Conduction anesthesia - Network of dental clinics in St. Petersburg

Features and principle of action of conduction anesthesia

Conduction anesthesia is a local anesthesia and involves the introduction of a drug into the peripheral region of the nerve that ensures the functioning of this part of the body. Dentists in most cases use conduction anesthesia to treat teeth located in the lower jaw.

The technique is aimed at blocking impulses transmitted from nerves to the brain. As soon as the drug enters the nerve, sensitivity is reduced to a minimum level. The duration of action of the anesthetic depends on the substance used.

A number of features of conduction anesthesia can be distinguished:

The injection is carried out with drugs, the concentration of which reaches 2%. Compared to other methods of pain relief, the content of active substances is at a high level.
Loss of sensitivity does not occur at the site of drug administration, but in the nerve that is located in this area of the body.
Conduction anesthesia has a minimal number of complications and side effects.
The method allows you to control the duration of pain relief and the area of effect of the drug.

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To motivate children for timely dental treatment, it is necessary that all interventions in the dental chair are minimally painful. This can only be achieved with high-quality anesthesia. In pediatric dental practice, of all types of anesthesia, infiltration, mandibular, torus and palatal anesthesia are most often used. In the lower jaw, mandibular anesthesia is often used, in which the inferior alveolar and lingual nerves are switched off. The area of anesthesia is: the mucous membrane and periosteum of the alveolar process on the lingual side on half of the jaw; anterior 2/3 halves of the tongue; half of the lower lip; all teeth on the corresponding half of the lower jaw: mucous membrane and periosteum on the vestibular side of the alveolar process, except for the area near the molars, which requires additional infiltration anesthesia, since this area is innervated by the buccal nerve. Fig.1.

Knowledge about the features of mandibular anesthesia is significant when planning measures to provide emergency care in emergency conditions and in the treatment of surgical pathology in children, therefore, during its implementation, you should know the following landmarks or features: the location of the bone tongue and the mandibular foramen on the medial surface of the lower branch jaws. There are anatomical differences in the size and proportions of the bones of the maxillofacial region in children, which must be taken into account when administering anesthesia.

In a 3-5 year old child, the mandibular tongue is located approximately at the level of the occlusal surface of the teeth; with age, the position of the tongue changes upward and posteriorly relative to the occlusal plane, and already in a 15-16 year old teenager it is located approximately 1 cm above it (as in an adult) , therefore, when carrying out anesthesia, the needle is injected not 1 cm above the chewing surface of the lower molars, as in adults, but at the level of the chewing surface of these teeth and the lower the younger the child.

The branch of the lower jaw in children 3-5 years old is twice as narrow as in an adult; the volume of the pterygomaxillary space in children is less than in adults, therefore the mandibular, lingual and buccal nerves are located closer to each other. The angle of the lower jaw in an infant is 140º-145º, due to which the mandibular foramen itself is located lower, being in the same plane with the chewing surface of the lower molars. With age, the angle of the lower jaw decreases due to the eruption of permanent teeth, including wisdom teeth. In preschool children, the needle penetrates soft tissue by 10-15 mm (in adults by 15-25 mm). Therefore, children are given pain relief with a short needle. For anesthesia of the inferior alveolar nerve, 0.5-1 ml is enough for children. anesthetic (adults 1.5-1.8 ml). In preschool age, using mandibular anesthesia, it is often possible to turn off the sensitivity of all three nerves (inferior alveolar, lingual, buccal) that innervate the teeth of the lower jaw, which makes it possible to use additional anesthesia of the buccal nerve less often.

In accordance with the growth of the jaws, the change in the location of the mandibular foramen has the following patterns: Fig. 2. In children 3-5 years old it is located 1-2 mm below the chewing surface of the teeth of the lower jaw, and in children over 6-8 years old - at the level of the chewing surface of these teeth, in children 9-11 years old - 3-5 mm higher level of the chewing surface of these teeth, 12 years and older - as in adults - 1 cm above the level of the chewing surface of these teeth.

Based on the above, it follows that mandibular anesthesia at different ages is carried out taking into account the anatomical features of the structure of the jaws, ignorance of which can lead to poor quality anesthesia and, consequently, to more painful necessary manipulations. As a result, the young patient is left with a negative memory of the dental appointment and a reluctance to be observed and treated in the future, which leads to the more frequent occurrence of advanced diseases.

Indications for conduction anesthesia

Implantation.
Carrying out surgical intervention (removal of cysts, granulomas, ulcers and benign neoplasms).
Therapy of dental diseases.
Preparation before surgery.
Removal of teeth or roots.
Inflammation in the oral cavity.
Carrying out preventive procedures to prevent periodontal diseases and caries.
Inability to use general anesthesia.

