What are the parts of the syringe?
- Needle adapter
- Syringe barrel
- Piston w harpoon
- Finger grip
- Thumb ring
- Needle: hub, shaft, bevel
- Cartridge: rubber diaphragm, aluminum cap, neck, band, plunger (indented from rim of glass)
What does a self aspirating syringe do?
Negative pressure so if vessel is entered will aspirate
What are the dimensions of a 25 gauge needle?
- Smaller gauge, bigger diameter
- .5mm outside
- .25mm lumen
What are the dimensions of a 30 gauge needle?
- Smaller gauge, bigger diameter
- .30mm outside .15 mm lumen
Where is the angle of deflection, and what is it influenced by?
From inner lumen to outer point of bevel, influenced by tissue resistance and needle pliancy, therefore hold tissue taught (less deflection & pain)
What is the relation between gauge and deflection?
Smaller gauge larger needle, less deflection, more force required (sometimes 5x)
What is the features of truject?
Double bevel, balanced (no) deflection
What are the levels of anesthesia techniques typically used intraorally?
- Infiltration: terminal brances only
- Field block: more proximal several branches
- Nerve block: prior to branching, everything distal
- Choose based on simplest most atraumatic
- (area, duration, infection?, age, hemostasis)
1% solution contains how many mg/mL?
Describe the nuclei of the trigeminal nerve?
- Proprioception, jaw jerk: MESENCEPHALIC (most rostral) (pons)
- Pain, temperature: SPINAL(medulla)
- touch pressure vibration: MAIN(pons)
What are the 3 divisions of the trigeminal?
- Opthalmic (V1)
- Maxillary (V2)
- Mandibular (V3)
What are the branches of the ophthalmic division (V1)?
- Lacrimal, frontal, nasociliary
- Exit: superior orbital fissure
- Sensory w autonomics (parasymp ciliary ganglion via short ciliary (miosis (pupil constriction ciliary muscles for accommodation of lens, sympathetic= mydriasis)
What are the autonomics of V1?
- Ciliary ganglion via short ciliary
- Para: miosis (pupillary contraction), lens accomodation
- Sym: mydriasis (dilation)
What are the branches of maxillary (V2)?
- Foramen rotundum into pterygopalatine fossa
- Infraorbital, zygomatic, 2 PTP trunks, PAN
What nerve does the ASA and MSA branch from?
- Infraorbital in orbital floor
- Continues to inferior palpebral, external nasal, superior labial
What does the zygomatic nerve branch into?
- Inferior orbital fissure
- Communicating to lacrimal nerve (parasymp)
- Zygomaticofacial (cutaneous) zygoma
- Zygomaticotemporal (cutaneous) anterior temporal
What are the branches of pterygopalatine nerves?
PTP ganglion: orbital (ethmoid, sphenoid), pharyngeal (sphenoid, nasopharyngeal mucosa & posterior auditory tube) posterior superior nasal, posterior inferior & nasopalatine (incisive canal) septal mucosa and anterior palate, greater palatine nerve s
Where are the para/pre and sym/post fibers to PTP from?
- CN VII via greater superficial petrosal
- Sym/post: Deep petrosal, ICA
- Both via pterygoid (vidian canal)
What area of anesthesia for supraperiostial?
Labial, buccal tissues adjacent to tooth, pulp
What is the site of insertion and depth for supraperiostial?
- Greatest concavity of mucobuccal fold toward apex of tooth to be anesthetized
- 3-4mm deep (parallel to long axis of tooth)
- variable volume 0.5-1.5mL based on tooth
What is the area of ASA?
3 anterior teeth, PDL, alveolar bone & labial gingiva
What is the site of insertion & depth for ASA?
- Greatest concavity of the mucobuccal fold adjacent, distal to apex of canine
- Variable depth, 1-1.5mL
What is the area of MSA?
Premolars, MB root of max 1st molar, PDL, adjacent bone and buccal soft tissue
What is insertion site of MSA?
- Greatest concavity of mucobuccal fold adjacent to 2nd premolar
- About 3 mm deep (variable), 1-1.5mL
What are the signs of MSA anesthesia?
Corner of upper lip, adjacent buccal mucosa and premolar teeth.
What percent is MSA absent, what innervates if missing?
What is the area for PSA?
Maxillary molars except MB of max 1st molar, PDL, adjacent bone & buccal soft tissue
What is the site of PSA?
