Myeloid A20 Regulates Periodontal Tissue Integrity and Temporomandibular Joint Structure.

Aim
To determine whether myeloid-specific deletion of A20 (TNFAIP3), a key negative regulator of NF-κB signaling, affects periodontal supporting tissues and temporomandibular joint integrity under baseline conditions.Methods
A20myel-KO and wild-type littermates were analyzed at 10-11 weeks of age using high-resolution micro-computed tomography and histology. Alveolar bone architecture, periodontal ligament space, epithelial morphology, and temporomandibular joint (TMJ) compartments were evaluated through quantitative micro-CT measurements and qualitative histological assessment.Results
A20myel-KO mice exhibited a craniofacial structural phenotype characterized by reduced alveolar bone volume fraction, widening of the periodontal ligament space, and altered dentoalveolar morphology. Histological analysis revealed epithelial architectural changes. In the TMJ, micro-CT demonstrated reduced bone volume fraction, accompanied by histological evidence of trabecular bone loss and altered condylar growth plate organization.Conclusion
A20-mediated regulation in myeloid cells contributes to the maintenance of periodontal and craniofacial skeletal homeostasis. Loss of this regulatory pathway was associated with structural alterations involving alveolar bone loss, periodontal ligament architecture, and temporomandibular joint morphology, suggesting that dysregulated myeloid inflammatory signaling may influence multiple craniofacial skeletal compartments even in the absence of experimentally induced inflammation.