hello all this is dr. O and in this video we're going to talk about the supportive structures
of the temporomandibular joint we're going to ask what major ligaments and other connective
tissue structures limit the range of motion of the temporal mandibular joint now let's start
with looking at the TMJ with the capsule still intact so well that's what we you can see in
this image over here as the capsule is still kind of encompassing that joint now in the
very lateral aspect of the capsule is where we find this lateral ligament so outlined here in
yellow is the lateral ligament and you can think of it as a sort of part of the capsule that will
restrict some posterior and lateral movements now if we go deeper we remove that capsule we
then see the articular disc sitting here on top of the mandibular condyle you can imagine the
coronoid process sitting here and this would then complete the portion of the mandible
that's been removed then just posterior to the disc but still within the capsule we find the
retro articular tissue and you can imagine tissue within the capsule could potentially limit some
range of motion so this contains our vasculature and any swelling or edema in the region can lead
to or be in relation to temporomandibular disorder or just TMJ syndrome in general
the next two structures we can see here are the extrinsic ligaments the first of them being the
stylo mandibular ligament now this is actually an extension from the fibrous capsule of the parotid
gland we see that it attaches to the styloid process superiorly here and then also inferiorly
along the ramus and the angle of the mandible the way it's oriented it does not have too much
of an influence on how the joint functions but it does serve to connect the cranium to the mandible
the second ligament is the pheno mandibular ligament or remember that this was found more
medial to the stylo mandibular ligament and also medial to the mandible so let's orient ourselves
in this image first off think you are sitting in the oral cavity we can see teeth molars here
and maxillary molars here and the wall here has been removed so that we can see into this space
but as we look into that space we see this bony feature of the mandible and that's the lingual
oh so you can imagine right about here kind of not shown in this image we might see the
inferior alveolar nerve as it enters into the mandible through the mandibular foramen
also in a future video we'll talk more about it but this nerve coming off of inferior
alveolar nerve is the nerve to the mylohyoid muscle so this comes off just before that
mandibular foramen and we see a nice example of it here but back to the ligaments thus we know
mandibular ligament will have its superior attachment on the spine of the sphenoid and
then an inferior attachment on the lingula of the mandible and it's tense when the TMJ
is in an intermediate position all right so let's take a look at these on our model here
we'll start by turning laterally here we see in purple the articular disk and then just behind
it is where we find the retro articular tissue or the retro disk old tissue all of that is an
encompassed or contained within the capsule so the articular capsule of the joint and
then laterally on the capsule they're sort of a thickening of it and that is the lateral ligament
now we see from kind of a medial posterior view this is our stylo
mandibular ligament and then more medial to that
we see the spino mandibular ligament kind of extending toward the area of the lingula
they're just another view so you can kind of see a little bit better so here here is
the stylo mandibular ligament and then more medially this what we were looking at before
is this Fino mandibular ligament so if you can imagine we're upside down now so that makes it
even easier to see what we're looking at imagine you're in the oral cavity looking laterally and
that'll help you kind of see what that image is showing us in the last slide
great so let's talk about the question now so the question is which supportive structure of
the TMJ is a capsular ligament is it the lateral ligament this Fino mandibular ligament or the
stylo mandibular ligament so take a second to pick your answer and then we'll talk about it
when you're ready so the correct answer here is the lateral ligament so the lateral ligament we
see kind of represented over here in yellow and it is capsular in that it is part of the capsule
essentially and it reinforces the capsule on the lateral side we see both the spino
mandibular ligament and the stylo mandibular ligament are further away from the capsules
now that's everything for this video thank you so much for your attention
and I look forward to seeing you in the next one
if you have questions at all always feel free to reach out or ask them on Piazza