1 Inflammation of the gingiva, bone loss, and increased gingival recession may progress slower than with other forms of periodontitis.  Periodontitis Associated with Systemic Diseases - Systemic diseases, such as heart disease, diabetes, and certain forms of arthritis, may have a correlation with periodontitis.
Main Content. An earthquake is ground shaking caused by a sudden movement of rock in the earthâs crust. Such movements occur along faults, which are thin zones of crushed rock separating blocks of crust.
Most earthquakes happen along boundaries between coastal plates, which are thick slabs of rocks. At the boundaries, the plates sometimes grind against each other, setting up strains that can result in earthquakes. Since most of the plate boundaries are on the ocean floor, must earthquakes actually occur under the ocean. More than 50 per cent of all earthquakes occur at the edge of the Pacific plates.