**4. Maxillary anesthesia techniques**

Different regional blocks and infiltration injections can be used for anesthetizing the maxilla. Some are described herein.

#### **4.1. Supraperiosteal injection (infiltration)**

This is the most common technique used for obtaining pulpal anesthesia and is more com‐ monly known as local infiltration. In this technique the patient is asked to partially open his mouth and the syringe is held parallel to the long axis of the tooth. The needle is inserted in the mucobuccal fold above the apex of the tooth and advanced until it touches the bone then withdrawn a little and the solution is deposited at a rate of 30 s/ml (Figure 5). If the solution is deposited while the needle touches the bone the solution is injected below the periosteum which is more painful and may cause post injection discomfort.

This is a very easy technique and has a high success rate but when several teeth require anesthesia or there is an infection or acute inflammation in the area of the injection regional

**Figure 5.** The infiltration technique

nerve blocks are preferred. In pediatric patients infiltration technique can also be used for anesthetizing mandibular primary teeth and in several studies it has been shown that in these patients infiltration technique has a comparable effectiveness to mandibular nerve block for dental procedures [14].

#### **4.2. Maxillary nerve block**

**The Maxillary (v2) nerve block** is an effective method for achieving anesthesia of the hemi‐ maxilla. With a single injection you can anesthetize all maxillary teeth of one side, buccal periodontium and bone overlying these teeth, soft tissue and bone of hard palate and part of the soft palate, skin of the lower eyelid, side of nose, cheek and upper lip. This nerve can be blocked through several approaches:

#### **4.3. High-Tuberosity approach**

The patient is positioned supine or semisupine and the patient's mouth partially open, the mandible is pulled toward the side of the injection and the soft tissues are retracted with the index finger. Then injection is done into the mucobuccal fold distal to the second molar at an angle of 45 degrees; next the needle is advanced posteriorly, superiorly and medially about 30mm and the solution is deposited [9].

### **4.4. Greater foramen approach**

In this approach we attend to insert the needle to the pterygopalatine fissure through the greater palatine foramen and affect the maxillary nerve as it passes through the fossa. We ask the patient to hold his mouth wide open. Palpate the greater palatine foramen medial to the distal aspect of the second molar. Insert the needle at an angle of 45 degree superiorly and distally to the foramen. After advancement about 30mm we deposit the anesthesia solution. This technique is painful and may be dangerous is rarely needed if ever and thus, is not recommended.

## **4.5. Posterior superior alveolar nerve block**

By blocking the posterior superior alveolar (PSA) nerve the molar teeth of maxilla, the associated bone and buccal gingiva will be anesthetized. It is shown that only in 28% of patients the middle superior alveolar nerve provides the mesiobuccal root of the first molar with sensory innervation, in this situation an extra injection (usually infiltration) is necessary to anesthetize the accessory innervations.

To block the PSA, we partially open the patient's mouth and pull the mandible to the side of injection. A short needle is used to prevent distal insertion of the needle which can produce a temporary (10 to 14 days) hematoma. The needle is inserted into the mucobuccal fold over the second molar and advanced about 16mm upwards, inwards and backwards. Then, the anesthesia solution is slowly deposited (Figure 6). [1]

**Figure 6.** The PSA nerve block

nerve blocks are preferred. In pediatric patients infiltration technique can also be used for anesthetizing mandibular primary teeth and in several studies it has been shown that in these patients infiltration technique has a comparable effectiveness to mandibular nerve block for

**The Maxillary (v2) nerve block** is an effective method for achieving anesthesia of the hemi‐ maxilla. With a single injection you can anesthetize all maxillary teeth of one side, buccal periodontium and bone overlying these teeth, soft tissue and bone of hard palate and part of the soft palate, skin of the lower eyelid, side of nose, cheek and upper lip. This nerve can be

The patient is positioned supine or semisupine and the patient's mouth partially open, the mandible is pulled toward the side of the injection and the soft tissues are retracted with the index finger. Then injection is done into the mucobuccal fold distal to the second molar at an angle of 45 degrees; next the needle is advanced posteriorly, superiorly and medially about

dental procedures [14].

