Maxillary Local Anesthesia - Infraorbital PDF

Techniques of Maxillary Anesthesia  Anterior Superior Alveolar Nerve Block (ASANB) Technique  Posterior Superior Alveolar Nerve Block (PSANB) Technique Dr. Ahmed Mohammed Saaduddin Assistant Professor Of Oral & Maxillofacial Surgery Consultant of Oral Surgery Batterjee Medical College –...

Techniques of Maxillary Anesthesia  Anterior Superior Alveolar Nerve Block (ASANB) Technique  Posterior Superior Alveolar Nerve Block (PSANB) Technique Dr. Ahmed Mohammed Saaduddin Assistant Professor Of Oral & Maxillofacial Surgery Consultant of Oral Surgery Batterjee Medical College – Jeddah Thursday 25th August 2024 Anatomy MAXILLARY NERVE: 1. Branches within the cranium a. Middle meningeal nerve 2. Branches within the pterygopalatine fossa a. Zygomatic nerve: I. Zygomaticotemporal nerve II. Zygomaticofacial nerve b. Pterygopalatine nerves I. Palatine branches (GP & LP nerves) II. Nasal branches (NP nerve) III. Orbital branches IV. Pharyngeal branch c. PSA nerve 3. Branches within the infraorbital canal a. MSA nerve b. ASA nerve 4. Branches on the face a. Inferior palpebral branches b. External nasal branches c. Superior labial branches Posterior Superior Alveolar Nerve Block (PSANB) Technique Posterior Superior Alveolar Nerve Block (PSANB) Technique Other Names: A. Zygomatic Block, B. Tuberosity Block. Nerves Anesthetized: PSAN. Areas Anesthetized: 1. Buccal mucoperiosteum over the maxillary molars, 2. Buccal and palatal alveolar plates of bone, 3. Periodontium of maxillary molars except for the MB root of 1st molar, 4. Pulps of maxillary molars except for the MB root of 1st molar, 5. Adjacent lining of the maxillary sinus. Posterior Superior Alveolar Nerve Block (PSANB) Technique The goal is to deposit local anesthetic close to the PSA nerves, located posterosuperior and medial to the maxillary tuberosity. Posterior Superior Alveolar Nerve Block (PSANB) Technique Indications: 1. Treatment procedure involving two or more maxillary molars. 2. When supraperiosteal injection has proved ineffective (e.g., due to thick zygomatic buttress over the apices of the first molar). 3. When supraperiosteal injection is contraindicated (e.g., with infection or acute inflammation). Contraindication: 1. Infection at the site of injection. 2. When the risk of hemorrhage is too great (as with a hemophiliac; patients taking drugs that can increase bleeding such as coumadin or clopidogrel (Plavix)), in which case a supraperiosteal infiltration or PDL injection is recommended). Posterior Superior Alveolar Nerve Block (PSANB) Technique Positive Aspiration: 3 % (High). Alternatives: 1. Supraperiosteal Infiltrations for PSAN. 2. Maxillary nerve block Armamentariums: 1. Short Needle (Length: 20 mm) & 25- or 27-gauge. 2. Aspirating Syringe. 3. Local Anesthetic Cartridge (with or without Vasoconstrictor) Posterior Superior Alveolar Nerve Block (PSANB) Technique Point of insertion: Height of the mucobuccal fold above the maxillary second molar. Target Area: PSAN as it enters the posterior surface of the maxilla (posterior, superior and medial) to maxillary tuberosity. Posterior Superior Alveolar Nerve Block (PSANB) Technique Technique: 1. Partially open the patient’s mouth, pulling the mandible to the side of the injection. 2. Retract the patient’s cheek with a mouth mirror (to minimize the risk of accidental needlestick injury to the administrator). 3. Pull the tissues at the injection site taut. 4. Insert the needle into the height of the mucobuccal fold over the second molar. Posterior Superior Alveolar Nerve Block (PSANB) Technique Technique: 5. Needle Orientation: Advance the needle slowly in an upward, inward, and backward direction in one movement (not three): o Upward: superiorly at a 45-degree angle to the occlusal plane. o Backward: posteriorly at a 45-degree angle to the long axis of the second molar. o Inward: medially at a 45-degree angle toward the midline & occlusal plane. Posterior Superior Alveolar Nerve Block (PSANB) Technique Technique: 6. Depth of needle insertion: o For Average Adults: ¾ of SHORT NEEDLE LENGTH = (16 mm) o For Smaller Adults & Children: ½ of SHORT NEEDLE LENGTH = (10 mm) ½ ¾ 1 Posterior Superior Alveolar Nerve Block (PSANB) Technique Technique: 7. Aspiration test in two perpendicular planes. 