Supraperiosteal Injection (Local Infiltration)

A supraperiosteal injection (Table 39-9), more commonly referred to as a local infiltration, involves depositing anesthetic solution near the apex of a single tooth, thus providing anesthesia of the tooth and the immediate surrounding area (Figure 39-55). This injection is most often used to anesthetize maxillary teeth. The rather thin, porous nature of the bone in the maxilla facilitates diffusion of the anesthetic solution from the deposition site to the apex of the tooth to be treated.

Figure 39-55 The syringe should be held parallel with the long axis of the tooth and inserted at the height of the mucobuccal fold over the tooth.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

By contrast, the mandible consists of much denser bone, which prevents diffusion of the anesthetic agent to the apices of the posterior teeth, therefore precluding the supraperiosteal injection in this area. A supraperiosteal injection may be used to anesthetize the central and lateral teeth in the mandible because the bone in this area is thinner and nutrient canals may be present. Figure 39-56 shows hand rests that may be used for a maxillary supraperiosteal injection and ASA and MSA nerve blocks.

Figure 39-56 A-E, Syringe orientation and hand rests and finger rests that may be used for a maxillary supraperiosteal injection and anterior superior alveolar and middle superior alveolar nerve blocks.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-57 Areas anesthetized with a local infiltration of a maxillary central incisor. The deposition site is at the apical region of the target tooth.

Figure 39-58 Penetration site for a supraperiosteal injection of the maxillary right central incisor.

Figure 39-59 Areas anesthetized with the anterior superior nerve block.

Figure 39-60 Penetration site for the anterior superior nerve block.

Figure 39-61 Syringe orientation for the anterior superior nerve block.

Figure 39-62 Area anesthetized by a middle superior alveolar nerve block.

Figure 39-63 Needle penetration for a middle superior alveolar nerve block.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Indications for this injection include the need for pulpal anesthesia of maxillary teeth when only a limited number of teeth are to be treated and for soft-tissue procedures to be performed on a circumscribed area. Because the anesthetic and vasoconstrictor are deposited so near the area to be treated, this injection provides effective hemostasis, which is often needed during dental hygiene care. Conversely, if there is infection or severe inflammation in the area, administration of the anesthetic solution at a distance from the area of inflammation (i.e., nerve block) provides better and safer pain control because of the presence of more normal tissue conditions at the deposition site. Furthermore, if a large area involving several teeth needs to be treated, the supraperiosteal injection is not suitable because of the need for multiple needle insertions and the necessity of administering large volumes of anesthetic solution.

Table 39-9 summarizes the criteria pertinent to a supraperiosteal injection and provides tips for success.

TABLE 39-9 Supraperiosteal Injection (Local Infiltration)

Anterior Superior Alveolar Field Block

The ASA nerve block is recommended for management of pain when treatment is to be done only on the maxillary anterior teeth. Table 39-10 describes the criteria specific to the ASA nerve block.

TABLE 39-10 Anterior Superior Alveolar (ASA) Field Block

Middle Superior Alveolar Field Block

The MSA nerve block is the injection of choice when treatment involves only the premolars or if the infraorbital nerve block fails to provide pain control distal to the maxillary canine (Table 39-11).

Figure 39-64 Position of needle between maxillary premolars for a middle superior alveolar nerve block.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Research indicates that the MSA nerve is present in only 28% to 40% of the population, in which case this area is most often innervated by the ASA nerve.¹ Regardless of its presence or absence, this area can be anesthetized easily by means of the MSA technique described in Table 39-11. This table provides the guidelines for administering an MSA nerve block and suggestions to ensure success.

TABLE 39-11 Middle Superior Alveolar (MSA) Nerve Block

Infraorbital Nerve Block

Whereas the ASA (see Table 39-10) and the MSA (see Table 39-11) nerve blocks can be employed by oral healthcare professionals when they are anesthetizing the maxillary anterior and premolar teeth, the infraorbital nerve block is the injection of choice for many authorities when pain control is provided to this area.¹ The infraorbital nerve block provides both pulpal and facial soft-tissue anesthesia of the maxillary central incisor through the premolars in approximately 60% of individuals.¹ One injection of 0.9 to 1.2 mL of solution provides pain control in a relatively large area, effectively minimizing needle penetrations and volume of solution administered. Despite these advantages, this injection is not used as often as indicated because many operators are fearful of injuring the client's eye. This fear, however, is unfounded, and when the appropriate procedures are followed, this injection is highly effective and safe (Figures 39-65, 39-66, and 39-67).

Figure 39-65 A, Palpate the infraorbital notch. B, Location of the infraorbital foramen in relation to the infraorbital notch.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-66 Using a finger over the foramen, lift the lip and hold the tissues in the mucobuccal fold taut.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-67 Insert the needle for infraorbital nerve block in mucobuccal fold over maxillary first premolar.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-68 Area anesthetized by an infraorbital nerve block in approximately 60% of individuals.

Figure 39-69 Position of the needle tip before deposition of local anesthetic at the infraorbital foramen.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Table 39-12 describes the criteria applicable to the infraorbital nerve block and includes directions for locating the infraorbital foramen and directing the needle and anesthetic solution to the nerve.

TABLE 39-12 Infraorbital (IO) Nerve Block

Posterior Superior Alveolar Nerve Block

The PSA nerve block, employed to anesthetize the maxillary molars, is preferred to supraperiosteal (infiltration) injections because it minimizes both the number of injections required and the volume of anesthetic solution administered. Also, because the anesthetic solution is deposited into an area of soft tissue with no bony landmarks (hence no bone contact), it is a comfortable injection for the client (Figures 39-70 and 39-71).

Figure 39-70 Needle at the target area for a posterior superior alveolar nerve block.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-71 Posterior superior alveolar nerve block using a “short” dental needle (approximately 20 mm in length).

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-72 Area anesthetized by the posterior superior alveolar nerve block.

Figure 39-73 A, Forty-five degrees to the maxillary occlusal plane. B, Forty-five degrees to the midsagittal plane. C, Orientation of syringe during the posterior superior alveolar nerve block.

Complete pulpal anesthesia is obtained in the first, second, and third molars in at least 60% of persons.¹⁴ Dissection studies reveal, however, that the MSA nerve, when present, may supply sensory innervation to the mesiobuccal root of the first molar, therefore necessitating either a supraperiosteal injection, an MSA nerve block, or an infraorbital nerve block to anesthetize the remainder of this tooth. Furthermore, if access is difficult or if the third molar is missing and treatment is limited to only the first and second molars, supraperiosteal injections may be substituted.

