PTH1R and primary failure of tooth eruption: The PTH1R ablation and cell fate alteration experiments in the mouse are interesting because they provide insight that is consistent with some of the key features associated with PFE; in particular, the ability of the tooth to establish an initial intra-osseous eruption pathway but then stop.12 Thus, in PFE, an initial eruption pathway is seemingly established through PTH1R function in the coronal enamel organ but subsequent movement towards the occlusal plane is disrupted through loss of receptor function in the dental follicle.