Objective To evaluate stress effect of COVID‐19 pandemic and Zagreb earthquakes on symptoms of temporomandibular disorders (TMD). Materials and Methods One hundred and two previously diagnosed TMD patients were contacted by email to participate in an online survey about impact of those events on current and/or new symptoms, perceived stress, anxiety and symptom intensity in time‐points at the baseline, following pandemic and following earthquake. We compared data between earthquake‐affected and non‐affected respondents. Results Response rate was 79.4%. Effects stress had on deterioration of symptoms were significantly different between earthquake‐affected and non‐affected (p = .024). In earthquake‐affected, numerical pain rating scale (NPRS) scores significantly increased between baseline and after COVID‐19 (p > .001) and between baseline and after earthquakes (p > .05). However, scores insignificantly dropped from COVID‐19 to after earthquakes time‐points. In earthquake‐affected, positive correlation was found between impact of COVID‐19 on stress and NPRS (p < .001) and between earthquakes’ impact on stress and NPRS (p < .001). Earthquake‐affected respondents reported significantly more new behavioral habits when compared to non‐affected (p = .048). Conclusions A series of stressful events do not necessarily have a cumulative effect, but are likely to have a complex interaction (e.g., acute stress might trigger the protective mechanisms), which could have decreased pain scores after the earthquakes.

Temporomandibular disorders (TMD) have been associated with altered salivary oxidative status, but the relation with pain source and pain severity isn’t clarified. With the aim to assess their interaction with TMD, we compared levels of selected salivary oxidative stress (OS) markers (glutathione peroxidase, superoxide dismutase, total antioxidant capacity (TAC), uric acid, 8-hydroxydeoxyguanosine, malondialdehyde) and salivary cortisol (SC) as a stress indicator, between 20 TMD patients and 15 healthy control subjects. In order to record differences relating to pain source and severity, patients were respectively classified according to specific diagnoses (myofascial pain or disc displacement (DD)), and pain intensity (high or low). TAC was significantly higher in TMD patients than in controls (morning p = 0.015; afternoon p = 0.005). Significant differences were also observed when TAC levels between high-intensity pain patients and controls were compared, as well as between DD patients and controls. In logistic regression analysis, higher levels of TAC were related to DD (morning OR: 1.66, 95%CI: 1.05–2.64, p = 0.029; afternoon OR: 2.10, 95%CI: 1.11–3.98, p = 0.021) and to high-intensity pain (morning OR: 1.81, 95%CI: 1.04–3.15, p = 0.037; afternoon OR: 1.79, 95%CI: 1.02–3.14, p = 0.043). We also found that morning SC was positively correlated with antioxidant parameters in TMD patients. Our data suggest compensatory mechanism as response to higher level of stress. This stress could be extrinsic and lead toward TMD, or intrinsic, emerging from established TMD, or could be both. The intensity and the source of pain should be considered important factors in future investigations evaluating salivary OS markers in TMD patients.

The present study evaluated diurnal variations and day-to-day fluctuations of salivary oxidative stress (OS) markers in healthy adult individuals. Whole unstimulated saliva was collected at 2 time intervals over 3 consecutive days. Glutathione peroxidase (GPX), superoxide dismutase (SOD), total antioxidant capacity (TAC), and uric acid (UA) were analyzed using spectrophotometric methods, while 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA) were determined using immunoassays. No significant differences for salivary OS markers between men and women were observed. For all examined OS markers, no significant day-to-day variations were demonstrated. Significant diurnal variations were found in salivary GPX, TAC and MDA levels. For SOD, TAC, GPX, and UA, good-to-moderate intraindividual coefficients of variations (CVs) were observed in more than 75% of the subjects. For MDA and 8-OHdG, intraindividual CVs > 35% were observed in 60% and 40% of the subjects, respectively. Between-subject variance was wide for all examined OS markers (CV% 30.08%–85.70%). Due to high intraindividual variability in the salivary concentrations of MDA and 8-OHdG, those markers cannot be reliably verified based on single measurements and multiple measurements over several days would provide more reliable information. Salivary SOD, TAC, GPX, and UA proved stable across three days of measurement. Trial Registration. ClinicalTrials.gov NCT03029494. Registered on 2017-01-19.

