This study sought to explain, both anatomically and functionally, how the cervical region of human teeth is structured and organized in order to address the following questions: 1) Why does External Cervical Resorption (ECR) occur in human dentition? 2) Why is there no ECR in gingivitis and periodontitis? 3) Why ECR can occur after dental trauma and internal bleaching? 4) Why does orthodontic movement not change the gingival color and volume during treatment? 5) Why does orthodontic movement not induce ECR although it is common knowledge that the cervical region can undergo much stress? The existence of sequestered antigens in the dentin, the presence of dentin gaps in the cervical region of all teeth, the reaction of the junctional epithelium and the gingival distribution of blood vessels may explain why ECR does not occur, nor do gingival color and volume change when teeth are orthodontically moved.
Tooth resorption; External cervical resorption; Orthodontic treatment; Gingiva
