ARE YOU NUMB YET? THE ANATOMY OF LOCAL ANESTHESIA PART 2: TECHNIQUES PHYSIOLOGIC FACTORS FOR DENTAL ANESTHESIA Alan W. Budenz, MS, DDS, MBA INJECTIONS Dept. of Biomedical Sciences and Vice Chair of Diagnostic Sciences & Services, Dept. of Dental Practice University of the Pacific, Arthur A. Dugoni School of Dentistry San Francisco, California Success versus Failure [email protected]
Failed Anesthetic: Measuring the Problem Physiology of Anesthetic Agents One of every three patients is not properly numb when the dentist or hygienist is ready to start (or actually starts) a dental procedure. How do we assess anesthesia? Is this “failed anesthetic”? 60%
Question the patient Soft tissue only 50% * Probe the area 46% Average 40% 42% 41% Failure 38% Rate is Cold test 30% 29% Pulpal tissue 31% Electric pulp tester 20% 19% 20% 17% 15% How is anesthetic success defined in studies? 10%
Frequency Frequency Anesthetic Failedof Ideal: 2 consecutive 80/80 readings with EPT within 15 0% IAN Blocks - 15 min. after injection Maxillary infiltrations - 10 min. after injection minutes of injection (and sustained for 60 mins) Delayed pulpal onset: occurs in the mandible of 19 – 27% Slide courtesy Dr. Mic Falkel of patients (even though soft tissue is numb) Delayed over 30 minutes in 8% Nusstein J et al. The challenges of successful * Average failure rate reported across 38 published studies mandibular anesthesia, Inside Dentistry, May 2008
Physiology of Anesthetic Agents Blocks versus Infiltrations
Onset of anesthesia: Advantages of infiltrations 1. Dependent upon anesthetic agent 1. Faster onset Concentration 2. Diffusion to the site Simple Lipid solubility 3. Safe Protein binding to receptor sites 4. Good hemostasis (with vasoconstrictor) 2. Dependent upon technique, block versus infiltration Disadvantages of infiltrations Infiltration has faster onset 1. Multiple injections for multiple teeth Block has longer duration 2. Shorter duration of anesthesia
1 Blocks versus Infiltrations Blocks versus Infiltrations Duration of pulpal anesthesia:
Dental anesthetic agents: all amides Infiltration Injections 70 2% Lidocaine plain 1. Lidocaine – plain or with vasoconstrictor 60 4% Prilocaine plain 2. Mepivacaine – plain or with vasoconstrictor 50 3% Mepivacaine plain 3. Prilocaine – plain or with vasoconstrictor 2% Lidocaine w/ vaso 4. Articaine – with vasoconstrictor Minutes 40 2% Mepivacaine w/ vaso 5. Bupivacaine – with vasoconstrictor 30 4% Prilocaine w/ vaso 20 4% Articaine w/ vaso 10 0.5% Bupivacaine 0 Manufacturer’s Product Inserts; Malamed, Handbook of Local Anesthesia, 5th Ed, Elsevier, 2004; Jastak, Yagiela, Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995
Blocks versus Infiltrations Duration of pulpal anesthesia: Blocks versus Infiltrations
Duration of anesthesia:and onset: Infiltration Block Injection 1. Dependent upon anesthetic agent 70 300 2% Lidocaine plain Concentration 60 250 4% Prilocaine plain DiffusionDiffusion fromto/from the thesite site 50 3% Mepivacaine plain 200 Lipid solubility 40 2% Lidocaine w/ vaso Protein binding to receptor sites 150 2% Mepivacaine w/ vaso 30 2. Dependent upon technique, block versus 100 4% Prilocaine w/ vaso 20 infiltration 4% Articaine w/ vaso 10 50 0.5% Bupivacaine 3. Dependent upon vasoconstrictor presence, but 0 0 NOT vasoconstrictor concentration*
Manufacturer’s Product Inserts; Malamed, Handbook of Local Anesthesia, 5th Ed, Elsevier, 2004; *Malamed, Handbook of Local Anesthesia, 5th Ed, Elsevier, 2004 Jastak, Yagiela, Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995
Physiology of Anesthetic Agents Physiology of Anesthetic Agents
1. Overall diameter (size) of the nerve bundle 3. Critical length = 3 nodes minimum (5 mm) 2. Amount of myelin (lipid) sheath present Anesthetic volume, tissue space & density Time for entire nerve bundle to be penetrated Central Core Theory: Peripheral fibers anesthetized first To most proximal structures (molars) Central fibers anesthetized last To most distal structures (incisors) DeJong RH, Physiology and Pharmacology Node of Ranvier Critical length of Local Anesthesia, 1970 Jastak, Yagiela, Donaldson, Local Anesthesia of Evers & Haegerstam, Introduction to Dental the Oral Cavity, WB Saunders Co, 1995 Local Anesthesia, Mediglobe, 1990
2 Physiology of Anesthetic Agents Reasons for Anesthetic Failures The “right” volume depends on many 1. Anatomical/physiological variations variables For infiltration injections, ½ to ¾ cartridge is 2. Technical errors of administration generally ideal 3. Patient anxiety Brunetto et al, Anesthetic efficacy of 3 volumes of lidocaine with epinephrine in maxillary infiltration anesthesia, Anesth Prog 55, 2008 4. Inflammation and infection For an inferior alveolar nerve block, 5. Defective/expired solutions Less than ½ cartridge tends to be ineffective ¾ – 1 cartridge is ideal Nusstein et al, Anesthetic efficacy of different volumes of lidocaine with epinephrine for inferior alveolar nerve blocks, Gen Dent 50, 2002
Wong MKS & Jacobsen PL, Reasons for local anesthesia failures, JADA Vol 123, Jan 1992
Reasons for Anesthetic Failures Reasons for Anesthetic Failures
1. Anatomical/physiological 2. Technical errors of administration variations Too high Wide flaring mandible Too low Wide flaring ramus Too anterior Long (A - P) ramus Too posterior Bulky musculature Too medial Large buccal fat pad Too lateral Class III occlusion Missing teeth Intravascular Children Accessory or anomalous nerve pathways
Reasons for Anesthetic Failures
1. Anatomical/physiological variations REVIEW OF ANATOMY
2. Technical errors of administration These two are General Anatomy and Landmarks for closely related: Mandibular Anesthesia We will solve by reviewing the anatomy and landmarks McMinn, Hutchings & Logan, Color Atlas of Head & Neck Anatomy, 2nd Ed, Mosby, 1994
3 The Masticator Space The Masticator Space
Includes the Temporal and Infratemporal Fossae The Infratemporal Fossa Boundaries: A = Maxillary tuberosity P = Styloid process M = Lateral pterygoid plate L = Ramus of mandible
Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 Lippincott Williams & Wilkins, 1999 Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001
Infratemporal Fossa The Masticator Space
Contents Muscles of mastication Medial Lateral Mandibular division of A Fascial Compartment: Trigeminal nerve, V 3 Derived from investing Chorda tympani layer of deep cervical branch of Facial nerve fascia