- Height of vestibule just distal to zygomatic process usually btwn DB of 2nd molar and MB of 3rd molar
- Direct needle UP, IN, BACK (45 down, 45 out)
- Shift mandible to side of injection to move coronoid process
- About 1.5cm deep (2/3rds short or ½ long needle)
What are the signs of PSA anesthesia?
Rarely determine unless subjected to treatment
What are the complications of PSA?
- Too far lateral: pterygoid venous plexus hematoma or incomplete anesthesia
- Too far anterior: bone, may lacerate PSA arterty, large hematoma
What is the area for IO block?
- ASA, MSA, inferior palpebral, external nasal, superior labial
- Midline to premolars, PDL, supporting bone and buccal tissue
- Reliable only in premolar region
What is the insertion site for IO?
- Buccal vestibule adjacent to 2nd premolar
- Locate infraorbital notch and move 5-10mm inferiorly to IO foramen (mark w/finger)
- 1.5 cm deep until bone
- 1.0 mL w finger pressed to aid flow into foramen
If you wanted to MSA and ASA both which would you do first?
Either do IO or start with MSA (may anesthetize site for ASA)
What is the area of the nasopalatine nerve block?
Palatal gingiva of 6 anterior and mucoperiosteum of anterior 1/3rd of hard palate
What is the site of insertion for nasopalatine?
- Laterally through mucosa at edge of incisive papilla
- 3-5mm deep
- 0.2-0.3 mL
What is the area of the greater palatine nerve block?
Mucoperiosteum of posterior 2/3 of hard palate to midline and associated gingiva
What is the site of insertion of greater palatine block?
- Just anterior to greater palatine foramen
- Foramen is 3/4mm anterior to vibrating line at junction of palate and alveolar process
- 5mm deep
- pts detect change in sensation
What is the area of a maxillary nerve block?
Entire hemimaxilla (anterior to molars may be weak)
What is the site of maxillary nerve block?
- 1. high tuberosity
- 2. pterygopalatine canal via greater palatine foramen
- 2.5-3cm deep to get about 1cm below main trunk
- 1.8mL additional cartridge may be necessary for high tuberosity
- numb from midface lower eyelid, upper lip, swallowing, stuffiness and lacrimal gland inhibition
What are the divisions of V3?
- Foramen ovale
- Motor (medial pterygoid, TVP, Ttympani)
- Sensory: meningeal
- Anterior: (motor masseter, deep temporal, lateral pterygoid), buccal (between superior and inferior later pterygoid and cross coronoid notch) cutaneous & buccal mucosa & gingiva to mandibular molars
- Posterior: motor (mylohyoid & anterior digastric) sensory (auriculotemporal (OTIC) (around neck of condyle emerges through parotid), lingual, IAN)
What nerves join lingual?
- CN VII via chorda tympani para/pre and SS taste (anterior 2/3) to submandibular ganglion
- Couse between medial pterygoid and medial ramus
- Lingual gingiva, mucosa and anterior 2/3rds of tongue
What are the relationships of the inferior alveolar nerve?
- Inferior to lateral pterygoid and lateral to pterygomandibular space, posterior and lateral to lingual nerve
- Gives off myohyoid (mylohyoid anterior digastric) sensory to cutaneous skin and sometimes mand incisors
- Terminal: mental (mental foramen) incisive (incisors & canines)
Where are the Otic ganglion fibers from?
- Para/pre via lesser superficial petrosal (glossopharyngeal)
- Symp/post Para/post auriculotemporal to parotid
What kind of saliva is secreted via para or symp innervation?
What innervates taste in tongue?
- VII: anterior 2/3
- IX: posterior 1/3
- X: epiglottis
What is the area and site of supraperiosteal mandibular?
- Area: single incisor, buccal gingiva and supporting PDL and bone
- SITE: depth of buccal vestibule approximate apex of root, can do between for dual action
- Few mm deep, don’t overinsert into mentalis
What is the area of the mental nerve bloack?
- Mental: labial mucosa, gingiva, lower lip
- Incisive: tooth pulps, PDL and supporting bone of teeth anterior to foramen (premolars to midline)
- Must enter mental foramen to reach nerve
What is the site of mental nerve block?
- Mental foramen: below apex of mand 2nd premolar or just anterior or posterior (palpate)
- 0.25mL into vestibule 1cm lateral to buccal surfces of teeth and distal to foramen
- advance 1cm inferior and medial to contact buccal plate
- deposit another 1.0mL soln
What is the area of a buccal nerve block?
- Cheek and posterior buccal gingiva (distal half to 2nd premolar and back)
- Aka long buccal
What is the insertion of the buccal nerve block?
