Oral Surgery Flashcards
Trigeminal nerve (CN V)
largest CN, the principal general sensory nerve to the head and face, sensory and motor
motor root exits foramen ovale
does CN V have parasympathetics at its origin?
NO
mandibular division of CN V innervates how many muscles?
8
CN V somatic SENSORY bodies of the ganglion’s sensory fibers enter the 3 divisions:
V1 Ophthlamic - ORBIT and SKIN above eyes
V2 Maxillary - nasal cavity, max teeth, palate, skin over maxilla
V3 Mandibular - mandible, TMJ, mand teeth, FOM, tongue, skin of mandible
CN V, axons of neurons enter the __ through the sensory root and terminate in 1 of 3 nuclei of the trigem sensory nuclear complex (3)
PONS
- mesencephalic - proprioception ex. muscle spindle
- main sensory - general sensation ex. touch
- spinal nucleus - pain and temp
proprioceptive fibers from muscles and TMJ found in which CN V division?
cell bodies of proprioceptive 1st order neurons are found in the __ nucleus
V3
mesencephalic NOT the trigem ganglion
branchiomeric motor fibers innervate which muscles?
Temporalis Masseter Medial and Lateral Pterygoids Anterior belly of the Digastric Mylohyoid Tensor tympani Tensor veli palatini
Mandibular Div (V3) of the trigem passes through __ and supplies sensory/motor? innervation to these muscles
foramen ovale
MOTOR
to tensor veli palatini, tensor tympani, muscles of mastication (temporalis, masster, lateral and medial pterygoids), anterior belly of digastric, mylohyoid muscles
CN V3 sensory innervation (4 nerves)
- long buccal (sensory only) -> cheek, md buccal gingiva
- auriculotemporal (sensory only) -> TMJ, auricle, external auditory meatus
- lingual (sensory only) -> FOM, mand lingual gingiva, anterior 2/3 tongue
- inferior alveolar nerve (sensory & motor!) -> mand teeth, chin skin, lower lip
massteric nerve is a branch of CN V3 that carries sensory/motor? fibers to the TMJ’s anterior portion
sensory
auriculotemporal nerve is a branch of VN V3 that provides major sensory/motor? innervation to the TMJ’s posterior portion
also transmits pain in the TMJ __ and __
SENSORY
pain in TMJ capsule and disc periphery
nerve to mylohyoid muscle is a branch of the mandibular nerve (V3), functions to?
elevate hyoid bone, base of tongue, FOM
-sublingual gland is superior to mylohyoid muscle
when the floor of the mouth is lowered surgically, the __ and __ muscles are detached
mylohyoid & genioglossus
suprahyoid muscles (4) and their innervations
- Digastrics (ant and post) - CN V3 (ant), CN VII (post)
- Mylohyoid - CN V3
- Geniohyoid - C1 via hypoglossal CN XII
- Stylohyoid - CN VII
infrahyoid muscles (4) and their innervations
- Thyrohyoid
- Omohyoid
- Sternohyoid
- Sternothyroid
all innervated by Ansa Cervicalis (loop formed by branches of cervical plexus C1, C2, C3)
hypoglossal nerve is a motor nerve supplying what muscles?
all intrinsic and extrinsic tongue muscles EXCEPT palatoglossus (vagus nerve)
unilateral lesions of the hypoglossal nerve cause deviation of the protruded tongue to the affected or opposite side?
affected side, cause of lack of fxn of genioglossus on diseased side
if the __ muscle is paralyzed, the tongue can fall back and obstruct the oropharyngeal airway
genioglossus
carotid sheath location? what does it contain?
lateral boundary of retropharyngeal space at level of oropharynx, deep to SCM muscle
contains carotid arteries, internal jugular vein, vagus nerve, deep cervical lymph nodes
when you retract the carotid sheath, the __ __ __ stays because it is not within the sheath
cervical sympathetic trunk
facial vein unites with the __ vein below the border of the mandible and empties into the internal jugular vein
retromandibular
internal jugular vein descends through neck inside carotid sheath, eventually to forms the
superior vena cava -> right atrium
max 1st molar innervated by what nerves
middle superior and posteiror superior alveolar
what injection must you give to ext all molars and 2nd PM?
long buccal
greater (anterior) palatine nerve is a branch of the maxillary (CN V2) that innervates?
