MOR 345 quiz 1 Terms and Studyguides
List the Acquired Facial Markings.
- Nasolabial Sulcus ~Transverse Frontal Sulci ~ Interciliary Sulci ~ BuccoFacial Sulcus ~ Superior Palpebral Sulcus ~ Inferior Palpebral Sulcus ~ Optic Facial Sulci ~ Labial Sulci ~ Mandibular Sulcus ~ Platysmal Sulci ~ Cords of the Neck
List the natural facial markings.
- Philtrum ~ Nasolabial Fold ~ Nasal Sulcus ~ Oblique Palpebral Sulcus ~ Angulus Oris Eminence ~ Angulus Oris Sulcus ~ Labiomental Sulcus ~ Submental Sulcus ~ Dimples
According to the lesson notes, what are three examples of pre-embalming restorative art treatments?
- aligning features - temporary sutures - suturing of clean cuts
Compare and contrast the condyle and the coronoid process.
- condyle: posterior, articulating process of the ramus of the mandible - coronoid process: anterior, non-articulating process of the ramus of the mandible
List three examples of "major" restorative art procedures
- feature reconstruction - attachment of dismembered body parts - deep wound cavity treatment
List and describe the 4 dimensions of form in Restorative Art.
- length: a vertical dimension - width: the dimension of an object measured across from side to side. - projection: The act of throwing forward; a part extending beyond the level of its surroundings. - contour: the outline or surface form
List the 3 heads of the Quadratus labii Superioris muscle.
- levator labii superioris alaque nasi - levator labii superioris - zygomaticus minor
List three examples of "minor" restorative art procedures.
- setting features - simple suturing to close incisions/minor lacerations - minor integumentary waxing
According to the lesson notes, what are three examples of post-embalming restorative art treatments?
- wax restorations - cosmetics - hypodermic tissue building
Describe the forms the Angulus Oris Sulcus may take in the various stages of life. Include Youth (Infancy), Maturity and Old Age.
- youth - angular - maturity - crevice extending inferiorly and obliquely from the end of the line of mouth closure - old age - can reverse direction and extend into upper integumentary lip.
Describe where the Frontal eminences are located.
1" below the hairline
How many basic facial profile views are there? What are they
3; convex, concave, vertical
glabella
A single bony prominence of the frontal bone located between the superciliary arches in the inferior part of the frontal bone above the root of the nose.
Describe the Transverse Frontal Sulci.
Acquired horizontal furrows of the forehead (Think Gordon Ramsay's surprised angry face)
Describe the Labial sulci.
Also known as Smoker's Lines - vertical furrows of the lips extending from within the mucous membranes into the integumentary lip
What mark is formed by the Buccinator muscle?
Bucco-facial sulcus (the vertical furrow/wrinkle in the soft tissues of cheek)
symmetry
Correspondence in size, shape, and relative position of parts that are on opposite sides of the face.
Another name for the frowning muscles
Corrugator muscles
Describe the Mandibular Sulcus.
Furrow beneath the mandible which rises vertically on the cheek
Another name for the Zygomaticus Major Muscle
Laughing or Smiling Muscle
Who has a greater prevalence of wrinkles, men or women? Why?
Men, because women have more soft adipose tissue
Name the 4 External Cranial Bones.
Occipital Bone, Parietal Bones, Temporal Bones, Frontal Bone
The sphincter muscle of the mouth
Orbicularis Oris a.k.a. Puckering Muscle
projection
The act of throwing forward; a part extending beyond the level of its surroundings.
restorative art
The care of the deceased to recreate natural form and color.
The Philtrum lies between what two structures?
The columna nase and the medial lobe of the mucous membrane of the upper lip (the nose and upper lip)
Cribiform plate
The horizontal plate of the ethmoid bone separating the cranial cavity from the nasal cavity.
mandible
The horseshoe-shaped bone forming the inferior jaw.
Describe the Labiomental Sulcus
The junction of the lower lip and the chin, which may appear as a furrow
Describe the Oblique Palpebral Sulcus.
The shallow, curving groove below the inner corner of the eyelids
Describe the Angulus Oris Eminence.