- Buccal nerve crosses deep tendon of temporatlis, retromolar triangle and external obliqe ridge at level of occlusal plane
- May inject as it crosses ramus in cheek (1cm below parotid duct or in buccal vestibule)
- Superficial at coronid notch and vestibule as it courses anteriorly
What is the technique for the buccal nerve block?
- Retract buccal fat pad & cheek
- Insert lateral and distal to last molar in arch at occlusal plane
- Insert 2-3mm and deposit 0.5mL
Where is the target for IAN?
Pterygomandibular space before nerve enters canal
What are the boundaries of the pterygomandibular space?
- Medial: medial pterygoid
- Lateral: mandibular ramus
- Superior: lateral pterygoid
- Posterior: parotid inc (ECA, retromandibular vein, facial n)
- Anterior: oral mucosa and buccinator m
What are the contents of the pterygomandibular space?
- IAN & lingual
- IA artery & vein
- Sphenomandibular ligament
- Loose CT
What is the area of IAN?
- Mand teet from retromolar to midline, buccal tissue anterior to mental foramen and supporting bone
- Lingual mucosa and tongue to midline
What is an obstacle for IAN?
Internal oblique ridge (therefore approach from CONTRALATERAL PREMOLARSs)
What landmarks are located for the IAN?
- Coronoid notch: deepest concavity of anterior ramus (bisect/upper thumb palpitation)
- Pterygomandibular raphe: roll of soft tissue behind 3rd molar superior and medial to blend w soft palate (insert just lateral)
What is the technique for IAN?
- 2-2.5cm deep to contact bone from contralateral premolars insertion just lateral to pterygomandibular raphe (bisecting thumbnail)
- withdraw halfway and inject rest to get lingual nerve
- What is an alternative to lingual block?
- Floor of mouth distal to area to be anesthetized
What are reasons for anesthesia failure?
- Anatomic: landmarks, barriers
- Physiologic: pH, inflammation, circadian (best at 2PM), genetic, anxiety, cultural, drug seeking
About what % have difficultly after single administration?
- 11% say they fail once per week
- anxiety is common denominator
What is the basic decicion tree for failed anesthesia?
- See if tougue or lip in anesthetized? Yes, accessory injections, No, REDO
- Short, small range supplement: PDL, intraosseous
- Long, multiple supplement: Gow-gates or akinosi
- Alternative: different batch, drug, (long acting, VC), high conc
- NO, opiod or ketamine
What seems to be more successful with hypersensivity?
Which mandibular nerve sometimes inervates mandibular teeth?
What is gow gates?
- True mandibular (all of V3)
- Used for pts with hx of failure or accessory
- Objective: anterior neck of condyle (upper) pterygomandibular space just below external pterygoid insertion
What is the angle desired for gow gates?
- Corner of mouth to tragus of ear(intertragic arch)
- Insert: height of ML cusp of max 2nd molar
- Thumb on coronoid notch, index finger on intertragic notch (opposite side of mouth)
- Wide open mouth to angle towards condyle
- Full cartridge and remain open to allow flow
What are indications for akinosi?
- Trismus, visual difficulty, hx of failure
- Fill pterygomandibular space
- More medial and inferior to gow-gates (may not include aricular temporal)
- No bony contact
What is the insertion height of akinsoi?
Mucogingival junction of max teeth
Describe the technique for akinosi.
- Gentle occlusion, retract tissues
- Advance into max vestibule, parallel to occlusal plane at height of mucogingival junction
- Penetrate retromolar mucosa above injection site of IAN about 2.5cm (halfway)
- Hub next to max 2nd
- Full cartridge
What are indications of intraosseous injections?
- Not primary, only secondary
- High success, rapid onset, short duration
- May benefit hemophiliacs or anti-coagulation pts
What is the effect of vasoconstrictor on intraosseous injections?
- VC: rapid systemic,
- No VC: short duration
What is a PDL injection?
- Actually intraosseous (intraligamentary)
- Gun trigger
- Blanching= not good
- Endodontic tx
What are negative reactions of PDL injection?
Necrosis of peridontium
What is the technique for intraseptal injections?
- (Stabident or x-tip)-drill Rt angle with gingiva to get to marrow space
- Not usually done between premolars since mental foramen is there
Describe some computer-controlled products.
- The wand: very slow inj, like a pen
- Comfort controlled, anaeject
What leads to LA complications?
Excessive doses & intravascular injections -> CNS toxicity 1st (CVS next)
How do you prevent intravascular injections?
