Mandibular Anaesthesia

1. Inferior Alveolar Nerve

a. Indications:

· Any procedure on the mandible that requires anaesthesia of pulps, buccal and lingual periodontium

b. Nerves

· Inferior alveolar nerve (mental and incisive branches)

· All pulps of mandibular teeth on that side up to the centrals (may get some cross innervation)

· Buccal periodontium anterior to the 1^st molar

· Usually get lingual nerve block, lingual periodontium, anterior 2/3 of the tongue and floor of the mouth

c. Technique

· 25g long needle

· Open mouth wide

· Palpate deepest part of external oblique ridge (coronoid notch)

· Slide finger medially to palpate internal oblique ridge (insertion just medial to this point)

· Pull finger laterally to coronoid notch in to keep tissue taut

· Syringe parallel to md occlusal plane (6-10mm above)

· Approach from over the contralateral bicuspid.

· Insertion pt: lateral aspect of the pteryogo-temporal depression, medial to the internal oblique ridge, lateral to the pterygo-mandibular raphe.

· Advance needle 25mm (2/3 buried)

· Hit bone, back off slightly, aspirate and inject ¾ to full cartridge (3/4 if planning to do a buccal block)

· If bone hit too soon, withdraw within tissue, redirect syringe more medially and advance again (repeat until correct depth).

· If bone not hit, withdraw within tissue, redirect syringe more laterally and advance again (repeat until correct depth).

d. Signs and Symptoms

· Numb lower lip on same side

· Slower onset 3-5min

· Numb tongue

2. Long Buccal Nerve Block

a. Indications

· Any procedure in the mandibular molars

· Especially for extractions of mandibular molars

· Follows the inferior alveolar block

b. Nerves

· Long buccal nerver

· Buccal periodontium from the 1^st molar back

c. Technique

· Use 25 gauge long needle (following inferior alveolar)

· Place thumb on external oblique ridge

· Pull tissue taut laterally

· Insert into mucous membrane lateral and distal to last molar (lateral to the alveolar bone)

· Angle syringe down toward mandible

· Insert 5mm until bone hit, bevel fcing bone, back off 0.5mm

· Aspirate, inject remaining cartridge (1/4 cartridge)

d. Signs and Symptoms

· Patient usually won’t feel anything

· Test with perio probe

3. Mental and Incisive Nerve Block

a. Indications

· For any procedure anterior to the 2^nd premolar

· Inferior alveolar block contraindicated

b. Nerves

· Mental nerve

· Incisive branch of inferior alveolar nerve

· Pulps of anterior mandibular teeth (1-5)

· Buccal mucous membrane anterior to mental foramen to midline

c. Technique

· Use 25 gauge short needle

· Retract cheek

· Insert needle into mucobuccal fold at mental foramen (between apices of 1^st and 2^nd premolars)

· Syringe at 30 degree angle to the long axis of the tooth

· Advance needle 5-6mm until bone hit, back off

· Aspirate and inject ½ - full cartridge

· Keep pressure distal to injection site to guide fluid into foramen

d. Signs and Symptoms

· Numbness of the lower lip (does not indicate that the incisive block was successful)

4. Gow-Gates

a. Indications

· Any procedure on the mandible

· When inferior alveolar block fails

· Buccal soft tissue anesthesia required distal to 1^st molar

b. Nerves

· Inferior alveolar nerve

· Long buccal nerve (75%a of time)

· Lingual nevre

· Mylohyoid nerve

· Auriculotemporal nerve

· Pulp of all teeth to midline

· Lingual and buccal periodontium

· Anterior 2/3 of tongue and floor of mouth

c. Technique

· 25 gauge long needle

· Locate extraoral landmarks – corner of mouth and intertragic area of ear

· Patient must open wide

· Palpate external oblique ridge and coronoid notch and pull tissue taut

· Align syringe in a plane parallel to extraoral landmarks

· Insertion point is lateral and superior to the inferior alveolar block

· Insert at height of maxillary occlusal plane, corresponds to ML ccusp of maxillary 2^nd molar, lateral margin of pterygotemporal depression, medial to temporalis muscle

· Advance needle 25 mm until bone hit at the neck of the condyle, back off

· Aspirate, inject full cartridge

· If bone not hit, redirect

d. Signs and Symptoms

· Numbness of lower lip, tongue, floor of mouth

· Must check buccal mucosa

5. Akinosi Technique

a. Indications

· Any procedure on a mandibular tooth

· When inferior alveolar block fails

· Good for patients with trismus

b. Nerves

· Inferior alveolar nerve

· Lingual nerve

· Mylohyoid nerve

· Buccal nerve sometimes (more variable than Gow Gates)

