The Norma Frontalis (pt.1)

The Norma Frontalis (pt.1)


Now, the norma frontalis, and it’s called
the “norma frontalis”, because the main bone that is forming it, is the frontal bone. But,
below the frontal bone, there are the two nasal bones, and below and lateral to the
nasal bones, there are the two maxilla. Above, and lateral to the maxilla, there are the
two zygomatic bones. Therefore, we have the frontal bone, the nasal, and the nasal articulates
with the maxilla, and the maxilla articulates laterally with the zygomatic bone. The, frontal
bone in the norma frontalis has a middle process, that will articulate with the two nasal bones,
therefore it’s called the nasal process. And, it has two lateral processes, which are going
to articulate with the zygomatic bone, therefore they are called the zygomatic processes . So,
this is the nasal process of the frontal and this is the zygomatic process that goes to
the zygomatic. And of course, the supraorbital margin, above the orbit is formed by the frontal
bone. The supraorbital margin, has a foramen inside it, that may be in the form of a notch,
in the case of a complete foramen. So, this foramen or notch is called the supraorbital
notch or foramen, and it allows the passage of the supraorbital nerve and vessels of the
scalp, thereby, the supraorbital nerve and the supraorbital artery to the scalp. Now,
the sutures that join the frontal bone to the nasal bone, this suture is called the
frontonasal suture. And, the suture that separates the two nasal bones is called the internasal
suture. And, the point of meeting of the frontonasal and the internasal sutures, is called the
nasion. Therefore, the nasion is the point of meeting of the frontonasal and the internasal
sutures. Opposite, to the nasion posteriorly, there is the inion, which is the most superficial
point of the external occipital protuberance. Therefore, this is the nasion and just above
the nasion, there is a part of the frontal bone, which is called the glabella, from arise
on each side the superciliary arch. The, glabella and the superciliary arches are not prominent
in female. Therefore, I have drawn the glabella and the superciliary arches here, because
this is a female skull and they are not prominent. When, the glabella is not prominent, then
the nasion will become superficial in the female. So, because this is a female skull,
the glabella is not apparent or clear and the superciliary arches are not clear and
therefore, the nasion becomes more superficial. If we look to a male skull, we’ll find that
the glabella is very prominent and doesn’t need any drawing as well as the superciliary
arches are very prominent, and of course this the supraorbital foramen, this is the supraorbital
notch as the supraorbital foramen in a form of a notch, and we have two notches here.
Therefore, in a male the glabella is very prominent and the superciliary arches are
very prominent and therefore, the nasion becomes deep, this is the frontonasal suture, this
is the nasal bone, this is the internasal suture and of course this is the nasion. Now,
when we come to the zygomatic bone. The, zygomatic bone articulates medially, with a part of
the maxilla. This, part of the maxilla is called the zygomatic process of the maxilla.
So, the zygomatic bone articulates medially with the zygomatic process of the maxilla,
and laterally, it gives two processes. A, process that goes up to the frontal bone and
it is called the frontal process. So, the frontal process of the zygomatic bone articulates
with the zygomatic process of the frontal. And posteriorly, gives this process that goes
to the temporal bone (this site of the temporal bone as it has been removed from here). So,
when we look to the other side, again, the zygomatic bone gives an upper process that
goes to the frontal and it is called the frontal process, and the process that goes backward
to the temporal bone is called the temporal process, of course the temporal bone gives
process to it, special to the zygomatic and is called the zygomatic process. So, any bone
gives a process to another bone, will take the name of the other bone i.e. the temporal
bone give zygomatic process and the zygomatic bone give a temporal process . The, two processes
together will from the zygomatic arch, which is a very important landmark in the norma
lateralis. Of course, the zygomatic bone has two external surfaces, a surface looking forward
to the face, which is called the facial surface. And, in the facial surface we’ll have a foramen,
that is called the zygomaticofacial foramen and it allows the passage of the zygomaticofacial
nerves and vessels. The, other surface that is facing the temporal bone, is called the
temporal surface, and it has a foramen, which is called the zygomaticotemporal foramen,
allowing the passage of the zygomaticotemporal nerve and vessels. Therefore, this is the
facial surface with the zygomaticofacial foramen, allowing the passage of the zygomaticofacial
nerve and vessels to the face. And, this is the temporal surface having the zygomaticotemporal
foramen, allowing the passage of the zygomaticotemporal nerve and vessels to the scalp.

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