Easy Day Flashcards
Sphenomandibular ligament is from
Meckels cartilage
- meckel’s creates the malleus, symphysis, mandible
What composes Keisselbach’s plexus
GASS
- greater palatine
- anterior ethmoid
- sphenopalatine
- superior labial
Location of greater palatine foramen
Posterior angle of the hard palate
- related to upper 3rd (55%)
- 2nd molar (12%)
- between 2nd and 3rd (19%)
- retromolar (14%)
- 0.35 cm from the posterior hard palate
Name the intramembranous bones
Skull
Facial bones except condyle
Clavicle
What passes through the optic canal
Ophthalmic artery or vein
Optic nerve
Optic artery
Sympathetic fibers
(Optic vein is in the superior orbital fissure)
Efferent and afferent of corneal reflex
Afferent: nasociliary of V1
Efferent: temporal and zygomatic of VII
Superior orbital fissure contents
CN III, IV, V1, VI
Superior ophthalmic v.
Cavernous plexus sympathetic fibers
Inferior orbital fissure contents
Zygomatic branch of V2, ascending branches from pterygopalatine ganglion
Infraorbital vessels
Where is the inferior oblique muscle located
Originate from medial orbital surface of maxilla
Perichondritis after otoplasty organisms
Staph aureus, e. Coli, pseudomonas
Ideal auriculocephalic angle
25-35 degrees
What age to consider otoplasty
4 years
Where is McGregor’s patch located
“Bloody gulch”
- area of zygomatic prominence with plexus of vessels and strong fibrous attachments that can present as skin dimpling or retraction (important in rhytidectomies)
What nerves are of concern of McGregor’s patch
Facial n. Becomes more superficial and buccal nerve lies deep
What direction should the chisel be directed when osteotomizing the pterygoid plates during lefort
Downward, forward, and medial
Where is the maxillary artery in the pterygomaxillary fossa
Approx 20-25 mm superior to the pterygomaxillary fissure
A 1 cm osteotome has a wide 1+ safety margin
How to prevent hemorrhage during Lefort
Only chisel back 30 mm on lateral nose to avoid DPAs
Where is Erb’s point and significance
6 cm inferior to ear lobule on POSTERIOR border of SCM
- greater auricular and accessory nerves just deep to fascia at this point
What surrounds the lacrimal sac
Lacrimal bone and frontal process of the maxilla
- also vascular plexus called cavernous body)
- anterior and posterior limbs of medial canthal tendon
What is the modiolus
Area of confluence of 5 facial expression muscles just lateral to the corner of the mouth
- represents the configuration of the nasolabial fold along with the cheek bone
- levator anguli oris, zygomaticus major, risorius, platysma, depressor anguli oris
Levator veli palatini inserts onto what
Palatine aponeurosis in normal people but onto hard palate in clefts
Facial muscles are usually innervated from the deep side except which muscles
Levator anguli superioris, buccinators, and mentalis
Where does the lacrimal duct exit
Opening of the nasolacrimal duct into the INFERIOR nasal meatus is partially covered by the VALVE OF HASNER
Name the visual field deficit in
1. Optic radiation and optic tract lesions
2. Optic chiasm lesions
3. Optic n. Injury
- Contralateral visual field deficit in both eyes (homonymous hemianopsia)
- Bitemporal hemianopsia
- Ipsilateral blind eye
What is the danger zone of the facial nerve as it crosses the zygomatic arch
0.8 to 3.2 cm anterior to the tragus
What attaches to Whitnall’s tubercle (lateral orbital tubercle) and why is it clinically important
Confluence of lateral canthal tendon
Inferior suspensory/Lockwood’s ligament
Multiple check ligaments of the lateral rectus that form the lateral retinaculum
- clinically important bc lateral canthal tendon should be reattached to the tubercle
- located 1 cm inferior to frontozygomatic suture and 3-4 mm internal to lateral orbital rim
What structure is an extension of periosteum in orbit
Orbital septum
What % of the time is the lingual n. Above the alveolar crest
14%
Generally located 2 mm medially and 3 mm inferiorly to crest on average in 3rd molar region
What is the most common reason for permanent lingual n. Injury
Lingual plate fracture
Indications for coronectomy
- Significant risk of nerve injury
- roots remain vital and get bony fill of socket
OR
- roots need extraction at later date but will migrate away from nerve as they should continue to erupt following crown removal
Most common radiographic finding associated with IAN damage with 3rds
Rood criteria
Loss of cortical border of nerve
Darkening of root
Deviation of canal
Optic canal is located how far posterior to the posterior ethmoid canal
4-7 mm posterior
General rule of medial orbit: 24, 12, 6
Anterior ethmoid = 24 mm posterior to anterior portion of lacrimal bone
Posterior ethmoid is 12 mm posterior to that
Optic canal is 6 mm posterior to that
MRI basics with T1 and T2
T1: hyperintense fat, hypointense fluid
T2: fat and fluid are both hyperintense
Marginal mandibular branch in relation to mandible anterior/posterior to facial artery
- anterior to crossing the facial artery, always superior to mandible
- posterior to crossing facial artery, below (19-53%) the mandible but never lower than 1.5 cm
- risdon incision is made 2 cm inferior to mandible
Why is Risdon incision made 2 cm inferior to the mandible
Posterior to where marginal mandibular branch crosses the facial artery, below the mandible 19-53% of time but never lower than 1.5 cm below mandible
What muscles are supplied by facial n.