· Buccal sof tissue anterior to mental foramen

· Anterior 2/3 of tongue

c. Technique

· 25 gauge long needle

· bend needle 15-20 degrees

· have patient close mouth, but not clenched

· retract cheek and palpate coronoid notch

· may ask patient to slide into lateral excursion on same side

· aim needle between coronoid process and maxillary molars, lateral to maxillary tuberosity and medial to ramus and coronoid process

· must be careful to miss the temporalis muscle

· advance needle 25mm, with bend lateral

· after inserting 1mm arc needle by swinging syringe barrel medially, barrel should be resting gently on the maxillary gingival once insertion complete

· do NOT hit bone, it so, probably too far laterally

· aspirate and inject full cartridge

· final insertion point is above the standard block and below Gow Gates

d. Signs and Symptoms

· Numb lip, tongue, floor of mouth

· Onset 5 minutes

· May get buccal nerve

Maxillary Anesthesia

6. Parperiosteal

a. Indications

· Pulpal anaesthesia of 1-2 maxillary teeth

· Soft tissue anesthesia of buccal gingival for surgical procedures

· Restorative treatments

· Only useful on maxilla where bone is thin

b. Nerves

· Pulp

· Buccal periodontium

· Terminal branches of superior alveolar nerves above apices of teeth

· Root area of tooth

c. Technique

· Use 25 or 27 gauge short needle

· Set up syringe

· Retract lip and pull tissue taut

· Needle should be parallel to the long axis of the tooth , and at an angle of 30 degrees to the maxilla

· Insert needle above apex of tooth, at height of the mucobuccal fold, 5mm away from the bone (to catch the nerve before it hits the tooth)

· Advance the needle 5-7 mm before bone is hit

· If too shallow, may distend tissue (ballooning) which can be painful for the patient

· Once bone hit, back off 0.5mm

· Aspirate and slowly inject

· For one tooth 1ml (1/2 cartridge) is enough

d. Signs and Symptoms

· Onset is very rapid 2-3 minutes

· Patient may not feel anything (if in posterior)

· Anterior area – lip will feel numb

· Use perio probe on buccal mucosa to check and compare to other tissue (should not feel anything sharp)

7. High Cuspid Block

· Indications

· Multiple procedures of central, lateral and canine

· Anterior teeth and sometimes 1^st premolar

· Buccal mucosa of anterior teeth for surgery

b. Nerves

· Anterior part of the anterior superior alveolar nerve

· Pulps of anterior teeth (central, lateral, canine and sometimes 1^st premolar)

· May need to supplement central due to cross innervation

· Buccal soft tissue of anterior

c. Technique

· Use 25 or 27 gauge short needle

· Set up syringe

· Retract lip and pull tissue taut

· Insert needle parallel to long axis of tooth and 30 degrees to the maxilla

· Aim for canine fossa, distal to apex of the canine

· Insertion is more superior distal and deeper than the paraperiosteal field block

· Advance needle 7mm before hitting bone, then back off 0.5mm

· Aspirate and inject up to full cartridge

d. Signs and Symptoms

· Upper lip anaesthetized

· May get side of the nose

· Test with perio probe

8. Infraorbital Nerve Block

a. Indications

· Multiple procedures from central to 2^nd premolar

· Used when paaperiosteal contraindicated due to abscess or ineffective due to dense bone

b. Nerves

· Anterior superior alveolar nerve

· Middle superior alveolar nerve (may get MB root of 1^st molar)

· Superior plexus of nerves

· Superior labial nerve

· Inferior palpeebral

· Lateral nasal

· Pulps and buccal soft tissue of central, lateral, canine, 1^st and 2^nd premolars (sometimes MB root of 1^st molar)

c. Technique

· 25 gauge short needle (may require long)

· palpate the infraorbital notch with non-dominant hand

· run finger inferiorly until palpate depression (5mm); this is the foramen

· palpating finger helps guide fluid into the foramen and guides the needle, preventing overinsertion.

