When we think about the different types of pain that exist, many things can come to mind. Let’s break it down scientifically for a moment.
Pain, more specifically musculoskeletal pain, is classified into 3 categories:
Neuropathic pain arises from damage to the nervous system and affects 7–10% of the general population. This type of pain feels like a burning or electrical pain, even a stabbing pain. Many patients report feeling like they are being shocked when these bolts of pain occur.
Another related pain is Sciatica, which many TMD patients suffer from. This is lower back pain caused by the sciatic nerve. Nerves do not typically heal well, so unfortunately patients that suffer from neuropathic pain will suffer from chronic pain throughout their lifetime.
Neuropathic pain in the orofacial region includes trigeminal neuralgia, glossopharyngeal neuralgia and Atypical Odontalgia. AO is usually localized in a tooth that has been misdiagnosed, which often leads a patient to have many unnecessary dental treatments in attempt to relieve pain. Two other comorbidities of AO are depression and anxiety, often intensified by pain.
Studies estimate that the incidence of chronic orofacial neuropathic pain is 5-10 per 100,000 people.
Orofacial pain is characterized as pain manifested in the face or oral cavity, including such disorders as TMD. As studies have shown, TMD has significant impact on physical and psychosocial factors. Its prevalence has been reported as three to five times more frequent in women.
It can be hypothesized that extracranial trigeminal nociceptive inputs arising from the craniofacial structures as a result of a TMD may influence the activation of the trigeminovascular system, since these nociceptive inputs convey in TNC where intracranial inputs do.
The trigeminal nerve (Cranial Nerve V) is a mixed-function, major cranial nerve (sensory, motor, and autonomic functions). This nerve is termed “trigeminal” due to its three main branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3). Sensitive axons of the trigeminal nerve innervate the majority of cranial and facial tissues, except the posterior area of the cranium, the mandibular angle, part of the external auditory canal and pavilion, and part of the pharynx.
Trigeminal Neuralgia is described as a severe, electric-like unilateral pain. It is localized most often in trigeminal nerves V2 and V3, intraorally and extraorally. Patients usually have a trigger spot, when stimulated, causes a great amount of pain (lasting seconds or minutes). TN will vanish for a while and then return months later sometimes, making it difficult for the patient to identify the problem, or even know what type of doctor to turn to for treatment.
Glossopharyngeal neuralgia is a less common condition associated with pain supplied by the glossopharyngeal nerve. Locations of pain include the tongue, throat, tonsils, larynx and ears. Triggers for this include swallowing, chewing, talking, coughing and head movements (basic functions of daily life). These episodes are also short-lasting, but can occur multiple times throughout the day, and can also go into remission for periods of time.
Nociceptive pain is the type of pain that we are all most familiar with. It arises from trouble in the tissues, reported to the brain by the nervous system. Examples include nausea, burns, stubbing your toe, getting stung by a bee, etc. In other words, it is recognizable and familiar. It is a necessary protective sensation to the human body.
Inflammatory/Other pain arises from a dysfunction like fibromyalgia, rather than damage. Historically, pain like this is seen as a “functional” pain disorder, when the patient is not incapacitated and still able to go about the functions of everyday life.
Fibromyalgia typically intensifies TMJ symptoms, and alternatively, when one or both temporomandibular joints are dislocated, fibromyalgia pain in the neck and upper back is amplified.
TMD and fibromyalgia produce similar painful symptoms:
It is well known that headaches and TMD are highly prevalent conditions in the general population. Evidence suggests that a clinical comorbidity migraines/headaches and TMD exists. Existing TMD may, therefore, influence and/or exacerbate a headache disorder, and a headache disorder may exacerbate a TMD condition.
Migraines are commonly thought of as just a headache that causes pain behind the eye, neck, and cranium; however, migraine headaches can also present in the lower part of the face, particularly in the teeth.
A physical evaluation of the TMJs includes a full head and neck examination for any signs of dysfunction or pain symptomatology. The physician should be looking for any joint sounds upon opening/closing, decreased ROM, and deviations in the opening/closing of the mouth to start. Imaging such as a closed MRI of the TMJ’s, tomograms and/or CT scan may be needed.
Conservative treatments for TMD include intraoral appliances, medication, physiotherapy, cognitive behavioral approaches, and potential surgical interventions.
Emotional factors play an important role in the treatment plan as well. Research has shown that high levels of fear of pain are associated with low levels of physical activity, often leading to a multitude of health issues (other than pain itself).
If you have any questions or would like more information on chronic pain and TMD, please visit our website or call us at 586.573.0438.
References
Chantaracherd P, John MT, Hodges JS, Schiffman EL. Temporomandibular joint disorders’ impact on pain, function, and disability. J Dent Res. 2015;94(3 Suppl):79S–86S.doi:10.1177/0022034514565793
Epker J, Gatchel RJ. Coping profile differences in the biopsychosocial functioning of patients with temporomandibular disorder. Psychosom Med. 2000;62(1):69–75.
Ghurye S, McMillan R. Pain-related temporomandibular disorder: current perspectives and evidence-based management. Dent Update. 2015;42(6):533–536. 539–542, 545–546.
Gil-Martínez A, Paris-Alemany A, López-de-Uralde-Villanueva I, La Touche R. Management of pain in patients with temporomandibular disorder (TMD): challenges and solutions. J Pain Res. 2018;11:571–587. Published 2018 Mar 16. doi:10.2147/JPR.S127950
Graff-Radford SB. Myofascial pain: diagnosis and management. Curr Pain Headache Rep. 2004;8(6):463–467.
Ohrbach R, Gale EN. Pressure pain thresholds, clinical assessment, and differential diagnosis: reliability and validity in patients with myogenic pain. Pain. 1989;39(2):157–169.
Okeson JP. Bell’s Orofacial Pains. The Clinical Management of Orofacial Pain. 6th ed. Carol Stream, IL: Quintessence Publishing Co, Inc; 2005.
Oono Y, Wang K, Baad-Hansen L, et al. Conditioned pain modulation in temporomandibular disorders (TMD) pain patients. Exp Brain Res. 2014;232(10):3111–3119.
Oral K, Bal Küçük B, Ebeoğlu B, Dinçer S. Etiology of temporomandibular disorder pain. Agri. 2009;21(3):89–94.
Romero-Reyes M, Uyanik JM. Orofacial pain management: current perspectives. J Pain Res. 2014;7:99–115. Published 2014 Feb 21. doi:10.2147/JPR.S37593
Sessle BJ. Neural mechanisms and pathways in craniofacial pain. Can J Neurol Sci. 1999;26(Suppl 3): S7–S11.
Sessle BJ. Peripheral and central mechanisms of orofacial pain and their clinical correlates. Minerva Anestesiol. 2005;71(4):117–136.
Sweeney L, Moss-Morris R, Czuber-Dochan W, Murrells T, Norton C. Developing a better biopsychosocial understanding of pain in inflammatory bowel disease: a cross-sectional study. Eur J Gastroenterol Hepatol. 2020;32(3):335-344.