Topical anesthesia in dentistry and drugs

Infiltration or application anesthesia in dentistry is carried out by soaking soft tissues with an anesthetic solution, as a result of which the nerve endings located in the treated area are blocked. With topical anesthesia, the anesthetic is applied without the use of a syringe. Using a cotton swab or your fingers, apply a small amount of the product, which subsequently penetrates approximately 3 mm inside and numbs the selected area. In dentistry, it is used to perform simple and quick operations associated with anesthesia of the oral mucosa, since it lasts, on average, from 10 to (in rare cases) 25 minutes. It is often preceded by subsequent injection anesthesia, especially if the patient is a child or is afraid of injections. There are also preparations for topical anesthesia in the form of aerosols. They are not widely used in dentistry due to difficulties in calculating dosage, as well as easy penetration into the respiratory tract and bloodstream, which increases the risk of complications.

Contraindications to conduction anesthesia

Poor blood clotting. This feature can lead to bleeding.
Allergy to used painkillers.
Disorders of the cardiovascular system (arrhythmia, ischemia, tachycardia, heart valve defects, etc.). These pathologies are not compatible with adrenaline, which can be used to constrict blood vessels.
The presence of inflammation or ulcers at the injection sites of the anesthetic drug.
Open wounds, infectious inflammations and contaminated wound surfaces on the patient’s extremities.
Childhood.
Mental disorders, unstable psycho-emotional background of the patient.
Patient refusal to use this type of anesthesia.

Contraindications

When choosing conduction anesthesia, both indications and contraindications are taken into account - since there are situations in which it seems necessary to use this particular method of pain relief, but it is not suitable for a particular patient. Contraindications are:

Allergic reactions to anesthetics (in some cases, the issue can be resolved by individually selecting an anesthetic solution that will not cause allergies in the patient).
Extensive and lengthy surgical interventions requiring other methods of pain relief.
Some serious cardiovascular diseases.
Decompensated diabetes mellitus.
Mental illness in the patient.
Pregnancy.
Injuries of the maxillofacial apparatus, which led to anatomical and topographic changes in this area.

Methods of administering conduction anesthesia

Methods of administering conduction anesthesia can be divided into 2 groups:

Extraoral. Used in the presence of inflammatory foci in the oral cavity. These include:

Submandibular. The pain medication blocks the inferior alveolar nerve.
Podzykulova. The drug is injected under the edge of the cheekbone arch.
Mandibular. The mandibular foramen loses sensitivity.

Once the anesthetic is injected into the treated area, the numbing effect occurs within 15 minutes. The duration of the anesthetic effect depends on the type of medication used.

Intraoral. These include:

Apodactylous. The alveolar nerve is blocked.
Torusal. The anesthetic is injected into the mandibular ridge. Molars and premolars lose sensitivity.
Tuberal. Anesthesia is injected into the area of the molars located on the upper jaw.
Infraorbital. It is used to block sensitivity in the anterior wall of the maxillary bone, mucous membrane and alveolar process.
Palatine. The palate and alveolar process are anesthetized.
Incisive. The anesthetic is injected between the upper canine and incisor. The hard palate, nasopalatine nerve and soft tissues surrounding the tooth become numb.

When administered intraorally, the effect occurs 10 minutes after injection.

Preparation for conduction anesthesia

Before performing the operation under general anesthesia, it is necessary to undergo a standard examination. During diagnosis, special attention should be paid to the patient’s neurological condition, his psyche and behavior.

Before the procedure, the specialist will explain in simple, accessible words about the sequence and method of administering anesthesia, as well as the sensations that may accompany the patient during pain relief. In addition, the doctor will definitely check the patient’s reaction to the anesthetic drug to make sure there is no allergic reaction.

The anesthesiologist must follow the rules when administering conduction anesthesia:

First of all, it is necessary to numb the skin using a gentle method.
The needle must be fixed in a strictly defined place in order for the anesthetic to reach the desired area.
Paresthesia must be present. It indicates that pain relief was carried out correctly and sensitivity has decreased.
Drugs should be administered in portions with aspiration samples to prevent them from entering the bloodstream.
During anesthesia, it is necessary to continuously monitor the patient's blood pressure and pulse.
The room in which the procedure is performed must be equipped with all the necessary instruments for pain relief, as well as means of resuscitation and treatment of possible complications.

Stages of administration of conduction anesthesia

A consultative appointment, during which a specialist determines the presence of chronic diseases and evaluates test results that may become contraindications to pain relief.
Detection of nerve endings that need to be anesthetized.
Disinfection of the skin puncture area with a special solution.
Injection of anesthetic into certain areas. At the same time, the rate of administration of the anesthetic is observed and the volume of the injected substance is controlled.
Monitoring the patient after pain relief.
Before the start of surgery, the patient is asked control questions to determine the level of sensitivity.

The duration of the analgesic effect depends on the drug used and its dosage. Modern painkillers retain their effect for up to 40-60 minutes.

Anesthesia of the inferior alveolar nerve

Review

Anesthesia is more difficult to achieve in the lower jaw than in the upper jaw due to the presence of denser cortical bone. It is necessary to create an anesthetic depot in the pterygomandibular space, in the area of the mandibular foramen, lateral to the sphenomandibular ligament. A certain depth of needle insertion and an exact angle are required to insert it into the pterygomandibular space.