Other considerations are safety and needle length. A long 25-gauge needle is often recommended for this injection. Problems associated with needle length, however, may result in an increased risk of hematoma formation. There are no anatomic safety features to prevent inadvertently inserting the needle too far posteriorly into the pterygoid plexus of veins and the facial artery, thereby causing a hematoma. Therefore, to minimize the risk of hematoma formation after the PSA nerve block, a short 25- or 27-gauge needle is recommended. Although depth of insertion with the long needle is 16 mm, or one half of its length, the short needle is inserted three fourths of its length. Thus the risk of overinsertion and hematoma formation decreases when a short needle is used. Regardless of the needle length used, multiple aspirations and slow anesthetic deposition are imperative to ensure a safe injection.

Table 39-13 provides the essential criteria for a PSA nerve block. Of particular significance to this injection is the syringe orientation of 45 degrees to the maxillary occlusal plane and 45 degrees to the midsagittal plane. This angulation, maintained throughout the injection, advances the needle around the maxillary tuberosity to reach the deposition site.

TABLE 39-13 Posterior Superior Alveolar (PSA) Nerve Block

Greater Palatine Nerve Block

The greater palatine nerve block is used to anesthetize the hard and soft palatal tissues overlying the molars and premolars; no pulpal anesthesia is obtained (see Figure 39-74). This nerve block provides anesthesia to a large area, thereby minimizing the number of needle penetrations and total amount of anesthetic solution needed; however, the greater palatine nerve can be blocked at any point after it emerges from the foramen and passes anteriorly between the hard and soft tissues. As a result, anesthesia is obtained only anterior to the site of the injection. For example, if treatment is limited to the first molar and premolars, the injection site should be slightly posterior to the first molar along the greater palatine nerve path. This practice ensures that the areas to be treated are anesthetized but that the posterior region of the palate is not unnecessarily anesthetized.

Table 39-14 provides the criteria pertinent for the administration of a greater palatine nerve block and includes suggestions for locating the greater palatine foramen and maximizing client comfort.

TABLE 39-14 Greater Palatine (GP) Nerve Block (Anterior Palatine)

Nasopalatine Nerve Block

The nasopalatine nerve block anesthetizes the palatal hard and soft tissues from the mesial aspect of the right premolar to the mesial aspect of the left premolar. As with the greater palatine nerve block, a minimal number of needle penetrations and a small amount of anesthetic solution are needed to anesthetize a wide area. Because the soft tissue is dense, firmly attached to the bone, and very sensitive, however, this nerve block is potentially the most painful of all the injections unless the protocol for an atraumatic injection is closely followed.

Two techniques are available for giving this injection. The first involves only one needle penetration on the lateral side of the incisive papilla (Figure 39-78, D). The second technique includes giving two or three sequential injections, one between the maxillary central incisors followed by a second penetration into the papilla between the maxillary central incisors. In some cases these two injections provide sufficient pain control for dental hygiene care. If not, an injection is made into the partially anesthetized palatal tissues on the lateral side of the incisive papilla to complete the nasopalatine nerve block (see Figure 39-78, A to D).

Figure 39-78 A, Topical anesthetic is applied to mucosa of the frenum. B, First injection, into the labial frenum. C, Use a finger of the opposite hand to stabilize the syringe during the second injection into the intended papilla between the central incisors. D, Pressure is maintained until the deposition of solution is completed. Needle penetration is just lateral to the incisive papilla.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-79 Area anesthetized with the nasopalatine nerve block.

Figure 39-80 Target area for a nasopalatine nerve block.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Each approach is acceptable, and dental hygienists should select the procedure they feel most comfortable with and that provides the most atraumatic injection possible for the client (Table 39-15).

TABLE 39-15 Nasopalatine (NP) Nerve Block

Inferior Alveolar Nerve Block and Lingual Nerve Block

The inferior alveolar and lingual nerve blocks are often employed when dental hygiene care involves the mandible. The biggest advantage is that one penetration anesthetizes the entire quadrant, with the exception of the facial soft tissue over the molars. The disadvantages, however, are formidable, and the success rate of the inferior alveolar nerve block is considerably lower than that of many other injections. Reasons for lack of success are as follows:

The anatomic variations with regard to the height of the mandibular foramen on the medial side of the ramus

Accessory innervation by means of the mylohyoid nerve or a bifid inferior alveolar nerve

The considerable depth of soft-tissue penetration needed to reach the nerve

In addition, the inferior alveolar nerve block has the highest rate of positive aspiration of all the intraoral injections.¹ Table 39-16 describes the criteria essential for administering the inferior alveolar and lingual nerve blocks. It is important to carefully follow the guidelines regarding the landmarks for the penetration and deposition sites to ensure a successful injection and minimize or eliminate complications. To determine the height of the injection, place the index finger or thumb of your nondominant hand in the coronoid notch (Figure 39-81). An imaginary line extends posteriorly from the fingertip in the coronoid notch to the deepest part of the pterygomandibular raphe, determining the height of injection. This imaginary line should be parallel with the occlusal plane of the mandibular molar teeth and usually lies 6 to 10 mm above the occlusal plane (Figure 39-82).

TABLE 39-16 Inferior Alveolar (IA) and Lingual (Li) Nerve Blocks

Figure 39-81 Landmarks on the mandible for the inferior alveolar and lingual nerve blocks.

Figure 39-82 The posterior border of the mandibular ramus can be approximated intraorally by using the pterygomandibular raphe as it turns superiorly toward the maxilla.

To locate the pterygomandibular triangle, roll the index finger or thumb of your nondominant hand from the coronoid notch to locate the internal oblique ridge (see Figure 39-81). The point of needle penetration is between the internal oblique ridge and the pterygomandibular raphe in the pterygomandibular triangle. The syringe barrel is placed in the corner of the mouth on the contralateral side (Figures 39-83 and 39-84).

Figure 39-83 Notice the placement of the syringe barrel at the corner of the mouth, usually corresponding to the premolars. The needle tip gently touches the most distal end of the pterygomandibular raphe.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-84 Placement of the needle and syringe for an inferior alveolar nerve block.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-85 Area anesthetized with the inferior alveolar and lingual nerve blocks.

