Physical mechanisms involved in the genesis of temporomandibular joint sounds

Abstract

Several different mechanisms are potentially capable of generating sounds in the temporomandibular joint (TMJ). These include impact, sliding and stick-slip friction, fluid dynamic effects and the release of elastic strain energy. It is the aim of this paper to provide a framework with which to separate sounds resulting from the different underlying causes. Each mechanism is described and its relevance to TMJ sounds and clinical significance discussed. Since it is not possible to observe these mechanisms in vivo the arguments are based mainly on analogies which are used to make predictions of the characteristic acoustic signatures of the sounds produced by these different mechanisms. In particular the changes in the characteristics of the sounds as parameters such as mandibular speed and loading are stressed. It is suggested that single short duration sounds (clicks) are due to impact, multiple short duration sounds (creaks) to stick-slip friction and defects of form and long duration sounds (crepitus) to simple sliding friction. Several other mechanisms which have no obvious clinical significance but which are capable of producing similar sounds are also described and methods of distinguishing them from the sounds that do have clinical implications are discussed.

Electrosonographic characteristics of sounds from temporomandibular joint disc replacement

“…Clicking is usually regarded as a DDR sound 6,11 , but it can be found in DDNR and even sometimes in the degenerated disease 13 . In this study, a characteristic waveform was found for sounds from all the DDR joints, but it had no relation with audible clicking in time; it is not the waveform of clicking.…”

Prevalence of Joint Noises in Patients With Temporomandibular Dysfunction and Its Association With Occlusive-Functional Parameters

“…Joint sounds are generally associated with intracapsular events (PRINZ, 1998). The possible causes of sounds are structural alterations, and the most frequent are hypermobility of the condyle-disk complex, displacement of the articular disc to the anterior, structural alterations of the articular surface, in addition to degenerative processes, which cause crackles (PRINZ, 1998). ;CONTI et al, 2000).…”

Relationship between sounds and disc displacement of the temporomandibular joint using magnetic resonance imaging

“…However, sounds may be heard in individuals who may or may not present the typical symptoms of temporomandibular disorders (TMD) (1). Different mechanisms are involved in the occurrence of TMJ sounds, which probably reflect some abnormality in the structure and function of the joint, such as the impact between joint structures, the deformation of these structures, and the changes in the quality of the synovial fluid.…”