The small convex prominence lateral to the end of the line of mouth closure
Levator labii superioris
This is the intermediate or "middle" head of the Quadratus Labii Superioris
Zygomaticus minor
This is the lateral (or outermost) head/belly of the Quadratus Labii Superioris which emphasizes the nasolabial fold
Levator labii superioris alaque nasi (Common elevator)
This is the medial (or inner) head of the Quadratus Labii Superioris
Define what is meant by natural facial markings.
Those markings which may be present at birth
The facial markings produced by the corrugators
Vertical intercilliary Sulci (vertical wrinkles between the eyes)
concave profile / infantine / retrousse
a basic facial form in which the forehead protrudes beyond the eyebrows while the chin protrudes beyond the plane of the upper lip
convex profile
a basic profile form in which the forehead recedes from the eyebrows while the chin recedes from the plane of the upper lip (most common).
Angle of the mandible
a bony angle formed by the junction of the posterior edge of the ramus of the mandible and the inferior surface of the body of the mandible
Alveolar process
a bony ridge found on the inferior surface of the maxilla and the superior surface of the mandible which contains the sockets for the teeth
Sulcus / Furrow / wrinkle
a crevice in the skin accompanied by adjacent elevation
triangular
a frontal head form in which the face is wider between the angles of the mandible than it is at the forehead
round / infantine
a frontal head form in which the head exhibits maximum curvature
square / strong
a frontal head form in which the head is broad and exhibits very little curvature; the forehead is wide and the angles of the mandible are usually low as well as wide
oval
a frontal head form in which the head is generally egg-shaped, with the cranium slightly wider than the jaws
oblong
a frontal head form in which the head is long and narrow throughout.
diamond
a frontal-view geometric head shape which is widest across the cheekbones, narrowing in width in both the forehead and the jaws.
Quadratus labii superioris
a large, 3-bellied muscle extending from the cheekbone and lower rim of the eyesocket to the orbicularis oris
Procerus (Concentrating muscle)
a long, thin slip of muscle over the bridge of the nose that draws the skin of the forehead inferiorly.
Levator palpebrae superioris
a muscle of facial expression which raises the upper palpebra.
Zygomaticus major (Laughing or Smiling muscle)
a muscle of the face which draws the superior lip posteriorly and superiorly
Sternocleidomastoid muscle (SCM)
a muscle of the neck that is attached to the mastoid process of the temporal bone and the sternum and clavicle; forms the lateral border of the neck
maxilla
a paired bone with several processes that form the skeletal base of most of the superior face, roof of the mouth, sides of the nasal cavity, and floor of the orbit
Convex-vertical profile
a profile variation in which the forehead recedes from the eyebrows while the chin and upper lip project equally to an imaginary vertical line.
Convex-concave profile
a profile variation in which the forehead recedes from the eyebrows while the chin protrudes beyond the plane of the upper lip.
eminence
a prominence or projection of a bone
Corrugator (Frowning muscle)
a pyramid-shaped muscle of facial expression which draws the eyebrows inferiorly and medially; located at the medial end of each eyebrow
condyle
a rounded prominence at the end of a bone forming an articulation; the posterior process of the ramus of the mandible
inverted triangle / heart
a three-sided figure whose base is superior to its apex; when used to describe a frontal-view geometric headshape, a head which is wide at the forehead and narrow at the jaw
mental eminence
a triangular projection on the interior portion of the anterior mandible
recession
a type of surface formed by the withdrawal of a part from its normal position.
color
a visual sensation perceived by the eye and the mind due to the activity and vibration of light
Those facial markings which may develop with age are known as
acquired facial markings
Alveolar prognathism
an abnormal protrusion of the alveolar process
Groove
an elongated depression in a relatively level plane or surface
Fold
an elongated prominence adjoining a surface
Bilateral view
an inferior or superior viewpoint which permits the comparison of two sides of an object or facial feature
face
anatomically, the region from the eyes to the base of the chin; physiognomically, the region from the normal hairline to the base of the chin.
