intraoral radiographic anatomy e lecture Flashcards
aims: to recognise normal radiographic anatomical features in the maxilla and mandible on radiographic film be aware of normal variations
what does radiolucency mean
object allows a lot of x rays to pass through it
maybe because its thin or made from non calcified tissues- then interacts with the x ray and is shown as dark on the film
what does radiopacity mean
due to an objects density or fitness x rays cannot reach the film and therefore seen as pale or white
if an object is radiopaque what does that mean
it is radio dense
where does the inter maxillary suture lie
upper ant PA( periapical) , the anode structure is a thin radiolucent line in the midline
where and how does the anterior nasal spine look
appears as a radiopaque v shaped line above the midline above the apices of the incisors
what can soft tissues do to the radiograph
they can create a shadow meaning they are superimposed on the image
how many openings are there to the pyriform fossa from the nasal end
2
how many openings are there to the pyriform fossa from the oral end
1
how does the nasal end look on a bisecting angle PA
it looks like two ovoid radiolucent structures just at the tip of the nasal spine
what might the nasal spine also look like
it might also look like a concavity next to the base of the nasal septum
what can the incisive canal develop
it can develop cysts
clinically what can be the issue with the incisive e foramen in the oral end
it can be projected over the apex of the tooth and can be mistaken for an inflammatory cyst
what does the oral end of the incisive foramen look like
there is a single radiolucency
what does the nasal septum look like
a radiopaque line
what lies either side of the nasal septum
the ant parts of the pyriform fossa
what is the nasal cavity also known as
the pyriform fossa
what does the inf concha look like
the bone is thin but mucous can be thick
what does he radiograph of the inf concha look like
a smooth rounded opacity due to the thick layer of mucous
which turbinate is shown on the radiograph
the inf nasal concha
why is only the inf nasal concha shown
as it is the largest and due to its position
what dos the canine fossa look like
less bone so less tissue therefore more radiolucency and poorly defined
how does the maxillary sinus look on a radiograph
it is radiolucent
what is another name for the maxillary sinus
the maxillary antrum
clinically what can the maxillary sinus be mistaken as
as a cyst
what is the Y line of ennis
An anatomical landmark created by the superimposition of the floor of the nasal cavity and the border of the maxillary sinus.
what does the y line of ennis depict
It shows that the leg of the y is the laternal side of the nose which is also the medial wall of the antrum
what does one prong of the y show
that it is the floor of the nose(pyriform fossa) and the other prong is the floor of the antrum
what does the floor of the nose look like on an occlusal or post PA
flat horizontal radiopaque line
what other soft tissue can be shown on a radiograph
a subtle line down at an angle- the nasolabial fold
how does the antrum look on a radiograph
undulating radiopaque line which can come as forward as the canine
what can be found within the antrum
septi can be found which are shown as radiopaque lines
which three structures are close in relationship q
the nose the zygomatic buttress and the antrum
what can be seen above the UR 5,6,7,8
we see the undulating antrum but also radiodensity
why do we see radiodensity near the UR 5,6,7,8
due to the zygoma, cheekbone or the malar bone
what is it called where the zygoma meets the maxilla
it is known as the buttress
what is the cheekbone also known as
the zygoma and the malar bone
what does the lateral view of the skull show
the relationship between the maxilla, the zygoma and the pterygoid plates
what is the hamulus part of
the medial pterygoid plate
what is part of the medial pterygoid plate
the hamulus
clinically what is important of the hamular notch
we should consider when making a denture to extend the denture into the hamular notch as this is where soft tissue can give slightly
what is the maxillary tuberosity
it is the bone related to the last molar and just posterior to it
which bone is posterior to the last molar
the maxillary tuberosity
what can be seen near the maxillary tuberosity
soft tissues
which process of the bone can create a shadow when taking a PA
the coronoid process of the mandible can sometimes be seen taking radiographs of the post maxillary teeth PAs
what is the nasal septum seen as on a ant occlusal PA
a vertical radiopaque line
when looking at an upside down occlusal view of the maxilla we can see two similar radiolucent structures what are they
the tearducts or nasal lacrimal ducts
why is it not the greater palatine fossa
the x ray doesnt pass through that way and we would deffo choke the patient trying to get that x ray
what would neurovascular channels look like on an x ray
tiny circular radiolucencies
what does the neurovascular channels supply
the blood and nerve supply to the teeth
what is an important branch of the maxillary division of the trigeminal nerve
the middle or posterior superior alveolar nerve
which CN is the trigeminal nerve
CN V
what can we see from the lingual aspect of the midline
thicker area of bone
radiopaque
the bone has ridges where muscle attaches- genial tubercule- and the genioglossus and genial hyoid muscle attaches
small foramen- the lingual foramen
why does the bone have ridges
where muscle can attach -the genial tubercle
which muscles attach to the genial tubercle
the genioglossus and the genial hyoid muscle
there is also a small foramen on the lingual aspect of the mandible
what is it
the lingual foramen
what nerve supplies the mandible
the inf alveolar nerve
what is the pathway of the inf alveolar nerve
passes along a bony canal where it reaches the premolar region and splits to the mental nerve via mental foramen and the incisive nerve via the incisive foramen
clinically what can be the issue with the inf alveolar nerve
it can be superimposed over a root and mistaken as pathology
how are caries seen on x rays
radiolucencies
what lies inferiorly to the mylohyoid ridge
the submandibular fossa
how does the the submandibular fossa look
relative radiolucency due to the thicker mylohyoid ridge above it also because it is thinner
what lies in the submandibular fossa
the submandibular gland
what is the shape of the submandibular gland
it lies in the submandibular fossa and then works round posteriorly to the mylohyoid muscle
what is another name for the chin
the mental protuberance
how does the chin show up in the x ray
as a radiodensity on the labial aspect of the ant part of the teeth slide 64
what tissues can be shown on the lingual aspect
the soft tissues such as the tongue