**4.2. Maxillary nerve block**

**Figure 5.** The infiltration technique

12 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

blocked through several approaches:

30mm and the solution is deposited [9].

**4.3. High-Tuberosity approach**

In pediatric patients with primary or early mixed dentition, the thick bone of zygomatic process lies over the buccal roots of the second primary and first permanent molars, attenuating the effectiveness of infiltration injection in this region. So in this situations a PSA nerve block may be used instead [15].

### **4.6. Middle superior alveolar nerve block**

As mentioned before the MSA exist only in 28% of people and provides sensory innervation to maxillary premolars and mesiobuccal root of the first molar. The MSA block is performed by delivering a buccal infiltration at the apex of the second premolar tooth.

#### **4.7. Anterior superior alveolar nerve block**

The Anterior Superior Alveolar nerve (ASA) supplies the maxillary incisors and canine teeth on one side and the soft and hard tissue adjacent to it. On the other hand the infraorbital nerve provides sensory innervation to the mucosa and skin surface of one half of the upper lip and part of the skin on lateral aspect of the nose; but because these two nerves can be anesthetized with one approach, the technique is either known as "ASA block" or "Infraorbital nerve block".

To perform this technique we locate the infraorbital foramen; to do so the infraorbital notch is palpated with the index finger then moved downward from the notch, the bone immediately inferior to the notch is convex, which is the roof of the infraorbital foramen, as we continue inferiorly a concavity is felt, this is the infraorbital foramen. When we press against it the patient senses a mild soreness. After the foramen is located we retract the lip and cheek of the patient, a syringe with a long needle is inserted into the mucobuccal fold at the apex of the first premolar. The syringe is held parallel to the long axis of the tooth and is advanced till it reaches near the foramen. The average depth of insertion into the tissue is 16mm (half of the length of a long needle) for an adult of average height. When the needle is in the target area, slowly deposit 0.9 to 1.2ml of the solution. You would be able to "feel" the anesthesia solution as it is deposited beneath the finger on the foramen. Maintain firm pressure with your finger over the injection site for 1 or 2 more minutes to increase the diffusion of the solution into the infraorbital foramen. For decreasing the pain on insertion of the needle and tearing of the periosteum insert the needle with an angled position (away from the bone) and solution is deposit while the needle is advanced through soft tissue [1].It is in no way necessary to enter the foramen.

#### **4.8. Greater palatine nerve block**

It is possible to anesthetize palatine tissue by palatal infiltration technique at any place needed but by performing a greater palatine nerve block the posterior portion of the hard palate and the overlying soft tissue anteriorly as far as the first premolar on one side will be anesthetized. The foramen creates a depression in the palate usually distal to the maxillary second molar, which can be located by palpating the area. Deposition of 0.5ml of anesthesia solution in the region of the greater palatine foramen will block the nerve [9].

A very rare complication is ischemia and necrosis of soft tissue of the injection region and it only happens when highly concentrated vasoconstrictor solution is used for hemostasis over a prolonged period [1]. It is in no way necessary to enter the foramen.

#### **4.9. Nasopalatine nerve block**

In pediatric patients with primary or early mixed dentition, the thick bone of zygomatic process lies over the buccal roots of the second primary and first permanent molars, attenuating the effectiveness of infiltration injection in this region. So in this situations a PSA nerve block may

As mentioned before the MSA exist only in 28% of people and provides sensory innervation to maxillary premolars and mesiobuccal root of the first molar. The MSA block is performed

The Anterior Superior Alveolar nerve (ASA) supplies the maxillary incisors and canine teeth on one side and the soft and hard tissue adjacent to it. On the other hand the infraorbital nerve provides sensory innervation to the mucosa and skin surface of one half of the upper lip and part of the skin on lateral aspect of the nose; but because these two nerves can be anesthetized with one approach, the technique is either known as "ASA block" or "Infraorbital nerve block".

