Dental anesthesia
Encyclopedia
Forms of dental anesthesia (or dental anaesthesia) are similar to general medical anesthesia
except for the use of nitrous oxide
, relatively uncommon outside of the dental field in the United States.
(also called xylocaine or lignocaine), a modern replacement for novocaine and procaine
. Its half-life
in the body is about 1.5–2 hours. Other local anesthetics in current use include articaine, septocaine
, marcaine (a long-acting anesthetic), and mepivacaine
. A combination of these may be used depending on the situation. Also, most agents come in two forms: with and without epinephrine
.
The most common technique, effective for the lower teeth and jaw, is inferior alveolar nerve anesthesia
. An injection blocks sensation in the inferior alveolar nerve
, which runs from the hinge of the jaw down the back of the mandible, connecting to the lower teeth, lower lip, chin, and tongue. 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.
The superior alveolar nerves
are not usually anesthetized directly because they are difficult to approach with a needle
. For this reason, the upper are usually anesthetized locally by inserting the needle beneath the oral mucosa
surrounding the teeth.
is a syringe
used by dentist
s for the injection of an anesthetic. It consists of a breech-loading syringe fitted with a sealed cartridge containing anesthetic solution.
The ancillary tool (generally part of a dental engine
) used to supply either water or air to the oral cavity for the purpose of cleaning debris away from the area the dentist is working on, is also referred to as a dental syringe.
A 3-way syringe has separate internal channels supplying air, water or a mist of air and water, created by combining the pressurized air with the waterflow. The syringe tip can be separated from the main body and replaced when necessary.
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
except for the use of nitrous oxide
Nitrous oxide
Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
, relatively uncommon outside of the dental field in the United States.
Local anesthetics
The most commonly used local anesthetic is lidocaineLidocaine
Lidocaine , Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery.- History :Lidocaine, the first amino...
(also called xylocaine or lignocaine), a modern replacement for novocaine and procaine
Procaine
Procaine is a local anesthetic drug of the amino ester group. It is used primarily to reduce the pain of intramuscular injection of penicillin, and it was also used in dentistry. Owing to the ubiquity of the trade name Novocain, in some regions procaine is referred to generically as novocaine...
. Its half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
in the body is about 1.5–2 hours. Other local anesthetics in current use include articaine, septocaine
Septocaine
Articaine is a dental local anesthetic. It is the most widely used local anesthetic in a number of European countries and is available in many countries around the world.-History:...
, marcaine (a long-acting anesthetic), and mepivacaine
Mepivacaine
Mepivacaine is a local anesthetic of the amide type. Mepivacaine has a reasonably rapid onset and medium duration of action and is marketed under various trade names including Carbocaine and Polocaine.Mepivacaine became available in the United States in the 1960s.Mepivacaine is used in any...
. A combination of these may be used depending on the situation. Also, most agents come in two forms: with and without epinephrine
Epinephrine
Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
.
The most common technique, effective for the lower teeth and jaw, is inferior alveolar nerve anesthesia
Inferior alveolar nerve anaesthesia
Inferior alveolar nerve anaesthesia is a technique for dental anaesthesia, used to cause numbness to the areas of the face innervated by the inferior alveolar nerve; namely, the lower lip and the teeth and gingivae of the mandible...
. An injection blocks sensation in the inferior alveolar nerve
Inferior alveolar nerve
The inferior alveolar nerve is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve .-Path:...
, which runs from the hinge of the jaw down the back of the mandible, connecting to the lower teeth, lower lip, chin, and tongue. The inferior alveolar nerve
Inferior alveolar nerve
The inferior alveolar nerve is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve .-Path:...
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
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
. Several nondental nerves are usually anesthetized during an inferior alveolar block. The mental nerve
Mental nerve
Mental nerve is a general somatic afferent nerve which provides sensation to the anterior aspects of the chin and lower lip as well as the buccal gingivae of the mandibular anterior teeth and the premolars...
