Repeated intracranial surgery confers a high risk for late PTE, possibly because people who need more surgery are more likely to have factors associated with worse brain trauma such as large hematomas or cerebral swelling. In addition, the chances of developing PTE differ by the location of the brain lesion: brain contusion that occurs on in one or the other of the frontal lobes has been found to carry a 20% PTE risk, while a contusion in one of the parietal lobes carries a 19% risk and one in a temporal lobe carries a 16% chance. When contusions occur in both hemispheres, the risk is 26% for the frontal lobes, 66% for the parietal, and 31% for the temporal. Post-traumatic seizures
The risk that a person will develop PTE is heightened but not 100% if PTS occur. Because many of the risk factors for both PTE and early PTS are the same, it is unknown whether the occurrence of PTS is a risk factor in and of itself. However, even independent of other common risk factors, early PTS have been found to increase the risk of PTE to over 25% in most studies. A person who has one late seizure is at even greater risk for having another than one who has early PTS; epilepsy occurs in 80% of people who have a late seizure.
Anterior disc displacement without reduction refers to an abnormal forward, bunched-up position of the articular disc which does not reduce. In this latter scenario, the disc is not intermediary between the condyle and the articular fossa as it should be, and hence the articular surfaces of the bones themselves are exposed to a greater degree of wear (which may predispose to osteoarthritis in later life). Degenerative joint disease
The general term "degenerative joint disease" refers to arthritis (both osteoarthritis and rheumatoid arthritis) and arthrosis. The term arthrosis may cause confusion since in the specialized TMD literature it means something slightly different from in the wider medical literature. In medicine generally, arthrosis can be a nonspecific term for a joint, any disease of a joint (or specifically degenerative joint disease), and is also used as a synonym for osteoarthritis. In the specialized literature that has evolved around TMD research, arthrosis is differentiated from arthritis by the presence of low and no inflammation respectively. Both are however equally degenerative. The TMJs are sometimes described as one of the most used joints in the body. Over time, either with normal use or with parafunctional use of the joint, wear and degeneration can occur, termed osteoarthritis. Rheumatoid arthritis, an autoimmune joint disease, can also affect the TMJs. Degenerative joint diseases may lead to defects in the shape of the tissues of the joint, limitation of function (e.g. restricted mandibular movements), and joint pain.