we're looking at intraoral radio radiography techniques in the previous video and we said white wings were a good example of intra oral inside the mouth we said paralleling is a good one and we also said bisecting is another intraoral radiographic technique another intra-oral radiographic technique is this one which is an occlusal radiograph that's just looking at the occlusal aspect and this is when you want to see the entire art and we do this this um radiograph along with other bitewings or ppas um as well so we don't just do an occlusal radiograph and not take the other radiographs if um you know if we're checking for carries or anything like that why do we do occlusal radiographs well there's many reasons one of the reasons is you know maybe there is a salivary stone somewhere and we want to check that out maybe they we think that there's a supernumerary teeth or an extra tooth somewhere and we want to check that out maybe there's some injury in the bone and we want to check that out um maybe there's some unexplained you know swelling or growth abnormality and we want to check that out so um there could be like you know stuff stuck in like a foreign object could have been stuck in and we want to check that out so sometimes an occlusal radiograph may be necessary so let's look at a question which would be an appropriate reason to expose an occlusal image mucosal salivary stones advanced bone loss or tmj disorders it would be salivary stone so a stone would definitely show up a solid base stone is you know you could show up here in the occlusal range of wrap um a mucocele is like a a soft tissue lesion and so soft tissue you won't even see it on the radiograph stone you would see on a radiograph because it's hard advanced bone loss you want a vertical bite one for that you don't want um or you could you could even actually look up advanced ball not actually the best ways for pa you could look at a periapical imaging so that you can see the bone loss um tmg we can't see the tmj anywhere here right we can't see the temporary mandibular joint anywhere here so that's not a great option best answer is b salivary stone number 18 so the another type of radiograph we take that is extra oral that takes outside of the mouth is a pan a panoramic image so which is a suitable use of using a panoramic image yeah the answer is b eruption pattern so sometimes um you know people with mixed dentition we might want to take a pan because we want to see what the eruption patterns are are they getting in all their teeth occlusal carries we won't be able to diagnose properly with pan um periapical pathology is better with pas not necessarily with pan periodontal bone loss again we could use vertical bitewings or pas paralleling um technique or bisecting technique just get pas for bone loss not a plan so pan is only good for eruption patterns so a panoramic x-ray looks like this a radiograph for pan looks like this it gives you an overall picture of not only the maxilla but also the mandible and its surrounding um intraoral structures and this is good because if you ever want to see impacted ate this is really good if you want to check for eruption patterns this is really good if there's any trauma somewhere we might want to take a pan if there's any very large lesions somewhere it would show up in a pan so many good reasons for pan but remember pan is not a standalone you also need to take or supplement it with other intraoral images when someone takes a pan it's important that they are biting on a the bite block um their frankfurt plane which is a frankfurt fort plane i'm going to show you a picture of it later is from the tragus of the earth this over here would be the frankfurt plane and it has to be parallel to the floor so imagine the floor you know being down here this line and this line are parallel to each other which is what we want so we want the tragus of the ear or the front foot plane should be parallel with the floor we want their spine straight so sometimes what we do is we get them to bring their feet forward so that the spine stays straight here we have an fms and here's a question that's asking what periapical film is placed in the top left corner of the fms of the full mouth series mount so top left corner of the fms is your maxillary right molar right this is the right side this is the left side but it's the mirror image we got to think of it as a mirror image so when we're looking at the top left corner of the fms is actually the mirror image it's actually the right side so it is the maxillary right molar okay let's look at some examples of radiographs that have gone wrong so this is a radiograph that has improper placement because this is supposed to be a pa and you don't see any apex you don't see the tip of the root the very bottom so this is improper placement what this person should have done is place the film a little bit lower so that we can get the apex what do you see wrong over here so this is for shortening so when your teeth root looks um short this is for shortening so how would you correct this if this was for shortening what can you do to correct it this is due to improv so when you have foreshortening or when you have elongation which is when your roots look when your teeth look really tall or for shortening is because of your vertical angulation so it's because if i were to bring this bigger so we can see better it's because of your vertical angulation it was off so imagine so this is for shortening okay imagine you're on an airplane okay so you're on an airplane this is your airplane and you're looking at it from way above everything looks short to you right so what would you need to do if you're in an airplane and everything looks really short all the buildings look really short what can you do to fix that well you could bring the airplane more down right you can bring the airplane more down or you can decrease the angulation so instead of the angulation being up high you could decrease it bring the number lower this is like 60 this is you know 30 so right over here is like 45 bring it lower over here so that you can get um it won't look too short to you so when you have for stretching what you need to do is you need to decrease the angulation you need to bring that airplane lower so you can see better so it doesn't look too short for you and when you have elongation like this again this is because of improper vertical angulation you could be like all the way here you could be so like you could be like an ant for example and you're looking above at a building and it looks so tall so what can you do as an ant well you could come fly up a little bit so it won't look so tall so here when you have elongation what you want to do with your pid is you want to increase the angulation you want to bring the pid up a little bit so that you can see it a lot better okay so when um elongation happens the teeth look long the x-ray tube is under so what happens