The temporomandibular joint is responsible for fundamental functions. However, mechanical overload or microtraumas can cause temporomandibular disorders (TMD). In addition to external factors, it is known that these conditions are involved in complex biological mechanisms, such as activation of the immune system, activation of the inflammatory process, and degradation of extracellular matrix (ECM) components. The ECM is a non-cellular three-dimensional macromolecular network; its most studied components is hyaluronic acid (HA). HA is naturally found in many tissues, and most of it has a high molecular weight. HA has attributed an essential role in the viscoelastic properties of the synovial fluid and other tissues. Additionally, it has been shown that HA molecules can contribute to other mechanisms in the processes of injury and healing. It has been speculated that the degradation product of high molecular weight HA in healthy tissues during injury, a low molecular weight HA, may act as damage-associated molecular patterns (DAMPs). DAMPs are multifunctional and structurally diverse molecules that play critical intracellular roles in the absence of injury or infection. However, after cellular damage or stress, these molecules promote the activation of the immune response. Fragments from the degradation of HA can also act as immune response activators. Low molecular weight HA would have the ability to act as a pro-inflammatory marker, promoting the activation and maturation of dendritic cells, the release of pro-inflammatory cytokines such as interleukin 1 beta (IL-1β), and tumor necrosis factor α (TNF-α). It also increases the expression of chemokines and cell proliferation. Many of the pro-inflammatory effects of low molecular weight HA are attributed to its interactions with the activation of toll-like receptors (TLRs 2 and 4). In contrast, the high molecular weight HA found in healthy tissues would act as an anti-inflammatory, inhibiting cell growth and differentiation, decreasing the production of inflammatory cytokines, and reducing phagocytosis by macrophages. These anti-inflammatory effects are mainly attributed to the interaction of high-weight HA with the CD44 receptor. In this study, we review the action of the HA as a DAMP and its functions on pain control, more specifically in orofacial origin (e.g., TMD).

This clinical trial aimed to compare the efficacy of two protocols using high molecular weight hyaluronic acid (HA) intra-articular injection in patients with temporomandibular joint (TMJ) osteoart...

Satellite glial cells (SGCs) play a critical role in the development and maintenance of chronic pain through complex interactions with inflammatory mediators and the opioid pathway. This systematic review synthesizes recent advances in the molecular mechanisms underlying SGC activation and implications for chronic pain management, particularly in conditions associated with the dorsal root ganglia (DRG) and trigeminal ganglia (TG). A systematic search was conducted in four databases (PubMed, Embase, Scopus, and Web of Science) covering studies published between January 2004 and May 2026. After screening 111 records, 19 studies were included. This review highlights how pro-inflammatory cytokines such as IL-1β, IL-1α, and TNF-α, as well as neurotransmitters like ATP and glutamate, contribute to SGC activation, neuroinflammation, and pain modulation. It also explores the role of receptors like CXCR4, TLR4, and P2X7 in SGCs in enhancing analgesic effects and their contributions to opioid tolerance and hyperalgesia. The findings underscore the potential of targeting SGCs to improve pain management outcomes across various pain models, including neuropathic, cancer-related, and visceral pain. Despite promising insights, variability in study methodologies and the complexity of glial–neuronal interactions present challenges. Future research should focus on standardizing experimental protocols and developing targeted therapies to modulate SGC activity to offer hope for patients suffering from chronic pain, particularly in managing opioid tolerance.

Injured birds pose a challenge in veterinary medicine, requiring innovative approaches for restoration of function and enhancing the quality of life. This case report describes the successful reconstruction of the mandibular beak of an Amazona aestiva parrot (Psittacidae) after a traumatic injury. The injury caused a fracture in the mandibular beak, resulting in significant limitation of function. Computed tomography imaging was used for surgical planning, allowing visualization of the remaining mandibular beak on the parrot's rhamphotheca and determination of the appropriate dimensions of the implanted plate. Plates were surgically applied to reconstruct the mandibular beak structure. The surgery followed an Enhanced Recovery After Surgery protocol, which resulted in enhanced mandibular beak function and total adjustment to the plates. Six months posttreatment, the beak components had fused, and the plates had detached. At the 1- and 2.5-year follow-up, veterinarian assessment noted no concerns with chewing or ingesting food. This study highlights the effectiveness of employing surgical techniques derived from dental expertise and utilizing biomaterials, such as human maxillofacial plates, to successfully reconstruct complex structures in birds.