A 42-year-old patient complains about tooth mobility, change of tooth position, foul taste, pain during food mastication. Objectively: teeth of both upper and lower jaws are mobile (2-3 degree), there are also diastems and diaereses. Tooth roots are dehisced by 1/2. There are serous purulent discharges from periodontal pockets. Orthopantomogram shows bony tissue destruction down to 2/3 of root length. There are bone pockets. What is the most probable diagnosis?