Maxillary artery and vein Envelopes mandible and muscles of mastication Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999 Hollinshead, Anatomy for Surgeons, Vol 1, The Head & Neck, 3rd Ed, Harper & Row, 1982
The Muscles of Mastication The Muscles of Mastication
Four total: 2 superficial Four total: 2 superficial
1. Temporalis 1. Temporalis 2. Masseter
Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001
4 The Muscles of Mastication The Muscles of Mastication
Four total: 2 superficial; 2 deep Four total: 2 superficial; 2 deep
1. Temporalis 1. Temporalis 2. Masseter 2. Masseter 3. Medial 3. Medial pterygoid pterygoid 4. Lateral pterygoid
Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001
Accessory Muscles of Mastication: Innervation of the Muscles of Facial Expression Infratemporal Fossa Oral musculature Levator labii superioris V3 Mandibular Levator anguli oris Division of the Zygomaticus major Trigeminal Nerve Buccinator Risorius The nerve of the first branchial arch, which gives origin to the Mentalis maxillary & mandibular arches Depressor anguli oris and the muscles of mastication Depressor labii inferioris Orbicularis oris
Platysma Agur, Grant’s Atlas of Anatomy, 9th Ed, Netter, Atlas of Human Anatomy, 2nd Ed, Novartis, 1997 Lippincott Williams & Wilkins, 1991
V3: Short stem, then splits into V3: Sensory & Motor Innervation 2 divisions
Stem: Motor to the 1. Medial Muscles of pterygoid nerve Mastication 2. Tensor
tympani nerve Sensory to all teeth 3. Tensor and oral tissues palatini nerve
4. Meningeal Enters through the branch Foramen Ovale
Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999 Lippincott Williams & Wilkins, 1999
5 V3: Anterior division V3: Posterior division
Motor branches: Sensory branches: 1. Deep temporal 1. Auriculotemporal nerves (2) nerve 2. Masseteric nerve 2. Lingual nerve 3. Lateral pterygoid 3. Inferior alveolar nerve nerve - mylohyoid One sensory branch: - mental Long Buccal nerve - incisive All sensory except Fehrenbach & Herring, Illustrated Anatomy Lateral View of the Head & Neck, WB Saunders Co, 1996 Mylohyoid nerve Fehrenbach & Herring, Illustrated Anatomy of the Head & Neck, WB Saunders Co, 1996
Additional Innervation in the V3: Posterior division Infratemporal Fossa Sensory branches: 1. Auriculotemporal Chorda tympani: • Branch of CN VII nerve 2. Lingual nerve • Carries taste fibers from anterior tongue 3. Inferior alveolar nerve • Secretomotor fibers to - mylohyoid salivary glands - mental - incisive Joins lingual nerve of All sensory except V3 in ITF
Fehrenbach & Herring, Illustrated Anatomy mylohyoid nerve Fehrenbach & Herring, Illustrated Anatomy of the Head & Neck, WB Saunders Co, 1996 Medial View of the Head & Neck, WB Saunders Co, 1996 Medial View
Blood Supply to the Blood Supply to the Infratemporal Fossa Infratemporal Fossa Maxillary artery Maxillary artery: Part 1: Mandibular 3 parts
1. Deep auricular 1. Mandibular 2. Anterior tympanic 2. Pterygoid 3. Middle meningeal 3. Pterygopalatine 4. Accessory middle meningeal 5. Inferior alveolar - mylohyoid, mental,
Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, & incisive branches Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999 Lippincott Williams & Wilkins, 1999
6 Blood Supply to the Blood Supply to the Infratemporal Fossa Infratemporal Fossa
Maxillary artery Maxillary artery Part 2: Pterygoid Part 3: Pterygopalatine 1. Posterior superior 1. Deep temporal (2) alveolar 2. Medial pterygoid 2. Infraorbital 3. Lateral pterygoid 3. Artery of pterygoid 4. Masseteric canal 5. Buccal 4. Pharyngeal branch 6. Lingual 5. Descending palatine 6. Sphenopalatine
Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001
Blood Supply to the Blood Supply to the Infratemporal Fossa Infratemporal Fossa
Pterygoid Venous Pterygoid Venous Plexus Plexus Connections to: 1. Cavernous sinus Primary drainage to 2. Facial vein Maxillary vein 3. Inferior ophthalmic vein 4. Pharyngeal plexus
Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001
Netter’s Atlas, 4th Ed, Saunders/Elsevier, 2006
View of infratemporal fossa View of infratemporal fossa with mandible resected fully dissected
Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999 Lippincott Williams & Wilkins, 1999
7 Infiltration Anesthesia Works well for the maxilla, but the mandible… Work fairly well for anteriors and bicuspids MANDIBULAR ANESTHESIA Widely varying predictability for molars Greater success using articaine & faster onset Lidocaine 45 – 67%; articaine 75 – 92% Lidocaine 6.1 – 11.1 minutes; articaine 4.2 – 4.7 minutes Conventional and Alternative Techniques
Facial Lingual Robertson et al, The anesthetic efficacy of articaine in buccal infiltration of mandibular posterior teeth, JADA Vol 138 No 8, 2007 Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Intraligamentary Anesthesia Intraligamentary Anesthesia
The periodontal ligament (PDL) injection The periodontal ligament (PDL) injection Requires separate injection for each root Requires separate injection for each root Duration unpredictable, generally quite short However…
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Intraligamentary Anesthesia Intraligamentary Anesthesia
The periodontal ligament (PDL) injection The periodontal ligament (PDL) injection Requires separate injection for each root Cautions: Duration unpredictable, generally quite short 1. Some case reports of bone and root resorption Less volume of anesthetic used compared to other Most reversible, but isolated irreversible cases techniques Incidence increases with increased force of injection Recommended to use plain, non-vasoconstrictor 2. Pediatric patients with primary or mixed dentition containing anesthetic agents 3. Prophylaxis recommended for “at risk” cardiac Injecting into a highly vascular space conditions (artificial valves, prior endocarditis, etc.) Patients are more likely to experience cardiovascular side effects if vasoconstrictor is used
8 Intraosseous Anesthesia Intraosseous Anesthesia
Penetrate the cortical First assess with plate between the roots radiograph for of two neighboring teeth adequate perforation Inject directly into the space cancellous bone Impaction? Will anesthetize both teeth Abcess? The Stabident System Periodontal The X-Tip System disease? The IntraFlow System Hypo intraosseous needles