The small triangular depression in the anterior part of the angulus oris eminence.
angulus orcis sulcus??
hard palate
anterior portion of the roof of the mouth
frontal (direct view)
anterior; the anterior view of the face or features
What is an alternate term for the vertical facial profile?
balanced
Anterior
before or in front of; an anatomical term of position and direction which denotes the front or forward part
inferior
beneath; lower; the underside of an organ or indicating a structure below another structure; toward the feet
The nasolabial fold lies between what 2 structures?
between the wing of the nose and the corner of the mouth
vomer
bone of the nasal cavity situated between the nasal passages on the median plane; it forms the inferior and posterior portion of the septum of the nose
zygomatic bone / zygoma / malar
bones of the cheek
Those facial bones that form a dome over the nasal cavity
bridge of the nose
Temporalis
broad fan-shaped muscle over the squama of the temporal bone; muscle of mastication which helps to close the mandible; the strongest of the chewing muscles
Another name for the Trumpeter's Muscle
buccinator
The vertical slightly curved furrow in the soft tissue of the cheek
bucco-facial sulcus
Another name for the Levator Labii Superioris Alaeque Nasi
common elevator
Which facial profile is least common?
concave / infantine / retrousse
What is the most common facial profile?
convex
The prominent vertical folds found on the neck.
cords of the neck
The insertion point of the temporalis muscle
coronoid process of mandible
The Transverse interciliary sulci are formed or accentuated by this muscle
corrugator / frowning muscle
The facial markings which are formed or enhanced by the action of the Orbicularis Occuli
creates the optic facial sulci
Another name for Optic Facial Sulci
crow's feet
convex
curved evenly; resembling a segment of the outer edge of a sphere
Describe the Incisive fossa.
depression found immediately below the 4 front teeth
Another name for the Quadratus Muscle
depressor labii inferiorus
The quadrilateral muscle that approaches the lower lip from below and attaches between the middle of the mouth and the angle of the mouth
depressor labii inferious / quadratus
Shallow depressions found in the soft tissue of the cheeks and/or chin
dimples
nasal bones
directly inferior to the glabella and forming a dome over the superior portion of the nasal cavity
Digastricus
double-bellied muscle which lies below the body of the mandible and draws the hyoid bone superiorly
What is the physiological function of the occipito-frontalis muscle?
draws the scalp posteriorly and raises the eyebrows
What facial markings are enhanced or formed by the Levator Angulis Oris?
emphasizes the presence of the nasolabial fold and the angulus oris eminence
Another name for the occipitofrontalis muscle
epicranius
Describe the location of the Sternocleidomastoid muscle
extends from the lobe of the ear to the clavicle
form
external shape; a mold for casting; produce a certain shape; to constitute existing elements
Acquired facial markings
facial markings that develop during one's lifetime, primarily as a result of repetitious use of certain muscles
An elongated prominence of flesh which abuts convexly against an adjacent surface
fold / eminence
The large opening of the occitipal bone is called the:
foramen magnum
The general shape of the skull can be observed from what three viewpoints?
frontal, side/profile, crown
Another name for a wrinkle
furrow
Describe the Superior Palpebral Sulcus
furrow located at the attached margin of the upper eyelid
Common transverse sulcus
furrow of the upper eyelid found approximately 1/8" - 1/4" from the line of eye closure
Describe the interciliary sulci.
furrows between the eyebrows (Gordon Ramsay's truly pissed off face)
Which transverse frontal sulci appear deeper than the others?
furrows nearest the eyebrows
Linear sulci
furrows of the eyelid which are short and broken, extending horizontally on the palpebrae themselves and which may fan from both the medial and lateral corners of the eyes.
Transverse frontal sulci
furrows which cross the forehead.
The singular elevation of the frontal bone found just superior to the bridge of the nose and medial from the superciliary arches
glabella
An elongated depression in a surface plane is known as a(n)
groove
three-quarter view
in reference to a photograph, a view which reveals the fullness of the cheeks.
The furrow of the lower (attached) border of the lower eyelid
inferior palpebral sulcrus
The movable portion of a muscle which is attached to muscle or skin
insertion
What is the purpose of the foramen magnum on a living body?
it is the opening through which the spinal cord passes from the brain into the spine
What is the purpose of the foramen magnum on a decapitated body?
it is used to reattach the head, by attaching one end of a rod to the bones of the spinal column and the other end through the foramen magnum
Asymmetry
lack of symmetry, balance, or proportion
Occipitofrontalis (Epicranius)
large singular muscle which covers the top and sides of the cranium. It draws the scalp posteriorly and inferiorly and raises the eyebrows
The muscle of the mouth which is located in the region of the upper canine teeth
levator anguli oris
The intermediate head of the Quadratus Labii Superioris and raises the upper lip
levator labii superioris
The muscle that raises the upper eyelid
levator palpebrae superioris
occipital bone
lowest part of the back and base of the cranium, forming a cradle for the brain
Do males or females have more definite facial markings due to muscle action?
males
The muscle which forms the exterior planes of the cheek
masseter
What are the 2 main muscles of mastication?
masseter and temporalis
The thick quadrilateral muscle located on the side of the face near the angle of the mandible
masseter?