, which supplies cutaneous innervation
Cutaneous innervation
Cutaneous innervation refers to the area of the skin which is supplied by a specific cutaneous nerve.Dermatomes are similar; however, a dermatome only specifies the area served by a spinal nerve...
to the anterior lip
Lip
Lips are a visible body part at the mouth of humans and many animals. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech...
and chin
Chin
In the human anatomy, the chin is the lowermost part of the face.It is formed by the lower front of the mandible.People show a wide variety of chin structures. See Cleft 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
Lingual nerve
The lingual nerve is a branch of the mandibular nerve , itself a branch of the trigeminal nerve, which supplies sensory innervation to the tongue...
can be anesthetized to produce a numb tongue
Tongue
The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...
. The facial nerve
Facial nerve
The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...
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
Paralysis
Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
or paresis
Paresis
Paresis is a condition typified by partial loss of voluntary movement or by impaired movement. When used without qualifiers, it usually refers to the limbs, but it also can be used to describe the muscles of the eyes , the stomach , and also the vocal cords...
), with the injected side of the face drooping because of flaccid muscles, which disappears when the anesthesia
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
wears off. If the facial nerve is cut by an improperly inserted needle, permanent facial palsy may occur.
The superior alveolar nerves
Superior alveolar nerves
Superior alveolar nerves can refer to:* Anterior superior alveolar nerve* Posterior superior alveolar nerve* Middle superior alveolar nerve...
are not usually anesthetized directly because they are difficult to approach with a needle
Hypodermic needle
A hypodermic needle is a hollow needle commonly used with a syringe to inject substances into the body or extract fluids from it...
. For this reason, the upper are usually anesthetized locally by inserting the needle beneath the oral mucosa
Oral mucosa
The oral mucosa is the mucous membrane epithelium of the mouth. It can be divided into three categories.*Masticatory mucosa, para-keratinized stratified squamous epithelium, found on the dorsum of the tongue, hard palate and attached gingiva....
surrounding the teeth.
Other anesthetics
- Nitrous oxideNitrous oxideNitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
(N2O), also known as "laughing gas", easily crosses the alveoli of the lung and is dissolved into the passing blood, where it travels to the brain, leaving a dissociated and euphoric feeling for most patients. N2O is typically used in conjunction with ProcaineProcaineProcaine is a local anesthetic drug of the amino ester group. It is used primarily to reduce the pain of intramuscular injection of penicillin, and it was also used in dentistry. Owing to the ubiquity of the trade name Novocain, in some regions procaine is referred to generically as novocaine...
. Nitrous oxide is used in combination with oxygen. Often (especially with children) a sweet-smelling fruity scent similar to an auto scent is used with the gas to inspire deep inhalation. Nitrous oxide nose respirators are available to dentists pre-scented with a fruity smell and used by some dentists especially on children. - EugenolEugenolEugenol is a phenylpropene, an allyl chain-substituted guaiacol. Eugenol is a member of the phenylpropanoids class of chemical compounds. It is a clear to pale yellow oily liquid extracted from certain essential oils especially from clove oil, nutmeg, cinnamon, basil and bay leaf. It is slightly...
— made from clove oil, this is a topical anesthetic also used in the common dental material ZOE (zinc oxide eugenolZinc Oxide EugenolZinc oxide eugenol is a material created by the combination of zinc oxide and eugenol contained in oil of cloves. An acid-base reaction takes place with the formation of zinc eugenolate chelate. The reaction is catalysed by water and is accelerated by the presence metal salts. ZOE can be used as...
). - Topical anestheticTopical anestheticA topical anesthetic is a local anesthetic that is used to numb the surface of a body part. They can be used to numb any area of the skin as well as the front of the eyeball, the inside of the nose, ear or throat, the anus and the genital area. Topical anesthetics are available in creams,...
s — benzocaineBenzocaineBenzocaine is a local anesthetic commonly used as a topical pain reliever, or in cough drops. It is the active ingredient in many over-the-counter anesthetic ointments...
