Facial Anatomy Flashcards
What is the ratio of Type I to Type II collagen in the skin?
0.334027777777778
Where are dense fibrous attachments between the superficial and deep facial fascias located?
Along the zygomatic arch, overlying the parotid gland, along the anterior border of the masseter muscle.
How does the skin age differently between Asians and Caucasians?
Asians develop fewer fine rhytids but more pigmented lesions than Caucasians.
How does the skin differ between Asians and Caucasians?
Asians have thicker skin with greater collagen density and are more prone to hypertrophic scarring and prolonged erythema.
What nerve parallels the superficial temporal vessels?
Auriculotemporal nerve.
What are the only mimetic muscles that receive innervation from VII on their superficial surfaces?
Buccinator, levator anguli oris, and mentalis muscles.
What muscle creates vertical and oblique rhytids in the medial eyebrow region?
Corrugator supercilii muscle.
What muscles draw the eyebrows medially?
Corrugator supercilii muscles.
Where are the branches of the facial nerve in relation to the SMAS?
Deep.
What is the relationship of the SMAS to the parotid gland?
Densely adherent to, yet distinct from, the parotid fascia.
What is the relationship of the SMAS to the lower eyelid?
It merges with the muscle fibers of the periorbital orbicularis oculi.
What is the relationship of the SMAS to the zygomatic arch?
It terminates 1em below the zygomatic arch.
What is the main difference between a keloid and a hypertrophic scar?
Keloids extend beyond the boundary of the original tissue injury; hypertrophic scars do not.
What is the relationship of the frontal branch of VII to the temporoparietal fascia?
Lies within it.
What ligaments support the soft tissue of the medial cheek?
Masseteric cutaneous ligaments.
What are the two types of retaining ligaments that support the facial skin?
Osteocutaneous ligaments and fusion of the superficial and deep fascias.
What muscle draws the medial edge of the brow inferiorly?
Procerus.
What lines are perpendicular to the line of force of the underlying muscle?
Relaxed skin tension lines.
What is the function of the auriculotemporal nerve?
Sensation of the scalp and auricle, and carries postganglionic parasympathetic nerves from the otic ganglion to the parotid gland to stimulate secretions.
What are the five layers of the epidermis from deep to superficial?
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.
What plane separates the temporoparietal fascia from the deep temporal fascia?
Subaponeurotic plane of loose areolar tissue.
What separates the superficial and deep layers of the deep temporal fascia?
Superficial temporal fat pad.
What is the only location in the face where the SMAS is not covered by the fascial-fatty layer?
Superior portion of the lower eyelid.
How does the aging process alter facial proportions?
The area from the subnasale to the menton decreases significantly in size compared to the other areas of the face.
What fat pad separates the temporalis muscle from the deep temporal fascia and the zygomatic arch?
The deep temporal fat pad, an extension of the buccal fat pad.
What is the SMAS?
Tissue plane of the face composed of fibrous and/or muscle tissue that is continuous with the platysma and lacks direct bony insertion.
What is the relationship of the frontal branch of VII to the zygomatic arch?
Travels over it on the surface of the loose areolar layer and superficial layer of the deep temporal fascia.
True/False: The buccal fat pad, parotid duct, facial artery and vein, and facial nerve lie in the same anatomic plane in the cheek.
True.
The dermis primarily contains what type(s) of collagen?
Type I (8o%) and Type III (15%).
What is the predominant type of collagen in scar tissue?
Type I.
Which type of collagen is a crucial component of the basement membrane?
Type IV.
What ligaments support the malar pad over the zygomatic eminence?
Zygomatic ligaments.
What is the normal distance from the helical rim to the skull
1 - 2 em.
Ideally, the nasal tip should lead the remainder of the profile by what distance
1 - 2 mm.
What is the ideal nasofrontal angle
125 - 135 degrees.
Where is the incision made using the external approach to chin augmentation
2 - 3 mm posterior to the submental crease.
