Alright let's talk about the moveable portion of the skull or the mandible a lot of times we
refer to this as the lower jaw and really this is the most robust in terms of the bones of
your skull because you have a lot of muscle attachment here particularly there's really
strong muscles of mastication so they all have to attach to the mandible in some way so we're looking
at an anterior view here you're gonna have the body of the mandible you're gonna have the ramus
of the mandible that's the part that projects up towards the skull and then you're going to
have the internal portion which we'll look at in just a moment so probably the most prominent
thing that you see here is that obviously this is where your mandibular teeth sit and this is a
good time to talk about the differences in terms of the teeth you have four types of teeth you
have your incisors which are the more anteriorly-placed you'll have a central incisor and a lateral
incisor next to that you'll have your canine you only have one canine per quadrant so four in terms
the entirety of your mouth so one canine sometimes it's a little bit more pointed with age this will
wear down typically now in adult dentition you'll have two premolars and a lot of times you hear
these referred to as bicuspids they're called bicuspids because they have two cusps to points
in terms of the bone now let's talk a little bit about the difference between adults and
juvenile dentition and juvenile dentition you do not have any premolars so premolars are unique
to adult dentition now moving more posteriorly you'll have three molars your first molar second
molar and third molar and we've often refer to the third molar as your wisdom teeth so most
people have had these removed some individuals never actually form wisdom teeth so the in this
particular individual they did have a third molar now in juveniles you'll have two molars but not a
third molar so that's why you have a differing amount of teeth in juveniles all right so let's
talk about some of this structures that you want to know in terms of the mandible when you're
looking at the ramus or this vertical portion the more anterior projection is referred to as your
coronoid process this is going to be the distal attachment of your temporalis muscle so this large
muscle that sits on the side of your your skull is going to attach on the temporalis right there
so one of the broadest muscles of the skull the more posterior projection is your mandibular
condyle and this was what is articulating with a mandibular fossa of your temporal bone and
this is going to be the mandible portion of your TMJ joint or your temporomandibular joint now
one other thing we want to look at this anterior view are these two foramina on either side these
are your mental foramen I always think about putting your you know really thinking hard
putting your hand right here thinking mental this is where V3 or your sensory branch of your third
division of your trigeminal nerve is going to exit so important in terms of providing sensory
innervation in this region okay now we're going to look inside in terms of the mandible and there's a
lot of important areas right here particularly in terms of clinical practice for dentists so let's
start with probably the most important region this is what's referred to as your mandibular
foramen you can see that it's kind of entering a canal right here your inferior alveolar nerve
is going to enter the bone in this region your inferior alveolar nerve is providing sensory
innervation to all of these mandibular teeth so if you think about a dentist that needs to
anesthetize this region they're going to in try to put the anesthetic right around this region
and it will knock out all that quadrant of the teeth right here so inferior alveolar nerve
or the third division of trigeminal nerve now how are you going to find that well obviously
they're very well trained but one thing they're gonna do is they're going to enter their finger
right around this region and feel what's referred to as the lingula your lingula is this little
projection of bone right here so they'll feel that they'll palpate that they'll put the anaesthetic
right in here so knock out half of these teeth if you're doing it here and if you were to put it in
this region knock out this half of the teeth all right also importantly you see right here
there's a buildup of bone this is referred to as the mylohyoid line so your mylohyoid muscle which
forms the floor of the mouth is going to attach here and you have two important glands right in
this region inferiorly you have your submandibular gland superiorly you have your sublingual gland
these are two of your salivary glands that are going to be associated with this region