· Keeping thumb over foramen, retract lip and pull tissue taut

· Insert needle parallel to long axis of tooth at 0 degrees to maxilla

· Insert needle at height of mucobuccal fold above the 1^st premolar

· Advance needle superiorly (15mm) until contacting the upper rim of the infraorbital foramen (with bevel facing bone)

· When bone hit back off 1-2mm and aspirate

· Inject one full cartridge

d. Signs and Symptoms

· Onset 3-5 minutes

· Buccal soft tissue from central and 2^nd premolar

· Lower eyelid, lateral nose, upper lip

9. Posterior Superior Alveolar Nerve Block

a. Indications

· Multiple procedures on maxillary molars

· MB root of 1^st molar has separate innervation and may require a separate block

· When paraperiosteal is contraindicated or ineffective

b. Nerves

· Posterior superior alveolar nerve

· Pulps and buccal periodontium of maxillary 1^st,2^nd and 3^rd molars

c. Technique

· 25 gauge short needle

· mouth is partially opened to retract cheek more easily

· palpate zygomatic arch and process

· insert needle at height of mucobuccal fold abve the maxillary 2^nd molar, at 45 degrees in all 3 planes of space

· in one motion advance the needle superiorly, medially and posteriorly

· try to bring needle close to the infratemporal surface

· there should be no resistance and there are no bony landmarks

· insert needle 15mm

· aspirate well since the pterygoid plexus of veins is in this area (needle should be anterior to the pterygoid plexus of veins)

· inject a full cartridge

d. Signs and Symptoms

· Buccal periodontium and bone overlying maxillary molars

· Usually no symptoms to patient

· Cheek may be numb

10. Greater Palatine Nerve Block

a. Indications

· Hard and soft tissue anaesthesia in palate from 1^st premolar to 3^rd molar

· Extractions of maxillary teeth 4-8

· Perio surgery

· Subgingival restorative procedures on maxilla (matrix band, retraction cord)

· When accessory innervation is required for paraperiosteal

b. Nerves

· Greater palatine nerve

· Palatal periodontium and bone from 4-8

c. Technique

· Use 25 gauge short needle

· Locate depression over the greater palatine foramen (10mm down from the 2^nd molar, at the junction of the alveolar ridge and palate)

· Direct syringe from opposite side of the mouth at 45 degrees to the palate and 90 degrees to the alveolar ridge

· Aim needle for the anterior aspect of the foramen

· Insert needle 5-7mm through mucosa until bone hit, then pull back 0.5mm

· Must be at least 5mm to prevent fluid from shooting out

· Bevel faces bone

· Aspirate and inject ¼ cartridge, will have to apply some pressure to get fluid in

· Look for tissue blanching

· Advise patient of discomfort until drug begins to work

e. Signs and Symptoms

· Numbness on roof of mouth, anteriorly to 1^st premolar, medially to midline

· If lesser palatine nerve hit (which may occur) patient will have difficulty swallowing

11. Nasopalatine Nerve Block

a. Indications

· Anteriorhard and soft tissue of palate from canine to canine

· Perio surgery

· Extractions

· Subgingival restorations (insertion of matrix bands

b. Nerves

· Nasopalatine nerve

· Anterior portion of the hard palate from mesial of right 1^st premolar to mesial of left 1^st premolar

c. Technique

· Use 25 or 27 gauge short needle

· Look for the incisive papilla, located over the foramen

· Insertion of needle lateral aspect of the papilla and the posterior ½ OR lateral to the papilla on the posterior ½

· Aim is to get needle in centre of the incisive foramen

· Advance needle 5mm until bone is contacted, back off 0.5mm

· Aspirate and inject slowly (need to apply pressure since tissue is very resistant) 1/8 to ¼ cartridge

· Look for tissue blanching

· Angle of needle depends on distance from midline (if at midline straight angle; if more lateral angle towards midline)

d. Signs and Symptoms

· Use perio probe to confirm anaesthesia

12. Maxillary Nerve Block

a. Indications

· Extensive work on one side of the jaw (all 7 teeth)

· Infection contraindicates other blocks

b. Nerves

· Maxillary branch of the trigeminal nerve

· Pulps of teeth 1-8

· Buccal and palatal periodontium

· Lip

· Later aspect of the nose

· Lower eyelid

c. Technique

1. High Tuberosity

· 25 gauge long needle

· start as if doing PSA nerve block (insert at 7-8 area)

· aim to bring needle all the way up, want tip at height of the infraorbital canal

· insert almost to full length of needle (30mm)

