Trigeminal neuralgia in dentistry

Trigeminal neuralgia is an orofacial pain condition that we dentists are the first to discover, because we often will complete a root canal or tooth extraction without pain relief.

This is the second in a series of posts about orofacial pain with difficult to diagnosis or unusual origin.

1. Cracked tooth syndrome
2. Trigeminal neuralgia (TN)    JADA
3. Atypical odontalgia 
4. Neuralgia-inducing cavitational osteonecrosis or NICO
5. Referred pain
6. Myofascial pain 
7. Burning Mouth Syndrome
8. Oral dysesthesia

Trigeminal neuralgia etiology and symptoms

As the name implies this is a pain that originates from some sort of issue with a nerve.  Compression or pressure, infection, or idiopathic may be the culprit in initially causing this pain to occur but for whatever reason the pain continues.  Sometimes there exists a trigger point where the patient can touch and activate the pain, sometimes none exist.  This pain can be very intense and will not respond to low levels of narcotics.  The pain occurs in bouts of electric like pain.  Like all neurologic pain, trigeminal neuralgia will be described as burning, tingling, stinging, electrical, piercing, cutting, or drilling. The Q-tip test can be helpful in determining central or trigeminal pain.

Many times this patient ends up with several root canals and or teeth pulled because they are unable to accurately describe the pain they are feeling and are desperate to relieve it.  Hits most commonly in the fifth decade of life.  Favors women slightly and those with MS are more likely to get.

Trigeminal neuralgia treatment

There are several treatment options for this condition from surgery to drugs depending on the cause.  This will likely be decided by a neurologist after viewing an MRI or MRA., can see what trying to rule out on MRI here.  Once a potential diagnosis of trigeminal neuralgia is made there is very little the dentist can do for the patient other than refer to neurologist or orofacial pain sub-specialist (Charles Greene or Joel Epstein).  Common medications in use alone or in different combinations include carbamazepine, baclofen, phenytoin and gabapentin.
I ran across this interesting more “holistic” approach of taking lemon fish oil 5 ml/day and palmitoyl ascorbate (PA) 1 g/twice daily; however, this sounds like “snake oil” to me.

Dr. Manish Kapadia has successfully treated some of our patients.

Trigeminal neuralgia classification

Trigeminal neuralgia classifications include typical, atypical, classical, idiopathic, secondary, or symptomatic.

Glossopharyngeal neuralgia

Glossopharyngeal neuralgia, which we do not have a post about, is basically the same as TN but occurs in the throat.  It is rare with an annual incidence rate somewhere around 7 per 1 million. However, lack of knowledge of it’s existence certainly results in lower diagnosis levels. Thought to be secondary to trauma in many cases.

Symptoms are pain when chewing (rarely), coughing, swallowing, yawning, talking, and laughing.  Pain is continuous, unilateral, burning or squeezing that exacerbates with stress. Furthermore there exists 2 sub-types of glossopharyngeal neuralgia, they are tympanic (ear) and oropharyngeal.  Very hard for patient to locate pain because deep in the mouth, pharynx, or ear.  Swallowing topical spray can be diagnostic. If it relieves the pain then the source may be glossopharyngeal neuralgia. Pain can be intense enough to cause patient to pass out and have tonic-clonic limb jerking. Article on AO TN and GPN Gen Dent Sept 2010

There are two forms, classic and secondary. Classic cases of glossopharyngeal neuralgia are from neurovascular compression. The secondary are from tumors, trauma, MS, carcinomas. Sude JADA 2019

Treatment includes TCAs, SSNRI, and anticonvulsants like pregabalin. TCAs then gabapentin is often the medications to try. Kohli JADA 2021

Post-traumatic Trigeminal Neuropathic Pain also known as Painful post-traumatic trigeminal neuropathy PPTN

Pain that typically starts after a dental procedure. Non-odontogenic that does not go away but a dentist can reduce or stop with local anesthetics. Usually the patient describes the pain as sharp, shooting and/or burning. We believe this occurs more than people know after root canals in particular. Treatment is best done by an orofacial pain expert but consists of s stent and 50/50 mix of 0.025% capsaicin in Orabase. It differs from persistent idiopathic facial pain (PIFP) due to PPTN having symptoms of allodynia and hyperalgesia vs dull pain and poor localization of the pain from PIFP.