Where should subperiosteal undermining begin during brow lift
2.5 em above the lateral orbital rim to avoid injury to the supraorbital nerve.
What is the ideal ratio of the length of the lower lip to the upper lip
2: I.
What is the normal incline of the vertical axis of the auricle
20 degrees.
What is the average upper lip length in males and females
24 mm in males, 20 mm in females.
What i-s the normal angle between the ear and the head
25 - 30 degrees.
What are the dimensions of the palpebral fissure when the eyes are open
30 x 10 mm.
What is the ideal nasofacial angle
36 - 40 degrees.
According to the Goode method for determining the nasofacial angle, a ratio of 0.55 corresponds to what angle
36 degrees.
What is the average lower lip length in males and females
50 mm in males, 46 mm in females.
What is the normal thickness of the chin pad
8 - II mm.
What is the normal angle of the nasal valve in Caucasians
9 - 15 degrees.
What is the ideal nasolabial angle
90 - 120 degrees.
What is the normal width of the auricle
About 55°/o of the length.
What is the normal vertical height of the auricle
About 6 em.
What provides dynamic support to the lower lid
Adhesion of the pretarsal portion of the orbicularis to the tarsal plate.
Which muscles depress the nose
Alar nasalis, depressor septi nasi muscles.
Where are dense fibrous attachments between the superficial and deep facial fascias located
Along the zygomatic arch, overlying the parotid gland, along the anterior border of the masseter muscle.
What is the Gonzales-Uiloa method of determining chin projection
Anterior chin should approximate a line perpendicular to the Frankfort horizontal line where it intersects the nasion.
How does the skin age differently between Asians and Caucasians
Asians develop fewer fine rhytids but more pigmented lesions than Caucasians.
How does the skin differ between Asians and Caucasians
Asians have thicker skin with greater collagen density and are more prone to hypertrophic scarring and prolonged erythema.
In the female, where should maximum brow elevation occur
At a line tangent and vertical to the lateral limbus of the eye.
What is the ideal brow position in a man
At the level of the supraorbital rim with a less pronounced arch.
What is the primary cause of jowls in the elderly patient
Attenuation of the masseteric cutaneous ligaments.
What are the only mimetic muscles that receive innervation from VII on their superficial surfaces
Buccinator, levator anguli oris, and mentalis muscles.
What are the lower eyelid retractors
Capsulopalpebral fascia and the inferior tarsal muscle.
What structure in the lower lid is analogous to the levator aponeurosis of the upper lid
Capsulopalpebral fascia.
What effect does separation of the upper lateral cartilages from the nasal bones have on the nasal airway?
Causes the middle of the nasal vault to cave in.
What structures make up the posterior lamella of the lid
Conjunctiva and the tarsal plate.
What are the major tip support mechanisms
Contour, size, and strength of the lateral crura; attachment of the medial crural footplate to the caudal septum; attachment of the caudal edge of the upper lateral cartilages to the cephalic border of the alar cartilages.
What muscle creates vertical and oblique rhytids in the medial eyebrow region
Corrugator supercilii muscle.
What muscles draw the eyebrows medially
Corrugator supercilii muscles.
Where are the branches of the facial nerve in relation to the SMAS
Deep.
What is the relationship of the SMAS to the parotid gland
Densely adherent to, yet distinct from, the parotid fascia.
What is the significance of a “negative vector” profile
Describes patients with protuberant eyes and hypoplastic malar eminence… fat should not be removed from these patients during blepharoplasty.
What is the significance of the position of the hyoid bone in rhytidectomy
Dictates the maximum improvement possible in the cervicomental angle; ideal position is high and posterior.
How does the aging process alter facial proportions
ETIC The area from the subnasale to the menton decreases significantly in size compared to the other areas of the face.
What is the anatomic basis of Hhanging columella?”
Excessively high arch of the alae, abnormally extreme curvature of the intermediate and medial crura, or overaggressive surgical removal of the lateral crus and adjacent soft tissue with subsequent cephalic contraction of alar margin.
