Dentistry and TMD

The American Academy of Orofacial Pain E-Newsletter
Spring 2005

As I entered the treatment room, the assistant informed me that the patient’s pain was in the upper right quadrant. I directed the patient to point to the area of pain and she pointed to a tooth with a mesio-occlusal restoration. As I reviewed patient’s health form, I noticed a few items checked, with the rest left blank, providing little insight to the cause.

I asked a question about the problem and the patient responded with a ten-minute review of the pain’s impact on her life, using up the time that was set aside for this emergency visit. When I interjected for more specific details, she provided a small clue, and then was off on another tangent about how angry she was with her previous dentist for placing this painful filling. I requested an x-ray and went to the next room for crown preparation.

Upon my return, the x-ray revealed no apical or pulpal involvement. Being unsure of the pain's etiology, in the area of her dental pain, I probed the periodontal pockets, asked her to bite on a Tooth Slooth, evaluated teeth for mobility, checked her occlusal contacts, and percussed each tooth. All of these tests were within normal limits.

In addition to having no definitive symptoms, the patient could not stay focused on my questions and kept rehashing her anger and the pain’s impact on her life. According to her, the previous dentist just replaced a silver filling that had recurrent decay around it, and now her teeth hurt, she can’t chew, and her life is all messed up.

The staff was trying to get me to return to the next room where the patient was waiting to continue my crown preparation procedure, but I felt bad about this patient's pain, her anger with her previous dentist, and my confusion about the etiology of her pain. Running late for the other patient, the staff upset, and my gut going into knots, I prescribed her an antibiotic and ibuprofen (in case it was pulpal hyperemia). The patient returned three days later informing me that the medications did not provide any symptom relief. I repeated the previous tests and the findings were again within normal limits. Her signs and symptoms did not fit my dental school diagnostic tree for a pulpal disorder, periodontal disorder, or cracked tooth, so I referred her to an endodontist for pulpal evaluation. The endodontist concluded the tooth was not the source of her pain.

The patient was once again back in my dental chair, in pain, and with a major chip on her shoulder. Still unsure of the pain's etiology, I referred her to an oral surgeon, who immediately referred her to an orofacial pain specialist.

I felt lucky that the patient was referred to an orofacial pain specialist, before she got more angry or convinced another dentist to provide irreversible procedures may have made her situation worse. Why do I say lucky? The surgeon informed me that the patient also had previous problems with her jaw, ears, neck, and headaches, which she did not tell me about during her emergency visits. She also had not told her previous dentist who replaced the filling about her these pains.

Case Report 1: A $5 million lawsuit in Durham, NC, was the result of wisdom teeth extraction being blamed for the patient's TMD. The patient similarly did not report prior jaw problems. The general dentist did not record the early TMD symptoms, which would have kept the him from being blamed for causing the TMJ pain.

There are many reasons an orofacial pain patient can be difficult for the general dentist to diagnose and manage. In this series of articles, I will discuss these difficulties and cover the following topics: 1) chronic pain is different, 2) need for additional information, 3) barriers to chronic pain care, 4) psychological instability, 5) anatomical instability, 6) toothache confusion, 7) occlusal confusion, 8) TMD/MPD confusion, 9) detecting orofacial pain, 10) legal entanglement cow, and 11) medical care.

Chronic Pain Is Different than Acute Pain

The American Academy of Orofacial Pain E-Newsletter
Fall 2005

Dentists diagnose most dental disorders by viewing the oral structure or a radiograph of it. The pain typically comes from one source (tooth), the treatment involves one modality (root canal, extraction, etc.), and the perceived pain is eliminated. In chronic pain, the perceived pain is more complex and if we remove the pain's source, the perceived pain may not stop.

A common misconception is that the nervous system is like the doorbell in your home. A

fixed system composed of a button (pain receptor), wire (peripheral nervous system), and bell (central nervous system). On the contrary, the nervous system is capable of major chemical, biological, and anatomical

shifts that can occur in both the peripheral as well as the central nervous systems.