Intraosseous Anesthesia Intraosseous Anesthesia
The Stabident System The Stabident System
Step 2: Step 1: Penetrate cortical plate Submucosal with perforator in infiltration to reduction gear slow- speed handpiece injection site Feel “drop” through See light tissue cortical plate blanching
Intraosseous Anesthesia Intraosseous Anesthesia
The Stabident System The Stabident System
Step 2: Step 2: Perforation/Injection site: Penetration/Injection site: 2 mm below gingival 2 mm 2 mm below gingival margin and between margin and between teeth teeth
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Perforation should only take 3 to 4 seconds
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
9 Intraosseous Anesthesia Intraosseous Anesthesia Reliable: 89% success rate The Stabident System Longer duration than PDL injections 15 to 30 minutes duration with non-vasoconstrictor containing anesthetic agent Step 3: Can extend duration with second injection in same site Only a small volume of anesthetic is needed (~0.9 ml) Insert syringe needle Pulpal anesthesia of tooth on either side of injection site through perforation and No lip anesthesia for anterior smile line assessment inject Recommended to use plain, non-vasoconstrictor containing anesthetic agents Watch for any backflow Injecting into a highly vascular space of anesthetic Patients are more likely to experience cardiovascular side
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 effects if vasoconstrictor is used
Mandibular Anesthesia Blocks versus Infiltrations
Mandible: Nerve blocks Needles Inferior alveolar nerve block Length Lingual nerve block Long 30 – 35 mm Long buccal nerve block Short 20 – 25 mm Mental (& incisive) nerve block Ultra-short ~10 mm Mylohyoid nerve block Gauge (25, 27, or 30) Complete mandibular division Patients report no perceived difference in pain due to nerve block needle gauge Gow-Gates mandibular division Aspiration requires more force the smaller the gauge block Vazirani – Akinosi mandibular Recommendation: 30 gauge short for infiltrations only; division block 25 or 27 gauge long needles are best for blocks Jastak, Yagiela & Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995 Flanagan T et al. Size doesn’t matter: Needle gauge and injection pain, General Dentistry, May – June, 2007
Needles Evolution Needles
Gauge: 25, 27, 30 Length For block injections: Gauge: 25 or 27 Aspiration Short 20 – 25 mm Length: long only Comfort Long 30 – 35 mm
Deflection Breakage
Standard Thin Walled Design Thin Walled, Increased Bore Design Tri-bevel needle
10 Mandibular Anesthesia Mandibular Anesthesia
Mandible: Landmarks Mandible: Nerve blocks Coronoid notch Mandibular notch Inferior alveolar nerve block Neck of condyle Bisection approach Coronoid process Coronoid notch External oblique ridge Internal oblique ridge/ mylohyoid line Mandibular foramen & lingula Mental foramen
Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, McMinn, Hutchings & Logan, Color Atlas of Jastak, Yagiela & Donaldson, Local Anesthesia of Lippincott Williams & Wilkins, 1999 Head & Neck Anatomy, 2nd Ed, Mosby, 1994 the Oral Cavity, WB Saunders Co, 1995
Mandibular Anesthesia Mandibular Anesthesia
Mandible: Nerve blocks Mandible: Nerve blocks Inferior alveolar nerve block Inferior alveolar nerve block Bisection approach Bisection approach Position of mandibular foramen Position of mandibular foramen Below mandibular occlusal Variable from infancy to adulthood plane in 75% Even with occlusal plane in 22.5%
Nicholson ML, A study of the position of the mandibular foramen in the adult human mandible, Anat Rec Vol 212, 1985
Evers & Haegerstam, Introduction to Dental Local Anaesthesia, Mediglobe, 1990
Mandibular Anesthesia Mandibular Anesthesia
Inferior alveolar nerve block Inferior alveolar nerve block Intraoral landmarks: Coronoid notch Intraoral landmarks: Coronoid notch 1. Coronoid notch 1. Coronoid notch 2. Internal oblique ridge 2. Internal oblique ridge 3. Pterygomandibular raphe 3. Pterygomandibular raphe
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Evers & Haegerstam, Introduction to Dental Local Anaesthesia, Mediglobe, 1990
11 Mandibular Anesthesia Mandibular Anesthesia
Inferior alveolar nerve block Inferior alveolar nerve block Coronoid notch Intraoral landmarks: Bisection technique: 3. Pterygomandibular raphe Depth 25 – 30 mm Needle Long Amount 2/3 - 3/4 cartridge Comfort level Moderate
After injection, sit patient up
Evers & Haegerstam, Introduction to Dental Blanton PL & Roda RS, The anatomy of local anesthesia, Evers & Haegerstam, Introduction to Dental Local Local Anaesthesia, Mediglobe, 1990 CDA Jour Vol 23 No 4, April 1995 Anaesthesia, Mediglobe, 1990
Mandibular Anesthesia Mandibular Anesthesia
Inferior alveolar nerve block Inferior alveolar nerve block Bisection approach Bisection technique: Based upon Unfortunately, anatomical 1. Anatomic norms structures vary widely Wide flaring mandible Bone structure Wide flaring ramus Muscle mass Long (A – P) ramus Nerve pathways Bulky muscles or buccal fat pad 2. Normal physiology Class III occlusion Healthy local environment Missing molars/edentulous McMinn, Hutchings & Logan, Color Atlas of Age/children nd Success rate of technique Head & Neck Anatomy, 2 Ed, Mosby, 1994 Prado FB et al, Morphological changes in the position of the mandibular foramen 65 – 86% (30 – 97%) in dentate and edentate Brazilian subjects, Clinical Anatomy Vol 23, 2010
Mandibular Anesthesia Mandibular Anesthesia
Inferior alveolar nerve block Inferior alveolar nerve block Bisection Technique Anesthetize IA, mental, and Bone contact incisive nerves
NO lingual anesthesia
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Fehrenbach & Herring, Illustrated Anatomy McMinn, Hutchings & Logan, Color Atlas of of the Head & Neck, WB Saunders Co, 1996 Blanton PL & Roda RS, The anatomy of local anesthesia, Head & Neck Anatomy, 2nd Ed, Mosby, 1994 CDA Jour Vol 23 No 4, April 1995
12 Mandibular Anesthesia Troubleshooting Mandibular Anesthesia
Inferior alveolar nerve block Lower lip and chin is numb Lingual nerve block Tongue is numb Anesthetize IA, mental, incisive, But the tooth is only partially numb! and lingual nerves Or the tooth is numb, but duration is short and/or anesthesia is not profound
Give a second injection at the same site?
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Go higher and deeper for a second injection?