, eugenolEugenolEugenol is a phenylpropene, an allyl chain-substituted guaiacol. Eugenol is a member of the phenylpropanoids class of chemical compounds. It is a clear to pale yellow oily liquid extracted from certain essential oils especially from clove oil, nutmeg, cinnamon, basil and bay leaf. It is slightly...
, and forms of xylocaine are used topically to numb various areas before injections or other minor procedures - General anesthesia — drugs such as midazolamMidazolamMidazolam is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potent anxiolytic,...
, ketamineKetamineKetamine is a drug used in human and veterinary medicine. Its hydrochloride salt is sold as Ketanest, Ketaset, and Ketalar. Pharmacologically, ketamine is classified as an NMDA receptor antagonist...
, propofolPropofolPropofol is a short-acting, intravenously administered hypnotic agent. Its uses include the induction and maintenance of general anesthesia, sedation for mechanically ventilated adults, and procedural sedation. Propofol is also commonly used in veterinary medicine...
and fentanyl are used to put the patient in a twilight sleepTwilight sleepTwilight sleep is an amnesic condition characterized by insensibility to pain without loss of consciousness, induced by an injection of morphine and scopolamine, especially to relieve the pain of childbirth...
or render them completely unconscious and unaware of pain. - Nebotamine a drug with similar effects to ketamineKetamineKetamine is a drug used in human and veterinary medicine. Its hydrochloride salt is sold as Ketanest, Ketaset, and Ketalar. Pharmacologically, ketamine is classified as an NMDA receptor antagonist...
is injected into the anterior lingual glands blocking action potentials from sending signals to the myelinated nerve. The potency of a the anesthetic is directly related to its lipid solubility, since 90% of the nerve cell membrane is composed of lipid. - MidazolamMidazolamMidazolam is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potent anxiolytic,...
(Versed), a drug that represses memories of the procedure, is usually given two hours prior to the procedure in combination with Tylenol in general anesthesiaGeneral anaesthesiaGeneral anaesthesia is a state of unconsciousness and loss of protective reflexes resulting from the administration of one or more general anaesthetic agents...
so the patient will go home with no memories of being in surgery. - SevofluraneSevofluraneSevoflurane , also called fluoromethyl hexafluoroisopropyl ether, is a sweet-smelling, nonflammable, highly fluorinated methyl isopropyl ether used for induction and maintenance of general anesthesia. Together with desflurane, it is replacing isoflurane and halothane in modern anesthesiology...
gas in combination with nitrous oxideNitrous oxideNitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
and oxygenOxygenOxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
is often used during general anesthesia followed by the use of isofluraneIsofluraneIsoflurane is a halogenated ether used for inhalational anesthesia. Together with enflurane and halothane, it replaced the flammable ethers used in the pioneer days of surgery. Its name comes from being a structural isomer of enflurane, hence they have the same empirical formula...
gas to maintain anesthesia during the procedure. In children sweet fruity scents are often used with the gases to inspire deep inhalation. Scents come in cherry, apple, bubblegumBubblegumBubblegum is a type of elastic chewing gum, designed to be blown out of the mouth as a bubble.-History:In 1928, Walter Diemer, an accountant for the Fleer Chewing Gum Company in Philadelphia, was experimenting with new gum recipes. One recipe was found to be less sticky than regular chewing gum,...
, watermelon, etc... - PropofolPropofolPropofol is a short-acting, intravenously administered hypnotic agent. Its uses include the induction and maintenance of general anesthesia, sedation for mechanically ventilated adults, and procedural sedation. Propofol is also commonly used in veterinary medicine...
a drug with similar effects to Sodium Pentathol is often used through intravenous infusion through an IV during general anesthesia after gasses are initiated. - MorphineMorphineMorphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...
is often used to control pain during the dental surgery under general anesthesia. The morphineMorphineMorphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...
is usually administered through IV. - KetorolacKetorolacKetorolac or ketorolac tromethamine is a non-steroidal anti-inflammatory drug in the family of heterocyclic acetic acid derivative, often used as an analgesic...
is often administered through IV to suppress both pain and inflammation while under general anesthesia.
