A nerve block is a medical procedure where an analgesic, also known as a pain medication, is injected around a nerve or group of nerves (Wiederhold et al., 2023). This temporarily prevents the nerve’s ability to send signals to the brain, including pain signals. In some cases, an anti-inflammatory is added to the injection if there is any concern of an inflammation-related nerve injury.

Facial nerve blocks are used to help manage pain in and around the face. It is most often used during surgery but can be used to manage chronic pain that does not respond to other, more conventional treatments. A nerve block can be complete, meaning that it will block the whole nerve, or partial, meaning that it will only affect a specific region of the nerve. The treating medical team will decide which is more appropriate on a case-by-case basis.

A maxillary nerve block injection (MNBI) is an injection that inserts analgesics around the maxillary nerve. First used in dentistry, it remains its most common use as a means of analgesia during dental procedures. It may also be used to help with chronic nerve pain or as part of a facial surgery pain management plan. A MNBI is rarely used due to the difficulty of pinpointing and reaching the maxillary nerve.

It is rare for the nerve block to include all of the maxillary nerve due to its central location and wide innervation area. MNBIs are usually done to block off a specific area and are called partial MNBIs.

The analgesic used in an MNBI may vary based on the length of the block, the location, and an individual’s medical analgesic history.

An MNBI is an injection that places an analgesic around a specific maxillary nerve region to block sensations past that area. The type of analgesic will depend on an individual’s medical history, with lidocaine being one of the most commonly used local analgesics (Wheeler, 2018). Local analgesics function by blocking the nerve’s ability to send and receive signals (Milani & Davis, 2023).

By blocking the calcium channels that initiate a neurochemical signal, it prevents the signal from happening (Cohen et al., 2023). It also increases the requirement for a signal to be sent through the nerve in the first place. Both of these effects mean that the threshold for a signal to be sent through the numbed nerve(s) is significantly increased, reducing the number of pain signals that arrive at the brain.

The MNBI can be done in a multitude of facial areas and depends heavily on the underlying reason for an MNBI. The size of the area affected by the MNBI can be very small, a single tooth, or encompass the full maxillary nerve region. In general, the medical team will keep the MNBI to the smallest possible area to achieve pain relief.

The reasons for getting an MNBI are numerous and include:

⦁ Dental cavity repairs
⦁ Dental surgery
⦁ Facial surgery in the maxillary nerve region
⦁ Trigeminal neuralgia involving the maxillary nerve (De Barreto Aranha et al., 2023)
⦁ Post-surgery pain treatment plan
⦁ Burning Mouth Syndrome
⦁ Chronic maxillary facial pain

This is not a complete list of disorders treated by MNBI.

An MNBI is not suitable for everyone (Royal Victoria Regional Health Centre, 2020, pp. 20-21). Your medical team may choose not to go with an MNBI if:

⦁ You have an infection at the chosen infection site.
⦁ You had an allergic or adverse reaction to a previous MNBI or analgesic injection.
⦁ You are on anticoagulants or have hemophilia.
⦁ You have chronic liver or renal issues.
⦁ You have a concussion or head trauma.

As an injection, an MNBI may cause:

⦁ Pain/bruising/tenderness/soreness at the injection site
⦁ Bleeding at the injection site
⦁ Minor infection at the injection site

As an analgesic, an MNBI may cause:

⦁ Excessive numbness
⦁ An allergic reaction to the analgesic
⦁ Nausea/Vomiting

In rare cases (> 0.1%), an MNBI may cause:

⦁ Temporary systemic toxicity due to a high analgesic dose
⦁ Excessive bleeding
⦁ Stroke
⦁ Heart attack
⦁ Seizures
⦁ Difficulty breathing/talking
⦁ Serious nerve damage
⦁ Severe allergic reaction

The use of an ultrasound while performing the injection can help reduce the risk of injury or bleeding.

When receiving MNBI, your medical team will choose the best analgesic and location for your treatment. Each analgesic will take a different amount of time to take effect and have different durations. Furthermore, the specific location of the MBI will determine what parts of the face are numbed.

In the case of MNBI for chronic maxillary pain, the expected time to start seeing results is quick but dependent on the analgesic used. Most start having an effect within half an hour. The duration of the block is similarly impacted by the analgesic used. There is a lack of research concerning the efficacy of MNBI as a part of chronic facial pain management. The few case studies published show that it can provide significant pain relief for up to six weeks, though no follow-ups were done afterward.

The Wilderman Medical Clinic offers maxillary nerve blocks using anatomical landmarks or ultrasound as part of the interventional pain clinic.

Cohen, B., Ruth, L. J., & Preuss, C. V. (2023, April 29). Opioid analgesics. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK459161/

Corniani, G., & Saal, H. P. (2020). Tactile innervation densities across the whole body. Journal of Neurophysiology, 124(4), 1229–1240. https://doi.org/10.1152/jn.00313.2020

De Barreto Aranha, R. L., Resende, R. G., & De Souza, F. A. (2023). Peripheral nerve blocks for acute trigeminal neuralgia involving maxillary and mandibular branches: a case report. Journal of Dental Anesthesia and Pain Medicine, 23(6), 357. https://doi.org/10.17245/jdapm.2023.23.6.357

Milani, D. a. Q., & Davis, D. D. (2023, July 3). Pain management medications. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK560692/

Royal Victoria Regional Health Centre. (2020). Acute Pain Service Reference Manual: Single Injection Nerve Blocks and Continuous Peripheral Nerve Blocks. In Royal Victoria Regional Health Centre. https://www.ppno.ca/wp-content/uploads/2022/02/APS-Single-Injection-Nerve-Blocks-and-Continuous-Peripheral-Nerve-Blocks-Learning-Manual.pdf

Shafique, S., & Das, J. M. (2023, June 5). Anatomy, head and neck, maxillary nerve. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK542277/

Wheeler, A. H., MD. (2018, June 19). Therapeutic injections for pain management: Types of therapeutic injections, guidelines for therapeutic application, technical application. https://emedicine.medscape.com/article/1143675-overview