Scientists have long known that the crocodilian species — which includes various types of crocodiles, alligators and caimans — have the strongest bites in the animal kingdom. What was not entirely understood was just how these aquatic reptiles are able to generate such extreme force.
But the recent discovery of a second jaw joint in alligators has provided new insight into the bite power of alligators and their crocodilian relatives. It may also lead to a better understanding of human jaw disorders, including temporomandibular joint disorder (TMJ), a common condition that can cause migraine-like headaches, jaw pain, and difficulty biting and chewing among other uncomfortable symptoms.
Jaw Joint Similarities in Alligators, Humans
Using high-tech imaging and 3-D modeling tools to assess the bones, cartilage, joints and tissues in the alligator head, a research team led by Casey Holliday, Ph.D., an assistant professor of anatomy at the University of Missouri, found that alligators have a secondary jaw joint. Most animals have only one type of jaw joint, although some species of reptiles, amphibians, fish and birds have multiple craniofacial joints.
This second joint in alligators helps distribute bite force and stabilize the jaw during feedings, according to a news release on the research from the Federation of American Societies for Experimental Biology (FASEB); Holliday recently presented his findings at the FASEB’s annual conference. The joint may help protect the crocodilian jaw during the violent, twisting attacks alligators, crocodiles and caimans use to seize their prey.
The crocodilian joint is similar to the temporomandibular joint in people. This joint, from which TMJ disorder derives its name, is active in all jaw movements, and it plays an instrumental role in biting and chewing, although humans generate only about 150 to 200 pounds per square inch (psi) of bite force compared to a saltwater crocodile’s 3,700 psi.
TMJ Causes and Treatments
Despite crocodilian species’ reputation as “living fossils,” researchers believe the second jaw joint is a byproduct of evolution and that its discovery could help further understanding of and treatment options for TMJ and other jaw disorders. TMJ is thought to affect at least 30 percent of American adults, although the number may be much higher, as the condition often goes undiagnosed or misdiagnosed.
Research into the causes of temporomandibular joint disorder is ongoing, but there are some known factors, most commonly bite conditions and jaw alignment problems. These afflictions can overtax the temporomandibular joints and strain the sensitive trigeminal nerve, which registers sensation throughout the face.
TMJ treatment depends on the source of the condition and unique physical features. Many patients with relatively mild TMJ may find relief with occasional TENS therapy, which uses low-level electrical current to essentially massage the jaw and allow the jaw to settle into a comfortable resting position. Others may benefit from an oral appliance that is custom-designed to hold the jaw in proper alignment.
If you or a loved one suffers from chronic headaches or jaw discomfort that have otherwise escaped diagnosis and treatment, please call the TMJ Therapy & Sleep Center of Colorado at (303) 691-0267 to schedule your consultation with a knowledgeable TMJ dentist. Dr. Kevin Berry has an extensive record of success helping patients from the greater Denver area find lasting relief from TMJ pain.