How does the incidence of complications following rhytidectomy differ between Asians and Caucasians
Flap necrosis is less common and hypertrophic scarring is more common in Asians.
What is the ideal alar to lobular ratio
I :I.
How is lower lid laxity defined
If > I 0 mm or >25% of the skin can be gathered without distortion of the rim.
Where should the chin lie in relation to a vertical line dropped from the lips
In males, the chin should meet the line; in females, the chin should lie 2-3 mm posterior.
What is the function of the deep head of the orbicularis oculi
Inserts on the posterior lacrimal crest and provides structural support to the lid.
What is the relationship of the SMAS to the lower eyelid
It merges with the muscle fibers of the periorbital orbicularis oculi.
What is the relationship of the SMAS to the zygomatic arch
It tenninates I em below the zygomatic arch.
Where is the frontal branch of VII most vulnerable during brow lift
Just above the lateral brow, I - 2 em from the orbital rim.
What does a medial epicanthal fold cover
Lacrimal lake.
What happens with disruption of the deep head
Lateral and anterior displacement of the medial canthal angle.
What are two angles used to determine chin projection
Legan angle (normal 12 degrees +/4), Merrifield Z angle (normal 80 degrees +/5).
What is the most common form of acquired eyelid ptosis
Levator aponeurosis disinsertion or dehiscence.
What structure divides the lacrimal gland into 2 lobes
Levator aponeurosis.
What is unique about the anatomy of the Asian eyelid
Levator muscle lacks attachment to the pretarsal skin, resulting in an absent pretarsal fold.
What is the relationship of the frontal branch of VII to the temporoparietal fascia
Lies within it.
What ligaments support the soft tissue of the medial cheek
Masseteric cutaneous ligaments.
What is the ideal brow position in a woman
Medial segment club-shaped and inferior to the lateral segment; peak of arch above the orbital rim at the lateral limbus; lid margin to brow distance >2 em.
Which of these uses the Frankfort horizontal line as a reference
Merrifield Z angle.
What is the difference between microgenia and micrognathia
Microgenia is a small mandible with normal occlusion; micrognathia is an underdeveloped mandible with class II occlusion.
Define mild, moderate, and marked ptosis.
Mild I - 2 mm, moderate 2 - 3 mm, marked >4 mm.
How does the ideal supratip break differ between men and women
More pronounced in women.
What are the nasal anatomic subunits
Nasal dorsum. nasal sidewalls, nasal tip, alar lobules, depressions of the supra-alar facets.
What are the minor tip support mechanisms
Nasal tip ligamentous aponeurosis; cartilaginous septum; nasal spine; strength and resilience of the medial crura; thickness of tip skin and subcutaneous tissue; supportive strength of the alar sidewalls.
What is retrognathia
Normal sized mandible with class II occlusion.
What structures make up the middle lamella
Orbital septum, capsulopalpebral fascia, posterior surface of orbicularis oculi.
Where does the lateral canthal tendon insert
Orbital tubercle located 5 mm posterior to the lateral orbital rim.
What are the 2 types of retaining ligaments that support the facial skin
Osteocutaneous ligaments and fusion of the superficial and deep fascias.
What lines the posterior surface of the eyelid
Palpebral conjunctiva.
What structures make up the anterior lamella of the lid
Pretarsal orbicularis oculi muscle and the eyelid skin.
Which muscles elevate the nose
Procerus, levator labii superioris alaeque nasi, anomalous nasi muscles.
What muscle draws the medial edge of the brow inferiorly
Procerus.
What are the typical features of the facial structure in Asians
Prominent malar imminences with relatively shallow midface, wide prominent mandibular angles, short and posteriorly-inclined chin, broad and flat nasal dorsum with limited tip projection and broad nasal base.
What is the primary cause of midface aging
Ptosis of the malar fat pads and diminished tone of the zygomatic musculature.
What is the most important surgical component of the septum
Quadrangular cartilage… provides midline support and can significantly influence the external appearance of the nose.
