PTH1R and primary failure of tooth eruption: In primary failure of eruption (PFE), clinical and radiographic characteristics are highly specific for PTHR1 effects18; and compared with responses in wild‐type (WT) mice, physiological responses to injected PTH ligands are acutely and severely disrupted in mice bearing the phosphorylation‐deficient (PD) PTHR1 knock‐in mutation.19