Aspiration & slow injections
What are the factors of LA toxicity?
- Inc w/potency, rate of injection, rapidity of inc blood levels alters toxicisty
- Inc paCO2 and dec pH
- Sedation increases cerebral blood flow and toxicity.
What impulses are affected as toxicity progresses?
- Inhibitory first
- Facilitatory next
- Eventually everything
- Low: sedation, analgesia, antiarrhythmic
- Intermediate: lightheaded, slurred speech, drowsiness, euphoria/dysphoria, diplopia, senory, muscle twitch
- High: disorientation, tremors, resp depression, tonic/clonic seizures
- Lethal: coma, rep arrest, CVS collapse
What are the max dose for articaine and lidocaine?
What is the max doses for mepivicaine w & w/o VC?
- With: 6.6 mg/kg
- Without: 5 mg/kg
What is the max dose for prilocaine?
What is the max dose for Bupivacaine?
What does % LA in solution represent?
Grams/100 mL therefore 1% = 10 mg/mL or 18mg per cartridge
What is the no-brainer method for LA dosage determination?
- Half a cartridge every 10 lbs UP TO 7 total.
- Xcart = Dmax*Wt(kg) / (Conc * 1.8)
What are overdosage factors?
Children, topical sprays, VC, IV, rapid, too much injected
What are some VC overdose consequences?
Syncope, hyperventilation, nausea, vomiting, inc or dec HR/BP
What are some things in LA that can cause allergies?
- Na+ Metabisulfite (anti-oxidant) always w/VC
- Do not confuse w/ sulfa
- Salads, fruits (wine, beer, cider) sausage meats, pickles, cheeses
- Methylparaben: highly allergic no longer in LA
Which kind of LA is more allergenic?
Ester since metabolized to PABA
What are signs that confused w/allergy?
Dizzy, lightheaded, faint, shaking, palpitations that went away with nothing or smelling salts.
What is methemoglobinemia and what LA predisposes?
- Cyanosis from oxidized Hb leding to >10% MetHb
- PRILOCAINE or sever benzocaine (use lidocaine spray instead)
- Beware mucosal damage
- Prilocaine: o-toluidine can block MetHb reductase
- 3-4 hrs after administration
What are complications of MetHb?
Unresponsive to O2, low SaO2, chocolate brown, send to ER but still give O2
What is MetHb tx?
1% methylene blue IV
What are some local complications?
Trismus, broken needle, hematoma, paresthesia, atypical anesthesia, cheek, lip biting, local tissue damage, infection
What causes muscular trismus?
- Injection into medial pterygoid & hematoma (too POSTERIOR or medial)
- LA: myotoxic, inc Ca2++
- Hemorrhage and scar formation could limit opening to a point where general anesthesia is needed
What is tx for trismus?
- Rest, heat (20mins), NSAIDS, muscle relaxant, stretching
- Tincture: lasts 2-3 days
What is protocol for broken needle?
Try to retrieve, refer to OMFS, inform malpractice
What is contraindicated for IAN?
30G needles, too thin
What is the most common causes of hematoma?
What are indications and tx for hematoma?
- Sudden swelling, limited motion
- Immediate pressure, ice
- Tincture: 7-14 days
- Prevention: know anatomy, short needle for PSA, minimize punctures
What is dysesthesia?
Painful altered sensation
What is hyperesthesia?
Increased stimulus sensitivity
What is Allodynia?
Pain from non-painful stimulus
What is parasthesia?
- Broad term for alterered or prolonged sensation beyond expected.
- Most transient resolve 8 weeks, yet fucked if it lasts longer
- Electric shock-> do not inject
- Note symptoms follow up in 1 month
Which LA’s lead to paresthesias?
- Articaine & prilocaine (both 4%)
- Sites lingual (unifasicular)
- Articaine also has highest market share in most studies
- DOSE-DEPENDENT most common factor
What procedures should 4% be used for?
INFILTRATIONS not IAN
What is the pathway for facial paralysis of LA?
- Into parotid during IAN
- Maxillary: IA artery anastomosis (middle meningeal, ophthalmic)
- Duration: same as soft tissue
- NO BONE NO INJECT
- Tx: remove contact, eye patch
- Diplopia (double vision), esotropia (cross eyed), amaurosis (blindness)
What drug speeds LA recovery?
What are LA signs of ischemia?
Stimulated adrenergic-> VC-> blanch-> tissue sloughing (PDL)
Which injections is infection most likely a problem?
- Intraosseous, PDL injections
- Avoid, through or into infected areasff