Dental anesthesia

Dentists usually inject anesthetic to block sensory transmission by the alveolar nerves. The superior alveolar nerves are not usually anesthetized directly because they are difficult to approach with a needle. For this reason, the maxillary teeth are usually anesthetized locally by inserting the needle beneath the oral mucosa surrounding the teeth. The inferior alveolar nerve probably is anesthetized more often than any other nerve in the body. To anesthetize this nerve, the dentist inserts the needle somewhat posterior to the patient’s last molar.

Several nondental nerves are usually anesthetized during an inferior alveolar block. The mental nerve, which supplies cutaneous innervation to the anterior lip and chin, is a distal branch of the inferior alveolar nerve. When the inferior alveolar nerve is blocked, the mental nerve is blocked also, resulting in a numb lip and chin. Nerves lying near the point where the inferior alveolar nerve enters the mandible often are also anesthetized during inferior alveolar anesthesia. For example, the lingual nerve can be anesthetized to produce a numb tongue. The facial nerve lies some distance from the inferior alveolar nerve, but in rare cases anesthetic can diffuse far enough posteriorly to anesthetize that nerve. The result is a temporary facial palsy (paralysis or paresis), with the injected side of the face drooping because of flaccid muscles, which disappears when the anesthesia wears off. If the facial nerve is cut by an improperly inserted needle, permanent facial palsy may occur.

POST-TEXT ASSIGNMENTS

Exercise 6. Look through the text and make up 10 questions to the text:

Exercise 7. Complete the sentences remembering the text:

1. Dentists usually inject anesthetic to …

2. The superior alveolar nerves are not usually anesthetized directly because …

3. The maxillary teeth are usually anesthetized locally by …

4. When the inferior alveolar nerve is blocked, the mental nerve is blocked also, resulting in …

5. If the facial nerve is cut by an improperly inserted needle …

Exercise 8. Agree or contradict the following statements:

1. The inferior alveolar nerve probably is not anesthetized more often than any other nerve in the body.

2. The dentist inserts the needle somewhat posterior to the patient’s last molar.

3. Several nondental nerves are usually anesthetized during an anterior alveolar block.

4. The mental nerve, which supplies cutaneous innervation to the anterior lip and chin, is a distal branch of the inferior alveolar nerve.

5. Nerves lying near the point where the inferior alveolar nerve enters the mandible often are also anesthetized during anterior alveolar anesthesia.

Exercise 9. Give a brief survey of the text.

TEST

1. Dentists usually inject … to block sensory transmission.

a) laxative

b) anesthetic

c) tonic

d) sleeping pills

e) tranquilizer

2. The … alveolar nerves are not usually anesthetized directly because they are difficult to approach with a needle.

a) anterior

b) inferior

c) superior

d) posterior

e) middle

3. The maxillary teeth are usually anesthetized locally … inserting the needle beneath the oral mucosa surrounding the teeth.

a) by b) with c) on d) in e) under

4. The inferior alveolar nerve probably is anesthetized more often than any other … in the body.

a) tooth

b) nerve

c) muscle

d) gum

e) tongue

5. To anesthetize this nerve, the dentist inserts the needle somewhat posterior to the patient’s last …

a) canine

b) wisdom tooth

c) molar

d) incisor

e) premolar

6. Several nondental nerves … usually anesthetized during an inferior alveolar block.

a) am

b) is

c) are

d) do

e) have

7. When the inferior alveolar nerve is blocked, the mental nerve is blocked also, resulting … a numb lip and chin.

a) on b) in c) of d) above e) over

8. Nerves lying near the point where the inferior alveolar nerve enters the … often are also anesthetized during inferior alveolar anesthesia.

a) maxilla

b) upper jaw

c) mandible

d) lower jaw

e) jaw

9. The … nerve lies some distance from the inferior alveolar nerve.

a) spinal

b) cranial

c) facial

d) cavernous

e) lumbar

10. If the facial nerve is … by an improperly inserted needle, permanent facial palsy may occur.

a) filled

b) extracted

c) cut

d) put

e) cut out