Figure 39-86 A, Premature bone contact on the lingula. B, Path of syringe orientation to correct for premature contact of bone.

Figure 39-87 A, The needle is too far posterior; no bone is contacted. B, Path of syringe orientation to correct needle position.

Figure 39-88 Direct the needle tip below the apical region of the tooth immediately posterior to the tooth in question.

Figure 39-89 Local infiltration of the mandibular incisors.

Appropriate care planning is important when the mandible is anesthetized. Bilateral inferior alveolar and lingual nerve blocks should be avoided. Such procedures produce anesthesia of the client's entire tongue and lingual soft tissues, resulting in an inability to swallow and enunciate and a lack of sensation. Thus anesthetizing the entire mandible creates a high risk of client self-injury to the soft tissues and is not recommended. The optimal care plan is to anesthetize only the right side or only the left side at one appointment. Another alternative is to administer the inferior alveolar nerve block to the side that requires the most treatment (particularly involving lingual tissue) or has the greatest number of teeth, and administer the incisive nerve block (see Table 39-19) on the opposite side. Because the incisive nerve block does not provide pain control to the lingual tissues, a lingual infiltration may be given, if necessary.

In many instances the deliberate deposition of anesthetic solution to anesthetize the lingual nerve is unnecessary because solution deposited for the inferior alveolar nerve block diffuses and anesthetizes the lingual nerve; however, a separate technique for a lingual nerve block is described in Table 39-16 in the event that deliberate deposition of anesthetic solution is needed.

Buccal Nerve Block

The buccal nerve block provides pain control to the soft tissues buccal to the mandibular molars. This injection, along with the inferior alveolar and lingual nerve blocks, anesthetizes the entire quadrant in which it is given. If dental hygiene care involves manipulation of the buccal tissues of the molars, such as therapeutic scaling, root planing, and soft-tissue curettage, this injection is indicated. If treatment does not include these tissues, however, the dental hygienist may simply forgo this injection. Unlike the other injections needed to anesthetize the mandible, the buccal nerve block is easy to administer (Figure 39-90) and has a high success rate. Table 39-17 describes technique for the buccal nerve block.

Figure 39-90 Syringe alignment. A, Parallel with the occlusal plane on the side of injection but buccal to it. B, Distal and buccal to the last molar.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-91 Area anesthetized with the buccal nerve block.

Figure 39-92 Hand rests for the buccal nerve block.

TABLE 39-17 Buccal Nerve Block (Long Buccal)

Mental Nerve Block

At or near the apices of the premolars, the mental nerve exits the mental foramen and innervates the facial soft tissues anterior to the foramen, the lower lip, and the chin on the side of the injection. Because of the easy access of the anatomic landmarks, the mental nerve block is simple to administer, has a high success rate, and is usually atraumatic (Figure 39-93).

Figure 39-93 Mental nerve block needle penetration site.

(From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.)

Figure 39-94 Area anesthetized with the mental nerve block.

Figure 39-95 Hand rests for the mental and incisive nerve blocks. When possible, hold the arms close to the body to increase stabilization.

Figure 39-96 Locate the mental nerve foramen by palpating the vestibule at the premolars.

Figure 39-97 Radiographs can assist in locating the mental foramen.

Figure 39-98 Area anesthetized with the incisive nerve block.

Although this injection has limited application in restorative dentistry, it may be used more commonly by dental hygienists doing gingival curettage in the anterior portion of the mandible. Because the mental nerve block does not provide pain control to the lingual tissues, a lingual infiltration may be needed.

Table 39-18 presents essential criteria for administration of the mental nerve block, including suggestions for locating the mental foramen.

TABLE 39-18 Mental Nerve Block

Incisive Nerve Block

The incisive nerve originates at the mental foramen and innervates the teeth anterior to the foramen. As a terminal branch of the inferior alveolar nerve, the incisive nerve is anesthetized when an inferior alveolar nerve block is successfully given. The incisive nerve block, however, may be the injection of choice in several instances. Because bilateral inferior alveolar and lingual nerve blocks are contraindicated as a result of client discomfort, an alternative may be to administer the inferior alveolar and lingual nerve blocks to the side needing the most treatment or having the greatest number of teeth and to administer the incisive nerve block on the other side. The incisive nerve block also may be used concurrently on both the right and left sides when dental hygiene care requires the incisive nerve block. If lingual soft tissues in isolated areas require anesthesia, local infiltration can be accomplished readily by inserting a 27-gauge short needle through the interdental papilla on both the mesial and distal aspect on the tooth being treated. Because the incisive nerve block already anesthetized the buccal soft tissues, the needle penetration is atraumatic. Local anesthetic solution should be deposited as the needle is advanced through the tissue toward the lingual aspect.

Table 39-19 presents the criteria necessary for administration of the incisive nerve block and suggestions for locating the mental foramen. Although some authorities recommend penetrating the needle into the mental foramen to reach the incisive nerve, anesthesia can be obtained much more easily and safely by depositing the solution outside the foramen and using digital pressure over the site to direct the anesthetic into the foramen.

TABLE 39-19 Incisive Nerve Block

Needle Breakage

The introduction of disposable stainless steel needles has significantly reduced the incidence of needle breakage; however, virtually all needle breaks are preventable. When breakage does occur, it is primarily caused by a sudden, unexpected movement by the client during needle insertion or by poor injection technique.¹ If a needle does break during insertion and can be retrieved without surgical intervention, no emergency exists. Those needles that are not retrieved most often remain in place and become encased by scar tissue. Leaving the needle in the tissue often produces fewer difficulties than the surgery required for its removal.

To prevent needle breakage, do the following:

Inform the client about the local anesthetic procedure both before and during the injection. Effective communication helps the individual anticipate the dental hygienist's actions and control anxiety.

Use long, large-gauge needles (e.g., 25-gauge) when penetrating significant tissue depth. These are less likely to break than smaller needles.

Never bend the needle, because it weakens the metal.

Advance the needle slowly. A forceful contact with bone may break the needle or may precipitate a quick movement by the client because of associated pain.

Never force a needle against firm resistance such as bone.

Do not change the direction of the needle while it is almost completely within the tissues. If it is necessary to redirect the needle, first withdraw almost completely out of the tissue and then modify the direction.

A needle should not be inserted into the tissues all the way to the hub. This juncture at the needle shaft and hub is the weakest part of the needle and is vulnerable to breakage. If needle breakage occurs at this point, a portion of the shaft must be exposed in order for the needle to be retrieved without surgery.

