What is defined as the displacement of the gingival margin apical to the cemento-enamel junction?

The displacement of the gingival margin apical to the cemento-enamel junction is defined as gingival recession. This condition occurs when the gum tissue surrounding the teeth wears away, exposing more of the tooth's root. It can result from various factors, including periodontal disease, aggressive tooth brushing, and other environmental or genetic influences.

Understanding gingival recession is important in periodontology because it can lead to increased tooth sensitivity, higher risk of root caries, and aesthetic concerns. Effective management of gingival recession is essential for maintaining periodontal health and enhancing the overall appearance of the patient's smile.

The other options are pertinent concepts in periodontology but do not describe the specific phenomenon of gingival recession. For instance, a periodontal pocket is related to the deepening of the sulcus due to periodontal disease, while plaque accumulation involves the buildup of biofilm on teeth. Tooth mobility refers to the looseness or lack of stability of a tooth within its socket. Each of these conditions plays a role in periodontal health but does not specifically describe the displacement of the gingival margin as seen in gingival recession.