A Novel Method of Temporomandibular Joint Hypermobility Diagnosis Based on Signal Analysis

Abstract

Despite the temporomandibular joint (TMJ) being a well-known anatomical structure its diagnosis may become difficult because physiological sounds accompanying joint movement can falsely indicate pathological symptoms. One example of such a situation is temporomandibular joint hypermobility (TMJH), which still requires comprehensive study. The commonly used official research diagnostic criteria for temporomandibular disorders (RDC/TMD) does not support the recognition of TMJH. Therefore, in this paper the authors propose a novel diagnostic method of TMJH based on the digital time–frequency analysis of sounds generated by TMJ. Forty-seven volunteers were diagnosed using the RDC/TMD questionnaire and auscultated with the Littmann 3200 electronic stethoscope on both sides of the head simultaneously. Recorded TMJ sounds were transferred to the computer via Bluetooth® for numerical analysis. The representation of the signals in the time–frequency domain was computed with the use of the Python Numpy and Matplotlib libraries and short-time Fourier transform. The research reveals characteristic time–frequency features in acoustic signals which can be used to detect TMJH. It is also proved that TMJH is a rare disorder; however, its prevalence at the level of around 4% is still significant.

A proposal for a database of sounds generated by temporomandibular joints and a tool for automated diagnosis based on an RDC/TMD questionnaire

“…The Finnish researchers confirmed in their study that the results obtained from the RDC/TMD questionnaire coincide with the results obtained from new questionnaire DC/TMD [15]. Nowadays, one of the additional diagnostic tools commonly used for temporomandibular joints (TMJ) examination is an auscultation [16][17][18][19][20][21]. Auscultation is the basic diagnostic tool used by clinicians of various specialisations.…”

Novel Diagnostic and Therapeutic Approaches to Temporomandibular Dysfunction: A Narrative Review

“…In fact, the noises caused by TMJ hypermobility are often errantly assumed to be caused by TMD [ 15 ]. Grochala et al conducted a study of noises emanating from the TMJ using a novel technique called signal analysis [ 16 ]. This is a non-invasive technique that uses an electronic stethoscope to record noises associated with the TMJ during the process of opening and closing.…”

Temporomandibular Joint Hypermobility Examination through Differentiation of Sounds

“…In order to achieve local spectral representation, we split the signal into atomic sections with the Blackman window of 512 samples length and 256 samples overlapping. The frequencies below 80 Hz were removed from spectrograms to emphasize higher harmonics that were responsible for the effect of clicking [31]. Usage of two independent stethoscopes is beneficial in terms of capability of identification which joint generates sounds but on the other hand, makes difficulties in interpretation.…”

“…That examination is safe for the patient and is easy even for inexperienced doctors. The measured signals from electronic stethoscopes are sent to the computer and the signals are analyzed [31].…”