GP foramen is where?
soft tissue to posterior 2/3 of hard palate -> canine (overlaps with nasopalatine)
btw 2nd and 3rd max molar, ~1 cm from palatal gingival marign toward midline
which cranial nerves have parasympathetic activity?
III
VII
IX
X
Cranial nerves (12)
I - olfactory - smell
II - optic - sight
III - oculomotor - eyeball movement, pupils, vision
IV - trochlear - eyeball movement
V - trigem - sensation to face, scalp, teeth, muscles of mastication, mandible movement
VI - abducens - eyeball movement
VII - facial - taste, face muscles, saliva secretion
VIII - vestibulocochlear - hearing, equilibrium
IX - glossopharyngeal - taste, sensory for cardiac, respiratory, bp reflexes, pharynx contraction, saliva
X - vagus - sensory in cardiac, respiratory, bp reflex, larynx, decr HR, peristalsis, incr. digestive secretions
XI - accessory - contract neck and shoulder
XII - hypoglossal - motor to tongue except palatoglossus
external carotid artery supplies?
passes through the __ gland
most of head and neck cept brain
through parotid salivary gland
terminates as max and superficial temporal arteries
maxillary artery supplies what?
3 branches
max and mand teeth, muscles of mastication, palate, nasal cavity
IA artery -> mand teeth
PSA artery -> post max teeth
ASA & MSA -> ant max teeth
venous return of both dental arches is?
pterygoid plexus of veins
greater (descending) palatine artery supplies?
hard palate, gingiva of max teeth and lateral nasal wall
lesser palatine also does tonsils
lingual artery supplies?
arises from? terminates as?
blood to tongue (also gets blood from tonsillar branch of facial artery and ascending pharyngeal artery)
also supplies FOM
arises from external carotid artery, terminates as deep lingual artery
does NOT accompany its nerve throughout its course
lingual artery branches (4)
suprahyoid
dorsal lingual
deep lingual - anterior 2/3 tongue
sublingual
inferior alveolar nerve and artery, and lingual nerve are found in the __ space?
PTERYGOMANDIBULAR SPACE btw medial pterygoid and ramus of mandible
IA nerve passes lateral to sphenomandibular ligament
tongue sensory innervation
lingual nerve (branch of V3) - ant 2/3 tongue
glossopharyngeal (CN IX) - post 1/3, vallate papillae, tonsil, nasopharynx, pharynx
vagus (CN X) via internal laryngeal nerve - near epiglottis
facial nerve (CN VII) via chorda tympani - taste to ant 2/3
facial nerve CN VII exits cranium through __ and extends laterally around mandible thorugh the __ gland
stylmastoid foramen
parotid gland
fxns of facial nerve
- motor - muscles of expression, post belly digastric, stylohyoid, stapedius
- sensory (proprioception) - muscles of facial expression
- motor (parasympathetic) - tear secretion from lacrimal gland, salivary from sublingual and submand glands
- sensory (taste and sweet) - taste buds ant 2/3 tongue, FOM, palate
Parotid gland is a pure __ gland supplied by general visceral efferent (motor) nerve fibers of the __ nerve.
Drained by?
supplied by what artery?
lymphatic drainage?
SEROUS, glossopharyngeal nerve
Stenson’s duct - pierces buccinator, crosses masster where it opens opposite max 2nd molar
external carotid artery
lymph -> parotid nodes to deep cervical lymph nodes
the only other adult salivary glands purely serous
Von Ebner’s
- around circumvallate papilla of tongue
- fxn to rinse food away from papilla
__ is a viral disease of the parotid gland
mumps
Wharton’s duct (submandibular) is closely related to what nerve?
innervated by?
blood supply from?
