TECHNIQUES OF LOCAL ANAESTHESIA Dr. Mahmoud Khalifa Prof & Consultant of OMFS ILOs You should be known and understand Types of LA techniques Indications of each one Maxillary techniques Mandibular techniques Basic steps for accurate tech Steps for infiltration tech Steps for NB tech Attention clinical, oral, and written Why the trigeminal nerve course is important for LA What is the difference between bone of mandible and maxilla Ophthalmic Nerve Maxillary Nerve Mandibular Nerve Definition L A is a local and temporary state of insensibility in an area without loss of consciousness Loss of pain sensation ( local analgesia) can be achieved by : Mechanical means →→pressure on main N T Physical means → cold application Chemical means → Drugs METHODS OF PRODUCTION OF L A Refrigerant effect Application of pressure Using of drugs Topical anaesthesia infiltration Nerve block L A can be produced by action of LA agent on Free nerve endings Terminal nerve endings Main nerve trunk Accordingly 1. Topical 2. Infiltration 3. Nerve block Techniques of local Anesthesia ♦ Local Infiltration: Small terminal nerve endings are flooded with local anesthetic solution. ♦Field Block Local anesthetic is deposited near the larger terminal nerve branches so the anesthetized area will be circumscribed ♦ Nerve Block Local anesthetic is deposited close to a main nerve trunk Infiltration techniques Bony infiltration Soft tissue infiltration intraseptal Supraperiosteal infiltration Intraosseus Sub periosteal infiltration Para periosteal infiltration Supplementary tech Intraligamintal (preiodontal) Intrapluplal Maxilla Mandible Main technique Anterior region Multiple foramina + thin cortex and spongy bone Mandibular Nerve Maxillary nerve Blocks block Intra-oral techniques Intra-oral techniques Inferior alveolar Posterior superior N B Standard (Direct) Infraorbital nerve block: indirect Greater palatine nerve block Gow-Gates Nasopalatine nerve block: Akinosi Maxillary nerve block Mental – Incisive Buccal Lingual Extra-oral techniques Extra-oral techniques mandibular,Inferior alveolar , mental Maxillary, infraorbital Factors affect the choice of LA technique 1. Area to be anaesthetized 2. Extent of surgery 3. Duration and profoundness required 4. Age of the patient 5. Need for haemostasis 6. Presence of infection 7. Skill of operator Infiltration techniques It is more commonly used and is successful in suitable cases when used in the indicated regions Submucosal Paraperiosteal Paraperiosteal infilteration Aim of tech: is deposit the LA solution in close proximity to the nerve fibers inside the bone Success of this technique depends on : Diffusion of LA solution through periosteum and minute foramina in the cortex then through the cancellous bone to reach the target nerve Regions for infiltration All maxillary region The anterior mandibular region NERVES TO BE ANESTHETIZED. AREAS TO BE ANESTHETIZED. ANATOMICAL LANDMARKS. INDICATIONS. CONTRAINDICATIONS. ADVANTAGES. DISADVANTAGES. TECHNIQUE. SYMPTOMS OF ANESTHESIA: A) SUBJECTIVE SYMPTOMS. B) OBJECTIVE SYMPTOMS. (infiltration anesthesia): Basic steps for all techniques ♦ Step 1 : Use a sterilized sharp needle ♦ Step 2:Check the flow of local anesthetic solution ♦ Step 3: Armamentum and anesthetic should be room temperature ♦ Step 4: Position the patient ♦ Step 5: Dry the tissue ♦ Step 6: Apply topical antiseptic ♦ Step 7A: Apply topical anesthetic ♦ Step 7B :Communicate with the patient. The patient should be in the semisupine position. The right handed operator should be in the eight o’clock position The left handed operator should be in the four o’clock position. Accessibility Visibility Comfortability Safety ♦ Step 8 :Establish a firm hand rest ♦ Step 9: Make the tissue taut ♦ Step 10:Keep the syringe out of the patient's line of sight. ♦ Step 11A:Insert the needle into the mucosa. ♦ Step 11B:Watch and communicate with the patient. ♦ Step 12 :Inject several drops of local anesthetic solution (optional). ♦ Step 13:Slowly advance the needle toward the target. ♦ Step 15: Aspirate. ♦ Step 16A: Slowly deposit the local anesthetic solution ♦ Step 16B: Communicate with the patient. ♦ Step 17: Slowly withdraw the syringe ♦ Step 18: Observe the patient summary of the atraumatic injection technique 1. Use a sterilized sharp needle. 11a. Insert the needle into the mucosa. 2. Check the flow of local anesthetic 11b. Watch and communicate with the patient. solution. 12. Inject several drops of local anesthetic solution 3. Determine whether to warm the (optional). anesthetic cartridge and/or syringe. 13. Slowly advance the needle toward the target. 4. Position the patient. I4. Deposit several drops of local anesthetic before 5. Dry the tissue. touching the periosteum. 