hello everyone and welcome back this is dr O
in this video we're going to talk through the temporal and infra-temporal
fossae so specifically what are the bony structures and landmarks
that will delineate these fossa and we'll talk about what is contained within them
so the temporal fossa tends to be a little bit more straightforward to kind of imagine the
space that it occupies and one of the the first things you want to think about is back to those
superior and inferior temporal lines and those are the attachment points we saw from temporalis
and the temporalis fascia those are running up and along here and that's the superior most
aspect of the temporal fossa now inferiorly we can see that it ends at the zygomatic
arch laterally and then at that infra temporal crest here in white
medially now within it we see the temporalis muscle and its fascia then its blood supplies
and nerves so we see the deep temporal arteries veins and nerves also the superficial temporal
artery will pass up and around we'll remember the superficial temporal artery is one of the terminal
branches of the external carotid artery and will come up to occupy and supply this space up here
also the zygomaticotemporal nerve which we'll talk about in future sessions will be within this space
now the medial most aspect of the temporal fossa is made up of a point
on the skull called the terion the terion is where the frontal
parietal temporal and sphenoid bones meet at this point we also see that there are actually middle
meningeal artery branches just deep to this point so this is a point where an injury can take place
leading to a epidural hematoma in the case of if that middle of an angel artery is disturbed
but it is an important point on the lateral side of the skull then if we're thinking about most
lateral so toward us or away from the slide toward the viewer that is the temporal fascia
so the temporal fascia is that that is running around superficial to that temporalis muscle
so let's take a look at what that looks like in somewhat of a 3d these are just going to
be annotations so they're not perfect but i hope that this kind of gives you a feel for the space
so from those superior and inferior temporal lines down to the zygomatic arch and that infra-temporal
crest so that space containing temporalis muscle its blood supply and other neurovasculature is
the temporal fossa now the infra-temporal fossa is a little bit less straightforward
so let's talk through some of its boundaries here we can see that posterior to the maxilla
is the first boundary then superiorly the greater wing of the sphenoid bone
and posteriorly we see that styloid process the mastoid process and the tympanic plate
of the temporal bone so within this space below the temporal bone is the infra-temporal fossa
now in terms of medial to lateral it is bounded laterally by the ramus of the mandible seen here
and medially by that lateral pterygoid plate so it's within this space here the inferior most
boundary will be at the point where the medial pterygoid attaches to the angle of the mandible
so right around here so you can imagine that it will fill in all of that space
i like to think about it in terms of sort of a cup shape although it is quite an irregularly
shaped structure so don't let this get too it's not exactly like this but hopefully the
schematic will help you so we'll note that the temporalis muscle sitting up within here
will attach down here onto the coronoid process and so it will
also traverse into the infra-temporal fossa as well as the temporal fossa
the other thing that we see in infra-temporal fossa will be those pterygoid muscles
around the pterygoid muscles we find the maxillary artery and its many branches as well as the
pterygoid venous plexus and then what we've been looking at earlier is all of that to do with v3 so
we see v3 and its branches the otic ganglion found medially to v3 and the chorda tympani joining
the lingual nerve in that infra-temporal fossa within this space heading toward the oral cavity
this one is a little harder to do on the skull but hopefully
um as we move around some of these lines these purple lines will make a little bit more sense
um but we can see here is sort of that superior boundary is where um the end of the temporal fossa
is laterally we see the ramus of the mandible as well as the angle of the mandible inferiorly
and then that lateral pterygoid plate immediately
superiorly we also are looking below that sphenoid bone but also below the temporal bone
and here you see the parts of the temporal bone that are more of the posterior aspect of it
so the infra-temporal fossa sits in this space and it actually has quite a few communications with
other spaces the first of which makes sense to us as we had just seen it is that temporal fossa
so you can imagine there is a communication between here and here from the temporal fossa
into the infra-temporal fossa and that is represented here on my cup
just as the superior roof kind of moving back and forth
so also superiorly we find the communication between the infra-temporal fossa
in the middle cranial fossa so this will be through foramen ovale and foramen spinosum all
of those structures we saw passing in and out of the infra-temporal fossa through those foramina
medially we can see this sort of tear-shaped structure
right about here and that is the targo maxillary fissure so the terrible maxillary fissure is the
entrance into now the space deep within here kind of shadowed is the targopalatine fossa
so put a pin in that we're coming back to it but for now we know that this is how you can go from
the infra-temporal fossa into the targo palatine fossa
the other communication is with the orbit and that's through the
infraorbital fissure so we'll remember you can look at this picture on the bottom left
the superior orbital fissure and then here we see nicely another sort of tear-shaped structure
an infraorbital fissure and that is sort of a almost continuous here you can see
with that terracopalatine excuse me with the terrible maxillary fissure so here is
paragon maxillary and here is infraorbital so that will then communicate with the orbit
so here we can see in black is shown
that space where the temporal fossa communicates with the infra-temporal fossa
next in blue we're going to see the foramina where the infra-temporal fossa communicates with
the middle cranial fossa so here we have the foramen ovale and foramen spinosum
now as we move medially where that green kind of teardrop shape is is that pterygomaxillary
fissure so sort of between the pterygoid plate the lateral pterygoid plate and the posterior maxilla
and then in yellow is the opening of the infraorbital
fissure leading into the orbit so there's a nice view of it
great so in order to kind of review what we've gone through based on what you see
in the infra-temporal fossa but also what we've seen previously in other of these mini lectures
i want you to try to write out or maybe diagram which structures enter or exit the infra-temporal
fossa through the pterygomaxillary fissure and the foramen ovale so pause the video
so you can take a second to write these things down and then we'll talk about it
when you're ready let's start with foreign valley so foramen ovale is in that roof and
we definitely have structures entering into the middle or excuse me we definitely have structures
entering into the infra-temporal fossa here what is our major structure coming through and forward
with lots of branches and that is v3 so foramen ovale is where v3 enters the infra-temporal fossa
now what about that tear-shaped pterygomaxillary fissure what structure might then lead into
that space so here we're talking about the maxillary
artery so through the pterygomaxillary fissure is where the maxillary artery exits
the infra-temporal fossa to then enter the pterygopalatine fossa so the third part remember of the
maxillary artery is the pterygopalatine part and many of its branches will happen within that space
all right that is everything for this video
thank you all for your attention and i look forward to seeing you in the next one