Runx2 heterozygosity alters homeostasis of the periodontal complex

Abstract

AbstractBackground and ObjectiveHaploinsufficiency of Runx2 (Runx2+/−) causes dental anomalies. However, little is known about the involvement of Runx2 in the maintenance of dentin, cementum, and the periodontal ligament (PDL) during adulthood. This study aimed to observe the effects of Runx2+/− on homeostasis of the periodontal complex.Materials and MethodsA total of 14 three‐month‐old Runx2+/− mice and their wild‐type littermates were examined using micro‐computed tomography, histology, and immunohistochemistry. Phenotypic alterations in the dentin, cementum, and PDL were characterized and quantified.ResultsHaploinsufficiency of Runx2 caused cellular changes in the PDL space including reduction of cell proliferation and apoptosis, and irregular attachment of the collagen fibers in the PDL space into the cementum. Absence of continuous thickness of cementum was also observed in Runx2+/− mice.ConclusionRunx2 is critical for cementum integrity and attachment of periodontal fibers. Because of its importance to cementum homeostasis, Runx2 is essential for homeostasis of periodontal complex.