Oral & Maxillofacial Regional Anesthesia
Oral surgical and dental procedures are often performed in an outpatient setting. Regional anesthesia is the most common method of anesthetizing the patient before office-based procedures. Several highly efficacious and practical techniques can be used to achieve anesthesia of the dentition and surrounding the hard and soft tissues of the maxilla and mandible. The type of procedure to be performed as well as the location of the procedure determine the technique of anesthesia to be used. Orofacial anesthetic techniques can be classified into three main categories: local infiltration, field block, and nerve block.
The local infiltration technique anesthetizes the terminal nerve endings of the dental plexus (Figure 36–1). This technique is indicated when an individual tooth or a specific isolated area requires anesthesia. The procedure is performed within the direct vicinity of the site of infiltration.
Anatomy of the trigeminal nerve. The sensory root of the trigeminal nerve gives rise to the ophthalmic division (V1), maxillary division (V2), and mandibular division (V3) from the trigeminal ganglion.
The field block anesthetizes the terminal nerve branches in the area of treatment. Treatment can then be performed in an area slightly distal to the site of injection. The deposition of local anesthetic at the apex of a tooth for the purposes of achieving pulpal and soft tissue anesthesia is often used by dental and maxillofacial practitioners. Although this is commonly termed “local infiltration,” since the terminal. Terminal nerve branches are anesthetized in this technique, such infiltration is more correctly termed as field block. In contrast, the nerve block anesthetizes the main branch of a specific nerve, allowing treatment to be performed in the region innervated by the nerve.1
This chapter reviews the essential anatomy of orofacial nerves and details the practical approaches to performing nerve blocks and infiltrational anesthesia for a variety of surgical procedures in this region.
ANATOMY OF THE TRIGEMINAL NERVE
Anesthesia of the teeth and the soft and hard tissues of the oral cavity can be achieved with block of the branches of the trigeminal nerve (fifth cranial nerve). In fact, regional, field, and local anesthesia of the maxilla and mandible is accomplished by the deposition of anesthetic solution near terminal nerve branches or a main nerve trunk of the trigeminal nerve.
The largest of all the cranial nerves, the trigeminal nerve gives rise to a small motor root, originating in the motor nucleus within the pons and medulla oblongata, and a larger sensory root, which finds its origin in the anterior aspect of the pons (see Figure 36–1). The nerve travels forward from the posterior cranial fossa to ...