PurposeThe aim of this study was to compare long-term effectiveness of stabilization splint (SS) with that of placebo splint (PS) in chronic TMD patients and to investigate differences in treatment outcomes based on diagnostic subgroups [disc displacement (DD)/myofascial pain (MP)].Materials and MethodsThirty-four female participants, diagnosed with chronic TMD, were classified in groups: one provided with SS and other with PS and were followed for six months. Treatment outcomes included spontaneous pain [visual analogue scale (VAS)], self-perceived quality of life (OHIP-14), pain-free maximal mouth opening (MCO), maximal mouth opening (MMO), level of perceived stress (PSS), characteristic pain intensity [graded chronic pain scale (GCPS)], and functional jaw limitation [jaw functional limitation scale (JFLS)].ResultsBaseline characteristics did not differ significantly between the two groups (p>0.05). After six months of treatment the changes in spontaneous pain and OHIP-14 scores differed significantly between treatment groups (p=0.004, p=0.02 respectively), with greater reduction in SS compared to the PS group. Pain-free maximal mouth opening did not change significantly over time, however MCO values differed significantly between the two treatment groups, with greater overall values in the SS compared to the PS group (p= 0.046), as well as between TMD subgroups, with greater overall values in MP compared to DD patients (p= 0.03). In the SS group, significant difference in JFLS categories was found between baseline and after 6 months of treatment in all except emotional and verbal expression (mastication p=0.00015; vertical jaw mobility p=0.00018). No such changes in JFLS categories were observed in the PS group.ConclusionsDuring 6-month period, SS was more effective than PS in reducing spontaneous pain and improving self-perceived quality of life and functional limitations of the lower jaw. Moreover, significantely higher values of pain-free mouth opening were observed in patients treated with stabilization splint. While placebo might be partly responsible for improving the symptoms of TMD, it seems that itcannot maintain a continual long-term positive therapeutic effect.

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Background Differences in the expression of oxidative stress (OS) markers between female patients with temporomandibular disorders (TMD) and healthy individuals indicate that OS plays a role in the pathogenesis of TMD. Because chronic exposure to stress generates oxidative damage during continuous stimulation of the hypothalamic-pituitary-adrenal axis, we expected that higher levels of cortisol might be associated with higher oxidative damage. Our aim was to test the association between OS markers, stress perception, and salivary cortisol (SC) in chronic, female TMD patients. We tracked changes in OS markers and SC during occlusal splint therapy in order to evaluate the influence of treatment on oxidative status. We hypothesized that the effects of TMD therapy would differ among individuals depending on the source and intensity of pain. Methods Sixteen female patients were recruited, and 12 finished the study. Clinical assessment and saliva sampling were performed at the baseline and follow-up appointments. Repeated measures analysis of variance and Pearson’s correlation were used for analyzing the data. Results After 3 months, a significant reduction in afternoon total antioxidant capacity (TAC) was observed ( p < 0.05). A significant reduction in afternoon malondialdehyde (MDA) ( p = 0.021) and a decrease in afternoon MDA to superoxide dismutase ratios ( p = 0.017) were present in high-intensity pain patients. At baseline, higher levels of perceived stress were significantly associated with higher morning cortisol ( ρ = 0.67). At the end of the therapy,  reduced  perceived stress was positively correlated with morning SC changes when considering all TMD patients, but the association between perceived stress with OS markers was present only in myofascial pain (MP) group. The effect of treatment on the self-perceived quality of life was more pronounced in female MP patients while the reduction of spontaneous pain was significantly greater in high-intensity pain patients. Conclusion Our data indicate that occlusal splint therapy in female TMD patients contributes to increasing their capacity to remove free radicals. The question remains whether or not TAC decreases in this process as a result of avoiding unnecessary processes, once the increase in antioxidants effectively compensates for OS. The intensity and the source of pain should be considered important factors in future investigations evaluating salivary OS markers and their association with perceived stress and SC in TMD patients. Trial registration ClinicalTrials.gov NCT03029494 . Registered on 2017-01-19.