When a needle breaks, do the following:

Remain calm; do not panic.

Instruct the client not to move. Do not remove your hand from the client's mouth, and keep the client's mouth open. If possible, place a bite block in the client's mouth.

If the needle fragment is protruding, attempt to remove it with cotton pliers or a hemostat.

If the needle fragment is not visible and cannot be readily retrieved:

Calmly inform the client; attempt to alleviate fears and apprehension.

Refer the client to an oral and maxillofacial surgeon for consultation.

Document the incident and the client's response in the client's chart. Keep the remaining needle fragment. Inform your insurance carrier immediately.

When a needle breaks, surgical removal should be considered, as follows:

If the needle fragment is superficial and easily located through radiologic and clinical examination, removal by an oral and maxillofacial surgeon is possible.

If, despite the superficial location, retrieval is unsuccessful, it is prudent to abandon the attempt and allow the needle fragment to remain in the tissue.

If the needle is located in deeper tissues or is difficult to locate, permit it to remain without an attempt at removal. There is considerable precedent to justify the retention of a fragment of a broken needle if removal appears difficult.

Pain during the Injection

Pain during local anesthetic agent administration may be attributed to several factors: a careless injection technique and callous attitude toward the client; a dull needle from multiple injections; a barbed needle from hitting bone; or rapid deposition of the anesthetic solution. It is not possible to ensure that every injection is totally free from discomfort because the reactions of clients vary; however, the dental hygienist should take every precaution to prevent pain during the injection or prevent its recurrence.

To prevent pain during injection, do the following:

Adhere to the proper techniques of administration as described in Procedure 39-3 and Tables 39-9 to 39-19.

Deposit a few drops and then wait 5 seconds before advancing the needle 2 to 3 mm. Repeat the process until the deposition site is reached.

Use sharp, disposable needles.

Apply topical anesthetic before insertion of the needle.

Use sterile anesthetic agents.

Inject the anesthetic agent slowly.

Store anesthetic solutions at room temperature and avoid using cartridge warmers.

Burning during the Injection

A burning sensation reported by the client during deposition of the local anesthetic agent may be caused by a local anesthetic with a vasopressor that is more acidic than the tissue in which it is deposited. The burning sensation, which lasts only a few seconds, disappears as anesthesia develops and is unapparent when the anesthesia fades. A more acute burning may occur, however, if the local anesthetic solution is contaminated from improper storage of the cartridge in a chemical disinfectant; if the cartridge is overheated in a cartridge warmer; if the expiration date of the solution has lapsed; or if the solution is deposited too rapidly, particularly on the palate. When burning occurs as a result of these factors, the tissue is damaged and subsequent postanesthetic trismus, edema, or possible paresthesia may develop.

To prevent burning during the injection, do the following:

Store the cartridges in a dark place at room temperature in the original container. Avoid storing cartridges in chemical disinfectants or using cartridge warmers.

Check the expiration date of each cartridge before use. Anesthetic solution that has exceeded the expiration date should be discarded.

Inject the anesthetic solution slowly.

Most often, burning during an injection is a temporary condition and needs no specific treatment.

Hematoma

A hematoma is a swelling and discoloration of the tissue resulting from the effusion of blood into the extravascular spaces (Figure 39-99). Hematomas occur subsequent to an inadvertent puncture of a blood vessel, particularly an artery, during local anesthetic administration. They appear most often after the administration of a PSA or inferior alveolar nerve block because the tissues associated with these injections are less dense and readily accommodate large volumes of blood. Bleeding continues until extravascular pressure exceeds intravascular pressure or until clotting occurs. A hematoma is less likely to develop after a palatal injection because of the density of the tissue in this area.

Figure 39-99 Hematoma resulting from administration of left mental block.

A hematoma that ensues after a PSA nerve block is the largest and most visible. The bleeding occurs in the infratemporal fossa, and swelling and discoloration appear on the side of the face. Clinical manifestations of a hematoma following an inferior alveolar nerve block include intraoral tissue discoloration and swelling on the lingual aspect of the ramus. Other than the bruise, which may or may not be visible extraorally, a hematoma may be accompanied by trismus and pain.

To prevent a hematoma, do the following:

Be attentive to anatomic detail involved in each injection.

Modify the injection technique as indicated by the client's anatomy. For example, the depth of needle penetration for a PSA nerve block may be shallower for a client with small anatomic features.

Use a short needle for the PSA nerve block to minimize the risk of overinsertion and the potential for hematoma formation.

Minimize the number of needle insertions.

Observe the appropriate techniques for local anesthetic administration.

Management includes the following:

If swelling appears, immediately apply direct pressure to the site of the bleeding for at least 2 minutes. For an inferior alveolar nerve block, the pressure point is the medial side of the ramus. For the mental or incisive nerve block, pressure is applied over the mental foramen. If hematoma formation follows an infraorbital nerve block, the pressure point is the skin over the infraorbital foramen. Unfortunately, it is difficult to apply pressure directly to the site of bleeding after a PSA nerve block because the vessels are located posterior, superior, and medial to the maxillary tuberosity. Pressure may be applied to the tissues of the mucofacial fold as far distally as the client can tolerate.

Apply ice to the region when hematoma formation begins. Ice constricts the blood vessels, minimizes the size of the hematoma, and acts as an analgesic.

Inform the client about the possibility of soreness and limitation of movement. If soreness develops, analgesics may be taken. Beginning the next day, warm, moist towels may be applied to the affected region for 20 minutes every hour. This provides comfort and helps blood resorption. Heat therapy should not commence for at least 4 to 6 hours after hematoma formation, however. Before this time, heat may produce further vasodilation and an even larger hematoma.

Advise the client that the swelling and discoloration will gradually disappear over 7 to 14 days.

Dismiss the client when the bleeding has stopped. Avoid further dental hygiene care in the area until signs and symptoms of the hematoma have disappeared. Document the incident and the client's response in the client's chart.

Facial Nerve Paralysis

Facial paralysis is a loss of motor function of the facial expression muscles. Unilateral facial nerve paralysis occurs when the local anesthetic solution is inadvertently deposited into the parotid gland, located on the posterior border of the ramus, during an inferior alveolar nerve block.

The loss of motor function is temporary and subsides in a few hours; however, during this time, the client is unable to control these muscles and the face appears lopsided. It also may be impossible for the client to voluntarily close the eye on the affected side. Fortunately, the corneal reflex is functional, and tears continue to lubricate the eye.

