Physical mechanisms involved in the genesis of temporomandibular joint sounds

Psychological distress and well-being: their association with temporomandibular disorder symptoms

OBJECTIVE

This study investigated the associations between temporomandibular disorder (TMD) symptoms, psychological distress, and well-being.

METHODS

A total of 372 university students were recruited and stratified into no TMD, TMD pain, TMJ sounds, and combined TMD groups. Psychological distress and well-being were assessed with the Depression, Anxiety, and Stress Scale-21 (DASS-21) and Scales of Psychological Well-being-18 (SPWB-18), respectively. Data were appraised with Kruskal-Wallis/Mann-Whitney U tests and logistic regression analysis (α = 0.05).

RESULTS

Significant differences in anxiety, stress, and autonomy scores were observed among the four groups, and psychological distress was mostly negatively correlated to psychological well-being. Multivariate analyses revealed that anxiety was associated with TMD pain, TMJ sounds, and combined TMD, while autonomy was related to TMJ sounds.

CONCLUSION

Participants with TMD symptoms generally experienced more psychological distress and lower autonomy. Anxiety appeared to increase the likelihood of TMD pain and/or TMJ sounds.

Condyle bone destruction: the association between temporomandibular joint vibration and finite element analysis

OBJECTIVE

The objective of the study is to investigate the stress distributions of condyle and articular disc at different mandibular plane angles and the association between the temporomandibular joint (TMJ) vibration and anatomical relationship.

SETTING AND SAMPLE POPULATION

Data from 195 untreated patients were analyzed. Patients were, respectively, divided into 3 groups, based on cone-beam computed tomography (CBCT): Group 0 presenting normal condyles, Group 1 presenting mild bone change, and Group 2 presenting severe bone change; based on magnetic resonance imaging (MRI): normal disc position (N), disc displacement with reduction (DDR) and disc displacement without reduction (DDNR); based on the mandibular plane angle: low, normal and high.

METHODS

(1) According to peak frequency, average amplitude, and occurrence phase, association was assessed between TMJ condition and TMJ vibration; (2) A three-dimensional finite element model of masticatory system was established and the relationship between mandibular plane angle and condyle bone destruction was described.

RESULTS

The average amplitude of TMJ vibration negatively correlated with pathological condition of the articular disc (p < 0.01). The angle of SN-MP was strongly relevant to bone destruction of condyle (p < 0.01), and the biomechanical analysis showed that with the increase of SN-MP angle, the area of stress concentration in the posterior slope of condyle rose.

CONCLUSIONS

The average amplitude of TMJ vibration decreased with the pathological position state of articular disc, and condyle bone destruction was positively associated with SN-MP angle.

Temporomandibular joint sounds and disc dislocations incidence after orotracheal intubation

The aim of this study was to analyze the temporomandibular joint (TMJ) disc displacement and articular sounds incidence after orotracheal intubation. A prospective cohort study was conducted in the Hospital Universitário do Oeste do Paraná (HUOP), in Cascavel, Brazil. 100 patients (aged 14–74 years, mean 44 years), 34 male and 66 female, in need of surgical procedure with orotracheal intubation were evaluated. The anterior disc displacement with reduction incidence and the nonclassifiable sounds incidence by the Research Diagnostic Criteria Axis I was evaluated in all patients after orotracheal intubation. The patients was evaluated one day before and until two days after the procedure. Eight percent present with anterior disc displacement with reduction and 10% presented nonclassifiable sounds after the orotracheal intubation. There was no correlation of any kind regarding gender related influence in the incidence of disc dislocations (P = 0.2591) and TMJ sounds (P = 0.487). Although anterior disc dislocations and TMJ sounds after anesthetic with orotracheal intubation presented a low incidence (8%–10%), it is recommended that the evaluation of TMJ signs and symptoms be done before the anesthetic procedure to take care with susceptible patients manipulation.

Electrosonographic characteristics of sounds from temporomandibular joint disc replacement

The purpose of this study was to investigate the waveform and electrosonographic characteristics of sounds emanating from internal derangement of the temporomandibular joint (TMJ). TMJ sounds were recorded from 10 joints of normal people (NP), 10 joints from patients with anterior disc displacement with reduction (DDR) and 20 joints from patients with anterior disc displacement without reduction (DDNR). The sounds were analyzed through fast Fourier transfer methods to observe their waveforms and electrosonographic characteristics. The observations were then used in differentially diagnosing internal derangement. Wave pattern and electrosonography (ESG) differed among the NP, DDR and DDNR groups. There was very little difference in frequency between the sounds from DDR and DDNR, but the amplitude of the DDR sounds was higher than those of DDNR and NP. The sensitivity and specificity of ESG diagnosis for DDR were 77.2% and 93.3%, respectively, while for DDNR they were 81.6% and 64.7%, respectively.