Glenn Clark, DDS, MS is an expert on sleep apnea, orofacial pain and oral medicine, and Temporomandibular Joint Disorder (TMJ). Dr. Clark serves as the Director for the Advanced Program in Orofacial Pain and Oral Medicine at the Herman Ostrow School of Dentistry of USC. View all posts by Dr. Glenn Clark →
Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system, specifically the brain and spinal cord. This disease affects women twice the amount as men. Onset commonly occurs between ages 20 and 50 years.
There are many negative consequences of multiple sclerosis. It is known to cause chronic neuroinflammation and demyelination. The cause of this disease remains unknown.
The idea that sympathetic pain exists is based on clinical findings seen in a small subset of patients suffering from neuropathic pain. Sympathetic pains occurs when the pain is clearly dependent on activity in the sympathetic nervous system. This is often referred to the ‘sympathetically maintained pains.’
Silas Weir Mitchell, who lived from 1830 to 1914, was the first to describe sympathetically maintained pains. During the Civil War, he studied nerve injuries. He described these pathological states and causalgia.
Sympathetic pains are classified into three groups:
Various Autonomic Dysfunctions
NPP with sympathetic activation
Complex Regional Pain Syndrome
Autonomic dysfunctions develop when certain Autonomic Nervous System (ANS) nerves are damaged. There are multiple types of the dysfunctions. Once common type is Raynaud’s Disease.
Raynaud’s Disease is characterized by constriction of the blood vessels. It can be caused or provoked by exposure to cold or extreme emotional stress.
Complex Neuropathic Pain (NPP with sympathetic activation) occurs when the pain is clearly aggravated by the sympathetic nervous system. For example, stress makes the pain more severe, and there is an enhanced vasoconstriction reaction associated with the pain. Complex NPP is sometimes described as sympathetic maintained pain and is distinguished from CRPS in that SMP is not as severe and does not meet all of the criteria for CRPS-I or CRPS-II.
There are two types of Complex Regional Pain Syndrome. The first is called Reflex Sympathetic Dystrophy (CRPS – I), commonly caused by an innocuous injury. The symptoms vary in duration and can develop over weeks or months. Sometimes, no symptoms can be identified. In CRPS – I, genetic predisposition is likely.
The second type is Causalgia (CRPS – II). This is caused by a clearcut nerve trunk injury. The onset of symptoms is immediate and obvious after the injury. The symptoms in CRPS – II are more severe than the symptoms of CRPS – I. Genetic predisposition is likely.
Over 1.5% of the population experiences Medication Overuse Headaches (MOH). This type is the most common migraine-like headache. People with MOH experience pain over 15 days each month. MOH ranges higher in women (2.6%) and people over 50 years of age (nearly 5%).
Motor neurectomy involves identifying the select branches of the motor nerve and perform radiofrequency lysis of the motor nerve itself. This will denervate a portion of the motor nerve and cause a resulting atrophy of the muscle. The area of the muscle that atrophies produce is irregular, and the resulting shape of the muscle is non-cosmetically acceptable.
In cases where the jaw opening ability is severely compromised due to ankylosis, it is necessary to perform surgical treatment of the TM joint. This involves a high condylectomy (removing approximately 4 mm on top of condyle) and grafting tissue between the bone components. In most cases, the oral surgeon will place an interposition autologous graft between the fossa and remaining portion of the condyle to prevent adhesion or re-ankylosis. One successful graft is a piece of temporal muscle fascia, although other autologous grafts have been used.
Bone scans are utilized to assess bone tissue growth. It is an older technology and less specific technology (2D) than SPECT (3D), but it still has a role in diagnosis of bone scan. After the injection of the nucleotide, a gamma camera is used to capture the radiation emitted by the radiotracer (nucleotide) and generates a representative two-dimensional image of the uptake. This method is used to determine if a TMJ lesion, such as osteochondroma, is still actively growing.
Trismus occurs when there is an involuntary restriction of active opening (<38mm) due to abnormal or inappropriate closer muscle activity during opening movement. This is called a co-contraction disorder; openers and jaw closers are contracting at the same time.
Below is an overview of seven common and uncommon maxillary growth disorders including severe skeletal malocclusion, unilateral hyperplasia, condylar hypertrophy, condylar hypoplasia, condylar neoplasia, masticatory muscle hypertrophy, and muscular neoplasia. Continue reading How to Diagnose 7 Maxillary Growth Disorders→
Learn how to diagnose, monitor, and treat different types of tooth wear including erosion, attrition, abrasion, and abfraction with this infographic based on Dr. Glenn Clark’s course on abnormal oral physiology and sensory disorders.