Evaluation of serum prolidase activity and oxidative stress in patients with temporomandibular joint internal derangement

Loss of Slc39a12 in hippocampal neurons is responsible for anxiety-like behavior caused by temporomandibular joint osteoarthritis

Background

An evident association between mood disorders and TMJ dysfunction has been demonstrated in previous studies. This study observed both the behavioral changes and the pathological changes in hippocampal tissue of rats in an animal model of TMJ-OA by injecting MIA into TMJ.

Methods

Eighteen SD rats were randomly assigned to the NC group and the MIA groups. A TMJ-OA model was established to assess the HWT in the TMJ region, and the rats were subjected to the OFT and EPM. HE, O-fast green staining, qRT-PCR and immunofluorescence were used to detect condylar damage. Serum and hippocampal oxidative stress levels were detected. Functions of genes obtained by RNA-Seq were investigated using H2O2, ZnCl2 and transfection of siRNA on HT22 cells.

Results

Injection of MIA resulted in disorganization of the chondrocyte layer on the condylar surface of rats, with reduced synthesis and increased degradation of the condylar cartilage matrix and reduced HWT. The results of the OFT and EPM showed that the rats in the MIA group developed anxiety-like behavior during the sixth week of MIA injection. Increased Nox4 expression, decreased SOD2 expression, elevated MDA level, and reduced GSH level were detected in serum and hippocampal neurons in the MIA group, with nuclear pyknosis and reduced Nissl bodies observed in neurons. The expression of Slc39a12 in hippocampal neurons of rats in the MIA group decreased. Slc39a12 knockdown in HT22 cells induced increased Nox4 expression, decreased SOD2 expression, increased MDA level, and reduced GSH and intracellular Zn2+. Oxidative stress in HT22 cells after transfection and H2O2 stimulation was reversed when ZnCl2 was added.

Conclusion

Loss of Slc39a12 in hippocampal neurons results in cellular oxidative stress, further leading to neuronal damage. This may potentially explain how TMJ-OA triggers anxiety-like behavior in rats.

Is there any differences in magnetic resonance imaging findings of painful temporomandibular joint between patients with and without vertigo?

Background/Aim: Temporomandibular disorder (TMD) is an umbrella term and consists of pathological situations about temporomandibular joint (TMJ) internal structure, masticatory muscle and associated structures. Otalgic complaints are included in the group of complaints within TMJ associated structures and are frequently seen with TMD. The aim of this study is to evaluate the magnetic resonance imaging findings (MRI) of patients who had unilateral pain in the preauricular region, diagnosed with vertigo. Material and Methods: The present retrospective and cross-sectional clinical study was carried out on patients presenting with preauricular pain referred to XXX University Faculty of Dentistry Department of Oral and Maxillofacial Surgery between 2018 and 2020. There were 2 groups as vertigo and health groups. MRI findings were the primary predictor variables, while pain was the primary outcome variable, recorded on a visual analog scale (VAS). Results: 120 patients were included in the study. The patients included in both groups are between 19 and 65 years of age and there is no significant statistical difference between mean ages of the groups (p>0.05). The VAS values varies between 6 and 9 in both groups. There is no significant statistical difference between mean VAS values of the groups (p>0.05). On the painful side there is no significant difference between the groups in terms of disc/condyle relation (p>0.05). On the other hand moderate effusion (61.4%) was significantly higher in the healthy group while severe effusion (54%) was significantly higher in the vertigo group (p<0.01). Conclusions: Although both groups had the same pain scale, it was observed that the vertigo group had more dramatic MRI findings in terms of disc/condyle relation and presence of effusion. This study is the first to evaluate the disc/condyle relation and the presence of effusion through MRI in vertigo patients diagnosed with TMD.

Association between Self-Reported Bruxism, Peripartum Depression and Myogenous Temporomandibular Disorders among Postpartum Women in Turkey

Background/Aim: It is possible to find studies in the literature evaluating the relationship among self-reported bruxism, psychological factors, and myogenous temporomandibular disorder. In addition, the relationship between these issues has not yet been clarified. The objective of this study was to evaluate the association between peripartum depression, self-reported bruxism, and myogenous temporomandibular disorders among postpartum women in Turkey.

