The aim of this study was to investigate the influence of tumor necrosis factor-α (TNF-α) in temporomandibular joint (TMJ) synovial fluid and blood on the treatment effect on TMJ pain by intra-articular injection of glucocorticoid in patients with chronic inflammatory TMJ disorders. High pretreatment level of TNF-α in the synovial fluid was associated with a decrease of TNF-α and elimination of pain upon maximal mouth opening. Elimination of this TMJ pain was accordingly associated with decrease in synovial fluid level of TNF-α. There was also a significant decrease of C-reactive protein and TMJ resting pain after treatment. In conclusion, this study indicates that presence of TNF-α in the synovial fluid predicts a treatment effect of intra-articular injection of glucocorticoid on TMJ movement pain in patients with chronic TMJ inflammatory disorders.

BackgroundSerotonin (5-HT) mediates pain by peripheral 5-HT3-receptors. Results from a few studies indicate that intramuscular injections of 5-HT3-antagonists may reduce musculoskeletal pain. The aim of this study was to investigate if repeated intramuscular tender-point injections of the 5-HT3-antagonist granisetron alleviate pain in patients with myofascial temporomandibular disorders (M-TMD).MethodsThis prospective, randomized, controlled, double blind, parallel-arm trial (RCT) was carried out during at two centers in Stockholm, Sweden. The randomization was performed by a researcher who did not participate in data collection with an internet-based application (www.randomization.com). 40 patients with a diagnose of M-TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were randomized to receive repeated injections, one week apart, with either granisetron (GRA; 3 mg) or isotonic saline as control (CTR).ResultsThe median weekly pain intensities decreased significantly at all follow-ups (1-, 2-, 6-months) in the GRA-group (Friedman test; P < 0.05), but not in the CTR-group (Friedman-test; P > 0.075). The numbers needed to treat (NNT) were 4 at the 1- and 6-month follow-ups, and 3.3 at the 2-month follow-up in favor of granisetron.ConclusionsRepeated intramuscular tender-point injections with granisetron provide a new pharmacological treatment possibility for myofascial pain patients with repeated intramuscular tender-point injections with the serotonin type 3 antagonist granisetron. It showed a clinically relevant pain reducing effect in the temporomandibular region, both in a short- and long-term aspect.Trial registrationEuropean Clinical Trials Database 2005-006042-41 as well as at Clinical Trials NCT02230371.

Purpose There is a well-known association between mental and behavioral disorders (MBD) and temporomandibular disorder (TMD), although the association has not been established in population-based samples. This study aimed to investigate this relationship using national population-based registry data. Patients and Methods This case–control study used prospectively collected data from Swedish national registries to investigate exposure to MBD and the probability of developing TMD in all Swedish citizens with hospital-diagnosed or surgically treated TMD between 1998 and 2016. Odds ratios were calculated using conditional logistic regression adjusted for educational level, living area, country of birth, musculoskeletal comorbidity, and history of orofacial/neck trauma. Results A statistically significant association between MBD and TMD was found for mood affective disorders (OR 1.4), neurotic, stress-related and somatoform disorders (OR 1.7), behavioral syndromes associated with psychological disturbances and physical factors (OR 1.4), disorders of adult personality and behavior (OR 1.4), disorders of psychological development (OR 1.3), behavioral and emotional disorders with onset usually occurring in childhood and adolescence (OR 1.4), and unspecified mental disorder (OR 1.3). The association was stronger for TMD requiring surgery, with the strongest association in patients with disorders of psychological development (OR 2.9). No significant association was found with schizophrenia, schizotypal and delusional disorders, or mental retardation. Conclusion The findings indicate an increased probability of TMD among patients with a history of certain MBD diagnoses, and a stronger association with TMD requiring surgery, specifically repeated surgery. This highlights the need for improved preoperative understanding of the impact of MBD on TMD, as TMD and chronic pain itself may have a negative impact on mental health.

The aims of this study were to investigate the influence of serotonin (5-HT) on the effects of intra-articular injections of glucocorticoid on pain of the temporomandibular joint (TMJ) in patients with inflammatory disorders of the TMJ. The pretreatment synovial fluid 5-HT was negatively, and plasma 5-HT positively, correlated to change in TMJ pain after treatment. The pretreatment plasma 5-HT was positively correlated to change in pressure-pain threshold after treatment. In conclusion, this study shows that local and systemic serotonergic mechanisms partly determine the effect of intra-articular glucocorticoid treatment on TMJ pain in patients with chronic TMJ arthritis of systemic nature, while change in pressure-pain threshold over the TMJ is influenced by systemic serotonergic mechanisms.

Background Temporomandibular disorders (TMD) are common and affect approximately 10% of the adult population. TMD is usually associated with headache, pain in the masticatory muscles and/or the temporomandibular joint, clicking or crepitations during mandibular movement as well as painful and/or reduced mouth opening. This study aimed to investigate the level TMD-patients use social insurance benefits before and after their first time of diagnosis or first surgical event, compared to the general population. Furthermore, the aim was to investigate the differences in the use of social insurance benefits between surgically and non-surgically treated TMD-patients that were diagnosed in a hospital setting. Methods All Swedish citizens aged 23–59 diagnosed with TMD in a hospital setting and/or surgically treated for the condition during 1998–2016 were identified via the Swedish National Board of Health and Welfare. A non-exposed comparison cohort was collected via the Total Population Registry. Outcome and sociodemographic data were collected via Statistics Sweden. Main outcome was annual net days on sick leave and disability pension five years before (-T5) and five years after (T5) diagnosis and/or surgical treatment (T0). Regression analysis was conducted with generalized estimated equations. Results The study included 219 255 individuals (73% female) – 19 934 in the exposed cohort and 199 321 in the comparison cohort. The exposed group was classified into three subgroups: non-surgical, surgically treated once, and surgically treated twice or more. The mean annual net days of sick leave and disability pension combined during the ten-year follow-up was 61 days in the non-surgical group, 76 days in the surgically treated once group, and 104 days in the surgically treated twice or more subgroup. The corresponding number for the non-exposed comparison cohort was 32 days. Conclusion Patients diagnosed with TMD in a hospital setting are 2–3 times more dependent on the use of social benefits than the general population. The reliance on sick leave and disability pension is seen as early as five years before diagnosis, and the reliance remains after surgical treatment. The reliance is stronger in patients with several surgical interventions. These findings indicate that patients diagnosed with TMD constitute a patient group with a high burden of health issues causing long-term dependence on social security benefits.