Analysis of TMJ vibration sounds before and after use of two types of occlusal splints

A systematic review of temporomandibular disorder diagnostic methods

Objective: To compile the screening tools used to study temporomandibular disorders (TMD), classify and analyze their potential application in the field of physiotherapy.Methods: All gathered data included randomized clinical trials on humans over 18 years of age pulled from three databases up to November 2019.Results: Nineteen articles were retained, in which the subjects included 1095 women and 385 men. The 32 valuation systems reported were classified as follows: direct, requiring observation and/or palpation in situ by a clinician, which can be subdivided into protocols and instrumental systems; and indirect, requiring neither observation nor palpation by a clinician, which can be subdivided into questionnaires and scales.Conclusion: In order to evaluate TMD, the best choice is to combine direct and indirect assessment methodologies. The valuation of pressure pain threshold with an algometer and Fonseca's Anamnestic Index in combination with Anamnestic Questionnaire CMD, respectively, seems to provide the best results.

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

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.

Comparison of TMJ vibration frequencies under different joint conditions

OBJECTIVE

To compare 10 Hz wide segments of the 0 to 1000 Hz frequency distributions of vibrations recorded from five stages of internally deranged and asymptomatic temporomandibular joints (TMJs).

METHODS

TMJ vibrations were recorded from 236 patients with five stages of TMJ dysfunction: (1) reducing partial disc displacement (PDDR, n=39); (2) acute reducing complete disc displacement (A-DDR, n=39); (3) chronic reducing complete disc displacement (C-DDR, n=55); (4) un-adapted, non-reducing, complete disc displacement (DDUA, n=57); and (5) well adapted, non-reducing, complete disc displacement (DDWA, n=46). A totally asymptomatic control group with quiet TMJs (AQ, n=43) and a group with vibrating TMJs (AWV, n=93), but otherwise asymptomatic were also recorded. Frequency distributions were calculated for each group using discrete Fourier transform methods in 10 Hz increments (0-10 Hz, 10-20 Hz,…, 990-1000 Hz). The 10 Hz segments were compared between the seven groups using Student's t test with Bonferroni adjustment.

RESULTS

There were significant differences (P<0.05) in all 21 comparisons for the three segments between 80 Hz and 110 Hz, in 20 of 21 comparisons between 180 and 200 Hz, in 19 of 21 comparisons between 110 and 180 Hz and between 50 and 80 Hz.

DISCUSSION

The segments of the frequency distributions from 80 to 110 Hz provided the best differentiation between all seven groups.

Distribution of temporomandibular joint vibration transfer to the opposite side

A vibration produced when a displaced temporomandibular disc reduces during opening can transfer some of its energy from the ipsilateral joint to the contralateral joint. The objective of this study was to measure what percentage of the ipsilateral vibration is transferred to the contralateral joint. The study included the temporomandibular joint (TMJ) vibrations of 144 (informed consent) subjects, (113 F, 31 M), with reducing displaced discs (DDR). Vibrations from 165 joints were recorded bilaterally with BioJVA (BioResearch Associates, Inc. Milwaukee, WI). In each case, any contralateral vibration was analyzed to verify that it was caused by the ipsilateral joint. The contralateral amplitude was divided by the ipsilateral amplitude and multiplied by 100 to produce a percentage of transfer. The percentage values (0-100%) were used to create a Relative Frequency Histogram with 20 classes (1-5%, 6-10%, 11-15%, etc.). The Relative Frequency Histogram graph revealed a three-mounded distribution of the percentage of transfer. One mound fell between 5 and 34 percent, one between 35 and 69 percent and the third between 70 and 98 percent. The appearance of a three-mounded distribution suggests that there may be three different failure modes leading to TMJ intemal derangements. Alternatively, it may be that failure of the disc's stabilizing ligaments leads to three different internal derangement conditions that are in some way distinct. The evidence of apparent tri-modality in this vibration data distribution suggests that there may be three different failure modes of disc displacement with reduction (e.g., anterior, anteromedial, and medio-lateral disc displacement). If so, identifying them could allow for a more detailed description of DDR. Therefore, further investigation of this 'tri-modal' distribution should be undertaken.

Comparison of three treatment options for painful temporomandibular joint clicking

A randomized clinical trial was performed to evaluate the efficacy of three treatment options, including anterior positioning splint therapy, physical therapy, and physical therapy in addition to splint therapy, in terms of treatment outcome, in patients with painful temporomandibular joint clicking. Sixty patients suffering from acute pain and dysfunction were divided randomly into three treatment groups. Twenty patients underwent anterior positioning splint therapy (group I), 20 patients received solely physical therapy (group II), and 20 subjects received physical treatment in addition to splinting (group III). All patients were examined before and after the treatment using a visual analogue scale (VAS) and digital palpation of joint sounds. The data were analyzed using the Kruskal-Wallis, one-way ANOVA and Tukey tests at a significance level of P < 0.05. In comparison with the baseline, subjective pain was decreased significantly (P < 0.05) in all three groups. A significant difference was observed between groups I and II (P <0.05), whereas no significant difference was detected between groups II and III. Six patients in group III did not continue the treatment after physical therapy. The numbers of pain-free patients were 12 in group I, 5 in group II and 9 in group III. We observed a reduction in the frequency of joint sounds across the entire sample (P < 0.05). Anterior positioning splint therapy appears to be the best treatment method for reduction of pain and joint sounds in patients with TMD, compared with the other two methods studied.