NOTUM and dentin dysplasia: In fact, studies in periodontal ligament stem cells have shown that inhibition of Wnt signaling is required for the maintenance of the osteogenic potential of these cells.46 Meanwhile, increased Wnt signaling, such as in klotho-deficient mice, results in accelerated cellular senescence.47 Furthermore, constitutive activation of Wnt signaling, such as in NOTUM knockout mice, manifests as dentin dysplasia, periodontal inflammation, and periapical abscess formation.6,8–10 These studies highlight the need for further investigation of the temporal regulation of these pathways.