Neurological Complications of Local Anesthesia in Dentistry: A Review

Abstract

Local anesthesia is a technique that temporarily desensitizes a specific body area, typically for a surgical procedure, dental work, or pain management. It is described as a sensation loss in a specific area of the body due to depression of excitation in the nerve endings or due to the inhibition of the conduction process within the peripheral nerves. It allows for safer and more comfortable medical procedures, reducing the need for general anesthesia and facilitating faster recovery. Local anesthesia is generally safe, but like any medical intervention, it carries potential risks and side effects. The complications related to local anesthetics can be assessed in terms of neurological, vascular, local, systemic, and neurological. In this review article, we discussed the neurological complications of local anesthesia related to the ophthalmic nerve, maxillary nerve, mandibular nerve, branches of the trigeminal nerve, and facial nerve. These include diplopia, ptosis, paralysis of the eye, blindness, paresthesia, trismus, soft tissue lesions, edema, hematoma, facial blanching, infection, allergy, overdose, neuralgia, facial palsy, etc.

Keywords: diagnosis; local anesthesia; neurological complication; prevention; regional nerve blocks.

Figure 1. Innervation of the face. (A) Dermatomes of the head, neck, and face. (B) Distribution of the three branches of the trigeminal nerve.

Used with permission from [65].

Figure 2. Signs of acute unilateral Bell’s palsy.

Used with permission from [125].

Figure 3. (A) Structures innervated by the facial nerve. The red (parasympathetic), blue (motor), and orange (sensory) lines demonstrate the multifunctionality of the facial nerve. (B) Superficial branches of the extracranial portion of the facial nerve.

Used with permission from [125].

Figure 4. Transverse section through the retromandibular region to demonstrate the path of direction of the needle during an inferior dental (ID) nerve block. The potential direction that deposited local anesthetic solution may take to enter the substance of the parotid gland, and consequently, the facial nerve is marked with a dotted line.

Used with permission from [99].