfaces, ventral surface, flora of mouth, and you're looking for ulceration, white patches, swellings, areas that look ulcerated and, hardened, for example, so obviously it can be tumours. So have a really good soft tissue assessment, dribbling that chlorhexidine solution round as you go, typically 0.12%.
Of course you can get already made like your hibita or sorry, you can make it from hibiane, make sure it's dilute to the 0.12%, or you can use something like hexa and something ready made. So we do our soft tissue check.
We also might need to debulk the calculus just to be able to see the teeth, in which case fine. Use a hand scaler or to be honest, a gloved fingernail, fine, it's not going to damage any teeth, but you just try to take chunks off. Don't scale at this point, because otherwise all your gingivy will bleed and it will throw all your scoring out.
So it's just try not to disturb the gingiva, but getting rid of the chunks of calculus. And after that, we're ready for our detailed. And dental examination.
And we're going to need a dental chart, basically a map of the mouth, and you can get down a lot of information very succinctly with a chart. So we'll need the chart and the probes. We also think about our X-rays and our biopsy.
So starting off with our probes, we've got a periodontal probe and there's lots of different patterns and an explorer probe, and again, there are lots of different patterns. The periodontal probe, probably the universally most useful for you, will be a Williams 14, 14W, and we've got a picture of it here. We've got a blunt atraumatic tip, but test it, make sure it really is atraumatic, and then align every millimetre for 3 millimetres.
Central line at the 5 millimetre point. So that's right here. How to draw a straight line with this.
And then we've got a gap of another 2 millimetres in a line. So we're on to 7 millimetres now, and then a single millimetre line for 3, so we get to 10 millimetres. So it's fine for cats and fine for dogs as well.
We're going to use that on every single tooth. Gently, gently insert it into the sulcus without any pressure, really light touch, and then walked gently around each tooth. And that way we'll pick up pockets and things like that.
So that's on every tooth. By contrast, the Explorer is a sharp needle-tipped instrument. We don't want to use it on teeth that we don't need to.
So if we have an index of suspicion, but we need a bit more than our visual assessment, then it can come in handy. So for example, is that a bit of decay? Is that a resortive lesion?
Have we got a hairline crack? Well, if looking isn't sufficient, then this will just tend to catch in any little discrepancies in the enamel. Again, enamel being like glass, it should just glide over, but it will tend to catch and you'll feel that through the explorer.
But it does scratch enamel, so we only want to use it where we do have suspicion and need more information. And then our chart, lots of different ones available. I really like these ones by Dr.
Crossley. They're also free, and they allow you space to draw and also to fill in all your abbreviations. So there's a key at the bottom there, the bottom right, we've got the key to abbreviations for lots of different.
Pathologies, you'll see that all the teeth are numbered, the teeth are drawn, so again, we can identify where a deep pocket is, where a fracture is and in what direction. We've also got the occlusion there on the right hand side, and then we've got the, the view at the top. From left and right that again just allows us to draw things on and clarify what's going on.
So when you do it, do it really well and do it really neatly as well because these can be cross referenced for referral for monitoring, and also of course potentially for medico legal purposes. So cover yourself and do a good job, and then archive, and you want to do it at All opportunities. So if we have an animal asleep for a routine operation, the anesthetic's fine, then while you're doing your operation, you could get your nurse, trainee nurse, vet student, work experience, whatever, to assist with the nurse, .
And to chart one or two teeth, for example, for a nurse, maybe in between anaesthetic checks. By the time you've finished the procedure, you've got a full assessment, which is really useful and a golden opportunity that rarely comes along to have a proper look in that mouth. So take your chance whenever you can do.
The other thing about the chart is you'll end up with a lot of information on it. The idea is that that's used to help you. So it's a diagnostic tool and we'll use it to think, OK, where do I need to take my X-rays, but also what work do I need to do most personally.
So we might have 10 teeth with problems, but it may be that today. Two of them stand out as the worst affected that might be causing pain, and that might be what we do and then discuss the other teeth that have got minor compromise, that kind of thing. One, from the point of view of capping cost, 2, for capping your time because, you know, you start off, you don't really know what's going on.
42 teeth later, you might have 42 different teeth to treat, you know, and how on earth can you estimate that properly? You, you can't do. And plus an extraction could be easy.
Or it can be difficult and take quite a lot of time. So it's notoriously difficult. So if we take our charts, and obviously we'll also be thinking about our X-rays, but if we take our charts and look at it and think, OK, what is most important for this animal for me to do today?