To perform this technique we locate the infraorbital foramen; to do so the infraorbital notch is palpated with the index finger then moved downward from the notch, the bone immediately inferior to the notch is convex, which is the roof of the infraorbital foramen, as we continue inferiorly a concavity is felt, this is the infraorbital foramen. When we press against it the patient senses a mild soreness. After the foramen is located we retract the lip and cheek of the patient, a syringe with a long needle is inserted into the mucobuccal fold at the apex of the first premolar. The syringe is held parallel to the long axis of the tooth and is advanced till it reaches near the foramen. The average depth of insertion into the tissue is 16mm (half of the length of a long needle) for an adult of average height. When the needle is in the target area, slowly deposit 0.9 to 1.2ml of the solution. You would be able to "feel" the anesthesia solution as it is deposited beneath the finger on the foramen. Maintain firm pressure with your finger over the injection site for 1 or 2 more minutes to increase the diffusion of the solution into the infraorbital foramen. For decreasing the pain on insertion of the needle and tearing of the periosteum insert the needle with an angled position (away from the bone) and solution is deposit while the needle is advanced through soft tissue [1].It is in no way necessary to enter the foramen.

It is possible to anesthetize palatine tissue by palatal infiltration technique at any place needed but by performing a greater palatine nerve block the posterior portion of the hard palate and the overlying soft tissue anteriorly as far as the first premolar on one side will be anesthetized. The foramen creates a depression in the palate usually distal to the maxillary second molar, which can be located by palpating the area. Deposition of 0.5ml of anesthesia solution in the

region of the greater palatine foramen will block the nerve [9].

by delivering a buccal infiltration at the apex of the second premolar tooth.

be used instead [15].

**4.6. Middle superior alveolar nerve block**

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**4.7. Anterior superior alveolar nerve block**

**4.8. Greater palatine nerve block**

This block anesthetizes the anterior portion of the hard palate (soft and hard tissue) bilaterally mesial to the first premolars. The technique can be performed by depositing 0.2 to 0.5 ml of anesthetic solution adjacent to the incisive papilla. Because the soft tissue in this area is dense, firmly adherent to underlying bone, and quite sensitive the injection in this area is very painful, so several methods are suggested to decrease the pain. One is anesthetizing the dental papilla between centrals labially and inserting the needle through it to the palatal side near the foramen and depositing a little solution to partially anesthetize the soft tissue overlying the nasopalatine nerve before the main injection [1].

#### **4.10. Anterior middle superior alveolar nerve block**

This is a relatively new technique, first demonstrated by Friedman and Hochman during development of a computer-controlled local anesthetic delivery (C-CLAD) system [16, 17]. This technique relies on the slow delivery and penetration of anesthetic solution through the porous cortical bone and the nutrient canals.

About 1.4 to 1.8ml of solution (one cartridge) should be deposited very slowly (0.5ml per minute) into the tissue halfway between the palatal midline and the premolar palatal gingival margin. This method is best performed with a C-CLAD. This method blocks the ASA and MSA so it anesthetizes the palate and the teeth anterior to the first molar and adjacent buccal attached gingiva. In studies the AMSA block is shown as effective as multiple maxillary infiltrations [18].

#### **4.11. Palatal anterior superior alveolar nerve block**

This method like the AMSA block relies on slow delivery of anesthetic solution via a C-CLAD system and was defined by Friedman and Hochman in the mid1990s [8, 17, 19]. In this approach 1.4 to 1.8ml of solution is deposited in the incisive canal at a rate of 0.5 ml per minute. This block anesthetize the pulp of the incisors and canine bilaterally, facial periodontal tissue associated with these same teeth and anterior hard palate. You should keep in mind that also the injection with a C-CLAD system is not painful but it will take about 3 or 4 minutes which some patients may be reluctant to tolerate.
