Intraligamentary anesthesia

Tuberous anesthesia

This type of anesthesia aims to anesthetize the upper molars (first, second, and third), as well as the periosteum and mucous membrane of the alveolar process from the buccal side. The posterior-lateral wall of the maxillary sinus also falls within the anesthesia zone.

The anterior border of anesthesia is variable and can extend up to the middle of the first premolar. This expansion of the zone occurs for several reasons:

• Presence of pronounced anastomoses with the middle superior alveolar branch.
• Atypical origin of the middle superior alveolar branch (together with the posterior branches).
• Complete absence of the middle branch (in this case, the premolars receive innervation from the posterior branches).
• Administration of an excessive volume of anesthetic that flows through the inferior orbital fissure.

Execution techniques (extraoral)

1. Egorov method: The injection point is on the skin at the anteroinferior angle of the zygomatic bone. The needle is inserted to a distance equal to the distance to the inferolateral angle of the orbit. The direction is upward and inward (45° to the sagittal plane, 90° to the Frankfort horizontal). 2–5 ml of the drug is injected. The needle passes through the buccal fat pad, bypassing the muscles of mastication and the pterygoid plexus.
2. Weisblatt method: Based on palpation and fixation of the zygomaticoalveolar crest with the fingers. The injection is made below the lower border of the zygomatic bone, advancing the needle toward the posterior surface of the crest, and then upward, inward, and backward to a depth of 2.0–2.5 cm.

Risks: Hemorrhage is possible in case of vascular injury. To prevent intravascular administration (especially of drugs containing adrenaline), an aspiration test is mandatory.

Infraorbital anesthesia

The goal of the technique is to block the peripheral branches of the infraorbital nerve (the so-called "minor goose's foot"), as well as the anterior and middle superior alveolar branches. The anesthetic is injected directly into the infraorbital canal or deposited at its exit.

Landmarks of the infraorbital foramen:

• Palpatory: groove (junction of the zygomatic process of the maxilla with the zygomatic bone), from which 0.5–0.75 cm is measured downward.
• By teeth: projection of a vertical line passing through the middle of the second premolar.
• By pupil: projection strictly downward from the pupil while looking straight ahead.

Technique (extraoral approach): The injection is made 1 cm downward and medial to the foramen projection. The needle is directed posteriorly, laterally, and superiorly (strictly against the axis of the canal). 0.5–1.0 ml of solution is released near the foramen, then the entrance to the canal is carefully located ("yielding sensation"), and the needle is inserted 7–10 mm deeper, injecting another 0.5–1.0 ml. The effect occurs in 3–5 minutes.

Intraoral approach is rarely used due to its complex technique and high risk of missing the canal. The needle is inserted 0.5 cm anterior to the transitional fold between the central and lateral incisors.

Anesthesia zone: Incisors, canines, premolars, alveolar process (vestibularly), walls of the maxillary sinus, and soft tissues (skin of the eyelid, nasal ala, upper lip). If anastomoses are present, additional administration of the anesthetic along the transitional fold is required.

Palatine anesthesia

Used to block the greater palatine nerve in the area of the greater palatine foramen. Standardly, it is projected at the level of the middle of the crown of the third molar (or posterior to the second molar if the third is absent).

Technique: The injection is made 1 cm anterior and medial to the foramen projection. The needle is advanced upward, backward, and outward until it contacts the bone, injecting 0.5 ml of solution.

Complications: Necrosis of the hard palate mucosa is extremely dangerous. It occurs when the solution is injected too rapidly under pressure, which compresses or ruptures sclerotic vessels (especially in the elderly). A feeling of nausea and gag reflex are also possible when blocking the soft palate nerves (if the drug is delivered too far posteriorly).

Incisive anesthesia

Aiming to block the nasopalatine nerve (n. nasopalatinus). The incisive foramen is located posterior to the incisive papilla (7–8 mm posterior to the gingival margin between the central incisors).

During the intraoral method, the patient's head is tilted back as far as possible. Preliminary topical anesthesia of the papilla is mandatory. The injection is performed slightly anterior to the foramen orifice (to compensate for the angle and enter parallel to the canal).

Two approaches are used:

1. Diffusion method: the needle is brought to the bone and 0.3–0.5 ml of solution is released, which independently penetrates into the canal.
2. Intracanal administration: the needle is advanced into the canal by 0.5–0.75 cm for a deeper block of anastomoses to the anterior dental plexus.

Class and exam questions

What else to study on this topic

• Characteristics of maxillary sinus innervation
• Anastomoses of the maxillary dental plexuses
• Technique of hydraulic vessel displacement
• Mechanism of diplopia development during infraorbital anesthesia
• Prevention of infraorbital neuritis

Other topics in "Chapter 12. Dental Anesthesia"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.