Inferior alveolar nerve block presentation

Inferior alveolar nerve block

1. INFERIOR ALVEOLAR NERVE BLOCK

2. Nerves nesthetized Inferior alveolar Incisive Mental Lingual Mylohyoid

3. Ar e a s anesthetized Mandibular teeth to the midline Body o f the mandible nd inferior portion o the ramus Buccal mucoperiosteum and mucous membrane in front o f the mental foramen Anterior 2/3 o the tongue nd floor of the oral cavity Lingual soft tissues and periosteum

4. Needle pathway during insertion With the mouth closed, the needle is aligned parallel to the occlusal plane nd positioned a t the level o f the mucogingival junction of the maxillary molars. The needle penetrates mucos just medial to the ramus and is inserted ap proximately one and quarter inches

5. Target areas

6. Technique With the patient seated comfortable in the dental chair , the operator stands to the patient s right side and slightly to the front . The patient is instructed to occlude the teeth The operator retracts the patient's lips exposing the maxillary teeth on the right side.

7. Retraction of the patient’s lip

8. The syringe is aligned parallel to the occlusal and saggital planes but positioned at the level of the mucogingival junction of the maxillary molars The needle penetrates the mucosa just medial to the ramus and is inserted apptoximately 1 ½ inches Following negative aspiration , the contents of the dental cartridge are slowly deposited.

9. Injection done medial to ramus

10. CONTENTS INTRODUCTION ANATOMY AND PHYSIOLOGY NERVES ANESTHISED AREAS ANESTHISED ANATOMICAL LANDMARKS INDICATIONS CONTRAINDICATIONS EQUIPMENT POSITION OF PATIENT AND ADMINISTRATOR PROCEDURE TECHNIQUES SIGNS AND SYMPTOMS FAILURE OF IANB COMPLICATIONS

11. INTRODUCTION The inferior alveolar nerve block (IANB) is among the most frequently used regional anesthetic techniques in dental practice.  Also known as mandibular nerve block This technique involves the targeted deposition of a local anesthetic solution in the vicinity of the mandibular foramen, where the inferior alveolar nerve enters the mandibular canal. 

12. ANATOMY AND PHYSIOLOGY MANDIBULAR NERVE The mandibular nerve is the third division of the trigeminal nerve (cranial nerve V, division V3). The mandibular nerve exits the skull via the foramen ovale at the base of the cranium and then divides into anterior and posterior branches.

13. LOCATION OF MANDIBULAR FORAMEN The mndibulr ormen is locted on the inner ( medil ) o the mndibulr rmus . This ormen is opening to the mndibulr cnl , which llows the inerior lveolr nerves nd vessels to pss through to innervte nd supply the lower teeth nd mndible . The position of the mandibular foramen can vary, and it is not always located midway along the anteroposterior dimension of the mandibular ramus . On average, the foramen lies approximately 2.75 mm posterior to the midpoint of the mandibular ramus . The distance between the mandibular foramen and the coronoid notch is estimated to be about 19 mm. The foramen may be positioned either at the level of or below the occlusal plane. The location of the mandibular foramen is relative to the occlusal plane, and it also varies with age.

14. NERVES ANESTHETISED Inferior alveolar nerve Incisive nerve Mental nerve Lingual nerve

15. AREAS ANESTHISED Mandibular teeth to the midline Body of the mandible Anterior 2/3 of the tongue and floor of the oral cavity Buccal mucoperiosteum , mucous membrane anterior to the mandibular 1 st molar Lingual soft tissues and periosteum

16. ANATOMICAL LANDMARKS Coronoid notch ( greatest concavity on the anterior border of the ramus ) Pterygomandibular raphe Occlusal plane of the mandibular posterior teeth

17. INDICATIONS Procedures on multiple mandibular teeth in one quadrant When buccal soft tissue anesthesia ( anterior to the 1 st molar is neccesary When lingual soft tissue anesthesia is necessary

18. CONTRAINDICATIONS Absolute contraindications Documented allergy to local anesthetic agents Infection or inflammation at the injection site Relative contraindications Severe trismus or limited mandibular opening Bleeding disorders or anticoagulant therapy Neurological disorders involving the mandibular nerve Psychological or behavioral conditions

19. EQUIPMENTS 1. Syringe A standard metal aspirating dental syringe is recommended, as it allows for controlled delivery of the anesthetic and enables both positive and negative aspiration, reducing the risk of inadvertent intravascular injection. Self-aspirating syringes may also improve ease of use and reduce operator fatigue. 2. Needle A long needle, typically 25- or 27-gauge and approximately 32 mm long, is preferred for reaching the target depth near the mandibular foramen. A 25-gauge needle is often favored for its improved rigidity and reduced risk of deflection, which enhances precision during deep tissue penetration. In patients with smaller mandibular anatomy or in pediatric cases, a 27-gauge long needle may be preferable to accommodate anatomical constraints while still providing sufficient length to reach the target site near the mandibular foramen. Single-use, presterilized needles should be used to prevent cross-contamination.