Troubleshooting Mandibular Anesthesia Troubleshooting Mandibular Anesthesia
The tooth is only partially numb! The tooth is only partially numb! Or the tooth is numb, but duration is short and/or Or the tooth is numb, but duration is short and/or anesthesia is not profound anesthesia is not profound Solution: give a second injection in the same site with Go higher and deeper for a different anesthetic agent a second injection? If a different anesthetic, or combination of anesthetics, is found to work better for a patient, Risk higher incidence of record that fact and start with that anesthetic at positive aspiration the next appointment There is no contraindication for combining any of Blanton PL & Roda RS, The anatomy of local anesthesia, CDA Jour, Vol 23 No 4, April 1995 the amide anesthetic agents
Troubleshooting Mandibular Anesthesia Mandibular Anesthesia
Lower lip and chin is numb Mandible: Nerve blocks Tongue is numb Inferior alveolar nerve block = “mandibular block” But the molar tooth is only partially numb! This is NOT a complete mandibular division nerve block! 1. Lingual nerve block given Give long buccal nerve in combination with IA block 2. No long buccal NO NO LB lingual nerve blockade anes anesthesia Common accessory Requires separate innervation, especially injection to molars Common accessory innervation to molars Jastak, Yagiela & Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995 Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
13 Troubleshooting Mandibular Anesthesia Mandibular Anesthesia Lower lip and chin is numb Long buccal nerve block Tongue is numb Accessory innervation to mandibular molars But the molar tooth is only Average of 27 foramina in the retromolar area or in partially numb! the superior medial region of the ramus above and Inferior alveolar and lingual anterior to the mandibular foramen Give the long buccal nerve Haveman & Tebo, Posterior accessory foramina of the human mandible, J Prosth Dent Vol 35, 1976 block
Long buccal The long buccal injection should be given to complement the IA & lingual blocks
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Mandibular Anesthesia Mandibular Anesthesia
Long buccal nerve block Long buccal nerve block In cadaver dissections, 37.5% of nerves entering the superior medial and retromolar regions of the mandible had direct connections with branches of the inferior alveolar nerve to the molars Carter RB & Keen EN, The intramandibular course of the inferior alveolar nerve, J Anat Vol 108, 1971
Jastak, Yagiela & Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Evers & Haegerstam, Introduction to Dental Meechan, Practical Dental Local Local Anaesthesia, Mediglobe, 1990 Anesthesia, Quintessence, 2002
Mandibular Anesthesia Mandibular Anesthesia
Long buccal nerve block Long buccal nerve block Accessory innervation to mandibular molars Accessory innervation to mandibular molars Depth 2 – 4 mm Needle Short Amount ½ cartridge Comfort level Moderate to high
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
14 Troubleshooting Mandibular Anesthesia Mandibular Anesthesia
You’ve given the IA and lingual block, and the long You’ve given the IA and lingual block, and the long buccal block buccal block But the tooth is still only partially numb! But the tooth is still only partially numb!
Solutions What can the problem For one tooth, buccal &/or be? lingual infiltration, PDL, or intraosseous injections What solutions should work well we try? For a quadrant, a mylohyoid nerve block may be best
Jastak, Yagiela & Donaldson, Local Anesthesia of Jastak, Yagiela & Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995 the Oral Cavity, WB Saunders Co, 1995
Mandibular Anesthesia Mandibular Anesthesia
Mylohyoid nerve block Mylohyoid nerve block Accessory innervation to any mandibular tooth Accessory innervation to any mandibular tooth
53% of mandibles had accessory foramina near the mylohyoid line, particularly in the premolar area.* *Haveman & Tebo, Posterior accessory foramina of the human mandible, J Prosth Dent Vol 35, 1976 Katakami K et al, Characteristics of accessory mental foramina on limited cone-beam computed tomography images, J Endod 34(12), 2008
In cadaver dissections, 50% exhibited branches of the mylohyoid nerve entering foramina in the lingual surface of the mandible. These nerves ended directly in the mandibular teeth or joined the incisive branch of the inferior alveolar nerve. Madeira et al, Clinical significance of supplementary innervation of the lower incisor teeth: A dissection study of the mylohyoid nerve, O Surg O Med O Pathol Vol 46, 1978 Fehrenbach & Herring, Illustrated Anatomy Medial View of the Head & Neck, WB Saunders Co, 1996
Mandibular Anesthesia Mandibular Anesthesia Mylohyoid nerve block Mylohyoid nerve block Accessory innervation to any Accessory innervation to any mandibular tooth mandibular tooth The point at which the mylohyoid nerve branched from the inferior alveolar nerve ranged from 5 to 23 mm above the mandibular foramen, with a mean distance of 14.7 mm.* Upon histological examination of the *Wilson et al, The inferior alveolar and mylohyoid nerves: An anatomic study and relationship mylohyoid nerve from its origin to its to local anesthesia of the anterior mandiblular teeth, JADA Vol 108 No 3, 1984 termination, the loss of small Bennett S & Townsend G, Distribution of the mylohyoid nerve: Anatomical variability and diameter pain and temperature clinical implications, Austral Endo J 27(3), 2001 fibers was detected along its entire length.
Frommer et al, The possible role of the mylohyoid nerve in mandibular posterior tooth sensation, JADA Vol 85, 1972 Przystanska A, Bruska M, Accessory mandibular foramina: histological and immunohistochemical studies of their contents, Arch Oral Biol 55(1), 2010 Jastak, Yagiela & Donaldson, Evers & Haegerstam, Introduction to Dental Local Anesthesia of the Oral Local Anaesthesia, Mediglobe, 1990 Cavity, WB Saunders Co, 1995
15 Mandibular Anesthesia Mandibular Anesthesia
Mylohyoid nerve block Mylohyoid nerve block Between mandible and Between mandible and sublingual fold sublingual fold Just distal to last tooth Just distal to last tooth to be worked on to be worked on Approximate apices of Approximate apices of roots roots Easiest for anterior teeth Easiest for anterior teeth Access to molars may be Access to molars may be difficult difficult Evers & Haegerstam, Introduction to Dental Local Anaesthesia, Mediglobe, 1990
Mandibular Anesthesia Troubleshooting Mandibular Anesthesia
Mylohyoid nerve block You’ve given the IA and lingual block, and the long Depth 2 – 4 mm buccal and mylohyoid blocks Needle Short But the tooth is Amount 1/3 – 1/2 still not completely numb! cartridge Comfort level High Give complete mandibular division nerve block for molars Good for any mandibular tooth
Evers & Haegerstam, Introduction to Dental Evers & Haegerstam, Introduction to Dental Local Anaesthesia, Mediglobe, 1990 Local Anaesthesia, Mediglobe, 1990
Mandibular Anesthesia Mandibular Anesthesia
Mandible: Nerve blocks NO NO Mandible: Nerve blocks Inferior alveolar nerve block LB lingual Inferior alveolar anes anesthesia Lingual nerve block “mandibular” block Long buccal nerve block Gow-Gates complete Mental (& incisive) nerve mandibular division block block Mylohyoid nerve block Complete mandibular division nerve block Gow-Gates mandibular division block Vazirani – Akinosi mandibular division block Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999
16 Mandibular Anesthesia Mandibular Anesthesia
Gow-Gates mandibular Gow-Gates mandibular division block division block Target: Contact bone at the neck of the condyle Landmarks 1. Alpha plane: from intertragic notch of the ear to corner of the mouth, and across to the opposite corner
of the mouth Alpha plane Malamed, Handbook of Local Anesthesia, Anterior – posterior 3rd Ed, Mosby Year Book, 1990 orientation
Mandibular Anesthesia Mandibular Anesthesia
Gow-Gates mandibular division block Gow-Gates mandibular division block The mouth must be open wide! The mouth must be open wide!
Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999 Lippincott Williams & Wilkins, 1999
Mandibular Anesthesia Mandibular Anesthesia
Gow-Gates mandibular division block Gow-Gates mandibular division block The mouth must be open wide! The mouth must be open wide! Establish the alpha plane Point of insertion: Maxillary vestibule off the distal- buccal cusp of the Modification: second molar or Finger behind the neck of the slightly behind condyle But at what angle?
The alpha plane
17 Mandibular Anesthesia Mandibular Anesthesia
Gow-Gates mandibular division block Gow-Gates mandibular division block Angle (medial – lateral angulation) = Beta plane Angle (medial – lateral angulation) = Beta plane The syringe is oriented parallel to the angulation of the Varies with width and flare of mandible and ramus tragus of the ear away from the face Aim for your extraoral finger behind the neck of the condyle
Gow-Gates & Watson, The Gow-Gates mandibular block: Further understanding, Anesth Prog 25 (6), 1977 Jastak, Yagiela & Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995
Mandibular Anesthesia Mandibular Anesthesia
Gow-Gates mandibular division block Gow-Gates mandibular division block The mouth must be open wide! Depth 25 – 28 mm (contact bone) Point of insertion: Maxillary vestibule off the distal- Needle Long buccal cusp of the Amount 1 – 2 cartridges second molar or Comfort level Moderate to high slightly behind Aim for your finger behind the neck of the condyle
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Mandibular Anesthesia Mandibular Anesthesia
Complete mandibular Vazirani – Akinosi mandibular division block division nerve block A closed mouth technique Vazirani – Akinosi mandibular division block A closed mouth technique
Wolfe SH, The Wolfe nerve block: A modified high mandibular Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 nerve block, Dentistry Today, June/July 1992
18 Mandibular Anesthesia Mandibular Anesthesia
Vazirani – Akinosi mandibular division block Vazirani – Akinosi mandibular division block A closed mouth technique Depth 25 – 30 mm (no bone contact) Needle Long Amount 1 cartridge Comfort level Moderate
Injection site visibility difficult with mouth closed
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Mandibular Anesthesia Mandibular Anesthesia
Vazirani – Akinosi mandibular division block Comparison of mandibular division nerve Modifications block techniques 1. Mouth slightly open Conventional (Halstead) technique 2. Use bent needle Gow-Gates technique Area of anesthesia Vazirani – Akinosi technique
Jastak, Yagiela & Donaldson, Local Anesthesia of Wolfe SH, The Wolfe nerve block: A modified high mandibular the Oral Cavity, WB Saunders Co, 1995 nerve block, Dentistry Today, June/July 1992 Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Mandibular Anesthesia Mandibular Anesthesia
Success rate of techniques Success rate of techniques Conventional 65 – 86% (30 – 97%) Conventional* 65 – 86% Gow-Gates 90 – 100% Gow-Gates * 90 – 100% Vazirani – Akinosi 76 – 93% Vazirani – Akinosi* 76 – 93%
* What volume of anesthetic But how is success defined? is being used?
19 Mandibular Anesthesia Mandibular Anesthesia
Success rate of techniques Success rate of techniques Conventional* 65 – 86% Conventional 65 – 86% Gow-Gates * 90 – 100% Gow-Gates * 90 – 100% Medial Lateral Vazirani – Akinosi* 76 – 93% Vazirani – Akinosi 76 – 93%
* Using 1 – 2 cartridges * Reliably anesthetizes the to flood masticator space most nerve branches with a single injection
Hollinshead, Anatomy for Surgeons, Vol 1, The Head & Neck, 3rd Ed, Harper & Row, 1982
Mandibular Anesthesia Mandibular Anesthesia Discomfort of injection Discomfort of injection All about the same All about the same Gow-Gates reliably anesthetizes the most nerve Gow-Gates perhaps more uncomfortable due to branches with a single injection requirement of having the mouth wide open
Mandibular Anesthesia Mandibular Anesthesia
Onset of Anesthesia Onset of anesthesia: At 5 min. At 10 min. 1. Dependent upon block versus infiltration Conventional 72 – 85% 79 – 90% technique Gow-Gates 45% 90% Technique of block to a lesser degree Vazirani – Akinosi 90% 90% 2. Dependent upon anesthetic agent Concentration Diffusion to the site Lipid solubility Protein binding to receptor sites
20 Mandibular Anesthesia Mandibular Anesthesia
Duration of anesthesia: Incidence of Positive Aspiration 1. Dependent upon block versus infiltration Conventional 3.6 – 22% technique, not technique of block Gow-Gates 0 – 2% 2. Dependent upon anesthetic agent Vazirani – Akinosi 2% Concentration Diffusion from the site Lipid solubility Protein binding to receptor sites 3. Dependent upon vasoconstrictor presence, but NOT vasoconstrictor concentration*
*Malamed, Handbook of Local Anesthesia, 5th Ed, Elsevier, 2004 Blanton PL & Roda RS, The anatomy of local anesthesia, Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, CDA Jour, Vol 23 No 4, April 1995 Lippincott Williams & Wilkins, 1999
Mandibular Anesthesia Mandibular Anesthesia
Incidence of Positive Aspiration Incidence of Other Undesirable Side Effects Conventional 3.6 – 22% 1. Hitting a nerve Gow-Gates 0 – 2% 2. Piercing a muscle Vazirani – Akinosi 2% 3. Injecting the parotid gland Most common with IA block 4. Anesthesia in the opposite arch 5. Other unusual events Most common with Vazirani -
Akinosi block Jastak, Yagiela & Donaldson, Local Anesthesia of Liebgott, The Anatomical Basis the Oral Cavity, WB Saunders Co, 1995 of Dentistry, 2nd Ed, Mosby, 2001
Mandibular Anesthesia Mandibular Anesthesia
Incidence of Other Undesirable Side Effects Incidence of Other Undesirable Side Effects 2. Piercing a muscle = Trismus 2. Piercing a muscle = Trismus Possible causes include insertion of the needle into a muscle and bleeding into a muscle Either may produce muscle spasm
McMinn, Hutchings & Logan, Color Atlas of Head & Neck Anatomy, 2nd Ed, Mosby, 1994
Evers & Haegerstam, Introduction to Dental Local Anaesthesia, Mediglobe, 1990
21 Mandibular Anesthesia Mandibular Anesthesia