To prevent facial nerve paralysis, do the following:

Adhere to the techniques recommended for the inferior alveolar nerve block.

Make sure the needle contacts bone (medial aspect of the ramus) before deposition of the local anesthetic solution.

If bone is not contacted, withdraw the needle almost entirely out of the tissue, bring the barrel of the syringe more posterior (thereby directing the needle more anterior), and readvance the needle until bone is contacted.

Following these steps precludes deposition of the solution into the parotid gland.

Within a short time after deposition of the anesthetic solution into the parotid gland, the client senses a weakening of the facial muscles on the affected side. The inferior alveolar nerve is not anesthetized. Management includes the following¹:

Reassure the client. Explain that the paralysis lasts only a few hours and resolves with no residual effects.

Instruct the client to remove contact lenses.

Ask the client to close the eyelid manually to keep the cornea lubricated.

There are no contraindications to proceeding with treatment at this time, but it may be advisable to reschedule the client.

Document the incident and the client's response in the client's chart.

Paresthesia

Prolonged anesthesia or paresthesia is a condition wherein the client experiences numbness for many hours or days after a local anesthetic injection. Paresthesia may be the result of irritation to the nerve after injection of an anesthetic agent that has been contaminated with alcohol or a disinfectant. The ensuing edema places pressure on the nerve, leading to paresthesia. Persistent anesthesia also may result from trauma to the nerve sheath caused by the needle contacting the nerve during an injection. Clients often report the sensation of an electric shock when this occurs. Finally, hemorrhage into or around the neural sheath may create pressure and subsequent paresthesia.

A complication of paresthesia is the client inadvertently precipitating a biting, thermal, or chemical injury from the diminished sensation in the area.

To prevent paresthesia, do the following:

Store dental cartridges properly. Avoid placing cartridges in disinfectants.

Follow the proper injection protocol as recommended in Procedure 39-3 and Tables 39-9 to 39-19.

Most often paresthesia involves the lingual nerve or the inferior alveolar nerve. The sensory deficit usually is minimal and rarely is accompanied by permanent nerve damage. Fortunately, most incidents resolve within 8 weeks. Recommendations for the management of a client with paresthesia are as follows¹:

Reassure the client. The client usually contacts the dental office the day after treatment to report continuing numbness. Explain that paresthesia after local anesthetic administration is not uncommon.

Arrange for an examination of the client by the dentist, who will determine the location and extent of paresthesia. Explain to the client that paresthesia often continues for 2 months and may last longer.

Arrange to have the client examined every 2 months until cessation of the paresthesia. Consultation with an oral and maxillofacial surgeon is advisable if paresthesia persists after 12 months or sooner if the client and dentist consider it appropriate.

Record the incident, conversations with the client, and all clinical findings in the client's chart. Inform your liability carrier of the circumstances.

Dental and dental hygiene care may continue. Avoid injecting into the area of the traumatized nerve, and employ alternative pain control techniques.

Trismus

Trismus, a spasm of the muscles of mastication that results in soreness and difficulty opening the mouth, most often occurs as a result of trauma to the muscles in the infratemporal space after intraoral injections. This trauma may be the result of multiple needle insertions, administration of an anesthetic solution contaminated with a disinfectant, injection of large amounts of local anesthetic solution into a restricted area causing distention of the tissues, hemorrhage that leads to muscle dysfunction as the blood is resorbed, or a low-grade infection.

To prevent trismus, do the following:

Store the local anesthetic cartridges properly. Avoid immersing the cartridges in a disinfectant.

Use sharp, sterile, disposable needles.

Follow appropriate infection-control protocol. Needles that become contaminated should be replaced.

Use minimal effective amounts of local anesthetic solution, and deposit the solution slowly.

Adhere to the recommended techniques of local anesthetic administration as outlined in Procedure 39-3 and Tables 39-9 to 39-19. Observe anatomic landmarks and strive to improve administration techniques. Each of these recommendations facilitates atraumatic injections and prevents repeated needle insertions.

Clients often complain of soreness and difficulty in opening the mouth the day after the administration of an inferior alveolar or a posterior superior nerve block. Recommendations for management of clients with trismus follow¹:

Arrange for an examination of the client by the dentist.

Start heat therapy immediately. Place moist, hot towels on the affected area for 20 minutes every hour. Analgesics may be recommended to manage the discomfort. Codeine and muscle relaxants may be prescribed by the dentist if needed.

Direct the client to open and close and move the mandible from side to side (lateral) for 5 minutes every 3 to 4 hours. This exercise may be accomplished by chewing gum.

Continue heat therapy, analgesics, and exercise until the client is free of symptoms. Improvement is often reported within 48 hours, and symptoms diminish gradually over several days.

If symptoms continue after 48 hours, the possibility of an infection exists. Antibiotic therapy (prescribed by the dentist) should be added to the recommended care regimen.

If severe pain and dysfunction continue despite therapy, refer the client to an oral and maxillofacial surgeon for consultation.

Record the incident, conversations with the client, the results of clinical examinations, and care recommended in the client's chart.

Avoid elective dental hygiene care until symptoms resolve and the client is more comfortable.

Infection

Infection from local anesthetic administration occurs rarely with the introduction of sterile disposable needles and glass cartridges; however, postinjection infection may be precipitated by contamination of the needle before the injection, improper handling of the local anesthesia armamentarium, or improper tissue preparation before the injection. When a contaminated needle or local anesthetic solution is introduced into the deeper tissues, infection may occur. If infection is not recognized and treated, trismus may ensue.

To prevent infection, do the following:

Use sterile, disposable needles.

Sheath the needle before use and resheath it after use to prevent it from coming in contact with nonsterile surfaces.

Use appropriate infection-control protocol when handling the anesthetic cartridges. Store the cartridges in their original container, and, if necessary, wipe the diaphragm of the cartridge with a disinfectant before syringe assembly.

To reduce microorganisms at the penetration site, wipe the tissue with gauze and apply a topical antiseptic before the initial needle insertion.

When infection occurs, the client often reports pain and dysfunction, similar to trismus, a few days after dental hygiene care. At this point signs and symptoms of infection often are not obvious, and immediate treatment includes procedures for managing trismus (e.g., heat therapy, physiotherapy, analgesics, and muscle relaxants). If the client does not respond to therapy within 3 days, an infection most likely exists, and antibiotic therapy should be prescribed by the dentist or physician. Document the recommended therapy and client progress in the client record.

