Jaw muscle and joint psychophysics-relevance for clinical orofacial pain practice and research. A narrative review

Diagnosis of jaw muscle and temporomandibular joint (TMJ) pain has been greatly standardized with the development and implementation of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). A significant part of the DC/TMD examination-pain on palpation and jaw movements-relies on psychophysical principles in the clinical procedures. Thus, it is essential that examiners are aware of the strengths and limitations of such techniques. Here we first review the background and psychophysical techniques used in the clinic and then discuss opportunities to apply both simple and more advanced modifications in research settings to further understand musculoskeletal pain mechanisms and signatures. The goal is to facilitate development of individualized treatment and precision medicine for which a good starting point seems to be careful pain phenotyping where psychophysical testing may play a substantial role.