The junctional epithelium, sometimes referenced by the initials JE, is the portion of the gingiva or gums that attaches the gums to the enamel, or the surface of the tooth. It’s a thin membrane, about 2-3 mm wide around each tooth, and is only about 15-30 cells thick coronally. Apically, the junctional epithelium tapers to just a single cell. This attachment between the gingiva and the tooth surface is replenished continually throughout a person’s life, about every 4-6 days. Compared to other epithelium in the mouth, which has a regeneration rate of about 6-12 days, the junctional epithelium has a high renewal rate. Junctional epithelium cells have wide intercellular spaces and are non-keratinized, and are responsible for maintaining the seal between the soft tissue of the gums and the tooth. These cells protect jawbone and tooth roots from plaque and bacteria, but in patients with gingivitis or periodontal disease, the seal is weakened.