have their natural teeth and maintain good oral hygiene. Participants were not suitable if they were experiencing (1) inflammatory joint disease, (2) orofacial pain unrelated to TMD, (3) chronic systemic diseases (i.e. diabetes, cardiovascular diseases, malignancies, and autoimmune diseases), (4) causes of headache, unrelated to TMD, listed in the International Classification of Headache Disorders (ICDH II), (5) periodontitis, oral lesions and gum swelling. Individuals who had already been under treatment for TMD were excluded. Finally, participants who use supplements and medication known to affect the oxidative status, and smoke were not able to take part in the study. Study design. Allocation. To reduce the waiting time and potential withdrawal until a sufficient number of participants are involved, we have chosen a randomization procedure based on our experience of enrolling 6-8 participants in 2 months. The patients were assigned into two treatment groups utilizing random block randomization with a block size of 8 and 6. Randomization was computer-generated, and participants were randomly assigned to two treatment arms, SS or PS. The allocation was prepared by the study's statistician prior to enrollment of the participants. Blinding. Participants were unaware of the differences of each intervention. The principal investigator (IZA), who conducted the baseline evaluations, was the only person aware of the participants' treatment conditions. All follow-up assessments were performed by the investigator (EV), blinded to the group allocation. Observer training. Ten randomly selected subjects, different from the ones included in the investigation, underwent repeated clinical examinations by two experienced examiners to assess signs and symptoms of TMD (according to DC/TMD). No significant differences were recognized between the first and the second measurements (p = 0.87-0.89, paired t-test). The weighted kappa statistics showed adequate agreement between the observers (κ = 0.86-0.88).

Objectives: (i) To evaluate the effect of three different interventions on treatment outcomes and (ii) to determine how the frequency of oral parafunction influences the effectiveness of the different therapeutic modalities.Methods: Forty-five participants were randomly assigned into three treatment groups [physical therapy (PT), stabilisation splint (SS) and control therapy (CT)]. According to Oral Behavior Checklist score, participants were divided into "high-frequency parafunction" (HFP) and low-frequency parafunction" (LFP) group. Primary (spontaneous pain and characteristic pain intensity) and secondary outcomes (range of mouth opening, anxiety symptoms, quality of life, perceived stress and global functional limitation) were evaluated during six-month treatment period.Results: Participants in PT group showed a significant reduction in characteristic pain intensity (p = .047, η 2 = 0.243) when compared to SS and CT group, but significant improvement in spontaneous pain was found in all treatment groups. Patients treated with PT and SS exhibited significantly stronger improvement in pain-free mouth opening than patients in CT group (3rd month: p=.037, η2=0.258; 6th month: p = .005, η 2 = 0.383). Within-group analyses showed significant decrease of perceived stress, anxiety symptoms and global functional limitation only in PT group over a sixmonth treatment period. Participants with HFP presented significantly greater levels of anxiety (3rd month: p = .009, η 2 = 0.275; 6th month: p = .041, η 2 = 0.176) than participants with LFP. Within-group analyses, however, showed significant improvement of anxiety, but also the decrease of perceived stress and improvement of global limitation for the HFP group but not for the LFP group. Conclusion:Although no treatment can be marked as superior in terms of spontaneous pain relief, PT was more effective when observing relief of characteristic pain intensity. In HFP group the reduction of anxiety, stress and functional limitation was present regardless of the applied therapy. Trial registration: ClinicalTrials.gov NCT04694274. Registered on 01/04/2021.