Dental Meds/LA Test 1 Flashcards
What is the largest/thickest cranial nerve?
Trigeminal (V)
The trigeminal nerve provides the majority of ? innervation of the teeth, bone, and soft tissue.
sensory
What are the two roots that the trigeminal nerve are composed of?
small motor root and large sensory root
pulpal anesthesia
from the inside out
infiltration/local anesthesia
surrounding soft tissue
What branch/division of the trigeminal nerve is sensory from muscles of forehead?
V1- Opthalmic
What branch/division of the trigeminal nerve is sensory from lower eyelids, zygoma, and upper lip?
V2- Maxillary
What branch/division of the trigeminal nerve is sensory from lateral scalp, skin anterior to ears, lower cheeks, lower lips, and anterior aspect of mandible?
V3- Mandibular
What branch/division of the trigeminal nerve is both sensory and motor?
V3- Mandibular
What branch/division of the trigeminal nerve is motor to muscles of mastication (temporalis, masseter, medial and lateral pterygoid, tensor veli palatine, and tensor tympani)
V3- Mandibular
Sensory root (3 branches) supplies the skin of the entire face and oral cavity except for what?
pharynx and base of tongue
Muscles of mastication
Masseter, temporalis, medial and lateral pterygoid
Motor root innervates
muscles of mastication, mylohyoid, anterior belly of digastric, Tensor (tympani, veli palatini)
What do the tensor muscles do?
pick up uvula and help you swallow
V1 exits where?
superior orbital fissure
V2 exits where?
foramen rotundum
V3 exits where?
foramen ovale (largest one)
What innervation? Skin (middle portion of face, lower eyelid, side of nose, upper lip) mucous membrane (nasopharynx, maxillary sinus, soft palate, hard palate, tonsil) , maxillary teeth and periodontal tissues.
V2- maxillary
V2 branches…pterygopalatine fossa
Nasopalatine nerve
Greater palatine nerve
Posterior superior alveolar nerve (PSA)
V2 branches…infraorbital canal
Middle superior alveolar nerve (MSA)
Anterior superior alveolar nerve (ASA)
infiltrations
right above tooth you want numb…one thing
PSA, MSA, ASA
nerve blocks…up higher
What innervation? Skin (temporal region, auricula, external auditory meatus, cheek, lower lip. chin region) Mucous membrane (cheek, tongue-anterior 2/3, mastoid cells) mandibular teeth and periodontal tissues, bone of mandible, TMJ, parotid gland (facial nerve runs thru)
V3 mandibular
IA injection..what nerves…posterior branch
lingual nerve, inferior alveolar nerve (mental and incisive), mylohyoid nerve
numbness happens from injection site where?
forward
osteology/properties of maxilla
cancellous bone - more porous, some areas paper thin, more vascularity…infiltrations work well
osteology/properties of mandible
largest/strongest bone, dense cortical bone
Inferior alveolar nerve enters where?
mandibular foramen
Height of mandibular foramen
about 1-19mm above level of occlusal plane
Types of non-disposable syringes
breech loading, metallic, cartridge-carpule type (aspirating or non-aspirating) and pressure type
Most common syringe used
breech loading, metallic, cartridge type - aspirating
silicone rubber stopper…aka
bung
positive pressure
applied to thumb ring, forces local anesthesia into needle lumen and into tissue
negative pressure
blood enters cartridge if needle tip is in lumen of vessel (aspiration test)
Aspirating syringe metallic: advantages
visible cartridge, aspiration with one hand, autoclavable, rust resistant, long lasting
Aspirating syringe metallic: disadvantages
weight (heavier than plastic), syringe is large, possibility of infection with improper care
MIltex petite syringe
reduced thumb ring, flared base on ring handle, shortened harpoon rod, wider wings
Pressure syringes
introduced 1970’s, pulpal anesthesia-isolated tooth mandibular arch…PDL, ILI
Plastic reusable aspirating syringe: advantages
kinder looking, lightweight, cartridge visible, easy to aspirate, rust resistant, long lasting, lower cost
Plastic reusable aspirating syringe: disadvantages
size may be too large for small hands, possibility of infection with improper care, deterioration of plastic with repeated autoclaving
Metallic self aspirating syringe: advantages
cartridge visible, easier to aspirate with small hands, autoclavable, rust resistant, long lasting, PISTON scored to indicate volume of LA administered
Metallic self aspirating syringe: disadvantages
weight, feeling of insecurity, finger MUST be moved
Self-aspirating syringe…
utilize elasticity of the rubber diaphragm in anesthetic cartridge to obtain negative pressure for aspiration
syringe complications…leakage
when reloading 2nd cartridge make sure needle penetrates middle of diaphragm.
syringe complications…broken cartridge
can result from bent harpoon, applying too much pressure, MOST common cause is cartridge damaged during shipping
bent harpoon
causes off-center puncture-cause plunger to rotate as it moves down
disengagement of harpoon during aspiration
harpoon dull, too much pressure applied
common needle material
stainless steel and disposable
Bevel/slant of needle
end of needle where anesthetic exits, can be long, medium, or short…
The greater the angle of the bevel with long axis of needle = ?
the greater degree of deflection as needle passes through soft tissue
Needles can be used up to ? times on same pt. before changing
3-4 tissue penetrations
Larger gauge needle = ?
