Evaluation of TMJ sound on the subject with TMJ disorder by Joint Vibration Analysis

Prevalence and severity of temporomandibular joint disorder in partially versus completely edentulous patients: A systematic review

Temporomandibular joint disorders (TMDs) following tooth loss may or may not be prevalent, but the risk of developing these disorders is always there due to changes in occlusion and vertical dimension, leading to changes in the disc-fossa relationship. The purpose of this systematic review was to evaluate the prevalence and severity of temporomandibular joint (TMJ) disorder in partially versus completely edentulous patients. An elaborated literature search was conducted in PubMed/Medline, Scopus, Web of Science, Lilacs, and Google Scholar databases including all articles about varied effects of partial and complete edentulism on the TMJ published from January 1, 2000, to January 1, 2022. After the meticulous screening, only publications which fulfilled the inclusion parameters were ultimately selected for full-text evaluation and tested for bias using the Joana Briggs Institute Appraisal tools for cross-sectional, case-control, and cohort studies. A total of 547 articles from various electronic databases and manual searches were found. After eliminating the duplicates and thorough screening, 13 studies were included for qualitative synthesis. Most of the studies demonstrated at least one or two signs of the presence of TMDs following tooth loss, the intensity/frequency of which increased in proportion to the number of missing teeth.

An evaluation of the effect of wearing complete dentures on temporomandibular joint vibrations over time using the joint vibration analyzer

Aim

To evaluate the changes in temporomandibular joint (TMJ) vibrations after insertion of the complete denture in edentulous patients.

Settings and Design

An observational in vivo study conducted to evaluate the changes in maximum mouth opening, total integrals, peak amplitude, and peak frequency in TMJ vibrations on the day of complete denture insertion and 6 months of follow up.

Materials and Methods

Twenty patients (male: 12 and female: 8) were selected for the fabrication of balanced complete dentures following conventional procedure. Joint vibration analysis was recorded using the joint vibration analyzer. The patients were instructed to open as wide as possible and close to the intercuspal position with rhythmic speed following the metronome projected on the screen. The TMJ vibrations were amplified and displayed as waveforms in a graphical representation by system software.

Statistical Analysis Used

Wilcoxon test.

Results

A significant decrease in the total integral (P = 0.001) and peak amplitude (P = 0.044) for opening and closing movements of the left and right joints was observed. There was no significant change in maximum mouth opening (P = 0.624). A decrease in peak frequency was noted only at left opening movements between the day of insertion and at 6 months (P = 0.025).

Conclusion

The function of TMJ mechanics was improved till 6 months after insertion of complete denture with balanced articulation (BA).

sEMG and Vibration System Monitoring for Differential Diagnosis in Temporomandibular Joint Disorders

The stomatognathic system represents an important element of human physiology, constituting a part of the digestive, respiratory, and sensory systems. One of the signs of temporomandibular joint disorders (TMD) can be the formation of vibroacoustic and electromyographic (sEMG) phenomena. The aim of the study was to evaluate the effectiveness of temporomandibular joint rehabilitation in patients suffering from locking of the temporomandibular joint (TMJ) articular disc by analysis of vibrations, sEMG registration of masseter muscles, and hypertension of masticatory muscles. In this paper, a new system for the diagnosis of TMD during rehabilitation is proposed, based on the use of vibration and sEMG signals. The operation of the system was illustrated in a case study, a 27-year-old woman with articular dysfunction of the TMJ. The first results of TMD diagnostics using the k-nearest neighbors method are also presented on a group of fifteen people (ten women and five men). Vibroacoustic registration of temporomandibular joints, sEMG registration of masseter muscles, and functional manual analysis of the TMJ were simultaneously assessed before employing splint therapy with stomatognathic physiotherapy. Analysis of vibrations with the monitoring of sEMG in dysfunctions of the TMJ can lead to improve differential diagnosis and can be an objective way of monitoring the rehabilitation process of TMD.

Assessment of the Temporomandibular Joint Function in Young Adults without Complaints from the Masticatory System

Objective of the study was to evaluate the clinical status of the masticatory system in young adults with full permanent dentition and no stomatognathic system complaints. The study involved 186 randomly selected people with full dental arches with normal occlusal conditions corresponding to Angle's Class I aged 18 - 21 years with an average age of 19 years. Subjects were clinically examined and temporomandibular joint (TMJ) vibrations were recorded during open-wide and close movements using BioJVA. Then, patients were categorized into groups according to Piper's classification system. The TMJs of the subjects were categorized according to the values of the vibration energy and the Piper protocol. This detected 33.4% of the joints with loosened ligaments, subluxation in 8.28%, initial signs of disc dysfunction in 5.08% and disc displacement without locking in 1.6 %. Median frequency differed significantly (p < 0.05) between the group of subjects with initial signs of TMJ dysfunction and other groups. Peak Frequency differed significantly (p < 0.05) between the healthy joints and those with TMJ subluxation. In this group of young healthy people, the majority of study joints generated small vibrations. However, a subset of people manifested higher vibrations that may indicate an early stage of TMJ dysfunction. Median Frequency was an important parameter for detecting initial symptoms of TMJ dysfunction. Peak Frequency was an important characteristic parameter for detecting TMJ subluxation.

Temporomandibular joint vibrations from totally asymptomatic subjects

OBJECTIVE

Precisely characterize the TMJ vibrations of a youthful, adult and completely asymptomatic population.

METHODS

TMJ vibrations were recorded from 237 asymptomatic subjects (163 f, 74 m) at Dayananda Sagar Institute in India. The subjects were selected, examined and informed (WMA Helsinki Declaration). TMJ vibrations were recorded bilaterally during maximal open - close. 6 parameters of the vibrations were analyzed between the left and right sides, between genders and with respect to age.

RESULTS

Mean vibration intensity was greater for females (p < 0.01) than males. A portion of the frequency spectrum < 300 Hz was also more intense for females (p < 0.022). Females 18 - 20 years old exhibited higher Peak Amplitude than 27 - 30 year olds (p < 0.025) and lower Median Frequency (p < 0.005).

CONCLUSIONS

A significant difference in TMJ vibrations was present between males and females, increased with age in females but not in males.

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.