*3.8.8. Usage for diagnosis of pain*

IRT is also used to determine the body's painful point. Gratt et al. classified temperature differences in patients with oropharynx pain following their 6-year clinical assessment. They reported that "patients with 'hot' thermograms had the clinical diagnoses of sympathetically maintained pain, peripheral nerve-mediated pain, temporomandibular joint arthropathy, and maxillary sinusitis. Subjects with 'cold' thermograms were demonstrated to have the clinical diagnoses of peripheral nerve-mediated pain and sympathetically independent pain. Subjects with 'normal' thermograms were demonstrated to have the clinical diagnosis of cracked tooth syndrome, trigeminal neuralgia, pretrigeminal neuralgia, or psychogenic facial pain" [44]. Furthermore, the linear-polarized near-infrared light irradiation (LPNIR), a non-invasive method, was defined as a relief treatment for patients with chronic pain from frozen shoulder, osteoarthritis, rheumatoid arthritis, post-herpetic neuralgia and other disorders [45].

The medical applications of IR-based technologies may help forensic scientists in medical malpractice claims, provide a preliminary diagnosis of the cause of death and detect the signs of trauma.