Incidence of Other Undesirable Side Effects Incidence of Other Undesirable Side Effects 2. Piercing a muscle = Trismus 2. Piercing a muscle = Trismus Trismus symptoms may appear within 1 to 6 Treatment days post-injection 1. Apply heat If there is no improvement within 2 to 3 days, or if the condition worsens, consider treating the 2. Recommend muscle relaxants (ibuprofen) patient for an infection 3. Analgesics/anti-inflammatories if needed Infection from an injection is rare 4. Exercises If an infection does occur, it will usually manifest itself initially as pain and trismus 1 day post- injection Symptoms commonly last 1 – 2 weeks or less
Mandibular Anesthesia Mandibular Anesthesia
Incidence of Other Undesirable Side Effects Injecting the parotid gland 3. Injecting the parotid gland Temporary facial paralysis: anesthesia of CN VII, the facial nerve, to the muscles of facial expression
Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 Netter, Atlas of Human Anatomy, 2nd Ed, Novartis, 1997
Mandibular Anesthesia Mandibular Anesthesia
Comparison of mandibular division nerve block Comparison of mandibular division nerve block techniques techniques Conventional (Halstead) technique Gow-Gates technique Advantages: Advantages: Very high success rate (90 – 100%) Most familiar and most widely used Extremely low incidence of positive aspirations Good success rate (65 – 86%+) Significantly reduced incidence of trismus and/or Disadvantages: paresthesia Higher success rates associated with increased incidence Single injection for anesthesia of inferior alveolar, of positive aspiration lingual, long buccal, and mylohyoid nerves Moderate incidence of trismus and/or paresthesia Disadvantages: Multiple injections required for anesthesia of inferior Technically a more difficult technique to master alveolar, lingual, long buccal, and mylohyoid nerves Slower onset of anesthesia Possible increased patient discomfort
22 Mandibular Anesthesia Mandibular Anesthesia
Comparison of mandibular division nerve block Comparison of mandibular division nerve block techniques techniques Vazirani – Akinosi technique Vazirani – Akinosi technique Advantages: Disadvantages: Moderate to high success rate (76 – 93%) Extremely low incidence of positive aspirations Increased potential for operator error due to no bone contact Significantly reduced incidence of trismus and/or paresthesia Higher incidence of unexpected and unusual side Potential single injection for anesthesia of inferior effects alveolar, lingual, long buccal, and mylohyoid nerves Least reliable technique to achieve anesthesia of long Less threatening to apprehensive patients (closed mouth) buccal nerve Ability to anesthetize both sensory and motor nerve branches uniquely useful for patients with severe trismus
Mandibular Anesthesia Mandibular Anesthesia The risk of nerve injury with administration of Comparison of mandibular prilocaine (Citanest) or articaine (Septocaine) division nerve block may be reduced by using “high” mandibular division techniques block techniques Conventional (Halstead) Gow-Gates technique technique Vazirani – Akinosi technique Gow-Gates technique Vazirani – Akinosi technique
So which technique is the best?
Wolfe SH, The Wolfe nerve block: A modified high mandibular nerve block, Dentistry Today, June/July 1992
Troubleshooting Anesthesia Troubleshooting Mandibular Anesthesia
The “Hot” Tooth Repeated failure to achieve adequate anesthesia First, give a block injection Take a panoramic radiograph The Gow-Gates mandibular division block has a significantly higher success rate than all other techniques Gow-Gates 52% Vazirani-Akinosi 41% Conventional IA 36% Buccal-plus-lingual infiltration 27% All with 4% articaine with 1:100,000 epinephrine No technique was fully acceptable by itself
Aggarwal V et al, Comparative evaluation of anesthetic efficacy of Gow-Gates mandibular conduction anesthesia, Vazirani-Akinosi technique, buccal-plus-lingual infiltrations, and conventional inferior alveolar nerve anesthesia in patients with irreversible pulpitis, O Surg O Med O Path O Radio Endo, Vol. 109 No 2, Feb. 2010
23 Troubleshooting Mandibular Anesthesia Troubleshooting Mandibular Anesthesia
Repeated failure to achieve adequate anesthesia Repeated failure to achieve adequate anesthesia Take a panoramic radiograph Take a panoramic radiograph Incidence of bifid IA nerve: 4 patients in 5,000 films
Grover PS & Lorton L, Bifid mandibular nerve as a possible cause of inadequate anesthesia in the mandible, Journ O Maxillofac Surg Vol 179, 1983 Mental foramen
Mandibular Anesthesia Mandibular Anesthesia
Mandible: Nerve blocks Mental (& incisive) nerve Mental (& incisive) nerve block block
Jastak, Yagiela & Donaldson, Local Anesthesia of Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Fehrenbach & Herring, Illustrated Anatomy the Oral Cavity, WB Saunders Co, 1995 Evers & Haegerstam, Introduction to Dental Local Anaesthesia, Mediglobe, 1990 of the Head & Neck, WB Saunders Co, 1996
Mandibular Anesthesia Mandibular Anesthesia
Mental (& incisive) nerve block Mental (& incisive) nerve block Depth 3 – 6 mm Needle Short Amount 1/3 -1/2 cartridge Comfort level High
After injection, massage site
Jastak, Yagiela & Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995
24 Maxillary Anesthesia REVIEW OF ANATOMY Trigeminal nerve, CN V Maxillary division, CN V2 Sensory only To all maxillary teeth and
gingiva
General Anatomy and Landmarks for Mandibular division, CN V3 Both motor and sensory Maxillary Anesthesia Sensory to all mandibular teeth and gingiva Motor to primary muscles of mastication
Fehrenbach & Herring, Illustrated Anatomy of the Head & Neck, WB Saunders Co, 1996
The Masticator Space Pterygopalatine Fossa Pterygopalatine fossa Infratemporal Fossa opens into medial wall Contents Boundaries: Maxillary division of A gap between the Trigeminal nerve, V maxilla anteriorly and the 2 lateral pterygoid plate of Pterygopalatine the sphenoid bone ganglion posteriorly Leaves an opening, the Terminus of maxillary pterygomaxillary fissure, artery into the infratemporal fossa
Medial wall: the palatine Fehrenbach & Herring, Illustrated Anatomy of the Head & Neck, bone & sphenopalatine WB Saunders Co, 1996
Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, foramen Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999 Lippincott Williams & Wilkins, 1999
Blood Supply to the Blood Supply to the Infratemporal Fossa Infratemporal Fossa
Maxillary artery Maxillary artery: Part 3: 3 parts Pterygopalatine