The bones which form the upper jaw
maxillae
Differentiate between the terms medial and lateral.
medial - toward the midline lateral - away from midline
The bony prominence of the chin
mental eminence
The muscle that wrinkles the chin
mentalis
superior
more elevated in place or position; higher; upper; anatomically towards the head.
Palpebra
movable, protective fold that opens and closes, covering the eye (eyelid)
Mentalis
muscle situated over the prominence of chin which elevates and protrudes the inferior lip and wrinkles the skin over the chin
The two bones which lie directly inferior to the Glabella
nasal bones
The small angular area formed by the junction of the posterior margin of the nasal wing and the superior end of the Nasolabial fold.
nasal sulcus
The prominence of the anterior part of the cheek.
nasolabial fold
The furrow which may develop along the medial margin of nasolabial fold
nasolabial sulcus
buccal depression
natural, shallow concavities of the cheeks which extend obliquely downward from the medial or lateral margins of the cheekbones
medial
nearer to the midline; opposite of lateral
Describe the mouth and nose of an oblong geometric head shape.
nose is long with prominent tip; mouth tends to narrow
The large muscle that covers the top and sides of the head
occipitofrontalis / epicranius
vertical concave profile
one in which the forehead and the eyebrows project equally to a vertical line and the chin protrudes more than the upper lip
vertical convex profile
one in which the forehead and the eyebrows project equally to a vertical line and the chin recedes from the projection of the upper lip
vertical profile / balanced
one in which the forehead, upper lip, and chin project equally to an imaginary vertical line
zygomatic arch depression
one of the lesser concavities of the face located on the lateral portion of the cheek inferior to the zygomatic arch
Those facial markings that radiate, laterally from the outer canthus of the eye, onto the side of the face
optic facial sulci (crow's feet)
The broad sphincter muscle that surrounds the eye
orbicularis oculi
The portion of a muscle which is attached to a fixed point
origin
What is the general shape of the skull?
oval
What is the most common geometric head form?
oval
frontal eminences
paired, rounded, unmargined prominences of the frontal bone found approximately one inch beneath the normal hairline
horizontal
parallel to the plane of the horizon; transverse plane
vertical
perpendicular to the plane of the horizon; balanced.
The vertical groove on the central plan of the upper integumentary lip
philtrum
The broad, flat superficial muscle of the neck
platysma
he transverse wrinkles of the neck are enhanced or caused by this muscle
platysma
The greatly dipping furrows across the neck
platysmal sulci
The long, thin muscle which extends vertically from the lower part of the nasal bone to the skin of the lower part of the forehead
procerus / concentrating muscle
mandibular prognathism
protrusion of the inferior jaw
maxillary prognathism
protrusion of the superior jaw
post-embalming treatments
restorative procedures performed after the embalming operation.
pre-embalming treatments
restorative procedures performed before the embalming operation.
median plane / midsagittal plane
situated or placed in the middle of the body dividing it into right and left halves
lines of the temple
slightly raised, curved ridges located at the boundary between the forehead and the temple region; marks the lateral border of the forehead
inclination
slope; deviation from the horizontal or vertical; oblique
The type of muscle which encircles a natural orifice of the body
sphincter
Orbicularis oculi
sphincter muscle that closes the eyelids; compresses the lacrimal sacs (tear production.)