It does not take long for the pain reporting system to begin to adapt; acute pain can start to transform into chronic pain in less time than we once thought and may start within a month. The rate and degree of change depend on the pain's severity, frequency, and duration; the individual's health; psychosocial makeup; and other factors. This transformation is similar to repeated stimulation of skin receptors from sun overexposure, causing a sunburn to hurt from nonpainful stimuli, e.g., taking a shower.

Repeated stimulation of the pain system causes:

1. The pain reporting fibers (C-fibers) to connect to the touch and pressure fibers (A-beta fibers) in the dorsal horn of the spinal cord, causing light touch be painful.

2. The production of alpha adrenergic receptors that is sensitive to adrenalin (stress chemical) in the dorsal horn. Now, instead of only having pain from walking on the arthritic foot, an individual may have foot pain from just being stressed.

3. Excessive production of an A-beta fiber neurochemical transmitter called glutamate, which activates a chemical process producing protein kinases. These kinases remove a magnesium plug in the C-fiber receptor (NMDA receptor), causing it to become more responsive to stimuli. This produces a phenomenon called “wind up,” in which silent pain fibers are opened to conduct pain signals.

4. C-fibers to produce copious amounts of a chemical neurotransmitter called substance-P, which diffuses to other areas of the spinal cord to activate second level neurons, causing silent nerve fibers to more readily activate pain impulses.

The continuous or recurrent pain sensitizes the system; the longer the pains exist, the more changes occur, and the more refractory the pain becomes. Therefore, time is of the essence when dealing with pain. A series of occlusal adjustments or dental treatments to a tooth should only be attempted for a short period of time, and only if it causes a reduction in the pain.

Case Report 1: A patient from Wilmington got hit in the face with a door and fractured a tooth. The patient reported jaw pain in the area of the tooth and the tooth was suspected as the source of pain. The tooth was crowned, then endodontically treated, then extracted, and then the space bridged, all without a decrease in her pain. When I anesthetized the area, there was not change in the pain. I asked her if she told her previous dentists this fact and she said "no." Her pain was found to be referred from the masseter and a cervical muscle.

Unfortunately in today’s legal world, a practitioner cannot just refer a patient and forget about him or her. The law does not limit our responsibility to just the referral. It is sad that the public is not similarly held responsible for their behavior. Difficulty may arise when a patient ends up with a specialist who uses invasive procedures to treat only one aspect of the pain or provides inappropriate treatment exacerbating the pain.

Case Report 2: Following the removal of her the wisdom teeth, a Durham, NC woman developed significant pain. She sought care from several local dentists and physicians with little benefit. An oral surgeon in Florida convinced her he could relieve her pain through TMJ surgeries. Following this, was no longer able to chew food, had twice the pain, and became chemically dependent to opioids. The doctor who removed the wisdom teeth received the blame for causing her TMD.

When a patient presents with chronic pain, dentists must keep several points in mind. First, we need to cross over from the visual world of dentistry (vision or x-rays) to the medical world of a bio-detective. Second, we need to cross over from single cause to multiple causes for the pain. Third, the pain reporting system is heightened (called central sensitization) and allows a painful stimulus to be more intensely perceived and with an expanded pain field. Fourth, stress becomes an aggravator for the pain. Fifth, we need to cross into the black hole between the worlds of dentistry and medicine. Sixth, we need to face the hassles of coordinating and communicating with a chronic pain team instead of attempting to treat the patient by ourselves. Seventh, insurance companies allow 12.5 minutes for acute pain examination, but chronic pain requires more intense data collection of several hours to ferret out the different pain suspects. Eighth, dentists are masters of pulpal and periodontal pain, but chronic pain requires extensive postgraduate dental education from many different specialties (neurology, anesthesiology, ENT, pharmacology, physical therapy, psychology, oncology, occlusion, anatomy, biochemistry, etc.). Welcome to the world of chronic pain!

Case Report 3: When my wife Phyllis began treatment for chronic daily headaches, I suspected her masticatory muscles were contributing to her headaches. I treated her masticatory myofascial pain with a splint and medications, which provided her moderate headache improvement. A physician found she also had a cervical disorder and recommended physical therapy. This provided her with additional headache relief.