8. Slow deposition of 0.9 mL(half-cartridge) up to 1.8 mL(full-cartridge) of anesthetic solution over (30 – 60) seconds with several aspirations during the injection. 10. Withdraw the needle from the tissue and immediately make the needle safe by “single hand scoop technique” for recapping the needle. 11. Dental treatment can be commenced after 3 to 5 minutes 1.8 mL 0.9 mL Posterior Superior Alveolar Nerve Block (PSANB) Technique Clinical Findings:  Subjective: 1. Tingling and numbness It is difficult to determine the extent of anesthesia subjectively and only a few patients may record numbness of buccal mucosa opposite to maxillary molars.  Objective: 1. Probing Test: Absence of pain during probing of facial mucosa of maxillary molars. 2. Electrical Pulp Tester: No response with maximal EPT output (80/80). 3. Freezing Spray (e.g., Endo-Ice): No response 4. Absence of pain during treatment. Posterior Superior Alveolar Nerve Block (PSANB) Technique Advantages: 1. High success rate (> 95 %). 2. Atraumatic technique as little pain is experienced by the patient receiving the PSA nerve block because: − The target area for the deposition of anesthetic solution is composed of loose connective tissue. − This technique doesn’t involve any bone contact. 3. Minimum number of necessary injections [one injection compared with the option of three infiltrations]. 4. Minimizes the total volume of local anesthetic solution administered [the equivalent volume of anesthetic solution necessary for three supraperiosteal injections is 1.8 ml]. Disadvantages: 1. Risk of diffuse intraoral hematoma in the buccal mandibular region. 2. Arbitrary technique as there are no bony landmarks during needle insertion. 3. Second injection is required for anesthesia of the first molar. (in approximately 30%) Posterior Superior Alveolar Nerve Block (PSANB) Technique Causes of Failures & Complicatons: # Cause Correction 1 Needle too lateral Redirect the needle tip medially 2 Needle not high enough Redirect the needle tip superiorly 3 Needle too far posterior Withdraw the needle to the proper depth HEMATOMA IN BUCCAL TISSUES OF THE MANDIBULAR ANESTHESIA MANDIBULAR REGION ▪ The deposition of local anesthetic lateral to the desired location ▪ The insertion of the needle too far posteriorly may result may produce various degrees of tongue and lower lip in injury of the pterygoid plexus of veins or perforation of anesthesia as the mandibular division of the trigeminal nerve is the maxillary artery. Accordingly, the use of a short needle located lateral to the PSA nerve. and attention to the penetration depth is highly critical in this technique. ▪ As there is no easily accessible intraoral area to which pressure can be applied to stop the hemorrhage. So, the bleeding will continue until the pressure of extravascular blood is equal to or greater than that of intravascular blood. Anterior Superior Alveolar Nerve Block (Infraorbital Nerve Block) Clinical Note: ▪ The middle superior alveolar (MSA) nerve is present in only 30% of the population. ▪ In the majority (70%) of the population the anterior superior alveolar nerve carries the function of the MSA nerve and supplies the ipsilateral maxillary anterior teeth, premolars, and the mesiobuccal root of the first molar (ASA). Other Names: INFRAORBITAL NERVE BLOCK Applied Anatomy To achieve successful IONB, the anesthetic solution should be allowed to enter the infraorbital canal through the infraorbital foramen. Nerves Anesthetized 1. Anterior superior alveolar Pulps of the maxillary incisors, canine, premolars and mesiobuccal root of the first molar on the injected side 2. Middle superior alveolar 3. Terminal Branches of Infraorbital Nerve: a. Inferior palpebral Lower eyelid b. Lateral nasal Lateral aspect of the nose c. Superior labial Upper lip  CLINICAL NOTE The ASA nerve block does not enjoy the popularity of the PSA nerve block, primarily due to two major factors: 1. General lack of experience with this. 2. Fear of injury to the patient’s eye. However, ASANB is a highly successful and extremely safe technique when the dentist adhere to the recommended injection protocol. Anterior Superior Alveolar Nerve Block Indications 1. Dental procedures involving more than two maxillary anterior teeth (incisors through premolars) and their overlying buccal tissues. 