Orbicularis oris (Puckering Muscle)
sphincter muscle which encircles the mouth and closes and puckers the lips.
protrusion
state or condition of being thrust forward or projecting
The mastoid process is used for the attachment of what muscle?
sternocleidomastoid (SCM)
The widest part of the neck is formed between these muscles
sternocleidomastoid muscles
The furrow or groove which lies at the juncture of the base of the chin and the submandibular area.
submental sulcus
The bony landmarks of the frontal bone that lie on the lower part of the forehead and just above the medial ends of the eyebrows
supercilliary arches
Which palpebral sulcus is wider (Inferior Palpebral Sulcus or Superior Palpebral Sulcus)?
superior
The widest measurement of the anterior plane of the face is measured between these bone
temporal process
The broad, fan shaped muscle that radiates above the ear
temporalis
Nasolabial fold
the anterior fold of the cheek which descends laterally along the upper lip from the wing of the nose.
frontal bone
the anterior third of the cranium, forming the forehead and the anterior portion of the roof of the skull
coronoid process
the anterior, non-articulating process of the ramus of the mandible which serves as the insertion for the temporalis muscle.
bridge of the nose
the arched portion of the nose which is supported by the nasal bones
origin
the attachment of a muscle which moves least (or not at all) when the muscle contracts; the beginning
parietal bones
the bones that form the roof and part of the sides of the skull
orbital cavity / eye socket
the bony region containing the eyeball
Nasolabial sulcus
the furrow lying medial and adjacent to the nasolabial fold.
Inferior palpebral sulcus
the furrow of the lower attached border of the inferior palpebra.
Superior palpebral sulcus
the furrow of the superior border of the superior palpebra.
Optic facial sulci / crow's feet
the furrows radiating from the lateral corner of the eye
Angulus oris sulcus
the groove at each end of the line of mouth closure
body of the mandible
the horizontal portion of the lower jaw
supercilliary arches
the inferior part of the forehead just superior to the median ends of the eyebrows
Submental sulcus
the junction of the base of the chin and the submandibular area, may appear as a furrow.
The widest measurement of the cranium is between what structures?
the parietal eminences
Where does bone ossification begin in the body?
the parietal eminences
cranium
the part of the skull which encloses the brain
Buccinator (Trumpeter's muscle)
the principle muscle of the cheek which compresses the cheeks and forms the lateral wall of the mouth
Mastication
the process of chewing
internal tissue building
the process of restoring natural fullness to the facial features during the embalming process using techniques such as a higher rate of flow, intermittent drainage, intravascular pressure, and humectant chemicals.
zygomatic arch / process
the processes on the temporal and zygomatic bones; determines the widest part of the face
nuchal line of occipital bone
the projection of bone at the posterior/inferior portion of the skull
parietal eminence
the rounded peak of the external convexity of the parietal bones; determines the widest part of the cranium
Physiognomy
the study of the structure and surface markings of the face and features
crown / vertex
the topmost part of the head
Bucco-facial sulcus
the vertical furrow of the cheek.
Philtrum
the vertical groove located medially on the superior integumentary lip
Interciliary sulci / frowning sulci
the vertical or transverse furrows between the eyebrows
squama
the vertical surface of the temporal bone
Platysma
thin layer of muscle covering anterior aspect of neck.
Natural facial markings
those markings which may be present at birth or are hereditary. If they are not present at birth, they are not acquired throughout the life of the individual.
Platysmal sulci / double chin
transverse, dipping furrows of the anterior neck
what is the least common geometric head form?
triangular
Anatomical position
used as a reference in describing body parts to one another, in which the body is erect, feet together, palms forward, and thumbs are pointed away
Which interciliary sulci are known to be the concentrating sulci? Which are known to be the frowning sulci?
vertical - frowning horizontal - concentrating
septum
vertical cartilage dividing nasal cavity into two chambers, responsible for asymmetry of the nose
labial sulci / smoker's lines
vertical furrows of the lips extending from within the mucous membranes into the integumentary lip
The widest part of the face is measured between these structures
zygomatic arches
Mandibular sulcus
furrow beneath the mandible which rises vertically on the cheek.
dental prognathism / buck teeth
Oblique insertion of the teeth; front teeth protrude
What are the two forms of dimples?
Rounded or vertical in form
What general shape does the philtrum resemble?
irregular parenthesis is the norm (also triangular, inverted triangular, and parallel)
If the eyes will not properly close, this muscle may (though should NOT) be severed to aid in eye closure
levator pelebrae superioris
What facial marking is enhanced by the Depressor Anguli Oris Muscle?
lines around mouth?