Edema

Edema, a swelling of the tissues, is a clinical sign of a complication. It may be caused by trauma during the injection, administration of contaminated solutions, hemorrhage, an infection, or an allergic response. Most often edema manifests as localized pain and dysfunction. In the most severe case, edema precipitated by an allergic response may produce airway obstruction and represents a life-threatening emergency.

To prevent edema, do the following:

Follow appropriate infection-control protocol when storing and handling components of the local anesthesia armamentarium.

Observe the guidelines for administering atraumatic injections, as described in Procedure 39-3.

Conduct an adequate preanesthetic client assessment before local anesthetic administration.

The course and treatment of edema depend on its cause.¹ When produced by the administration of a contaminated anesthetic solution or traumatic injection, edema usually subsides in 1 to 3 days without treatment. Analgesics may be recommended. If edema is caused by hemorrhage, the tissue appears discolored and should be managed in the same manner as a hematoma. Resolution of the edema may take 7 to 14 days as the blood is resorbed into the tissues. Edema produced by infection often becomes progressively worse. If the pain and dysfunction do not subside in 3 days, antibiotic therapy may be instituted by the dentist or physician. The treatment of edema caused by an allergic reaction depends on the degree and location of the tissue swelling. If there is no airway obstruction, treatment involves the administration of intramuscular and oral antihistamines and consultation with an allergist or physician. If the edema occurs in an area where it compromises the airway, the recommendations outlined in the section on systemic complications should be followed.

Tissue Sloughing

Surface layers of epithelium may be lost because of tissue irritation caused by the application of topical anesthetic for an extended period or a client's heightened sensitivity to the local anesthetic. A sterile abscess—a form of tissue sloughing most frequently occurring on the hard palate—may develop after prolonged ischemia induced by the inclusion of a vasoconstrictor in the local anesthetic agent.

To prevent tissue sloughing, do the following:

Use topical anesthetics appropriately. Apply a limited amount of topical anesthetic to the tissue for 1 to 2 minutes to minimize irritation and maximize effectiveness.

When using vasoconstrictors for hemostasis, avoid using high concentrations. Epinephrine 1:50,000 and norepinephrine (Levophed) 1:30,000 are the agents most likely to cause prolonged ischemia leading to a sterile abscess.

Tissue sloughing usually requires no treatment and disappears within a few days. A sterile abscess resolves in 7 to 10 days. Analgesics may be recommended for discomfort, and topical ointment can be applied to minimize irritation. Document the progress and response of the client in the client's record.

Soft-Tissue Trauma

Lip, tongue, or cheek trauma results when the client inadvertently chews or bites these tissues while they are still anesthetized. Trauma—most often observed in children or in mentally or physically disabled individuals—may lead to swelling and significant discomfort when the anesthesia subsides.

To prevent soft-tissue trauma, do the following:

Select a local anesthetic agent with appropriate duration for the length of the dental hygiene appointment.

Warn the client not to eat, drink, or test the anesthetized area by biting until normal sensation has returned. The client's guardian also should be advised of the potential for injury.

If anesthesia is still present on dismissal, place a cotton roll between the teeth and soft tissues. The cotton roll can be held in position with dental floss wrapped around the teeth.

Warning stickers may be placed on children to serve as a reminder to the child and the guardian to be careful.

Management of soft-tissue trauma includes the following:

Coat the lip with petrolatum to minimize irritation and discomfort.

Recommend warm saline rinses to help decrease swelling.

Recommend analgesics for pain.

If infection occurs, the dentist or physician may prescribe antibiotic therapy.

Postanesthetic Intraoral Lesions

Intraoral lesions, such as those from aphthous stomatitis or herpes simplex virus, may develop after the administration of local anesthesia or trauma to the intraoral tissues. Aphthous stomatitis occurs on tissue not attached to bone, such as the mucofacial fold or inner lip. Herpes simplex virus lesions may develop intraorally on tissues attached to bone, such as the hard palate, or extraorally. Trauma to the area by a needle or any equipment used during the dental hygiene care appointment may activate herpetic recurrence.

Preventing the development of postanesthetic intraoral lesions is impossible in susceptible clients; however, minimizing trauma during procedures for local anesthetic administration is advisable.

Approximately 2 days after the dental hygiene care appointment, the client reports ulcerations and intense pain, usually near the injection site(s). If the discomfort is tolerable, no management is necessary. If the pain is acute, topical anesthetic solutions or protective pastes, such as Orabase, may provide relief. The lesions last for 7 to 10 days. Reassure the client, and document the occurrence of the lesion in the client's record.

Local Anesthetic Overdose

A drug overdose reaction or toxic reaction is defined as those signs and symptoms that result from overly high blood levels of a drug in various organs and tissues.¹ Normally the drug is continually absorbed from its site of administration into the circulation. Concurrently the drug is being removed from the blood as it undergoes redistribution and biotransformation. When this equilibrium exists, high blood levels of the drug seldom occur. If this equilibrium is altered, however, the elevation of the blood level of the drug may be sufficient to produce an overdose reaction.

Many factors influence the rate at which a local anesthetic drug level is elevated and the length of time it remains elevated. The presence of one or more of these factors predisposes the client to the development of an overdose reaction. These factors are divided into predisposing client factors and drug factors. Client factors modify the response of an individual to the usual drug dosage. Drug factors involve the drug and its site of administration. Table 39-20 describes how each of these factors influences the potential for an overdose reaction.

TABLE 39-20 Predisposing Factors to Local Anesthetic Overdose Reaction

Adapted from Malamed SF: Medical emergencies in the dental office, ed 6, St Louis, 2007, Mosby.

Causes and Prevention

High blood levels of local anesthetics may occur in one or more of the following ways¹:

Biotransformation of the anesthetic is unusually slow.

Elimination of the anesthetic from the body through the kidneys is unusually slow.

The total dose administered is too large.

Absorption of the anesthetic from the site of injection is unusually rapid.

The anesthetic is inadvertently administered intravascularly.

The first two potential causes of an overdose—delayed biotransformation and elimination of the anesthetic agent—relate to the health of the client. Therefore it is imperative that the dental hygienist carefully assess the client's health status, obtain medical consultation if necessary, and modify the dental hygiene care plan as indicated to prevent drug-related complications.

