In which state of the periodontium does the junctional epithelium first exhibit extended epithelial ridges into the gingival connective tissue?

The junctional epithelium is an important component of the periodontium that serves as the interface between the tooth and the surrounding gingival tissue. In gingivitis, there is inflammation of the gums, which can lead to changes in the morphology of the junctional epithelium. One of these changes includes the extension of epithelial ridges into the underlying connective tissue.

During gingivitis, the inflammatory response may cause the junctional epithelium to adapt by proliferating and forming extensions or "epithelial ridges." This adaptation is a reaction of the body as it attempts to cope with the dental plaque and inflammatory factors present. This extended morphology is not present in a healthy periodontium, where the junctional epithelium is more smoothly attached to the tooth surface, nor is it a characteristic of periodontitis, where deeper tissue destruction occurs and the epithelium may exhibit different destructive patterns rather than extensions.

Therefore, the state of gingivitis is when the junctional epithelium first shows these extended epithelial ridges, highlighting the effects of inflammation and the body's response to the presence of plaque accumulation.