Masseter
major muscle of mastication
major restoration
one requiring a long period of time, are extensive, require advanced technical skill, and expressed written consent to perform.
minor restoration
one requiring minimum effort, skill, or time to complete.
posterior
position of direction toward the back
occipital protuberance
prominence at the center of the external surface of the occipital bone
The narrow, superficial muscle which runs across the cheek and attaches at the angle of the mouth
risorius
What is an alternate term for the infantine geometric head shape?
round
How many geometric head shapes are there?
seven
Dimples
shallow depressions located on the cheek or chin
oblique
slanting or inclined, neither perpendicular nor horizontal
What is an alternate term for the square geometric head shape?
strong
complexion
the color and texture of the skin, especially that of the face
temporal cavity
the concave surface of the head overlying the temporal bone
incisive fossa
the depression between the mental eminence and the inferior incisor teeth.
width
the dimension of an object measured across from side to side.
columna nasi
the fleshy termination of the nasal septum at the base of the nose; located between the nostrils; the most inferior part of the mass of the nose
Labiomental sulcus
the junction of the lower integumentary lip and the superior border of the chin, which may appear as a furrow. The deeper the incisive fossa, the more prominent the labiomental sulcus.
Directionally, how are facial markings related to the muscle that creates them?
the lie perpendicular to the muscles that make them
norm
the most common characteristics of each feature; typical, common, average
insertion
the movable portion of a muscle which is attached to muscle or skin
Levator anguli oris
the muscle located in the area of the canine teeth which elevates the angle of the mouth.
Depressor anguli oris (Triangularis)
the muscle located inferior to the lateral portion of the mouth
Depressor labii inferiorus (Quadratus)
the muscle located inferior to the medial portion of the mouth
Risorius
the narrow superficial band of muscle which pulls the angle of the mouth laterally
foramen magnum
the opening in the occipital bone through which the spinal cord passes
external auditory meatus
the opening or passageway of the ear
nasal cavity
the orifice in the bony face bounded by the margins of the nasal bones and the maxilla
contour
the outline or surface form
mastoid process
the rounded projection on the inferior portion of the temporal bones just posterior to the lobe of the ear
Oblique palpebral sulcus
the shallow, curving groove below the inner corner of the eyelids.
Nasal spine of the maxilla
the sharp, bony projection located medially at the inferior margin of the nasal cavity.
profile / silhouette
the side view of the human head
Angulus oris eminence
the small convex prominence lateral to the end of the line of mouth closure.
mandibular fossa
the small oval depression on the zygomatic process of the temporal bone into which the condyle of the mandible articulates, just anterior to the external auditory meatus.
buccal cavity
the space between the lips and the gums and teeth; the vestibule of the oral cavity
supra-orbital margin
the superior rim of the eye socket
Bilateral
two sides
Describe the location of the Depressor Anguli Oris.
under the corners of the mouth
ramus
vertical portion of the mandible
Cords of the neck
vertical prominences of the neck
The bony structure which projects anteriorly from the squama of the temporal bone
zygomatic arch
The muscle located lateral of the Quadratus Labii Superioris that descends obliquely from the posterior portion of the cheekbone to the angle of mouth
zygomaticus major
The lateral head of the Quadratus Labii Superioris
zygomaticus minor
Another name for the Depressor Anguli Oris Muscle
Triangularis Muscle
According to the lesson notes, what are three examples of co-embalming restorative art treatments?
- internal tissue building - sustaining feature alignment - swelling control
lateral
a direction or projection which is away from the midline; to the side
Concave-convex profile
a facial profile in which the forehead protrudes beyond the eyebrows while the chin recedes from the plane of the upper lip
Infranasal prognathism
a form of prognathism in which the base of the nasal cavity protrudes abnormally
depression
a hollow or shallow concave area in a surface
Describe the Quadratus Labii Superioris muscle.
a large 3 bellied muscle extending from the upper cheeckbone/eyesocket to the upper lip
The medial head of the Quadratus Labii Superioris
- levator labii superioris
concave
exhibiting a depressed or hollow surface; a concavity
cartilage
A specialized type of dense connective tissue; attached to the ends of bones and forming parts of structures, such as the nasal septum and the framework of the ear.
Concave-vertical profile
facial profile in which the forehead protrudes beyond the eyebrows while the upper lip and chin project equally to an imaginary vertical line
What, if any, is the difference between the male and female skull after puberty?
female skulls are generall smaller
Vertical lines
fine linear tracings extending vertically on both upper and lower mucous membranes
temporal bone
form the inferior portion of the sides and base of the cranium; inferior to the parietal bones and anterior to the occipital bone