1. Posterior superior
alveolar 1. Mandibular 2. Pterygoid 2. Infraorbital 3. Pterygopalatine 3. Artery of pterygoid canal 4. Pharyngeal branch 5. Descending palatine 6. Sphenopalatine
Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 Lippincott Williams & Wilkins, 1999
25 Blood Supply to the Infratemporal Fossa Maxillary Anesthesia Maxilla: Nerves Pterygoid Venous Infraorbital nerve Plexus Anterior superior alveolar nerve Primary drainage to Maxillary vein Middle superior alveolar nerve Posterior superior
alveolar nerve
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001
Maxillary Anesthesia Maxilla: Nerves Infraorbital nerve MAXILLARY ANESTHESIA Anterior superior alveolar nerve Middle superior alveolar nerve Conventional and Alternative Techniques Posterior superior alveolar nerve
Meechan, Practical Dental Local Greater palatine nerve Anesthesia, Quintessence, 2002 Lesser palatine nerve
Maxillary Anesthesia Maxillary Anesthesia
Two basic types of injections Infiltrations 1. Infiltrations 2. Blocks
Infiltrations
Work well throughout maxilla
Greater success using articaine
Faster onset; perhaps more profound, better duration? * zygomatic buttress Frequent palatal anesthesia with buccal infiltration
Costa DG et al, Onset and duration periods of articaine and lidocaine McMinn, Hutchings & Logan, Color Atlas of Evers & Haegerstam, Introduction to Dental on maxillary infiltration, Quintessence Int Vol 36 No 3, 2005 Head & Neck Anatomy, 2nd Ed, Mosby, 1994 Local Anaesthesia, Mediglobe, 1990
26 Maxillary Anesthesia Maxillary Anesthesia
Maxillary blocks: Maxilla: Nerve blocks Anterior & middle superior Anterior & middle alveolar nerve block superior alveolar nerve Infraorbital nerve block AMSA palatal block block ASA palatal block Infraorbital nerve block Posterior superior alveolar approach
nerve block
Nasopalatine nerve block Greater palatine nerve block Complete maxillary
division block Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Maxillary Anesthesia Maxillary Anesthesia
Anterior & middle Anterior & middle superior alveolar nerve superior alveolar nerve block block Infraorbital nerve block Infraorbital nerve block approach approach
Delivered at the infraorbital Delivered at the foramen infraorbital foramen Palpate the inferior orbital
rim
Evers & Haegerstam, Introduction to Dental Local Anaesthesia, Mediglobe, 1990 Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999
Maxillary Anesthesia Maxillary Anesthesia
Anterior & middle Anterior & middle superior alveolar nerve block superior alveolar Infraorbital nerve block approach nerve block Depth 3 – 15 mm Infraorbital nerve Needle Short block approach Amount 1/3 - 1/2 cartridge Comfort level Moderate to high (technique dependent) Delivered at the infraorbital foramen Palpate the inferior orbital rim Drop 10 mm below lowest point
27 Maxillary Anesthesia Maxillary Anesthesia
Anterior & middle superior alveolar nerve block Anterior & middle superior alveolar nerve block Infraorbital nerve block approach Infraorbital nerve block approach Comfort level Moderate to high (technique dependent) This can’t really happen! Keep finger over inferior rim
Jastak, Yagiela & Donaldson, Local Anesthesia of the Oral Cavity, WB Saunders Co, 1995
Maxillary Anesthesia Maxillary Anesthesia
Anterior & middle Anterior & middle superior superior alveolar nerve alveolar nerve block block The AMSA palatal approach Infraorbital approach (P-AMSA injection) MSA absent in ~28% of patients
X
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Evers & Haegerstam, Introduction to Dental Local Anaesthesia, Mediglobe, 1990
Maxillary Anesthesia Maxillary Anesthesia
Anterior & middle superior alveolar nerve blocks Anterior & middle superior alveolar nerve block The AMSA palatal approach (P-AMSA injection) The AMSA palatal approach vs. infraorbital Depth 2 – 4 mm approach Advantages Needle Short X 1. Buccal and palatal anesthesia Amount ≤1/4 cartridge of articaine of bicuspids and incisors X Y Comfort level Moderate 2. No lip anesthesia Y Y 3. More reliable anesthesia of middle superior alveolar nerve/bicuspids Disadvantages 1. Shorter duration 2. A palatal injection Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
28 Maxillary Anesthesia Maxillary Anesthesia
Techniques to minimize the discomfort of Maxilla: Nerve blocks palatal injections The ASA palatal approach 1. Topical anesthesia (P-ASA injection) 2. Pressure distraction/analgesia To bilaterally anesthetize: Incisor pulps 3. Slow injection with small volumes Buccal gingiva 4. Buccal infiltrations Anterior palatal tissue 5. Explain all that you do to minimize the discomfort
© Milestone Scientific, Inc. 2007
Maxillary Anesthesia Maxillary Anesthesia
Bilateral anterior superior alveolar nerve block Posterior superior alveolar nerve block The ASA palatal approach (P-ASA injection) 1. Inject from side of incisive papilla initially, then gently shift to vertical orientation as enter incisive canal 2. SLOWLY inject 1/4 – 1/3 cartridge of articaine
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Fehrenbach & Herring, Illustrated Anatomy of the Head & Neck, WB Saunders Co, 1996 © Milestone Scientific, Inc. 2007
Maxillary Anesthesia Maxillary Anesthesia
Posterior superior alveolar nerve block Posterior superior alveolar nerve block
Fehrenbach & Herring, Illustrated Anatomy McMinn, Hutchings & Logan, Color Atlas of Evers & Haegerstam, Introduction to Dental of the Head & Neck, WB Saunders Co, 1996 Head & Neck Anatomy, 2nd Ed, Mosby, 1994 Local Anaesthesia, Mediglobe, 1990
29 Maxillary Anesthesia Maxillary Anesthesia
Posterior superior alveolar nerve block Hematoma A hematoma may form Depth 12 – 18 mm independently of aspiration results. Needle Long
Amount 3/4 cartridge Aspiration results merely Comfort level High report the contents at the needle tip at the time of
aspirating High risk of positive Haas DA, Localized complications from local anesthesia, aspiration and hematoma CDA Jour Vol 26 No 9, 1998
Courtesy Dr. H. Shirazi
Maxillary Anesthesia Maxillary Anesthesia
Hematoma Hematoma The vessels most The vessels most commonly associated commonly associated with hematomas are with hematomas are 1. Pterygoid venous plexus 1. Pterygoid venous plexus 2. Posterior superior 2. Posterior superior alveolar vessels alveolar vessels 3. Inferior alveolar vessels 3. Inferior alveolar vessels