2. When supraperiosteal injections have been ineffective because of dense cortical bone. 3. Inflammation or infection (which contraindicates supraperiosteal injection). However, if cellulitis is present, the maxillary nerve block may be indicated instead of the ASA nerve block. Contraindications 1. Discrete treatment areas (one or two teeth only; supraperiosteal injection preferred). 2. When hemostasis of a localized area is desirable. Advantages: In comparison with the infiltration technique, it minimizes the volume of solution used and the number of needle punctures necessary to achieve anesthesia in the same field with a longer anesthetic effect. Positive Aspiration: Negligible (0.7%). Disadvantages: Doesn’t provide hemostasis in the operative field. Anterior Superior Alveolar Nerve Block Basic Armamentaria Auxiliary Armamentaria ▪ Long Needle ▪ Topical Antiseptic ▪ Aspirating Syringe ▪ Topical Anesthetic and its applicator ▪ Local Anesthetic cartridge ± VC ▪ Hemostat & College Cotton Tweezer Anterior Superior Alveolar Nerve Block Position of the Patient: Position the patient supine or semisupine with the neck extended slightly to avoid the interference of the patient’s chest with the syringe. Position of the Dentist (Right-Handed Dentist): ▪ The dentist should stand on the right side of the chair. ▪ The dentist should stand or sit directly facing the patient. Prepare the Tissue At The Site Of Injection: Prepare the tissues at the injection site (height of the mucobuccal fold) for penetration: I. Dry with sterile gauze. II. Apply a topical antiseptic (optional). III. Apply topical anesthetic for a minimum of 1 minute. Anterior Superior Alveolar Nerve Block Locate the infraorbital foramen: 1. Feel the infraorbital notch. 2. Move your finger downward from the notch, applying gentle pressure to the tissues. 3. The bone immediately inferior to the notch is convex (felt as an outward bulge). This represents the lower border of the orbit and the roof of the infraorbital foramen. 4. As your finger continues inferiorly, a concavity is felt; this is the infraorbital foramen [this point is on a line with the pupil of the eye when the patient looks straight forward]. 5. While applying pressure, feel the outlines of the infraorbital foramen at this site [the patient senses a mild soreness when the foramen is palpated as the infraorbital nerve is pressed against bone]. Anterior Superior Alveolar Nerve Block Applied Anatomy: ▪ The Infraorbital foramen is shaped like a flattened funnel with its opening directed downward and medially. ▪ Accordingly, the needle must approach the foramen from its medial side. L M Anterior Superior Alveolar Nerve Block Locate the infraorbital foramen: Intra-Oral Anterior Superior Alveolar Nerve Block Tissue Retraction: ▪ Place the bulbous portion of the index finger of the nondominant hand over the foramen, ▪ Ask the patient to partially close his/her mouth, ▪ Insert the thumb of the nondominant hand in the mucobuccal fold, ▪ Retract the lip between the index & thumb fingers. Anterior Superior Alveolar Nerve Block Point of Needle Insertion Height of the mucobuccal fold over the first premolar with the bevel facing bone ▪ The infraorbital foramen is shaped like a flattened funnel with its opening directed downward and medially. ▪ Accordingly, the needle must approach the foramen from its medial side by inserting the needle into the height of the mucobuccal fold over any tooth from the second premolar anteriorly to the central incisor. However, the first premolar usually provides the shortest and most accurate route to the target area. Anterior Superior Alveolar Nerve Block Needle Orientation The needle is oriented parallel to the long axis of the ipsilateral maxillary first premolar. Depth of Needle Penetration: The average penetration depth of needle for an adult of average height is 16 mm (equivalent to half the length of a long needle). Anterior Superior Alveolar Nerve Block Safety Measures: ▪ Advance the needle slowly until the bone is gently contacted.  