LINGUAL NERVE
parasympathetic secretomotor fibers from FACIAL NERVE
FACIAL ARTERY
sublingual gland is the smallest salivary gland that contains mostly ___ acini
MUCOUS
- in FOM below tongue, close to midline
- has many small RIVIAN ducts
- secretory units are mucous secreting with serous demilumes
lymphatic drainage from the sublingual and submandibular glands goes to what lymph nodes
submandibular, deep cervical
sometimes the numerous sublingual ducts join to make a main excretory duct called __ that empties into the __ duct
Bartholin’s Duct -> submandibular
in the H&N, all lymph ultimately rains into the __ lymph nodes
deep cervical
- form a chain along course of the internal jugular vein
- efferent lymph vessels join to form jugular lymph trunk, drains into thoracic duct or right lymphatic duct
regional lymph nodes (3)
- parotid
- submandibular - max and mand teeth, ant 2/3 tongue, paranasal sinuses
- submental - mand incisors and gingiva, tip tongue, FOM, center lip
maxillary sinuses open into
innervation?
hiatus semilunaris
max division of trigem nerve (CN V2 - incl ASA, PSA, MSA, infraorbital)
antibiotics to treat sinus infxns
ampicillin - sinusitis from upper respiratory infxns
penicillin and amoxicillin - sinusitis caused by odontogenic foci
max sinus communication
if tooth or large fragment displaced, what do you do?
if small then just allow blood clot
if fragment then remove it, if you can’t get it thru socket then use Caldwell-Luc approach
integrity of max sinus floor is at greater risk with surgery removing a single remaining max molar cause of
possible ankylosis
pterygopalatine fossa is a small space where?
what nerve and artery passes through?
behind and below orbital cavity
max nerve (V2) and artery
buccinator originates from 3 areas:
what arteries supply it?
action?
pterygomandibular raphe (btw buccinator and superior constrictor), maxillary and mandibular alveolar processes
facial and maxillary arteries
action - compress cheeks against molars for sucking and blowing
these muscles are the primary protractors of the mandible
lateral pterygoids
-open and protrude, mandible side to side
ex. right lateral movement, the LEFT is the mover
mandible deviates toward/away site of injury in condylar ankylosis, unilateral condylar fracture, latearl pterygoid injury
TOWARD
mandible deviates toward/away site of injury in cases of condylar hyperplasia
AWAY
what muscle forms the roof of the pterygomandibular space?
lateral pterygoid
masticator space is composed of what 3 spaces?
infxns are almost always of dental origin from what region?
symptoms?
masseteric, pterygomandibular, temporal
mandibular molar region
TRISMUS, pain, swelling
needle tract infxn after IA block initially involve what space?
pterygomandibular
most definite clinical sign indicating extension of odontogenic infxn into masticator space
TRISMUS
-can also be caused by passing needle through medial pterygoid muscle during IA block
temperomandibular joint is the articulation btw mandibular condyle and squamous portion of what bone?
temporal
TMJ components (4)
- mandibular condyle (condyloid process)
- articular fossa (mandibular or glenoid)
- articular eminence (articular tubercule)
- articular disc (meniscus)
condyle surface is covered with
vascular layer of fibrous CT
articular fossa (mandib or glenoid)
concave fossa, anterior 3/4 of larger mandib fossa
NON-FUNCTIONING
articular eminence (articular tubercule) is a
CONVEX ridge lined with fibrous CT (fibrocartilage)
FUNCTIONAL and articular portion of the TMJ
articular disc is
bioconcave, saddle shaped, made of fibrous CT
- central intermediate zone separates anterior and posterior bands
- posterior band has RETRODISCAL tissue/bilaminar zone which is VASCULAR and INNERVATED
- anterior band is thinner, contiguous with capsular, condyle, superior belly of lateral pterygoid
muscles acting on TMJ
masseter, temporalis, pterygoids, digastric
3 TMJ ligaments are
- Temperomandibular (lateral)
- Stylomandibular
- Sphenomandibular
Temperomandibular ligament
fxn?
major one from articular eminence to condyle, the ONLY one that directl ysupports TMJ capsule
-prevents posterior and inferior displacement of condyle
Stylomandibular ligament
accessory ligament, separates infratemporal from parotid region, located on POSTERIOR border of mandible
Sphenomandibular ligament
accessory ligament, located on MEDIAL surface of mandible
4 arteries that vascularize TMJ
- Middle meningeal (branch of maxillary, terminal branch of external carotid)
- Ascending pharyngeal
- Deep auricular
- Superficial temporal (terminal branch of external carotid)
TMJ syndrome divided in 3 categories
- Myofascial pain
- Internal derangement (disc displacement)
- Degenerative join disease (osteoarthritis)
what’s the syndrome that’s the most common cause of TMJ pain?
