FIGURE 3.

(a) Staging is a measurement of the severity of a patient's condition at any given point. The model is based on the extension of tissue/organ injury and host's factors. At the time of intervention, the severity of the apical periodontitis condition will affect not only the prognosis but also the use of treatment resources (i.e. number of visits, root‐end procedure and guided tissue regeneration). Observe how the interaction of periradicular bone loss and immune factors can increase the severity of the disease's stage. An extensive amount of periradicular bone loss in an immunocompromised patient reflects the presence of an advance stage in the grading system compared with an immunocompetent patient with minimal or no periradicular bone loss. (b) The severity of periradicular bone loss has been reported as a predictor factor for lack of complete healing. Note the different stages of bone loss; the severity of the disease not only affects the periapex but also the furcation and lateral root areas in advance stages (3–4). The extension of bone loss combined with the patient's medical information and other aggravating factors can affect the prognosis and treatment plan decisions. Graph modified from Gonella et al. (1984)