The two major clinical features of most temporomandibular disorders are pain and dysfunction. While other signs and symptoms may also be present and require attention, these two are the main reason most people seek professional care. As Lund and others have pointed out [1, 2], the dysfunction usually is a consequence of the pain rather than its cause, so primary therapeutic attention should be directed at the pain. When pain is relieved, improved function can be anticipated. If an orthodontist needs to provide a patient with basic TMD treatment, i.e., conservative management of their pain and dysfunction, then the therapies administered should be supported by science and evidence.

TMD treatments are now based on a biopsychosocial model rather than the historical, dental-based model [3–5]. That is, the field of TMD management has moved away from treatments related to conventional dentistry via altering the occlusion and realigning jaw relationships to treatments based on the biomedical and psychosocial sciences. The contemporary biopsychosocial model attempts to integrate the host of biologic, clinical, and behavioral factors that may account for the onset, maintenance, and remission of TMD [6]. The factors that are receiving the most attention and research in the understanding of TMD today are genetics (vulnerabilities related to pain), imaging of the pain-involved brain, endocrinology, behavioral risk factors, sexual dimorphism, and psychosocial traits and states [7]. There also is considerable interest in the issue of comorbid pain conditions, which are found in a large number of TMD patients, and a significant amount of research is focused on the problem of chronicity (who is at risk, and why?).

TMD signs and symptoms can develop in any individual at any time. In many cases, these can be transient phenomena like a sore jaw muscle, a painful joint following a minor trauma, or limited opening after a dental appointment. Also, many patients observed during a screening exam (see Chap.​ 3) may have occasional jaw pain, or a painless TMJ click or an odd opening and closing pattern, but these do not rise to the level of being a clinical case of TMD. When actual TMD problems do arise, that group of patients is often in their mid to late teens or they are young or middle-aged adults rather than children and the elderly. Prevalence of TMDs in women is twice more common than in men [8]. Based on these facts, the likelihood of an orthodontic patient developing TMD signs or symptoms before, during, or after treatment is definitely a possibility. It has been shown that over the long term most cases of TMD pain and dysfunction generally tend to resolve or improve [9, 10]. This however does not obviate an orthodontist’s professional obligation to recognize TMD problems when they do arise, to inform and educate those patients about the conservative treatment protocols, and if needed either engage in the treatment or effect the necessary referral to an appropriate specialist to manage the patient’s TMD.

There are conservative and reversible TMD treatments that orthodontists can provide for patients, or at least understand their use by other practitioners. These include patient self-directed care, physical therapies, cognitive-behavioral therapies, biofeedback, pharmacologic agents, and oral occlusal appliances [11].

It is important to understand that TMDs are generally cyclic in nature, so symptoms often gradually progress from mild to moderate to severe, and then they can move toward a downward phase which ends up as mild to no symptoms. Therefore, practitioners may provide some form of treatment during the downward side of the cycle and get symptom relief. The practitioner may then incorrectly assume that the treatment rendered was responsible for this symptom improvement, but in fact it is possible that the patient was getting better on his or her own due to the cyclic nature of TMD [12, 13].

It is well known that patients experiencing TMD-related pain and dysfunction frequently are anxious about what is happening to them, especially if they have been led to believe that they have a structural problem requiring irreversible treatment procedures. Assuming that a preliminary diagnosis of some type of TMD has been established, it is important for the orthodontist to reduce that anxiety by communication with the patient. For this phase of interaction to proceed smoothly, however, the orthodontist must be knowledgeable about current concepts of TMD. Whereas previous concepts about these disorders have included a heavy emphasis on structural mal-alignments and functional bite disharmonies, most modern authorities regard TMD problems as benign musculoskeletal conditions that are likely to be addressed successfully by simple and reversible measures [14]. Therefore, it is not necessary to provide extensive (and oftentimes expensive) structural corrections in most cases. Long-term studies have shown that 80–90 % of these patients can expect good short-term results with little or no long-term problems after conservative orthopedic therapy to reduce pain and restore normal function [15, 16].

The orthodontist who is aware of these positive data can easily allay the anxiety of TMD patients by reassuring the patients that: