Yang NY, et al. - Experts detected the distribution and expression of IL-1 in periapical lesions in primary teeth and evaluated the association between the cytokines and the degree of inflammatory cell infiltration. Findings suggested an increase in inflammatory severity with an increase in the expression levels of the cytokines IL-1α and IL-1β in periapical granulomas from primary teeth and in the progression of periapical lesions, it appeared to be a contributing factor.