20. 3. Local Anesthetic Cartridge Standard 1.8 mL dental cartridges containing an amide-type local anesthetic ( eg , 2% lidocaine with 1:100,000 epinephrine) are commonly used. The choice of anesthetic agent and vasoconstrictor concentration depends on the procedure’s duration, the patient’s medical history, and specific surgical requirements. 4. Topical Anesthetic A topical anesthetic gel or spray (commonly 20% benzocaine ) is applied to the mucosal insertion site 1 to 2 minutes before needle penetration to minimize discomfort and facilitate smooth needle entry. 5. Protective and Ancillary Materials Cotton gauze is used to dry the mucosa before applying the topical anesthetic. Disposable gloves, masks, and eye protection are worn to ensure adherence to infection control protocols. A mirror and explorer can assist with tissue retraction and identification of anatomical landmarks. A sharps container is required to safely dispose of used needles and cartridges after injection.

21. POSITION OF THE PATIENT AND ADMINISTRATOR Position the patient in supine or semisupine position

22. PROCEDURE 3 parameters must be considered during the administration : Height of injection Anteroposterior site of injection Penetration depth

23. Height of injection Place the inde finger or thumb of your left hand in the coronoid notch An imaginary line etends posteriorly from the finger tip in the coronoid notch to the deepest part of thr pterygomandibular raphe

24. Anteroposterior site of injection Needle penetration occurs at the intersection of 2 points : Along the horiontal line On a vertical line about ¾ distance from the anterior border of the ramus .

25. Penetration depth Bone must be contacted Average depth of penetration to bony contact will be 20-25 mm, approimately 2/3 to ¾ the length of a long dental needle.

26. TECHNIQUE A 25 gauge needle is preferred Area of insertion : mucous membrane on the medial side of the ramus of the mandible , at the intersection of two lines Target area : inferior alveolar nerve as it passes downwards to the mandibular foramen. Landmarks Orientation of the needle bevel Procedure

27. Different techniques Classical inferior alveolar nerve block Method of clarks and Holmes Technique of Angelo Sargenti Fischer 1, 2, 3 technique Anterior ramus technique Vasirani Akinosi technique Gow Gates technique Etraoral approach

28. GOW GTES Nerves nesthetized Inerior lveolr Mentl Incisive Lingful Mylohyoid Uriculotemporl Buccl

29. res nesthized mndubulr teeth to the midline Buccl mucoperiosteum & mucous membrne on the side o injection Nterior 2/3 of the tongue & loor o the orl cvity Lingful sot tissues & periosteum Body o the mndible , inerior portion o the rmus Skin over the zygfom , posterior portion o the cheek , temporl regions

30. Antomicl lndmrks Nterior borger o the rmus Tendon o temporl muscle Corner o the mouth Intertrgic notch o the er Externl er

31. Technique Ptient is plced in the supine position Opertor is positioned to the right & slightly in ront o ptient Ptient keeps mouth open widely & remins in tht position until injection is completed N imginry line is drwn rfom the corner o the mouth to the intertrgic notch o the er The nterior border o the rmus is plpted & the tendon o the temporl muscle is identiied Opertor visully ligns the introrl & extrorl lndmrks & the nedle is introduced through the mucos just medil to the temporl tendon & directed towrd the trget re The meedle should be dvnced until the ove region o the condylr neck is contcted Depth o insertion should not exceed 25 to 27 mm

32. SIGNS AND SYMPTOMS Subjective : Tingling or numbness of the lower lip Tingling or numbness of the tongue Objective : No pain is felt during dental therapy

33. FAILURE OF IANB Deposition of anesthetic too low ( below the mandibular foramen ) Deposition of anesthetic too far anteriorly ( laterally ) on the ramus Incomplete anesthesia of central and lateral incisor.

34. COMPLICATIONS Local Complications Hematoma formation Trismus Needle breakage Pain during injection Soft tissue injury 2. Neurological Complications Transient or permanent nerve injury Facial Nerve Paralysis 3. Systemic complications Intravascular injection and systemic Allergic Infection

35. V A ZIR A NI A KINOSI Akinosi closed mouth mandibular nerve block is a n intraoral technique to provide both anesthesia & motor blockade in cases o f severe unilateral trismus