It is highly improbable that short term orthodontics will cause problems with the temporomandibular joint.
When I hear this question, I think back to the question posed by Dr. Barry Glassman:
When do the teeth occlude? “WHEN?” is when the teeth are together; one point in space within the entire envelope of function. I also realize that the “WHEN?” is independent of the shape and arrangement of the teeth. The primary concern with craniofacial pain and temporomandibular dysfunction is THAT the teeth are in contact, as opposed to HOW the teeth are in contact (or what the occlusal scheme happens to be). Temporomandibular joints are not damaged when the mandible is in rest position. They are damaged by load (bruxism), and it has been shown that altering occlusion does not increase bruxism.[10-12] There is a modifier to this, however. Although occlusal factors do not make our patients brux more, these factors can make bruxers brux differently. In his lectures, Dr. Jim Boyd often refers to the parafunctional quad; four factors that are important when evaluating a patient’s parafunction: Intensity, Duration, Frequency and Position. When evaluating the occlusion and its effects on bruxism, it seems that position and intensity ARE the most relevant because in particular mandibular positions, the contacting teeth have an effect on the intensity of bruxism. For this reason interferences present a paradox. Interferences are poor indicators of temporomandibular disorders and bruxism [10-12]. However, studies such as conducted by Liu in 1998 concluded that malocclusions with interferences do have an increased risk for developing TMD. Le Bell observed that subjects with a history of TMD reacted to artificial interferences more than those with no history of TMD. In other words, those who brux will be worse with interferences than without, but in those that do not brux, interferences are inconsequential. The caution, it seems, should be in identifying patients with pre-existing symptoms and therefore vulnerability to temporomandibular disorder, rather than focusing on the occlusion itself.