· do not hit bone

· aspirate and inject full cartridge

· high chance of hematoma

2. Greater Palatine canal

· 25 gauge long needle

· Start off doing a greater palatine neve block

· May need to bend needle

· Patient must open wide

· Try to advance needle slowly up canal, to depth of 30mm

· Aspirate and inject full cartridge

d. Signs and Symptoms

· Numbness of buccal and palatal soft tissue, lip, side of nose and lower eyelid

Local Anesthetic

1. Maximum dose for healthy 70 kg adult per appointment:

Anaesthetic	Category	Potency/ Duration	pKa (onset)	Lipid Solubility	Dose (70kg)	Solutions	Other Info
Lidocaine (octacaine, xylocaine)	Xylidine	Intermediate	7.6-7.7	3	Plain: 300 EPL: 500	2% L 2% L 1:100 000 2% L 1:200 000 2% L 1:50 000 à for hemostasis topical 1-5% (cream, spray, etc)	65 % binding
Mepivicaine (polocaine, isocaine, carbocaine)	Xylidine	Intermediate	7.6-7.7 slow onset b/c spherical	5	Plain: 300 EPL: 500 (400)	3% M 2% M + neocobefrin 1:20 000	80 % binding poorly handled by fetal liver, use with caution in pregnancy
Bupivacaine (marcaine)	Xylidine	High/long	8.1	2	Plain: 175 EPL: 225	0.5% B 1:200 000	90 % binding -long lasting, good for post-op pain relief -better for nerve block than infiltration -spherical, pKa = 8.1, thus long to act, slow onset
*Prilocaine (citanest)	Toludine	Intermediate	7.6-7.7	4	Plain: 600 EPL: 600 (400)	4% P 4 % P 1:200 000	55 % binding The best! 1) lowest protein binding 2) lowest vasodilatory 3) plasma decay curve a, b, g curves are fastest 4) highest hepatic extraction ratio 5) fasteset hepatic and renal clearance 6) extrahepatic metabolism (lungs, kidney) But: problems 1) Methemoglobinemia 2) Secondary amine 3) Fetal Hb
*Ultracaine (articaine)	Thiophene	intermediate		6	Plain: --- EPL: <12 à 5 mg/kg > 12 à 7 mg/kg	4% U 1:100 000 4% U 1:200 000	90 % binding secondary amine
Tetracaine	Spinal				Maximum dose 20 - 50 mg	0.2 – 2 % solutions, as topical anaesthetic spray (0.7 mg/spray). Very toxic.
Propoxycaine 0.4% + Procaine 2% (ravocaine)	Ester					Only injectable ester, not available in Canada
Benzocaine (hurricaine, americaine)	Ester					1% - 20% solutions available to be used topically only. Extremely water-insoluble (no termainal amine)
Procaine	Ester	Low/short		7
Cocaine	Ester
Etidocaine	sequestration			1
EMLA						2.5% Lido + 2.5% Prilo, topical only	Not used much in dentistry, more in medicine

* not used on mandibular blocks, increase risk of Paraesthesia

2. Contraindications for use of vasoconstrictor

a. Absolute

1. lack of knowledge of pharmacology of drug

2. uncontrolled CV disease (e.g. HTN, unstable angina)

3. uncontrolled hyperthyroidism

4. bisulphite allergy

b. Relative – weigh risk vs. benefit, use reduced dose (1:200,000 solution) of 0.04 mg max.

1. controlled CV disease

2. use of drugs

(a) TCAs (prevent reuptake of catecholamines)

(b) Digitalis (h slope of phase 4 of heart beat, predisposes to abnormal rhythms)

(c) b blockers (non-cardioselective mainly) – get unopposed a g hBP

(d) phenothiazines (anti-psychotics) – block a, get unopposed b g iBP

(e) cocaine

(f) nicotine

(g) halothane

(h) cold remedies (especially with ephedrine)

(i) thyroid supplements (synthetic) – sensitize b adrenoreceptors to exogenous catecholamines

(j) pregnancy - a property decreases placental blood flow

· epi toxicity manifested as sympathomimetic effects, e.g. hHR, hBP, palpitations (awareness of heart beat), restlessness, pallor (pale), cool/clammy skin, headache, nausea

c. Prevention of toxic reaction to epi

1. aspirate

2. never exceed max. dose (0.2 mg healthy, 0.04 mg medically compromised)

- adjust dose wrt age, size, med. history, procedure

3. Formulations for dental purposes:

a. 1 : 50,000 solutions

= 1 g (1000mg) Epi / 50,000 ml of solution

-there is 1.8 ml of LA in the carpule (“but for our calculations lets round it off to 2 ml”)

= 0.02 mg/ml X 2 ml = 0.04 mg Epi in one cartridge

(high potency, infiltration at the site of incision)

-this formulation has ONLY one indication, hemostasis!

-if do use for hemostasis, there is a increase chance for rebound to increase bleeding and also increase post operational pain

b. 1 : 100,000 solutions

= 1g (1000mg) Epi / 100,000 ml of solution

= 0.01 mg/ml X 2 ml = 0.02 mg Epi in one cartridge

-no indication for this solution in dentistry –“but will hear otherwise in restorative where use is simply b/c of tradition” – so still commonly used.

c. 1 : 200,000 solutions

= 1 g (1000mg) Epi / 200,000 ml of solution

= 0.005 mg epi / ml of solution X 2 ml = 0.01 mg Epi in one cartridge