Ch. 11 F.B., Nasal, and Orbits Flashcards
what are the 14 facial bones
- 2 maxillae (maxillary bones)
- 2 zygomatic bones
- 2 lacrimal bones
- 2 nasal bones
- 2 inferior nasal conchae
- 2 palatine bones
- vomer
- mandible
which of the facial bones are located internally and not visible on a dry skeleton from the exterior
two palatine bones and the vomer
largest immovable bones of the face
maxillae/maxillary bones
the only facial bone larger than the maxillae
mandible - movable
structurally the most important bones of the upper face; all other bones of the upper facial area are closely associated with these bones
maxillary bones/maxillae
the right and left maxillary bones are solidly united at the midline below what
nasal septum
each maxilla assists in the formation of these 3 cavities of the face
- mouth
- nasal cavity
- one orbit
what does each maxilla consists of
a body and 4 processes projecting from the body
centrally located portion of the maxilla that lies lateral to the nose
body
process of the maxilla that projects upward along the lateral border of the nose toward the frontal bone
frontal process
process of the maxilla that projects laterally to unite with the zygoma
zygomatic process
the inferior aspect of the body of each maxilla
alveolar process
8 upper teeth occur along the inferior margin of what process
each alveolar process of the maxilla
the two maxillae are solidly united in the midline anteriorly, what is at the upper part of this union
anterior nasal spine
a blow to the nose sometimes results in separation of this from the maxillae
nasal spine
a point at the superior aspect of the anterior nasal spine
acanthion
the body of each maxillary bone contains a large, air-filled cavity known as what
maxillary sinus
several air-filled cavities are found in certain bones of the skull, these sinuses communicate with the nasal cavity and are collectively called what
paranasal sinuses
process of each maxillary bone that can only be demonstrated on an inferior view of the two maxillae
palatine process
these form the anterior portion of the roof of the mouth
two palatine processes
what do the 2 palatine processes of the maxillae form
hard/bony palate
the two palatine processes are solidly united at the midline to form what type of joint
synarthrodial (immovable) joint
common congenital defect - an opening between the palatine processes that is caused by incomplete joining of the two bones
cleft palate
the horizontal portion of what two other facial bones forms the posterior part of the hard palate
palatine bones
these two small inferior portions of the sphenoid bone of the cranium are also seen on the inferior view of the hard palate; similar to feet of the outstretched legs of a bat
pterygoid hamuli
what bones does each maxilla articulate with
2 cranial bones
- frontal
- ethmoid
7 facial bones
- zygoma
- lacrimal
- nasal
- palatine
- inferior nasal concha
- vomer
- adjacent maxilla
located lateral to the zygomatic process of each maxilla
zygoma
these bones form the prominences of the cheeks and make up the lower outer portion of the orbits
zygomatic bones (malar bones)
projecting posteriorly from the zygoma is a slender process that connects with the zygomatic process of the temporal bone to form this
zygomatic arch
a delicate structure that sometimes is fractured or “caved in” by a blow to the cheek
zygomatic arch
what is the anterior end/ portion of the zygomatic arch formed by
zygoma
what is the posterior end/portion of the zygomatic arch formed by
zygomatic process of the temporal bone
positioning landmark; prominent portion of the zygoma
zygomatic prominence
what does each zygoma articulate with
3 cranial bones
- frontal
- sphenoid
- temporal
1 facial bone
- maxilla
thinnest and most fragile bones in the entire body
lacrimal and nasal bones
two bones, about the size and shape of fingernails, that lie anteriorly on the medial side of each orbit just posterior to the frontal process of the maxillae; closely associated with the tear ducts
lacrimal bones
form the bridge of the nose and are variable in size
two fused nasal bones
these bones lie anterior and superomedial to the frontal process of the maxillae and inferior to the frontal bone
nasal bones
these bones are closely associated with the tear ducts
lacrimal bones
point of junction of the two nasal bones with the frontal bone
nasion
what does each lacrimal bone articulate with
2 cranial bones
- frontal
- ethmoid
2 facial bones
- maxilla
- inferior nasal concha
what does each nasal bone articulate with
2 cranial bones
- frontal
- ethmoid
2 facial bones
- maxilla
- adjacent nasal bone
within the nasal cavity are two platelike, curved (scroll-shaped) facial bones called what
inferior nasal conchae (turbinates)
these two bones project from the lateral walls of the nasal cavity on each side and extend medially
inferior nasal conchae (turbinates)
how many nasal conchae are there
3 pairs
- superior and middle (ethmoid bone)
- inferior (facial bone)
the effect of these is to divide the nasal cavities into compartments; these irregular compartments break up or mix the flow of air coming into the nasal cavities before it reaches the lungs
3 pairs of nasal conchae
incoming air is warmed and cleaned as it comes in contact with these
mucous membrane covering conchae
these structures of the ethmoid bone help to separate the cranium from the facial bone mass
- cribriform plate
- crista galli
each of these bones is roughly L-shaped and they are located internally and not visible from the outside
palatine bones
the vertical portion of the palatine bone extends upward between what
one maxilla and one pterygoid plate of the sphenoid
the horizontal portion of the palatine bone helps to make up what
posterior portion of the hard palate
the most superior small tip of the palatine can be seen where
posterior aspect of the orbit
what does each inferior nasal concha articulate with
1 cranial bone
- ethmoid
3 facial bones
- maxilla
- lacrimal
- palatine
what does each palatine bone articulate with
2 cranial bones
- sphenoid
- ethmoid
4 facial bones
- maxilla
- inferior nasal concha
- vomer
- adjacent palatine
these two bones form the bony nasal septum
- ethmoid
- vomer
the nasal septum is formed superiorly by what bone
perpendicular plate of the ethmoid bone
the nasal septum is formed inferiorly by what bone
vomer bone