Muscles of facial expression
Stapedus
Posterior belly of digastric
Stylohyloid
What glands supplied by parasympathetics from facial n.
Sublingual
Submandibular
Lacrimal glands
What nerve supplies parasympathetics to the parotid
Glossopharyngeal (IX)
What muscles does the vagus supply
Cricothyroid
Levator veli palatine
Salpingopharyngeus
Palatoglossus
Palatopharyngeus
Sup/mid/inferior pharyngeal constrictors
Muscles of the larynx
What intrinsic muscle of the larynx is NOT supplied by the recurrent laryngeal
Cricothyroid (superior laryngeal n.)
What muscles does the hypoglossal supply
All muscles of the tongue EXCEPT THE PALATOGLOSSUS (X)
What muscle does the glossopharyngeal supply
Stylopharyngeus
What muscles are supplied by CN V
Mastication muscles, tensor veli palatini, mylohyoid, anterior digastric, tensor tympani
Taste to posterior 1/3 of tongue
Glossopharyngeal (IX)
Taste to posterior epiglottis
Vagus n. (X)
Nerve that carries sensory info from carotid sinus to carotid body
IX
What does the nucleus of Edinger-Westphal supply
Parasympathetics to the iris sphincter and ciliary muscles via CN III
Superior salivary nucleus function
Parasympathetics to the lacrimal, sublingual, submandibular glands via CN VII
Solitary nucleus function
Taste from facial n., glossopharyngeal and vagus n.
Chemo/mechano receptors from carotid body via CN IX and aortic body via X
Nucleus ambiguus function
Motor neurons to CN IX and X supplied muscles
Inferior salivatory nucleus function
Parasympathetics to parotid via CN IX
What derives from the 1st brachial arch
- Mastication muscles, anterior digastric, mylohyoid, tensor tympani, tensor veli palatine
- Trigeminal n. (V)
- Maxillary artery, external carotid artery
What derives from the 2nd brachial arch
- Facial n. (VII)
- Facial muscles
- Stapedial a. And hyoid a.
What derives from the 3rd brachial arch
- Glossopharyngeal n. (IX)
- Stylopharyngeus m.
- Common and internal carotid arteries
- INFERIOR parathyroid
What derives from the 4th brachial arch
- Vagus (superior laryngeal n.)
- Cricothyroid m.
- Intrinsic soft palate muscles except tensor veli palatine
- Thyroid cartilage
- SUPERIOR thyroids
- Epiglottic cartilage
What is derived from the 6th brachial arch
- Vagus n. (Recurrent laryngeal)
- All intrinsic larynx muscles EXCEPT cricothyroid
What divides the lateral pharyngeal space
Styloid process
Fascial attachments of the levator veli palatini called the aponeurosis of Zuckerkandl and Testut
Where should extraoral incision for drainage of superior/deep temporal spaces be placed
Essentially a Gilles approach incision
Where should extraoral incision for drainage of submandibular, sublingual, submasseteric and pterygomandibular spaces be placed
Essentially smaller versions of a Risdon incision
- incision large enough to get your finger into
Blunt dissection with tonsils, Kelly’s or your finger +/- drain placement t
Where should extraoral incision for lateral pharyngeal and retropharyngeal spaces be placed
Very low risdon type incision
OR
Vertically down the anterior border of the SCM if need to go deeper or access carotid sheath
Lymph node levels of the neck
Level 1: submandibular (Ia) and submental (Ib)
Level II: upper 1/3 of jugular from skull base to inferior border of hyoid
- posterior border is the posterior SCM and anterior is sternohyoid
Level III: from hyoid to inferior cricoid cartilage and bounded anteriorly and posterior just like II
Level IV: inferior cricoid to clavicle along the SCM
Level V: posterior SCM back to anterior trap and extends from apex of SCM and trap junction down to clavicle
Level VI: central compartment between carotids and bounded superiorly by hyoid and inferiorly by sternal notch
What is the lymph node on the cricothyroid membrane called that is frequently encountered in thyroidectomy just deep to the thyroid
Delphian lymph node
Antihypertensive with fat and glucose metabolism destruction
Beta-blocking anti-HTN
Name the lung volumes and what makes up each
- Inspiratory capacity = Inspiratory reserve volume + Tidal volume
- vital capacity = IRV + TV + ERV
- Functional residual capacity = ERV + residual volume