4. Mental vessels 4. Mental vessels
Haas DA, Localized complications from Haas DA, Localized complications from local anesthesia, CDA Jour Vol 26 No 9, local anesthesia, CDA Jour Vol 26 1998 No 9, 1998
Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 McMinn, Hutchings & Logan, Color Atlas of Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999 Head & Neck Anatomy, 2nd Ed, Mosby, 1994
Maxillary Anesthesia Maxillary Anesthesia
Hematoma Maxilla: Nerve blocks Arterial vs. Venous Nasopalatine nerve block Fast Slow Red Blue Warm Normal
Management 1. Initial ice pack and pressure 2. Analgesics/anti-inflammatories (usually not needed) Liebgott, The Anatomical Basis of Dentistry, 2nd Ed, Mosby, 2001 3. Rest Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
30 Maxillary Anesthesia Maxillary Anesthesia
Nasopalatine nerve block Nasopalatine nerve block The Three-Step technique The Three-Step technique 1. Buccal infiltration over either central incisor 1. Buccal infiltration over either central incisor 2. Infiltrate central papilla
Maxillary Anesthesia Maxillary Anesthesia
Nasopalatine nerve block Nasopalatine nerve block The Three-Step technique 1. Buccal infiltration over either central incisor Depth 2 – 4 mm 2. Infiltrate central papilla Needle Short 3. Inject nasopalatine (incisive) papilla Amount ½ cartridge total, or less, for all three injections Comfort level Moderate to high
Computer-Controlled Delivery Systems Computer-Controlled Delivery Systems
The “Wand”: Single Tooth Anesthesia (STA) system The “Wand”: STA Milestone Scientific Can give all traditional The Comfort Control Syringe injections Dentsply, Inc. Safer PDL injections
Objective is to deliver the anesthetic at a rate and Painless palatal injections pressure that is below the threshold of pain Potentially pain-free injections Reduced volumes of anesthetic injected Can use for primary or secondary anesthetic injections
31 Computer-Controlled Delivery Systems Computer-Controlled Delivery Systems
The Comfort Control Syringe The Wand STA system Can give all traditional injections The Comfort Control Syringe Safer PDL injections Painless palatal injections Primary or secondary anesthesia
Maxillary Anesthesia Maxillary Anesthesia
Greater palatine nerve block Greater palatine nerve block
Fehrenbach & Herring, Illustrated Anatomy of the Head & Neck, WB Saunders Co, 1996 Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
Maxillary Anesthesia Maxillary Anesthesia
Greater palatine nerve block Greater palatine nerve block
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002
32 Maxillary Anesthesia Maxillary Anesthesia
Greater palatine nerve block Maxilla: Nerve blocks Depth 2 – 4 mm Complete maxillary division block Needle Short With 2 injections Amount 1/4 - 1/3 cartridge With 1+ cartridges Two approaches Comfort level Moderate to high PSA (lateral)
approach Greater palatine canal approach
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 McMinn, Hutchings & Logan, Color Atlas of Head & Neck Anatomy, 2nd Ed, Mosby, 1994
Pterygopalatine Fossa Maxillary Anesthesia
Contents Complete maxillary division block Maxillary division of PSA (lateral) approach
Trigeminal nerve, V2 Pterygopalatine ganglion Terminus of maxillary artery
Fehrenbach & Herring, Illustrated Anatomy of the Head & Neck, PSA approach WB Saunders Co, 1996
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999 Lippincott Williams & Wilkins, 1999
Maxillary Anesthesia Maxillary Anesthesia
Complete maxillary division block Complete maxillary division block PSA (lateral) approach Greater palatine canal approach High risk of hematoma
PSA approach McMinn, Hutchings & Logan, Color Atlas of Fehrenbach & Herring, Illustrated Anatomy Meechan, Practical Dental Local Agur & Lee, Grant’s Atlas of Anatomy, Head & Neck Anatomy, 2nd Ed, Mosby, 1994 of the Head & Neck, WB Saunders Co, 1996 Anesthesia, Quintessence, 2002 10th Ed, Lippincott Williams & Wilkins, 1999
33 Maxillary Anesthesia Maxillary Anesthesia
Greater palatine canal approach Complete maxillary division block 1. Give greater palatine block injection Greater palatine canal approach 2. Re-palpate the greater palatine foramen 3. With a single penetration, gently probe for the foramen 3. With a single penetration, gently probe 4. Passively insert needle up canal for the foramen
Maxillary Anesthesia Maxillary Anesthesia
Complete maxillary division block Complete maxillary division block Greater palatine canal approach With either approach, may anesthetize zygomatic
Depth Varies, ~15 mm branch of V2 Needle Long Innervation to lacrimal (tear) gland Amount 1 cartridge Comfort level Moderate
Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 Liebgott, The Anatomical Basis of Dentistry, Mosby, 1986 Agur & Lee, Grant’s Atlas of Anatomy, 10th Ed, Lippincott Williams & Wilkins, 1999
Troubleshooting Maxillary Anesthesia Troubleshooting Maxillary Anesthesia
Give buccal infiltration in anterior region* Buccal tissue is numb Tissue under eye blanches Tooth is still sensitive! and/or There is a facial twitch/spasm Give palatal injection Stay calm or 1. Stimulated facial nerve Use articaine for buccal infiltrations 2. Contact with blood vessel Often produces palatal anesthesia 3. Muscle contact/spasm 4. Localized vasoconstriction Meechan, Practical Dental Local Anesthesia, Quintessence, 2002 *May occur with PSA and inferior alveolar blocks as well
34 Reasons for Anesthetic Failures What defines success?
1. Anatomical/physiological “Adequate anesthesia to variations insure patient comfort for the duration of the 2. Technical errors of procedure” administration
3. Patient anxiety Different for each 4. Inflammation and procedure
infection Different for each
5. Defective/expired patient solutions
What defines success? Keys to Success
Anesthetic failures happen Infiltration The “Three Strikes Rule” Block 3 attempts at anesthesia, then stop So which technique is the best?
It depends on: 1. What you need to do It’s not about “fault” 2. On the specific patient It’s not the patient’s fault It’s not your fault 3. On your comfort zone Failures happen 4. Proper Technique
5. Proper anesthetic agent Reschedule the patient!
Keys to Success
It’s the thought that counts
35