The three remaining causes of an overdose reaction—excessive dose, rapid absorption, and intravascular injection—may be prevented through adherence to proper technique of local anesthetic agent administration. Thus careful assessment of the client before dental hygiene care and proper administration technique minimize the risk of a local anesthetic overdose.

Biotransformation and Elimination of the Anesthetic

Ester anesthetics are biotransformed primarily in the blood by the enzyme pseudocholinesterase, which causes the drug to undergo hydrolysis to para-aminobenzoic acid. Clients with a familial history of atypical pseudocholinesterase may be unable to detoxify ester anesthetic agents at the usual rate. As a result, high blood levels of anesthetic may develop. Amide anesthetics may be administered to these individuals without an increased risk of overdose.

Biotransformation of amide anesthetics occurs in the liver. A history of liver disease may indicate some hepatic dysfunction, and the ability of the liver to biotransform amide anesthetics may be compromised. Clients with a history of liver disease who are ambulatory may still receive amide local anesthetics; however, only small amounts should be injected because average amounts may produce an overdose reaction.

Both ester and amide anesthetics are eliminated to some degree through the kidneys. Renal dysfunction may delay elimination of the local anesthetic from the blood, precipitating accumulated levels of local anesthetic and increased potential for an overdose. Those clients who have significant renal impairment or who require renal dialysis should receive the minimal amount of local anesthetic needed for effective pain control.

Excessive Total Dose of Anesthetic

If an excessive total dose of local anesthetic is administered to a client, toxic effects develop. Responses to drugs vary considerably, but guidelines exist for the dental hygienist to calculate maximal safe doses of local anesthetic agents based on body weight. The dental hygienist also needs to factor in the client's age and physical status and adjust the dose accordingly. A more detailed discussion can be found under the earlier section on maximal safe doses of local anesthetics.

Rapid Absorption of Anesthetic into the Circulation

The addition of a vasoconstricting drug in the local anesthetic solution reduces the systemic toxicity of the anesthetic agent by slowing its absorption into the CVS. Therefore, unless specifically contraindicated because of health status or limited duration of dental hygiene care, local anesthetic solutions containing a vasoconstrictor should be employed. A vasoconstrictor minimizes the potential for an overdose reaction and subsequently increases client safety.

Topical anesthetic agents applied to the oral mucosa are absorbed rapidly into the circulation. The concentration of these topical agents is much greater than that of injectable anesthetic solutions. When small amounts are used in a localized area, there is little chance of complications developing. If topical anesthetic agents are applied over a large area such as a quadrant or the entire arch, a significant increase in blood level may occur, precipitating an overdose reaction.¹ To prevent complications with topical anesthetics, it is recommended to limit the area of application and avoid topical anesthetic aerosol sprays because of lack of dosage control and sterility concerns.

Intravascular Injection

The introduction of a local anesthetic solution directly into the bloodstream via an intravascular injection (intravenous or intra-arterial) may produce an overdose response. An intravascular injection may result with any intraoral injection; however, it is more likely to occur during a nerve block, particularly an inferior alveolar, mental, incisive, or PSA nerve block.

Fortunately, an overdose reaction from an intravascular injection can be prevented by having a complete knowledge of the anatomic features of the area to be anesthetized and by adhering to careful injection technique. This includes using an aspirating syringe, using a 25- or 27-gauge needle, aspirating in two planes before deposition, and slowly administering the anesthetic agent.

Clinical Manifestations and Management

The onset, intensity, and duration of a local anesthetic toxic reaction may vary depending on the original cause of the overdose. Table 39-21 compares the various patterns of local anesthetic overdose reactions.

TABLE 39-21 Comparison of Patterns of Local Anesthetic Overdose

Table 39-22 describes the clinical signs and symptoms that may occur during an overdose reaction (with minimal-to-moderate and moderate-to-high blood levels of anesthetic) and the procedures for managing a local anesthetic overdose response. Management of an overdose response depends on the severity of the reaction. Most often the reaction is mild and transitory, with little or no specific treatment need.¹ A severe or longer-duration reaction necessitates prompt recognition and immediate care.

TABLE 39-22 Clinical Manifestations and Management of a Local Anesthetic Overdose Reaction

Signs and Symptoms	Management
Minimal to Moderate Blood Levels (Mild Overdose Reaction)
Confusion Talkativeness Apprehension Excitedness Lightheadedness Dizziness Ringing in ears (tinnitus) Headache Slurred speech Generalized stutter Muscular twitching and tremor of face and extremities Blurred vision, unable to focus Numbness of perioral tissues Flushed or chilled feeling Drowsiness, disorientation Elevated blood pressure Elevated heart rate Elevated respiratory rate Loss of consciousness	Terminate procedure. Reassure client. Position client comfortably. Administer oxygen. Provide basic life support as indicated. Monitor vital signs. Summon medical assistance if needed. Allow client to recover, and discharge.
Moderate to High Blood Levels (Severe Overdose Reaction)
Tonic-clonic seizure, followed by: Central nervous system depression Depressed blood pressure, heart rate, and respiratory rate Unconsciousness	Terminate procedure. Position client supine, legs elevated. Summon medical assistance. Manage seizure: protect client from injury. Provide basic life support as indicated. Administer oxygen. Monitor vital signs. Administer an anticonvulsant (prolonged seizure). Transport client to hospital after stabilization.

Some data from Malamed SF: Medical emergencies in the dental office, ed 6, St Louis, 2007, Mosby.

Epinephrine Overdose

Although several vasoconstrictors are currently used in oral healthcare (Table 39-23), epinephrine is the most potent and most widely employed. Consequently, overdose reactions occur more often with epinephrine than with other vasopressor agents because the latter agents are weaker and are used less frequently.

TABLE 39-23 Clinical Manifestations and Management of a Client with an Epinephrine Overdose Reaction

Some data from Malamed SF: Medical emergencies in the dental office, ed 6, St Louis, 2007, Mosby.

Allergy

Allergic reactions are the result of an antigen-antibody response to a specific agent. Exposure to an initial dose of a medication causes an immunologic response. The drug acts as an antigen, prompting antibodies to be produced. As a result, administration of a subsequent dose causes the client to develop an allergic response to the drug, its chemical preservative, or a metabolite. Once clients manifest a specific drug allergy, they remain allergic to that drug indefinitely.