The needle must contact the bone at the roof (upper rim) of the infraorbital foramen to prevent inadvertent over-insertion & possible puncture of the orbit.  The needle should not be palpable; if it is felt, its path is too superficial (away from the bone). Then, withdraw the needle and redirect it toward the target area. Anterior Superior Alveolar Nerve Block Aspiration: ▪ It should be performed at least twice before the local anesthetic is administered. ▪ For the second aspiration test, rotate the syringe about 45 degrees to change the orientation of the bevel to exclude the possibility of false negative aspiration [The bevel of the needle is inside a blood vessel and abutting the vessel wall]. PRECAUTION TO PREVENT OVERINSERTION OF THE NEEDLE: ▪ Estimate the proper depth of penetration before injection, ▪ Be sure that the needle tip must contact the infraorbital rim of bone that forms the superior rim of the infraorbital foramen, ▪ Exert finger pressure over the infraorbital foramen. Intra-Oral Anterior Superior Alveolar Nerve Block ▪ Amount of Required LA - Using a 25-gauge long needle, slowly deposit 0.9 ml (1/2 cartridge) up to 1.2 ml (2/3 cartridge) over 30 - 40 seconds, respectively. - The administrator should feel the deposited anesthetic solution beneath the finger pad on the foramen. - Little or no swelling should be visible as the solution is deposited ▪ Completion of the Technique: - Slowly withdraw the needle from the tissues. - Immediately make the needle safe. - Maintain direct finger pressure over the injection site for 1 – 2 minutes to increase the diffusion of local anesthetic solution into the infraorbital foramen. 2ൗ ½ 3 - Wait for 3 to 5 minutes before commencing the planned dental procedure. 0.9 ml 1.2 ml Intra-Oral Anterior Superior Alveolar Nerve Block ▪ Clinical Findings:  Subjective: Tingling and numbness of the ipsilateral lower eyelid, side of the nose, upper lip, teeth & soft tissues along the distribution of the ASA and MSA nerves.  Objective: 1. Probing Test: absence of pain during probing of facial mucosa of anterior and premolar teeth 2. Electric Pulp Tester: no response to maximal EPT output (80/80). 3. Thermal Pulp Test using Freezing Spray (e.g., Endo-Ice): no response 4. Absence of pain during treatment 9e.g., cavity test). Causes For Failure of ASANB 1. Needle contacting bone inferior to the infraorbital foramen results in anesthesia of the lower eyelid, lateral side of the nose, and upper lip may develop with little or no dental anesthesia. ▪ Correction: − Keep the needle in line with the infraorbital foramen. − Estimate the depth of penetration before injecting anesthetic. 2. Needle deviation medial or lateral to the infraorbital foramen. ▪ Correction − Keep the needle orientation toward the foramen during its advancement through the tissue. Alternative Techniques 1. Basic Injection Techniques: o Infiltration technique. o Maxillary Nerve block 2. Supplementary Injection Techniques: o Periodontal ligament Injection Complications of ASANB Hematoma Across The Lower Eyelid Temporary Double Vision (Horizontal Diplopia). It can be prevented by the application of pressure It is caused by the diffusion of anesthesia into the orbit and during and after administration of the IONB over the the anesthetization of the motor nerves innervating the foramen for 2 to 3 minutes. extra-orbital orbital muscles. The dentist should assure the patient that the situation lasts for only a few minutes. Medical Error: ▪ The failure to complete the intended plan due to deviations from the standard care process may result in patient injury. ▪ Example: injury of the eyeball during ASANB. Reference  Reference Techniques of Maxillary Anesthesia. Malamed S. Stanley. Handbook of Local Anesthesia. Elsevier. 7th Edition; Chapter 13: 204 - 238. THANK YOU