Tempromandibular dysfunction (TMD) syndrome has become more apparent during and after orthodontic treatment, and more patients attend dental practices suffering from this painful condition. Since it is difficult to know whether TMD pain is completely attributed it to orthodontic therapy or to other subclinical disorders, it is essential to do systematic screening of the tempromandibular joint (TMJ) area for patients prior to commencing therapy, not only for forensic reasons but also for risk assessment. Clinical examination includes medium-frequency joint vibration to report the initial symptoms in TMJ subluxation and to detect the early or latent TMJ dysfunction.

Dysfunction of the masticatory muscles and TMJ start with small, unnoticeable abnormalities with minor pain which the patients can easily adapt to it; however, pain propagation is governed by a number of factors including health status, social life and age. The early phase of TMD could be overlooked or undiagnosed and left untreated; approximately 75% of population would experience early-phase TMD without noticing. A dental team should possess broad clinical experience to diagnose an analyze TMD in every patient; clinical examination and history questionnaire must be used to evaluate each patient with existing TMD even if it was asymptomatic.

Joint vibration is one of the modern methods used for examining patients in an easy, painless and fast way. This method is capable of detecting minor changes in the joint or masticatory muscles and can thus aid in preventing further worsening of TMD. These changes can be internal derangement, altered locomotor masticatory system or loose joint ligaments. Treatment of existing TMD requires physical therapy such as stretching and contracting exercises with/without high masticatory forces to manage the so-called hypermobile joint.

Subluxation of the joint could be diagnosed with electrovibratography during mouth opening; this method tracks condylar displacement and disc displacement using small vibrations of low intensity and measures the range of motion of the joint. It thus gives enough evidence about pathological changes of TMJ.