is the angulation should be increased bring up the undulation if you have foreshortening what's happening is the x-ray tube is over two over two up high that's why the teeth look short so you want to decrease or bring the pid or the x-ray tube a little bit lower the overlap contact area between these two teeth is the result of what what do you think is causing this overlap contact yeah it is horizontal angulation so horizontal angulation causes overlap vertical angulation causes foreshortening and elongation but horizontal angulation causes this overlap improper receptor placement replace receptor placement would be like a cone cut or would you know cut off the abcs which we do not see here not related okay this is a non-diagnostic right-wing image why why is this not a good bitewing image yeah overlap right we can see lots of overlap here so we can't check for cavities if it's like that we can't check for radiolucencies in here so the overlap is causing um this and again the the reason for this is incorrect horizontal angulation so when you don't what should happen is if you have you know your teeth over here you're when you aim the radiograph it should aim you know in those areas right in between the context of your teeth but if it goes like this way then you're gonna get overlap with not aiming correctly so you really need to aim the x-rays right in between the teeth the rays should go right in between the teeth you don't want it to go off because then you can get overlaps this is a cone catch right so a comb cut is happening when you don't have when you're not placing the pid correctly in that in that aimed area in the area you need to be aiming at the patient states that movement occurred during x-ray exposure which error will result on the image so sometimes patients move when even though we tell them not to what can happen decrease sharpness so it would look i actually have a picture of it the sharpness of the image would look like this see how it's blurry that's what happens when someone moves while you're taking a radiograph it will look blurry so there's a decrease in sharpness it won't look better it won't increase its sharpness it won't magnify if the decrease in distortion is not affected by movement so the only thing that happens is decrease in sharpness as we see here is very blurry not sharp at all when we were looking at the pan i was talking about the frankfurt plane which is right here so from the tragus of the ear all the way down and it should be parallel to the floor which means the floor is right here at the bottom it should be parallel so the lines should be parallel to each other now sometimes if they take their chin and they what they do is they put the chin down because that that way this is not parallel now because they've tilted it if they put the chin down this is what's gonna happen you're gonna get like this type of pattern where the front foot plane has been angled down and if they put the chin up and they don't you know rest it on the chin pad and they put it up the frankfurt plane also goes up and that's why you get this type of image happening where the chin has been you know positioned too far up so the front four plane has angled has been angled upward look at what's happening here we can get some you know it doesn't look good over here and the reason why you see this blurriness over here is because of the focal trough so focal drop is i'm going to show you actually a picture so we can see better this whole area is the focal track okay the mandibular area right here and you want it to be positioned appropriately now you want you don't want it to be positioned too far forward you don't want it positioned too far back the focal chop should be positioned perfectly so this is the bite block all right where when you have the pan what you want is you want them to bite down and they should feel this groove and you want them to bite down on this glue because when you do you're going to get a perfect image this here there they have a metal ring right here just to show that the metal ring turns out perfectly even though you're not supposed to have jewelry when you have pan this is just um to show you that the metal ring would come out perfectly if you were to bite down on it correctly but watch what happens to the metal ring and also the teeth when you're positioned too far back so let's say this person is biting down and they don't even bite down on the bite block they're way too far back watch what is happening to the metal ring and a mandibular teeth do you see how it is being magnified like them inside of it being normal it's become magnified and the teeth also look a little magnified too so that's what can happen when you're too far back so when you're not biting down on it um like this and your jaw is too far back that's what can happen so that's what we see here magnification because the mandible or their mouth really was positioned too far back too far posterior and this is what's happening when it's positioned too in um too far anterior so it looks like this they bit on it like instead of on the groove in the bite block they went way ahead okay and they bit on this by block and what's happening is you're getting the minification or the it's becoming smaller the metal ring instead of it looking like this has become like this and even the anterior teeth look a little smaller as well which tooth has been restored with amalgam so let's look here where do you see amalgamation i can zoom in here so we can look at it better you see amalgam here where do you see amalgam here where do you see amalgam this teacher this is the three seven this is the second molar um also the one eight if you wish to look at it universal our numbering system and amalgam is a lot more um or paid compared to like composite for example which is less rigid opaque this will not be gold because if it was gold you would see that the border is more well defined and well developed amalgam the borders are a little less defined a little rough here so the answer to this is 18 which is in fdi is the 3 7 the second motor okay number 57 what is the number of natural teeth present in the maxillary arc do you see any natural teeth over here i do not so i don't see any roots right these are all um implants eight implants have been placed here so no natural teeth are there the mandibular anterior teeth are slightly narrowed and diminished in size what is the appropriate step to correct this positioning error so see how it is diminished and slightly [Music] narrowed so it's kind of minute it's like a narrow version of the teeth that happens because the teeth have been slightly pushed i have been pushed slightly posterior into the vocal drop so let's look at this image again when you have it you know um here it's narrowed right so because it's narrowed because this what happened was the mandibular arc was placed too forward so we need to bring it back a little bit we need to bring this mandible a little back and when we do that we're going to get normal um images so to fix this it's asking what is the appropriate step to fix this well bring the teeth slightly posterior into the focal drop that's the way to fix it so that it will not look narrow because right now the teeth are too forward here this is um from the darby's comprehensive review and it goes over the guidelines for prescribing radiographs really important to look at because if you're a child and you can see what's interesting here is you can see all the proximal surfaces because when you're a child and you look at you know the teeth usually they have spacing in between teeth so you can see the measles and distals then you don't need radiographs but when it's too tight together then you know when you don't have open proximal contacts then you mainly and there's evidence of disease then you may need radiographs and so that's what this blurb over here is saying if you're a teenager then typically what you need is bite wings and pan you only need an a full mouth radiographer like an fms only if you see like lots of disease generalized disease or history of extensive dental treatment otherwise vitamins and pas would do with adults you have your you have your own the radiographic examination is based on clinical signs and symptoms so if we see there is a reason for radiographs and we'll prescribe it um or the dentist will prescribe it the key thing i want you to know is that we don't take radiographs every six months religiously but we don't take radiographs every you know uh three months religiously there has to be a need it has to be client specific so with children typically what we're doing is if we see this client often then what the dentist would do is they would do um posterior bitewings every six months or every 12 months only if they cannot see the proximal surfaces if they can't see the mesials and distals when we're looking at someone who has periodontal disease we use clinical judgment so the dentist would use clinical judgment to decide whether we want to do bitewings pas or you know just take pas on just areas where there is periodontal disease clinically so the dentist would decide and again that's what i'm trying to get at is client specific clinical judgment would need to be made we don't treat all clients the same way we give them all the same radiographs now it's all dependent is all client specific dependent on their caries risk is dependent on their periodontal disease status this is um a way to see what is regulation and what is radio opaque so if we look at enamel enamel is white therefore radio opaque dentin also kind of looks white therefore radio opaque cementum is right here and i want to show you um this other image that i have over here where it tells you that cementum doesn't show up as radiopacovidge you lose it but pulp does pulp shows up as radiolucent so if you look over here this is the pulp number four that is regulation by periodontal ligament so you can see the periodontal ligament right here and sometimes when there's mobility you can get a widened periodontal ligament area and so that appears redulucent and that is not mentioned here but this is a pdl space and what they're referring to is the periodontal ligament space lamina jira that's the bone right here the outline of the bone that is radio opaque alveolar crest is radio opaque the crest of the bone here i want you to just be familiar with all of these different anatomy and what i want you to know is that anytime you have a fossa an orbit a canal or a sinus those are all radiolucent because those are all like holes if you will so if you look at this these are this is like a hole okay it's like a mental this is the mental foramen foramen is an opening so it's a hole if you think of the trying to think here what to look at number 16 if you look at my maxillary sinus the sinus is in space an air sac um a space so therefore it would be radiolucent if you look at it's very hard to find that canal but the mandibular canal it would look radio loosen because canal is a hole so anything that's a hole um an opening would look a space would look radial loosen but anything that is a projection for example like a process is a projection a condyle is a projection uh tuberosity could be you know is a projection that would look more radio opaque so which term describes a radio opaque landmark a white landmark yeah that's a process so think of i'll give you an example here actually when we look at the image if we look at the let's see here i can look at the coronoid process so the coronoid process this is the so this is the condyle right here and the coronoid process would be sticking out somewhere around here so it is radio opaque okay coronoid process so the condyle is on one end and the coronoid process is on the other anaconda so if you look at it you remember what the mandibular jaw kind of looks like this would be the condyle this would be the coronoid process there's a projection of bone that is sticking out and when you have a projection of something sticking out it is radio opaque everything else process suture canal that is radiolucent because it's like a hole so a fossa is the shallow scooped out area of the bone a suture is where two um bones meet it's like a line of union between two adjacent or adjoining bones and a canal again radiology is like a tube like passageway so there's no actual bone here it's just um a scooped out area or just a line between two bones or just a tube right which uh passageway through the bone so process is something sticking out this is a good um table where it tells you you know what composite could look radio opaque or radiolucent and i'm going to show you that typically it's radio opaque but the old composites were looking radio loose lucinda i'll show you a picture implants are radio opaque um let's see what else amalgam and gold are radio opaque so let's look at some pictures look at this right here do you think these are carries or do you think these are composites this is actually composite because it's boxed out okay so when you see it boxed out like that um and it's well defined the border it is composite if it was not well defined then it would be carry so because it's well defined it is composite um so these are composites this over here number two is a poston core which turns out as which comes out as radio opaque with the porcelain fused metal crown number three again is another crown pfm crown this is a composite so this is the newer composite you can see it's more radio picked the older ones typically look regiolucent now they have filler particles in there which make it more rigid opaque this is amalgam okay and again when you look at the borders it's not 100 well defined hence amalgam and not gold if it was gold you would see it more well defined and these are crowns and they have endodontic material these are pfm porcelain fused to metal crayons