Introduction: Untreated carious lesions in primary teeth can negatively affect a child's quality of life, but they can also cause long-term adverse effects on permanent teeth. Untreated carious lesions in primary teeth progress to inflammation of the dental pulp, which is followed by the development of apical periodontitis.

Aim: The aim is to review and summarize the available evidence in the specialized literature on the relationship between periapical complications in primary teeth and their association with pathological changes in the developing tooth structures of permanent teeth, such as the formation of follicular cysts or defects in the enamel structure.

Materials and methods: A systematic review of the scientific literature in PubMed, Scopus, and Web of Science was performed. An analysis was made of scientific publications that examine periapical inflammatory processes affecting mainly primary molars, as well as their potential for the development of follicular cysts.

Results: It was found that periapical infection of primary teeth is associated with defects in the enamel (hypoplasia, hypomineralization), eruption abnormalities, dilacerations, ankylosis, delayed or impaired root development, and the development of inflammatory follicular cysts.

Conclusion: Persistent inflammatory processes associated with periapical lesions have a negative effect on the follicular tissues of permanent teeth. This can lead to structural changes in these tissues, as well as to the formation of follicular cysts and eruption disorders.