What structures are found in the nasal valve area
Septum, upper lateral cartilages, and anterior head of the inferior turbinates.
What are the causes of lower lip eversion
Skeletal deep bite, lower tooth procumberance, excess lip weight and bulk.
What is the ideal configuration of the alar margin
S-shaped, exposing 2 - 3 mm of the caudal columella on lateral view.
What plane separates the temporoparietal fascia from the deep temporal fascia
Subaponeurotic plane of loose areolar tissue.
What separates the superficial and deep layers of the deep temporal fascia
Superficial temporal fat pad.
What is the only location in the face where the SMAS is not covered by the fascial-fatty layer
Superior portion of the lower eyelid.
What is the single most important aesthetic quality of the nasal tip and base
Symmetry.
What provides static support to the lower lid
Tarsal plate and its associated medial and lateral canthal tendons.
What is the nasal valve
The angle between the caudal quadrangular cartilage and the distal upper lateral cartilages.
What does the gray line divide
The anterior and posterior lamella.
What fat pad separates the temporalis muscle from the deep temporal fascia and the zygomatic arch
The deep temporal fat pad, an extension of the buccal fat pad.
What measurement can be use to determine deficiency in the malar area
The distance from the malar prominence to the nasolabial groove on lateral projection (ideally >5 mm).
What is Powell’s modification of the Baum method
The ideal ration is 2.8: I, corresponding to an angle of 36 degrees.
What is the normal superior limit of the auricle
The level of the brow.
What is the normal position of the lower lip in relation to the upper lip and chin
The most anterior portion of the white roll should lie slightly posterior to the upper lip and lie in the same plane as the soft tissue chin point.
What creates the gray line in the lid margin
The muscle of Riolan.
What is the Baum method for determining the nasofacial angle
The ratio of a vertical line drawn from the nasofrontal angle to the subnasale to a horizontal line perpendicular to the vertical line that passes through the tip; ideally this ratio is 2: I, which corresponds to a 42 degree angle.
What is the Simons method for determining the nasofacial angle
The ratio of the length of the upper lip to the length of the base of the nose is ideally I: I.
What structure forms the medial canthal tendon
The superficial head of the pretarsal fibers of the orbicularis oculi muscle.
When dissecting from the temporal region to the zygomatic arch, where does the deep temporal fascia divide into superficial and deep layers
The temporal line of fusion at the level of the superior orbital rim.
What happens to the fascia as dissection continues towards the zygomatic arch
The temporoparietal fascia and the superficial layer of the deep temporal fascia fuse I em above the zygomatic arch.
What is the only septal component that is paired
The vomer… may be bilaminar owing to its dual embryonic origin.
How does the platysma muscle differ between Asians and Caucasians
Thicker in Asians, with lower incidence of diastasis.
What are the major anatomic features that determine tip projection
Thickness and character of tip skin; shape and strength of alar cartilages; length of infratip lobule and columella; anatomy of the quadrangular cartilage (especially the anterior septal angle); size of the nasal spine and premaxilla.
What are the physical signs of aponeurosis disinsertion
Thin upper lid skin and high lid fold with good levator function (>I 0 mm).
What is the SMAS
Tissue plane of the face composed of fibrous and/or muscle tissue that is continuous with the platysma and lacks direct bony insertion.
What are the other muscles of the nose (the compressor and dilators)
Transverse nasalis, compressor narium minor, dilator naris anterior muscles.
What is the relationship of the frontal branch of VII to the zygomatic arch
Travels over it on the surface of the loose areolar layer and superficial layer of the deep temporal fascia.
T/F: With aging, Asians will accumulate greater volumes of fat than Caucasians
True.
T /F: The buccal fat pad, parotid duct, facial artery and vein, and facial nerve lie in the same anatomic plane in the cheek.
True.
What is Hering’s law
Unilateral ptosis with contralateral lid retraction… if you cover the ptotic eye with a patch for 30 - 60 min, the retracted eye will settle into the normal position and the ptotic eye will reveal itself.