If the technique is followed, 2 nerves lose sensitivity:

• Inferior alveolar nerve (and its branches - incisive and mental nerves)

• Lingual nerve

Scope of anesthesia:

• All teeth of the lower jaw (inferior alveolar nerve)

• Epithelium of the anterior 2/3 of the tongue (lingual nerve)

• Entire lingual gingival surface and mucous membrane (lingual nerve)

• The entire buccal gum surface and mucosa from the premolars to the midline (mental nerve)

• Skin of the lower lip (mental nerve)

Methodology

Stages:

• Direct the needle deep into the mucosa between the deepest part of the coronoid notch (which should correspond to the apex of the mandibular foramen) and lateral to the pterygomandibular suture

• Guide the needle away from the contralateral premolars, then align and advance along the occlusal plane of the mandible.

• The needle will reach the lower jaw after the needle has penetrated 20-25 mm (if you immediately feel an emphasis on the bone, then this is the temporal crest, and it is necessary

Drugs used

The success of conduction anesthesia depends not only on the technique used, but also on the drugs used. The following medications are used for this pain relief technique:

Solutions of the Articaine series. They have a long lifespan and high efficiency. These include:

Ultracaine.
Septanest.
Ubistezin.

Lidocaine. It is a highly effective anesthetic and at the same time contains a minimal amount of toxic substances.
Melivacaine. The duration of action of this drug is about 40 minutes. Melivacaine has no contraindications for use.
Novocaine. This is perhaps the most frequently used remedy. It is characterized by low toxicity and rapid hydrolysis in the body.

Technique of mandibular anesthesia

In pediatric dentistry, this type of anesthesia is performed intraorally. There are various methods, but this one has proven to be the best.

The dentist determines the point at the intersection of the two lines. The horizontal line is a line running along the chewing surface of the lower molars or 3-5 mm above. The vertical line follows the direction of the pterygomaxillary fold.
The injection is made at the intersection of these lines.
After the injection, the needle is gradually advanced, releasing the solution, along the bone by 1.1-1.2 cm. During this period, up to 1 ml of medication must be injected.
The correct position is this: the bevel of the needle is directed towards the bone, the syringe is deflected in the opposite direction.
After the injection, the soft tissue in the injection area is pressed against the bone for 1-2 minutes.

Advantages and disadvantages of conduction anesthesia

Advantages:

The drug can be administered outside the surgical site.
Anesthesia has a long-lasting effect. A specialist can monitor the duration of action of the medication.
To achieve the desired effect, small doses of painkillers are sufficient.
There is no deformation of soft tissues in the operated area.
When exposed to conduction anesthesia, salivary activity decreases.
The technique is safe, so it can be used from the age of 12, and also in some cases in pregnant and lactating women.
The cost of the procedure is affordable.

Flaws:

In order for anesthesia to pass without complications, the specialist must have certain skills and sufficient experience.
There is a high probability of the anesthetic entering a blood vessel.
Restricted use by age (only from 12 years old).
Risk of injury to nerves or blood vessels.

Anesthetic injection technique

Consultation with a dentist, during which a specialist identifies the presence of any chronic diseases that may be a contraindication to one or another anesthesia.
Identification of nerve endings whose sensitivity must be blocked.
Treating the injection area with a disinfectant.
Administration of the drug chosen by the specialist. In this case, the required dosage of the anesthetic and its rate of administration are calculated.
Monitoring the patient after drug administration.

Immediately before the start of treatment, the patient is asked questions to understand the threshold of sensitivity and the effect of anesthesia.

The duration of action depends on the chosen anesthetic and dosage.

The anesthesia procedure is performed according to the following rules:

the anesthetic temperature should be 36.6 degrees;
anesthesia is injected into the nerve itself or into the trunk;
in some cases, before administering the anesthetic, the injection site is treated with an anesthetic;
The procedure is performed exclusively with sterile materials.

The main advantages of conduction anesthesia:

the possibility of administering the drug outside the operated area;
long-term effect, the duration of which can be controlled by a doctor;
a minimum amount of administered drug is required;
soft tissues in the treatment area are not deformed;
salivation activity decreases;
safety of the technique;
affordable price.

Flaws

the injection technique requires certain skills from a specialist;
when administering the drug, it is possible to injure a nerve or vessel;
age restrictions (not applicable under 12 years of age).

Possible complications

In the practice of specialists at the World of Dentistry clinic, severe complications after conduction anesthesia occur in extremely rare cases. Negative effects include neuropathy and an inadequate response of the body to the administered drug. Complications that are normal and go away on their own include:

Muscle weakness.
Goosebumps effect.
Partial loss of sensitivity.

The above symptoms disappear without a trace a maximum of a month after the procedure. Damaged nerves are completely restored.