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Introduction Primary failure of eruption (PFE) is defined as the partial or complete failure of eruption of at least one posterior tooth, without any mechanical obstacle. A better understanding of the biological mechanisms involved in PFE would enable us to refine the diagnostic and prognostic criteria. This rare disease is currently related to PTH1R gene variants. This gene codes for a transmembrane receptor involved in bone metabolism. However, there is little evidence linking PFE and bone remodeling abnormalities such as external root resorption. External root resorption is the loss of cementum and dentin tissues, resulting from the activation of clastic cells. Materials and methods Human teeth affected by PFE were extracted, and histological sections were made after fixation of the tissues in 4% PFA. The observations were correlated with three-dimensional imaging using cone beam computed tomography (CBCT) carried out in the preoperative phase Results Histological and radiographic analysis confirm the presence of ankylosis areas in patients with no history of orthodontic treatment. Large areas of resorption of external root replacement were detected. Discussion The results call into question the causal link between the appearance of ankylosis areas and the establishment of orthodontic traction in patients with PFE. The installation of an orthodontic force in this context could actually be an aggravating factor, accelerating the processes of ankylosis or triggering them earlier. Conclusion With or without orthodontic treatment, teeth with PFE are likely to progress to ankylosis and replacement external root resorption.