What ligaments support the malar pad over the zygomatic eminence
Zygomatic ligaments.
What is the craniofacial ratio in adulthood?
2:1
What is the craniofacial ratio at birth?
8:1
What is normal interincisal opening?
40-50 mm.
What are the weakest areas of the mandible?
Area around the 3rd molar, socket of the canine tooth, and the condyle.
Where is Dorello’s canal and what nerve does it contain?
Between the petrous tip and the sphenoid bone; contains VI and the inferior petrosal sinus
What are the horizontal buttresses of the midface?
Frontal bar and cranial base, zygomatic arch and temporal process of the zygoma, maxillary palate and alveolus, and the greater wing and pterygoid plates of the sphenoid.
What is the foramen ofMorgagni?
Gap between superior constrictor muscle and skull base.
What structure is found in Meckel’s cave?
Gasserian ganglion of V.
What type of joint is the temporomandibular joint (TMJ)?
Ginglymoarthrodial (hinge/sliding) joint.
Due to these differences, which facial fractures are more prominent in children than in adults?
High facial fractures (orbital roof and temporal bone fractures).
What is the normal inclination of the orbital floor?
Inclines superiorly at a 30-degree angle from anterior to posterior and at a 45-degree angle from lateral to medial.
What structures pass through the mandibular foramen?
Inferior alveolar artery and nerve.
Why is the midface inherently prone to deficient projection?
It lacks good sagittal buttresses.
What muscle protracts the mandible?
Lateral pterygoid muscle.
Does the foramen rotundum lie lateral or medial to the pterygoid canal?
Lateral.
What is the most prominent portion of the zygomaticomaxillary complex (ZMC)?
Malar eminence.
Name the foramen through which the structure passes?
Meningeal branch of V3: Foramen spinosum.
Terminal branch of V2: Infraorbital foramen.
V3 and accessory meningeal artery: Foramen ovale.
Sphenopalatine artery: Sphenopalatine foramen.
Ill,IV, VI,and V1: Superior orbital fissure.
V2: Foramen rotundum
What are the three paired vertical buttresses of the midface?
Nasomaxillary, zygomaticomaxillary, and pterygomaxillary.
What is the weakest part of the entire ZMC complex?
Orbital floor.
‘What is the name of the opening through which the maxillary artery passes after giving rise to infraorbital and posterior superior alveolar branches?
Pterygomaxillary fissure.
What is the clinical significance of the foramen of Morgagni?
Serves as a potential route for spread of nasopharyngeal tumors to the skull base and brain.
The pterygoid plates are part of which bone?
Sphenoid.
‘What is the name of the maxillary artery after it passes through the pterygomaxillary fissure?
Sphenopalatine artery.
What opening in the medial wall of the pterygopalatine fossa permits the passage of neurovascular structures into the nasal passages?
Sphenopalatine foramen.
What is the largest artery in the pterygopalatine fossa?
Sphenopalatine.
What are the four bony attachments to the skull radiating from the malar eminence?
Superior attachment to the frontal bone (frontozygomatic suture);
medial attachment to the maxilla (zygomaticomaxillary suture);
lateral attachment to the temporal bone (zygomaticotemporal suture);
Deep attachment to the greater wing of the sphenoid (zygomaticosphenoidal suture).
What muscle inserts on the disk of the TMJ?
Superior part of the lateral pterygoid muscle.
What are the horizontal buttresses of the nasoethmoidal region?
Superiorly, the frontal bone and bilateral superior orbital rims; inferiorly, the bilateral inferior orbital rims.
What determines the projection of the upper face?
The frontal bar (supraorbital rims and frontal sinuses).
What are the vertical buttresses of the nasoethmoidal region?
The paired “central fragments” arising from the frontal process of the maxilla and internal angular process of the frontal bone.
True/False: The medial pterygoid muscle elevates the mandible.
True.
Which of these is strongest?
Zygomaticofrontal buttress.