6. Apply topical antiseptic (optional). 15. Aspirate. 7a. Apply topical anesthetic. 16a. Slowly deposit the local anesthetic solution. 7b. Communicate with the patient. 16b. Communicate with the patient. 8. Establish a firm hand rest. 17. Slowly withdraw the syringe. Cap the needle and 9. Make the tissue taut. discard. I0. Keep the syringe out of the patient's line 18. Observe the patient after the injection. of sight. 19. Record the injection on the patient's chart. Techniques of Maxillary Anesthesia Techniques of Maxillary Anesthesia ♦ Local Infiltration: Small terminal nerve endings are flooded with local anesthetic solution. ♦ Nerve Block Local anesthetic is deposited close to a main nerve trunk 1 Supraperiosteal (infiltration), recommended for limited treatment protocols 2 Periodontal ligament (PDL, intraligamentary) injection, 3 Intraseptal injection, 4 Intracrestal injection, 5 Intraosseous (IO) injection, 6 Posterior superior alveolar (PSA) nerve block 7 Infraorbital nerve block 8 Greater (anterior) palatine nerve block 9 Nasopalatine nerve block 10 Maxillary (V2, second division) nerve block ( intra oral +extra oral) Paraperiosteal infilteration Nerves Anesthetized Large terminal branches of the dental plexus. (buccal) Branches of greater palatine or nasopalatine n (palatally) Areas Anesthetized Pulp , periodontal legmints and supporting alveolar bone , buccal mucoperiosteum + lingual mucoperiosteum Indications 1 Pulpal anesthesia of the maxillary teeth when treatment is limited to one or two teeth 2 Soft tissue anesthesia when indicated for surgical procedures in a circumscribed area Contraindications 1. Infection or acute inflammation in the area of injection. 2. Dense bone covering the apices of teeth Advantages 1 High success rate (>95%) 2 Technically easy injection 3 Usually entirely atraumatic Disadvantages Not recommended for large areas because of the need for multiple needle insertions and the necessity to administer larger total volumes of local anesthetic. Positive Aspiration Negligible, but possible (<1%). Alternatives PDL, IO, regional nerve block. Technique 1. A 27-gauge short needle is recommended. 2. Area of insertion: height of the mucobuccal fold above the apex of the tooth being anesthetized 3. Target area: apical region of the tooth to be anesthetized 4. Landmarks: * Buccl ( 2 imaginary lines) a Mucobuccal fold b-long axis of tooth *Palatal midway between 2 line a- midpalatal suture line b- palatal free gingival line 5 Orientation of the bevel *: toward bone 6 procedure: a Prepare tissue at the injection site. (1) Clean with sterile dry gauze. (2) Apply topical antiseptic (optional). (3) Apply topical anesthetic for minimum of 1 minute. b Orient needle so bevel faces bone. c Lift the lip, pulling the tissue taut. d Hold the syringe parallel with the long axis of the tooth e Insert the needle into the height of the mucobuccal fold over the target tooth. f Advance the needle until its bevel is at or above the apical region of the tooth g Aspirate . If negative deposit LA solution slowly over 60 seconds. (Do not allow the tissues to balloon.) h Slowly withdraw the syringe. i Make the needle safe. j Wait 3 to 5 minutes before commencing the dental procedure. Signs and Symptoms 1 Subjective: feeling of numbness in the area of administration 2 Objective: use of electrical pulp testing (EPT) with no response from tooth with maximal EPT output (80/80) 3 Absence of pain during treatment Safety Features 1 Minimal risk of intravascular administration 2 Slow injection of anesthetic; aspiration Mandibular infiltration tech Infiltration tech Young age with primary dentition Anterior region Failures of anesthesia 1 Needle tip lies below the apex (along the root) of the tooth Depositing anesthetic solution below the apex of a maxillary tooth results in excellent soft tissue anesthesia but poor or absent pulpal anesthesia. 2 Needle tip lies too far from the bone (solution deposited in buccal soft tissues). To correct: Redirect the needle closer to the periosteum Nerve block techniques Infraorbital Nerve Block The anterior superior alveolar (ASA) nerve block or infraorbital nerve block is a useful technique for → the maxillary central and lateral incisors and canine as well as premolars and the surrounding soft tissue on the buccal aspect. The infraorbital foramen lies just inferior to the notch usually in line with the second premolar Nerves Anesthetized 1 Anterior superior alveolar 2 Middle superior alveolar 3 Infraorbital nerve a Inferior palpebral b Lateral nasal c Superior labial Areas Anesthetized 1 Pulps of the maxillary central incisor through the canine on the injected side 2 In about 72% of patients, pulps of the maxillary premolars and mesiobuccal root of the first molar 3 Buccal