myofascial pain dysfunction (MPD)
- involves muscles of mastication
- STRESS related
- responds to night guard
internal derangement (disc displacement) is
most common direction for disc to be displaced?
abnormal relationship of articular disc to condyle, fossa and articular eminence
anteriorly - retrodiscal tissue (bilaminar zone) becomes abnormally stretched
if posterior band returns to normal position then this condition is called
anterior displacement with reduction
“pop” or “click”
subluxation (dislocation or open lock) is when
pt can’t close mouth
disc displacement WITH redxn is when
signs?
disc is out of place, hear a “click”, painless
patient has normal opening or “S” shaped, TMJ is only ROTATING (not translating), reciprocal clicking on opening and closing
-on closing, the disc is forward to condyle
disc displacement WITHOUT reduction (closed lock) is when
jaw deviates toward/opposite affected side?
what direction are disc displacements?
clicking and opping is gone with limited opening and pain, a HARD-END feel
deviates TO affected side
NO reciprocal click
most displacements -> ANTERIOR and MEDIAL
most common cause of restricted mandibular movement is
disc interference disorders
best way to palpate posterior aspect of the condyle is?
EXTERNALLY over posterior surface of condyle with mouth open
-palpate laterally in front of external auditory meatus while pt opens and closes
what is the best incision to expose the TMJ?
preauricular
anterior to external ear, parallel to superficial temporal artery, be careful of facial nerve
__ approach is the standard to approach the mandibular ramus and neck of the condyle
Submandibular (Risdom)
the most common cause of TMJ ankylosis
TRAUMA
most common complication of rheumatoid arthritis
ankylosis
control of __ is vital to tx any pt with a facial fracture
airway
highest incidence of fractures occurs in what population
young males 15-24, trauma
3 muscle groups displace the condyles
- masseter, medial pterygoid, temporalis
- ELEVATE mandible during mastication, causes UPward displacement of proximal segment - digastric, mylohyoid, geniohyoid, lateral pterygoid
- DEPRESS mandible and displaces DISTAL segment inferiorly and posteriorly - lateral pterygoid
- FORWARD displacement of condylar head when the condylar neck is fractured
30% of fractures in the mandible happen in the
25% in the
22% in the
17% in the
- ANGLE - proximal segment usually displaced anteriorly and superiorly
- condylar neck
- symphysis (chin)
- body of mandible
- ramus (2%)
- coronoid process (1%)
on opening, pt’s mandible deviates toward/opposite injury?
TOWARD
most common pathognomonic sign of mandibular fracture is
MALOCCLUSION
open reduction is?
most common site is?
indications?
the reduction of a fractured bone by manipulation after incision into skin and muscle over fracture site
mostly at ANGLE of mandible
best when teeth are missing in one or more of the fractured segments, when there’s continued gross displacement of the segments
condylar neck fractures best treated by what method?
CLOSED reduction
closed reduction is?
intermaxillary fixation is?
rdxn of fractured bone by manipulation without incision into skin
applying wires or elastics btw jaws, most common is PRE-FAB arch bars
bilateral sagittal split osteotomy most common to correct?