Material and Methods: This study included 220 women, whom were asked about their bruxism behaviour during day and during sleep. Besides, all of them assessed with Short-Form Fonseca’s Anamnestic Index for myogenous temporomandibular disorder and the Edinburgh postnatal depression scale for peripartum depression.

Results: The results showed that, self-reported bruxism was observed at a statistically significantly higher rate (94.3%) in peripartum depression group. 86.5% of the patients with self-reported bruxism had myogenous temporomandibular disorder (p<0.001). As a result, 80.0% of the patients with peripartum depression had myogenous temporomandibular disorder (p<0.001).

Conclusions: In conclusion, a significant relationship has been found between peripartum depression and self-reported bruxism, self-reported bruxism and myogenous temporomandibular disorder, and peripartum depression and myogenous temporomandibular disorder. The present study is the first to evaluate the relationship between peripartum depression, self-reported bruxism, and myogenous temporomandibular disorder so it could be considered as a pilot attempt, and further studies using more representative samples are encouraged.

Evaluation of the Oxidative Stress Level and Serum Prolidase Activity in Patients with Sleep Bruxism

Aims and Objective:

Sleep bruxism is a complicated disease, and its cause remains controversial. If the etiology of bruxism is resolved, the treatment can be adjusted to the prevailing aetiological factor. Thus, the aim of this study was to evaluate the oxidative stress level and serum prolidase activity in patients with sleep bruxism.

Materials and Methods:

Seventy healthy subjects and 51 patients with sleep bruxism were included in this study, and blood samples from all patients were collected. Serum samples were analyzed for total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and prolidase activity.

Results:

The prolidase, TOS, and OSI levels were significantly higher in patients with bruxism than in the healthy controls (p = 0.001, p = 0.001, p = 0.001, respectively). The TAS level was significantly lower in bruxism patients than in healthy controls (p = 0.003).

Conclusion:

The increased TOS, OSI, and prolidase levels and decreased TAS levels could be assumed to result in oxidative injury in patients with sleep bruxism. However, the study could not determine whether oxidative imbalance and increased serum prolidase levels could be a cause or a result of bruxism.

Does clinical findings correlate with magnetic resonance imaging (MRI) findings in patients with temporomandibular joint (TMJ) pain? A cross sectional study

Background

Although magnetic resonance imaging (MRI) helps to clearly visualize the disorders in temporomandibular joint (TMJ), the relationship between cross-sectional and clinical findings has not been precisely established. The aim of this study was to evaluate the relationship between clinical symptoms and MRI findings in individuals with TMJ pain.

Material and Methods

This cross-sectional study, conducted on the clinical and MRI findings of the patients, who applied to Uşak University, Oral and Maxillofacial Surgery Clinic with TMJ pain between the years 2016-2019. The primary predictor variables were MRI findings; disc position (normal, disc displacement with reduction (DDWR), disc displacement without reduction (DDWOR)), disc structural distortion (normal, folded, lengthened, round, biconvex, thick), condyle degeneration type (normal, moderate, severe) and joint effusion (JE) (absent, present). The primary outcome variable was pain, recorded on a visual analog scale (VAS) (numbered between 0-10). The other variables were demographic variables (age/gender). The relationship between clinical and MRI findings were statistically evaluated. The data were analysed by Kruskal Wallis and Mann Whitney U test. Chi-square (x2) test was used for categorical variable comparisons. P values < .05 were considered to indicate statistical significance.

Results

Clinical and MRI records of 700 TMJ, from 350 patients with the mean age of the 31 (12-65) were evaluated in this study. Statistically significant differences were found between; disc position and pain, disc position and JE; JE and pain; disc structural distortion and pain; and disc structural distortion and disc position. JE was seen more common in DDWOR group. The most common disc distortion, seen in patients with JE, is the folded type.

Conclusions

The present study can infer that pain is associated with disc position, JE, disc structural distortion, and DDWOR is associated with JE. Folded type disc is the most common disc type in TMJ with JE.

Key words:Internal derangement, TMJ, MRI evaluation, disc morphology, disc position, condyle degeneration, joint effusion.