what is the nasal septum formed anteriorly by
septal cartilage
thin, triangular bone that forms that inferoposterior part of the nasal septum
vomer
describes the clinical condition wherein the nasal septum is deflected or displaced laterally from the midline of the nose
deviated nasal septum
the surface of which bone is marked by small, furrowlike depressions for blood vessels, a source of nose bleed with trauma to the nasal area
vomer
where does deviation of the nasal septum usually specifically occur
junction between septal cartilage and the vomer
largest facial bone and only movable bone in the adult skull
mandible
the mandible originates from 2 separate bones the two bones in the infant join to become one at what age
approx. 1 year
this divides each half of the mandible into two main parts
angle (gonion)
area of the mandible anterior to the angle
body
area of the mandible superior to the angle
ramus
extends along the entire superior portion of the body of the mandible
alveolar process
the anterior aspect of the adult mandible is best seen from this view
frontal view
the single body of the mandible forms from each lateral half and unites at the anterior midline; what is the union of the mandible called
symphysis pf mandible (symphysis menti)
flat triangular area below the symphysis, marked by two knob-like protuberances that project forward
mental protuberance
what is the center of the mental protuberance described as
mental point
located on each half of the body of the mandible - serves as passageways for the mental artery and vein and mental nerve (branch of inferior alveolar nerve) that innervates the lower lip and chin
mental foramen
the upper portion of each ramus terminates in a U-shaped notch called what
mandibular notch
the process at the anterior end of the mandibular notch is called what
coronoid process
process that lies just inferior to the zygomatic arch and serves as a site for muscle attachment
coronoid process
posterior process of the upper ramus
condyloid process
the condyloid process of the upper ramus consists of two parts , what is the round end of the condyloid process
condyle/head
constricted area directly below the condyle of the upper ramus
neck
the condyle of the condyloid process fits into what
TM fossa of the temporal bone (forms TMJ)
the horseshoe shape of the mandible is well visualized on what projection
submentovertical (SMV)
what way do the coronoid processes of the mandible project on the SMV projection
lateral
what way do the condyles project of the mandible on an SMV projection
medial
the only movable joint in the skull
temporomandibular joint (TMJ)
where is the TMJ located in relation to the EAM
just anterior and slightly superior
what type of joint is the TMJ
synovial (bicondylar) (plae;gliding)
what type of joints are the teeth with the mandible and maxillae
fibrous (gomphosis)
how is each orbit shaped
cone-shaped
the rim of the orbit, which corresponds to the outer circular portion of the cone called
base
what is the posterior portion of the cone of the orbit called
apex
what does the apex of the orbit correspond to; which the optic nerve passes
optic foramen
how does the long axis of the orbit project
upward and toward midline
with the OML parallel to the floor, how does each orbit project specifically
superiorly 30 degrees and medially 37 degrees
to radiograph either optic foramen how does a patient need to be positioned
extend chin 30 degrees and rotate head 37 degrees
how many bones is each orbit composed of
7 bones:
3 cranial
- frontal
- sphenoid
- ethmoid
4 facial bones
- maxilla
- zygoma
- lacrimal
- palatine
what bones is the circumference/circular base of each orbit made up of
- frontal bone (orbital plate)
- maxilla (facial bone)
- zygoma (facial bone)
forms most of the roof of the orbit
orbital plate of the frontal bone
forms much of the lateral wall and some of the floor of the orbit
zygoma
a portion of this helps form the floor of the orbit
maxilla
a portion of the medial wall of the orbit is formed by this thin bone
lacrimal
these make up most of the posterior orbit
sphenoid and ethmoid
only a small bit of this bone contributes to the innermost posterior portion of the floor of each orbit
palatine
small hole in the sphenoid bone that is located posteriorly at the apex of the cone-shaped orbit; allows passage of the optic nerve (CN II) - continuation of the retina
optic foramen
cleft or opening between the greater and lesser wings of the sphenoid bone, located lateral to the optic foramen; allows transmission of 4 primary cranial nerves (CN III to CN VI) - control movement eye and eyelid
superior orbital fissure
opening between the maxilla, zygomatic bone, and greater wing of the sphenoid; allows transmission of the maxillary branch of CNV - permits entry of sensory innervation for the cheek, nose, upper lip, and teeth
inferior orbital fissure
small root of bone that separates the superior orbital fissure from the optic canal
sphenoid strut
small canal into which the optic foramen opens
optic canal
any abnormal enlargement of the optic nerve could cause erosion of this, which is actually a portion of the lateral wall of the optic canal
sphenoid strut
for the parietoacanthial (waters) projection, the CR is parallel with this
MML
in the parietoacanthial (Waters) projection, where are the petrous ridges demonstrated
below the maxillae and maxillary sinuses
where is CR according to Bontrager for lateral facial bones
zygoma (midway between outer canthus and EAM)
how do you position the modified parietoacanthial projection
LML perp to IR (OML forms 55 degree angel with IR)
how do you position for PA axial (caldwell)
OML perp to IR, CR angled 15 degrees caudad and exit nasion
how do you position for the parietoacanthial (waters)
MML perp to IR (OML forms 37 degree angle with IR)
what is CR according to Bontrager for lateral nasal bones
1/2” inferior to nasion
what is CR for superoinferior tangential (axial) of nasal bones
IR perp to GAL, CR to nasion and angle so CR is parallel with GAL (CR skims glabella and anterior upper teeth)
what is CR according to Bontrager for submentovertical (SMV) for zygomatic arches
IOML parallel with IR, CR at level 1.5” inferior to mandibular symphysis (CR perp to IOML)
what should the angle between the MSP and plane of IR measure for parieto-orbital oblique projection (Rhese)
53 degrees