Clinical Manifestations and Management

The amount of time that elapses between exposure to an allergenic agent and manifestation of signs and symptoms is important. As a rule, the more rapid the onset of signs and symptoms after exposure, the more severe the ultimate reaction.² Conversely, the greater the time between exposure and onset of signs and symptoms, the less severe the reaction. This time factor helps the dental hygienist determine the appropriate management of the reaction.

The most common allergic reaction associated with local anesthetics is a dermatologic reaction. A skin reaction that appears alone or after a considerable lapse of time (60 minutes or more) is usually not life-threatening; however, if a skin reaction develops rapidly, it may be the first indication of an ensuing generalized reaction.

An allergic reaction may manifest solely in the respiratory tract or may accompany other systemic responses. In slowly evolving generalized allergic reactions, respiratory distress follows skin and gastrointestinal reactions but occurs before cardiovascular signs and symptoms.

Generalized anaphylaxis is the most life-threatening allergic reaction. Most reactions develop quickly, reaching maximum intensity within 5 to 30 minutes of exposure, although delayed responses have been reported.²

Table 39-24 describes the signs and symptoms and the management of clients with dermatologic and respiratory reactions and generalized anaphylaxis. The reaction types are further defined as delayed or immediate.

CLIENT EDUCATION TIPS

Explain the advantages of receiving a local anesthetic agent during dental hygiene procedures that may produce discomfort.

Explain measures taken to ensure comfortable local anesthetic delivery.

Explain normal, anticipated sensations associated with local anesthesia, including areas that will be anesthetized and the anticipated duration of the anesthesia.

Explain the importance of following postoperative instructions to minimize the possibility of self-inflicted soft-tissue injury.

LEGAL, ETHICAL, AND SAFETY ISSUES

It is the legal responsibility of the dental hygienist to practice within the scope authorized by state law concerning local anesthetic agent delivery.

It is imperative that the dental hygienist carefully evaluate the client's health history to determine suitability for local anesthetic procedures.

The client treatment record must accurately reflect any local anesthetic procedure completed, including complete drug name and amount agent delivered.

KEY CONCEPTS

Local anesthesia is the temporary loss of sensation in a circumscribed area brought about by the reduction of nerve membrane permeability to sodium ions. When sodium ions are blocked, the nerve cell cannot depolarize, stopping transmission of a stimulus to the brain.

Local anesthetic agents are classified chemically as either amides or esters, which differ in how they are metabolized: esters are metabolized in the blood by pseudocholinesterase, and amides are metabolized in the liver.

Local anesthetic agents produce vasodilation. For the maximum anesthetic effect, vasoconstrictors are often combined with local anesthetics to slow down absorption, reduce hemorrhage, and increase the length of time the anesthesia is effective.

Many local anesthetic drugs are available. The clinician must choose the best agent for the circumstances, considering each of the following: the health of the client, medications taken by the client, possible client allergies, the amount of time anesthesia is desired, the areas being anesthetized, the planned procedure and injections, the client's past response to anesthesia, and the possible need for hemostasis.

There is a maximum amount of local anesthetic agent and vasoconstrictor that can safely be administered to a client at one time. This amount varies with the client's weight, health status, and age, and the specific agent administered.

A thorough health history evaluation before local anesthetic delivery is crucial. Many medications influence a client's response to local anesthesia. There are also several systemic conditions that require modifications of local anesthetic delivery, such as pregnancy, hyperthyroidism, liver dysfunction, renal dysfunction, allergies to sulfa or bisulfite, atypical plasma cholinesterase, methemoglobinemia, and malignant hyperthermia.

Medications that are excreted renally may be retained in the body of the diabetic client with kidney disease, causing toxic effects. When local anesthetic agents are administered, minimal use of vasoconstrictors is required because epinephrine is capable of raising blood glucose.

The local anesthetic armamentarium includes a syringe, a needle, local anesthetic agent, topical anesthetic agent, cotton-tipped applicators, gauze, cotton forceps, and a mouth mirror.

Oral anesthetic procedures involve the maxillary and mandibular branches of cranial nerve V, the trigeminal nerve.

There are three categories of local anesthetic procedures: local infiltration, field block, and nerve block. These differ in the relationship between the area anesthetized and the area of delivery of the anesthetic agent, and in the scope of the area anesthetized; nerve blocks are delivered further from the treatment site and anesthetize a larger area when compared with local infiltrations, which are delivered directly at the apex of the target tooth and anesthetize only one to two teeth.

The attitude and demeanor of the clinician have a significant impact on the comfort of the client and the overall success of the local anesthetic injection.

Local anesthetic procedures for maxillary anesthesia include local infiltration, anterior superior alveolar field block, middle superior alveolar field block, infraorbital nerve block, posterior superior alveolar nerve block, greater palatine nerve block, and nasopalatine nerve block.

Local anesthetic procedures for mandibular anesthesia include inferior alveolar nerve block, lingual nerve block, buccal nerve block, mental nerve block, and incisive nerve block.

Local anesthetic delivery has the potential to cause both local and systemic complications. Potential local complications include needle breakage, pain during injection, burning during injection, hematoma, facial nerve paralysis, paresthesia, trismus, infection, edema, tissue sloughing, soft-tissue trauma, and postanesthetic intraoral lesions. Potential systemic complications include local anesthetic overdose, epinephrine overdose, and allergy. Most of these potential complications can be avoided with proper preanesthetic client assessment, careful selection of anesthetic agent, conscientious delivery techniques, and proper postoperative instructions.

CRITICAL THINKING EXERCISES

Scenario: Ms. S.

Client Profile: 45-year-old woman who lives alone.

Chief Complaint: “I want my periodontal maintenance scheduled at 4-month intervals. I have experienced discomfort during previous scaling throughout my upper jaw.”

Dental History: Past history of orthodontic treatment. Received four quadrants of scaling and root planing 3 years ago with a very good result. Third molars removed. Low caries rate. Clinically client exhibits extensive maxillary buccal recession.

Social History: Limited social drinking, nonsmoker, exercises regularly.

Health History: Noncontributory; weighs 123 lb.

Oral Health Behaviors: Client is compliant with homecare regimen and maintains appropriate recare schedule.

Assessment: Client requires local anesthetics to allow for comfortable periodontal maintenance.

Review the previous client profile and make the following determinations:

Client suitability for local anesthetic agent administration

Preferred local anesthetic agent

Preferred injection(s)

Maximum dose of local anesthetic agent