Temporomandibular joint disorders in skeletal class II patients referred to orthognathic surgery: A cross-sectional study.

OBJECTIVES: The aim of this study was to assess the prevalence of Temporomandibular Disorders (TMD) in subjects with skeletal class II dentofacial deformity referred for orthognathic surgery, as well as to elucidate its association with sociodemographic and psychosocial features. METHODS: This was a cross-sectional study using the Research Diagnostic Criteria for Temporomandibular Disorders. The sample comprised class II skeletal patients referred to an Oral and Maxillofacial Surgery center in the Brazilian Northeast. RESULTS: Seventy-three subjects were enrolled and completed the data collection, which consisted of a physical examination according to Axis I of the Research Diagnostic Criteria for Temporomandibular Disorders and facial analysis. Women represented 82.2% of the sample. Among the assessed subjects, 68.5% were already undergoing orthodontic treatment, and the mean overjet of patients was 6.97 mm. The prevalence of TMD in this sample was 46.6%, with muscular disorders being the most common. Patients with an anteroposterior discrepancy greater than 7 mm showed a higher occurrence of TMD (p = 0.017). CONCLUSION: This study demonstrated a high prevalence of TMD in skeletal class II patients referred for orthognathic surgery, especially in those with a pronounced overjet, being Group I (muscular disorders) and Group III (degenerative disorders) the most prevalent.

Soluble epoxide hydrolase inhibition avoid formalin-induced inflammatory hyperalgesia in the temporomandibular joint.

Epoxyeicosatrienoic acids (EETs) are endogenous molecules that exerts effective antinociceptive and resolutive actions. However, because of their rapid metabolism by the soluble epoxide hydrolase (sEH), EETs are unable to remain bioavailable. Therefore, the aim of this study was to investigate whether local sEH inhibition could prevent inflammatory hyperalgesia in the temporomandibular joint (TMJ) of rats. For that, rats were pre-treated with an intra-TMJ injection of TPPU, followed by the noxious stimulus (1.5% of formalin intra-articular) to evaluate nociceptive behavior. Histological analysis was conducted to explore the inflammatory exudate and mast cell degranulation. Periarticular tissue over the TMJ was used to measure inflammatory lipids and cytokines/chemokine by Enzyme-Linked Immunosorbent Assay (ELISA). We demonstrated that peripheral pretreatment with TPPU prevents formalin-induced inflammatory hyperalgesia in the TMJ, and this effect is strictly local. Moreover, TPPU mitigates the leukocyte exudate in the TMJ, as well as inflammatory lipids mediators. Mast cell number and degranulation were abrogated by TPPU, and the inflammatory cytokine levels were decreased by TPPU. On the other hand, TPPU up-regulated the release of interleukin 10 (IL-10), an anti-inflammatory cytokine. We provide evidence that locally sEH by intra-TMJ injection of TPPU produces an antinociceptive and anti-inflammatory effect on rats' TMJ.