less deflection, greater accuracy, less chance of breakage, easier aspiration
Dot on the hub of needle indicates ?
bevel placement - bevel towards nerve
Shaft/ shank of needle
tip of needle, through the hub, and penetrates cartridge
Hub of needle
plastic or metal piece that attaches to syringe, pre-threaded or self-threading
Weakest part of the needle
hub - NEVER insert, most rigid, receives greatest stress
needle gauge
diameter of lumen… smaller the number greater the diameter
Aspiration test and needle gauge
100%- 25, 87%- 27, 2%- 30
needle length
20mm (hub to tip) short, 32mm (hub to tip) long
Problems- needle breaks
elastic properties of tissue allow rebound- covers/buries needle, if 5mm or more is visible use hemostats to remove
Problems- needle bending
fatigues needle, no reason to bend to properly administer
How many ml of anesthetic in cartridge?
1.8 ml
If aluminum cap of carpule is distorted then?
throw away
LA cartridge storage
room temp, don’t immerse in disinfectant, warmers not recommended
Bubble in cartrige
nitrogen gas. 1-2m normal…larger indication of freazing and exansion
Burning upon injection
normal response to pH of drug, cartridge contains bisulfate
Additional armamentarium
topical anesthetic, applicator sticks, cotton gauze, hemostats
topical anesthetic
prior to needle penetration, benzocaine = most common, lidocaine, ointment/sprays
what happens when topical left to long?
causes tissue to sluff
hemostats/cotton pliers
removal of broken needle
Most common medical emergency in office with local anesthesia
5 minutes after administration - syncope
related to STRESS not the drug
Three critical phases of injection
Penetration site
Deposition site
Aspiration
Penetration site
tissue is barely penetrated…stop and hold
Deposition site
Proceed to optimum deposition point and then stop and hold
Aspiration
when you reach optimum depth and angle…announce positive or negative
WREB critical errors
Anesthetic w/out epi
Check expiration date
Needle MUST NOT touch any extra or intra oral surface prior to insertion
steps of initial procedure
position patient
dry tissue (optional)
topical anesthetic 1-2 min.
three primary types of injection
local infiltration, field block, nerve block
local infiltration
area flooded with anesthetic, smaller area, dependent on diffusion, tx in same area as injection
field block
LA deposited near the larger terminal nerve branches, maxillary injections administered at apex of area to be treated, involves tissue in or around one or two teeth
nerve block
LA deposited close to main nerve trunk, usually at a distance from the operative…PSA, MSA, ASA, IA
MSA- penetration and deposition site
penetration: apical to second premolar, height of mucobuccal fold
deposition: apical to apex of 2nd premolar (1/2 to 2/3 of cartridge)
PSA- penetration site
height of mucobuccal fold apical to second molar
PSA- landmarks
mucobuccal fold, maxillary tuberosity, zygomatic process, DB root of maxillary 2nd molar, buttress of the zygoma
PSA degrees and needle depth
45, 45, 45, and 1/2 long needle…3/4 short needle
Greater palatine nerve block-penetration
anterior to greater palatine foramen
Greater palatine nerve block landmarks
greater palatine foramen…junction between max. alveolar process and palatine bone…only need a few drops of anesthetic
ASA- landmarks
mucobuccal fold, infraorbital notch, infraorbital foramen
Anterior trunk of mandibular nerve
lateral pterygoid muscle, masseter muscle, temporalis muscle, buccal
posterior trunk of mandibular nerve
auriculotemporal nerve, IA nerve (mental and incisive), lingual nerve (anterior 2/3 of tongue, mucosa floor of mouth, all mandibular, lingual gingiva
Chorda Tympani nerve
joins lingual nerve (runs in bundle), submandibular and sublingual glands, taste- anterior 2/3 of tongue
mandibular nerve descends down ? before entering ? canal gives off ? nerve
medial side of ramus, mandibular, mylohyoid
when mandibular nerve enters mandibular canal it becomes?
inferior alveolar nerve…anesthesia to IA, mental nerve, incisive nerve, lingual nerve
IA nerve exits? and remains?
mental foramen (mental nerve), alveolar bone (incisive nerve)
Mandibular injection landmarks
lingula, pterygomandibular raphe, coronoid notch, angle of mandible, occlusal plane of mandibular post. teeth
WREB mandibular injection site bordered:
medially by pterygomandibular raphe, laterally by internal oblique ridge, height of the coronoid notch
angle and depth, barrel of syringe IA injection
long needle = 2/3, short needle = 4/5…syringe over premolar contralateral side…needle is parallel to occlusal plane of mandibular teeth.
Buccal nerve block insertion
mucous membrane distal and buccal to most distal molar
Buccal nerve block deposition
buccal nerve as it passes over the anterior border of ramus
Buccal nerve block landmarks
mandibular molars and mucobuccal fold
mental nerve only…areas anesthetized
buccal mucous membranes anterior to the mental foramen, to the midline and skin of the lower lip
Mental nerve penetration site
mucobuccal fold- canine/first premolar
incisive nerve (mental and incisive)…area anesthetized
buccal mucous membrane anterior to the mental foramen, lower lip and skin if chin, premolars, canine, and incisors, pulpal nerve fibers to premolars, cuspid, incisors