mandibular retrognathia (Class II malocclusion)
split mandible can be advanced or set back
*position of condyle is UNCHANGED
vertical ramus osteotomy is used to correct
mandibular PROgnathism
body osteotomy is used to correct
mandibular PROgnathism (Class III malocclusion) -ext mand teeth bilaterally (usually PMs)
ways to immobilize a fracture (4)
- Barton bandage
- Intermaxillary fixation (IMF)
- external skeletal fixation
- Direct intraosseous wiring + IMF, traditional method after OPEN RDXN
greenstick fracture
mand fracture that extends only thru cortical portion of bone without complete fracture; most common in KIDS
classifications of mandibular fractures (3)
- simple - 2 parts with no external communication (closed)
- compound - communicates with outside (open), most common complication is INFECTION
- comminuted - multiple fractures of a single bone that can be either single or compound
unfavorable fracture occurs if fracture line results in ___
favorable fracture occurs if fracture line __
muscle pull displacing the fracture segment
prevents displacement of fracture by muscle pull
midfacial fractures affect these 3 structures
maxilla
zygoma
nasoorbital ethmoid complex
6 types of midfacial fractures
- LeFort I
- LeFort II
- LeFort III
- Zygomatic complex
- Zygomatic arch
- Nasoorbital Ethmoid
- LeFort I - HORIZONTAL, causes OPEN BITE, used to correct Mx RETROgnathia
- LeFort II - PYRAMIDAL, PARESTHESIA common over infraorbital nerve
- LeFort III - TRANSVERSE or CRANIOFACIAL dysfunction, restricted mandibular movement
- Zyogmatic complex - most common, can have paresthesia, hematoma in sinus, impaired ocular muscle
- Zygomatic arch - no probs
- Nasoorbital Ethmoid
what are the 1st and 2nd most common fractures of facial bones?
- nasal
2. zygomatic bone
signs and symptoms of zygomatic fracture
binocular diplopia, trismus, ipsilateral epistaxis
what view is best to evaluate orbital rim areas?
Water’s view
symptoms of fracture of infraorbital rim?
numb upper lip, cheek, nose on affected side
3 radiographic views for midfacial fractures
- Water’s
- PA skull
- submental vertex
blows to the maxilla drive the maxilla in what direction? results in what kind of bite?
back and down -> open bite or impinged airway
segmental osteotomy is?
maxilla sectioned into 2+ pieces
fracture healing (4)
- Endosteal proliferaiton - in bone
- Periosteal proliferation - in CT
- Primary (bone to bone) healing - endosteal and periosteal proliferation
- Secondary bone healing - mostly endosteal proliferation
3 phases for healing bone
- hemorrhage - first 10 days
- callus formation - in 10-20 days, then a secondary callus
- functional reconstruction - line up Haversion systems, bold will be molded, takes 2-3 years
4 reasons fractures don’t heal
- ischemia
- excess mobility
- interposition of soft tissue
- infection
___ is the most of often sequela of fractures
FAT embolism
3 types of inappropriate healing
- delayed-union: satisfactory healing
- non-union: failure of segments to unite properly
- mal-union: can be delayed or complete union in an improper position
Geudel’s stages of general anesthesia (4)
1- Amnesia & Analgesia - best monitor is VERBAL
2- Delirium/Disinhibition & Excitement - loss of consciousness, onset of total anesthesia
3- Surgical Anesthesia - regular pattern of breathing, total loss of consciousness, 4 planes, spinal reflexes depressed, no pain reflexes
4- Premortem or Medullary Depression - signals danger, dilated pupils, cold skin, low bp, cardiac arrest imminent, severe respiratory and cardiovascular depression
3 agents for surgical anesthesia
cyclopropane - good muscle relaxant
halothane - not good muscle relaxant, not good analgesic, halogenated hydrocarbons are assoc. with liver damage if toxic doses are used
methoxyflurane - good muscle relaxant, respiratory depressant, good analgesic
ASA classes (6)
I - healthy
II - mild systemic disease
III - severe disease not incapacitating
IV - severe systemic disease, threat to life
V - moribound pt not expected to survive without operation
VI - brain dead
elements of general anesthesia include (4)
analgesia
relaxation
hyporeflexia
narcosis
__ is the last area of the brain depressed during general anesthesia
medulla
-contains cardiac, vasomotor, respiratory centers of the brain
most reliable sign of “oxygen want” is
increased pulse rate
cyanosis may also be present
most common emergency during outpatient general anesthesia is
respiratory obstruction
best anesthetic technique used in OS to avoid aspiration of blood or other debris when a pt is under general is
endotracheal intubation with pharyngeal packs
pt with __ infxn is contraindicated in general anesthesai
acute respiratory
Induction is
starts with admin of anesthetic and continues until desired level of pt unresponsiveness is reached
rate and recovery depends on rate of change of tension in tissue, blood supply to lungs, pulmonary ventilation, concentration of anesthetic influence