Regional Dental Nerve Blocks

• decreases the amount of injectable and gas inhalants needed
• lower cost
• increase patient safety since lower levels of general anes are needed
• decreased recover time
• greater patient comfort

decreased risk of hypertension, tachycardia, and tachypnea due to decreased oral pain

• injection into circulation could cause myocardial depression and cardiac dysrhythmia
• ocular damage caused by improper infraorbital nerve block technique
• cheek or tongue damage during recovery

• infiltration anesthesia
• splash technique
• regional nerve block

applying small amounts of local anesthesia into the gingiva, mucosa, periodontal ligament space/alveolar periosteum

used only for small number of teeth that need to be blocked or as adjunct to intraorbital blocks

anesthetic agent is dropped onto or into area being treated

no

routine dental cleaning procedures

for all painful oral surgeries and should be preceded by regional nerve blocks

• tumor resection
• biopsy
• reconstruction surgery
• oral lacerations, foreign bodies
• jaw fractures
• fractured teeth
• root canals
• pulptomies
• extractions
• flap surgery and root planning
• oral resorptive lesions

local anesthetic agent is injected just into the foramen

• inraorbital foramen
• palatine/maxillary foramen
• inferior alveolar foramen (mandibular block)
• mental foramen

• drugs
• 25 - 22g needles with 5/8 - 1 inch length
• 1 - 3 cc syringes
• surgical scrub
• dog and cat skulls for anatomical guidance

5 - 10 minutes

60 - 90 minutes

2% lidocaine 2 mg/kg

• 4 lbs:  0.18 ml
• 5 lbs:  0.22 ml
• 10 lbs:  0.45 ml

add it to saline

and 1/10 of volume as sodium bicarbonate (example - if using 1 ml of lidocaine add 0.1 ml of sodium bicarbonate)

15 - 30 minutes

4 - 8 hours

0.5% bupivicaine 2 mg/kg

• 4 lbs:  0.72 ml
• 5 lbs:  0.90 ml
• 10 lbs:  1.8 ml
• 50 lbs:  9 ml

mix with saline

add 1/10 volume as sodium bicarbonate (example:  is using 1 ml of bupivicaine add 0.1 ml of sodium bicarbonate)

cut doses in half

• 0.5 - 1.0 ml per site in dogs
• the cumulative dose during any procedure should not exceed 2 mg/kg

• 0.01 - 0.3 ml per site
• the cumulative dose during any procedure should not exceed 2 mg/kg

quick onset

2 - 2.5 hours

• dogs:  0.25 - 1 ml depending on size
• cacts:  0.25 - 0.5 ml depending on size
• maximum dose:  2 mg/kg

yes

• onset:  5 - 10 minutes from the lidocaine
• duration:  4 - 6 hours from bupivicaine

4 - 6 hourse

for balanced anesthesia

• dogs:  0.1 - 1.0 ml per site
• cats & small dogs:  0.1 - 0.3 ml per site

lengthens the effects of the agents by 50%

cardiotoxic

bupivicaine

• locate the foramen
• insert the needle bevel down (towards the bone)
• aim to insert the needle just to or slightly into the canal
• aspirate
• rotate the needle 1/4 a turn
• aspirate again
• rotate the needle 1/4 a turn
• aspirate the needle a third time to be sure you are not in a blood vessel
• slowly inject
• place a finger over the foramen for 20 - 30 seconds after withdrawing the needle

• upper lip
• nose
• roof of nasal cavity
• skiin ventral to the infraorbital foramen
• maxillary incisors, canine, and first 2 premolars

• lift lip and palpate foramen
• insert needle through buccacl mucosa where it forms a crease
• direct needle (bevel down?) toward the floor of the foramen in a rostrocaudal direction, just at the foramen
• aspirate and rotate three times
• inject and hold pressure on foramen

• maxillary 4th premolars
• molars
• hard tissue caudal to the maxillary 4th premolar (hard and soft palate)

• visualize the midline of the palate and the palatal root of the 4th premolar
• draw an imaginary line for each
• halfway across the line is the opening of the major palatine foramen

no because of large vessels in the foramen

with the patient's mouth open, palpate the notch at the rostral ventral aspect of the zygomatic arch as it meets the bone surrounding the last maxillary molar

• insert the needle perpendicular to the horizonal line of the palate directly adjacent to the bone at the ventral border of the zygomatic arch
• walk  the needle slightly cranially along the cranial side of the maxilla to a level just beyond the root tips of the last molar
• aspirate 3 times
• apply digital pressure 30 - 60 seconds

mandibular block

• blocks all teeth in the mandible
• also blocks soft and hard tissues

located on the lingual surface of the mandible, halfway between the caudal curve of the mandible and the angular process

extra-oral and intra-oral

• clip and prep a small area at the angle of the mandible
• slide your finger inside the mouth until you feel an indentation
• from the outside, insert the needle through the skin until the needle hits the mandibular notch
• aspirate three times and inject

• place the animal lateally so the side you want to block is down
• palpate the foramen on the down side
• direct the syringe across the tongue from the up side of the mouth
• aspirate 3 times and inject

• 1st and 2nd premolars
• canines
• incisors
• soft and hard tissues of the mandible rostral to the 2nd premolar

there are 3 and we use the middle one

• insert needle bevel down into the submucosa in a rostral to caudal direction and advance just to the entrance of the foramen
• aspirate 3 times

3 -7 days