Other drugs often used during general anesthesia
- Decadron a steroid is often administered through IV to suppress inflammation and swelling resulting during the surgery while under general anesthesia.
- OndansetronOndansetronOndansetron is a serotonin 5-HT3 receptor antagonist used mainly as an antiemetic , often following chemotherapy. Its effects are thought to be on both peripheral and central nerves...
brand named Zofran is often administered to prevent nausea during the surgery which may result from the blood draining into the stomach while under general anesthesia, or it is given to the patient after the procedure for postoperative nausea which may result from the anesthesia itself which was administered.
Blocks
- Electrical nerve blocksNerve blockRegional nerve blockade, or more commonly nerve block, is a general term used to refer to the injection of local anesthetic onto or near nerves for temporary control of pain. It can also be used as a diagnostic tool to identify specific nerves as pain generators...
— a technology that involves using electrical current to block the reception or generation of pain signals. - Branch block — a common form of local dental anesthesia, blocks the reception of pain for one quadrant of the mouth at a time. Typically given in the buccal surface (cheek). (IAB, MNB are types of this block)
- Dental block — given below the tooth in question. Used usually for minor procedures such as fillings.
- Palatal block— given into the hard palate, useful in numbing the upper teeth.
- Intraosseous — an injection of local anesthetic given directly into the osseous (bone) structure of the tooth.
- Intrapulpal — an injection of local anesthetic given directly into the pulp of the tooth to completely desensitize the tooth.
- AcupunctureAcupunctureAcupuncture is a type of alternative medicine that treats patients by insertion and manipulation of solid, generally thin needles in the body....
or accupressure — An alternative to chemical or electrical blocks, but is rarely used.
Dental syringe
A dental syringeDental syringe
A dental syringe is a syringe used by dentists for the injection of an anesthetic. It consists of a breech-loading syringe fitted with a sealed cartridge containing anesthetic solution....
is a syringe
Syringe
A syringe is a simple pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube , allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube...
used by dentist
Dentist
A dentist, also known as a 'dental surgeon', is a doctor that specializes in the diagnosis, prevention, and treatment of diseases and conditions of the oral cavity. The dentist's supporting team aides in providing oral health services...
s for the injection of an anesthetic. It consists of a breech-loading syringe fitted with a sealed cartridge containing anesthetic solution.
The ancillary tool (generally part of a dental engine
Dental engine
A dental engine is a large chair-side appliance found in a dentist's office. At minimum, a dental engine serves as a source of mechanical or pneumatic power for one or more handpieces; typically, it will also include a small faucet and a spit-sink, which the patient can use for rinsing, as well as...
) used to supply either water or air to the oral cavity for the purpose of cleaning debris away from the area the dentist is working on, is also referred to as a dental syringe.
A 3-way syringe has separate internal channels supplying air, water or a mist of air and water, created by combining the pressurized air with the waterflow. The syringe tip can be separated from the main body and replaced when necessary.
General anesthesia
Dentists who have completed a training program in anesthesiology may also administer general IV and inhalation anesthetic agents.See also
- Dental surgeryDental surgeryDental surgery is any of a number of medical procedures that involve artificially modifying dentition, in other words surgery of the teeth and jaw bones.-Types:Some of the more common are:...
- Dental AnesthesiologyDental anesthesiologyDental anesthesiology is the specialty of dentistry that deals with the management of pain through the use of advanced local and general anesthesia techniques.-Australia and New Zealand:...
- National Dental Board of Anesthesiology
- American Dental Society of Anesthesiology
- American Dental Board of AnesthesiologyAmerican Dental Board of AnesthesiologyThe American Dental Board of Anesthesiology examines and certifies dentists who complete an accredited program of anesthesiology training in the United States or Canada. Dentists may apply for Board Certification through the ADBA which requires ongoing and continual post-graduate education for...
External links
- United States National Medical Library Intraligamentary application