What can I fit in the time remaining? And also what do I feel comfy and confident doing? And then that's what you do and the rest can be talked about.
You can talk to referral people, and you can just discuss general things with colleagues, with the clients, etc. But don't think that just because it's on the chart, you need to treat it and you need to treat it now because that very, very often is not the case. In fact, it very often isn't a very good idea and will end up with overtreatment and stress effects.
What do we put on the chart? Well, anything that's abnormal, all pathologies. So, the so-called depth we don't put on, you know, if we were just measuring 23 millimetres and there's no attachment loss, then that's normal, so we don't write that on.
I don't write calculus, I don't write plaque scores because we're gonna take it off if someone's not brushing, there's gonna be tonnes of it anyway. So it's really just the pathology. So obviously, yes, pockets and things like that, .
And abscesses and tracts and so forth, but calculus plaque, no, and normal so called depth, no, if it's if it's normal, then great. And normal, you know, clinical health for gingivve we don't tell people about it, it's a G 0 you'll see at the moment, we just don't write it. Also, before and after treatments, of course, we need to show what's our hit list and which ones we've then gone on to finally extract.
So, periodontal diseases, we've got gingivitis, we've got periodontitis, so let's just look at gingivitis first, and this inflamed gingiva will tend to bleed. So that's really how we, we score. We use our periodontal probe very gently, otherwise everything will bleed, and we're looking for the cardinal signs of inflammation.
So we've got erythema, edoema, swelling, and also tendency to bleed. Well, actually it can be quite sensitive as well. So We score between 0 and 3, but we never write 0, as I say, because that's clinical health, whereas 3 is our most extreme level, where we've got a very, very inflamed gingiva that pretty much bleed spontaneously.
So here's a classic 0. Nice baby pink gingiva. We've got this narrow tapering down towards the tooth to a knife edge, rather than swelling, etc.
And it's, yep, no erythema, it certainly doesn't bleed on probing young animal or animal that has its teeth brushed every day. G Zero, we don't write it's clinical health. Here's a G1, so there's no bleeding on probing, but we can see that we've got a little bit of erythema, and maybe a little bit of edoema as well.
So, that's telling us we've got inflammation, but it's very mild. So mild gingivitis, G1. Stepping up things, we're onto a G2, now a moderate gingivitis.
Again, these signs, erythema, edoema, to varying levels, but crucially, as we gently run that proro, there's a delayed little bit of bleeding. Very minor amount but still is there, and that takes us to our G2. If we get bleeding virtually as soon as we touch the ginger, then that will be our G3, severe gingivitis.
Now, periodontitis is our next stage, and it's where, yep, we will have gingivitis involved. You don't get periodontiis without it, but perdontitis is where we're now involving all four periodontal tissues. We've Go our gingiva, our alveolar bone, our periodontal ligament fibres, and our cementum all involved and being compromised, so we end up with loss of attachment.
And that shows itself as things like pockets developing, the gingiva receding because it's following the bone loss. The loss of bone between the roots of a multi-rooted tooth, vocational bone loss we call that. And then eventually, of course, if you lose enough attachment, then your tooth is going to become mobile.
So a periodontal pocket we measure in millimetres. Recession and exposure of the roots, we also measure in millimetres and that's between the new abnormal receded gingival margin and where it should have been attached once upon a time, which we basically take to be the cemento enamel junction. We can measure the difference between cemento enamel junction line and where our gingival margin is now.
So again, in millimetres. Bone loss in the vocational area, we use our probebe at 90 degrees to the tooth. Try and pop it through between the roots, obviously it shouldn't really go anywhere, so don't try and force it, but if you have got lost there, then hopefully that will pick it up.
But don't forget, this is a, a, an F3 we call it, so a through and through lesion. We go in one side, pop out the other. It doesn't matter which way you started probing, you'll still end up with the same answer on this.
But if you had an F. Shallow cave underneath the tooth, if you will, or an F2, a greater amount of undermining under the tooth, then. It could be on one or both sides.
So if you only probe, which is common, on the buckle aspect, If actually all the loss is on the palatal, you'll have missed it. So you need to make sure that you probe gently on all sides of allocations. So with the triple rooted tooth, that's gonna give you 3 of them.
Once you've got the information down on the chart, then we would use that to guide us on where to take our X-rays, where is most relevant. Some people might do full mouth all the time. It's not a wrong thing necessarily, but certainly it goes against the grain with human teaching, .
