CHARACTERIZATION OF THE NEUROIMMUNOLOGICAL KINETICS OF OROFACIAL TISSUES IN RATS WITH OCCLUSAL OVERUSE

• Grant number: 23/05864-5
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2024
• End date: August 31, 2026
• Field of knowledge: Biological Sciences - Pharmacology - Biochemical and Molecular Pharmacology
• Principal Investigator: Henrique Ballassini Abdalla
• Grantee: Henrique Ballassini Abdalla
• Host Institution: Centro de Pesquisas Odontológicas São Leopoldo Mandic. Faculdade São Leopoldo Mandic (SLMANDIC). Sociedade Regional de Ensino e Saúde S/S Ltda (SRES). Campinas , SP, Brazil
• Associated researchers: Juliana Trindade Clemente Napimoga ; Marcelo Henrique Napimoga

Abstract

Occlusal overuse or traumatic occlusion as a trigger or aggravating factor of painful temporomandibular joint disorders is one of the main controversial issues in the dentistry field. Previous studies have shown that experimental traumatic occlusion induced by metallic crowns induces a long-term inflammatory hypernociception in the temporomandibular joint, increased expression of voltage-gated sodium channel Nav1.7 in neuronal cells in the trigeminal ganglion, and an inflammatory reaction in the periodontium, inducing bone loss. The cross-interaction between the neural and immune systems modifies the inflammatory profile and cell phenotype, facilitating the tissue degeneration progression; however, the mechanisms are still unclear. This project aims to characterize the neuroimmunological kinetics of orofacial tissues, particularly periodontal tissue, submandibular lymph nodes, and central nervous system control areas, impacted by experimental traumatic occlusion. For this, the impact of occlusal overuse will be evaluated through a pre-established model of experimental traumatic occlusion induced by a metallic crown cemented in the first lower right molar of Wistar rats, the following parameters: (I) the immunological profile of the gingival periodontium and submandibular lymph nodes against the persistent neuroinflammatory process induced by experimental traumatic occlusion; and (II) the neuroimmunological profile of the sensitization of the trigeminal ganglion and central nervous system (subnucleus caudalis and cerebellum) induced by experimental traumatic occlusion and possible alterations in the patterns of behavioral responses linked to learning capacity, memory, and locomotion. Understanding the mechanisms involved in the neuroimmunological kinetics of persistent degenerative conditions of orofacial tissues subjected to occlusal overuse is a crucial element for reviewing the clinical approach to patients with this condition and validating more robust assessment instruments in conducting clinical studies. It is worth noting that painful inflammatory conditions of orofacial tissues are the most common cause of chronic pain development. (AU)