You've got to justify your exposures and, you know, there's a cost element to all there's a cost and a time element, so for cats, we very often do do full mouth series, particularly because of resorptive lesions. But in dogs, I tend to cherry pick and most of my colleagues do the same as well. So we would look at where we've got pathology on our chart and that's where we take our X-rays, .
The exposure with X-rays, again, it's a little bit of a question mark in, in animals, but, you know, . It is something that we bother about in people, particularly where you are firing an X-ray through an eye area. And of course, you know, we're not expecting some sudden thing to occur, but it's stochastic, so we're building up the doses basically each time we're taking image after image, and we just worry about that a little bit.
So particularly with our eyes, they've gone to 1/10 of the dose, so I, you want to, if you're gonna fire through an eye, it's, it's gonna happen in your cats and dogs, try and get it right first time, and then we've got very, very few of these, exposures going on. So, because the majority of each tooth is actually roots, and added to that, most pathology shows either on or around the roots, then if we don't have X-rays, we're gonna miss an awful lot of information. And you know, 60 to 70% is out of view.
So clearly it's gonna be very difficult to get a good diagnosis and develop a really good treatment plan if actually we're guessing the vast majority. That's in truth, what we do if we don't have the X-rays. It helps you because it means that you know when you've got a fused root, a missing root, ankylosis.
A fractured route, that kind of thing, you know, before you start and therefore you're forewarned and forearmed, and you can tackle the cases far better. So crucial to making a diagnosis and therefore a treatment plan, and then obviously for monitoring for advanced techniques, it's critical. It's not a school view obviously.
It's these little intro radiographs which for many years I used to film a long time ago. Now we're really all on digital, either direct CR it doesn't really matter too much. When do we take our X-rays?
Well, basically, when we've got any pathology in the mouth, which either isn't or we don't think is purely soft tissue. So we don't for gingivitis, of course, but for everything else, pretty much, yes, we do. And that includes before and after extractions so that we see what we're up against.
We can base our treatment plan on those, and then we can see whether we've completed accurately afterwards. And if you have, fantastic. If you haven't, then at least you know.
And it's a learning tool and it means that someone can help you if you think you can't get the roots back, etc. Again, we'll talk about that in our extraction techniques, etc. So yeah, big difference between the school and the intraoral.
The introra's got lots of detail. I can see that I've got a type 2 resorptive lesion at end stage. That's with our 307.
Same cat, but school view. I can tell it's a cat with teeth. There it ends, really.
So you can see it's really useful where we think we might have something sinister. We can see if we've got bone invasion, bone lysis here, on the right, we've got a cat with a very aggressive tumour, but actually it wasn't obvious clinically. But the minute you take an X-ray, it's patently obvious.
Dog there again, unfortunately it's a box of people think, oh yeah, they've got lumpy gums. So let's be burn off the epulids or cut off the epis, obviously using high temperature is a bad idea in their teeth and periodontal tissues. And that's what happened to this dog, and they kept on throwing them in the bin and they assessing, oh, it's a box and get lumps.
Yes they do. They also get tumours, of course. Unfortunately, one of those epilids happened to be a malignant melanoma.
And then we're pretty soon at the point of no return where we've already got spread before we think about surgery and also, you know, margins are gonna be a nightmare for a tumour that's pretty big. So when you do take your biopsy, make sure they're good, give a good history, explain the X-rays to your histopathologist, include a copy of the chart as well. But what you want is a wedge of tissue.
FNA's not much use, wedge, we're taking something about the size of your little finger, nail or more. We want an adequate depth if you've got X-rays showing that we've got bone involvement, then try and get a bit of bone with your sample. And that area, that zone where we're going from normal to abnormal tissue, but obviously we also want to make sure that we're not going to compromise any margins.
If your result doesn't really match your clinical picture, then pick up the phone to your pathologist. You can get second opinions, you can get slides made, etc. The mouth does some pretty funny things, and in the human world, they would be using an oral histopathologist, whereas our poor old histopathologists are looking at all sorts of bits of tissue from all over the body, all different species.
So, . You know, sometimes it's not gonna be quite correct and you'll often get a better answer if you then have a chat to them. So, in summary, our investigation using our probe, our chart, our visual assessment, that's gonna look at about 30 to 40% of each tooth.
The rest, it's hidden out of view, it's the root, so we've got to use imaging, and X-ray is still the gold standard for looking at teeth. Make sure that you keep everything nice and safe, it's well archived so that everyone can access. OK.
And then we'll look at our diseases, or abnormalities, and the things that cause us indication for extraction.