Perio means around, and dontal refers to teeth. Periodontal diseases are infections of the structures around the teeth, which include the gums, periodontal ligament and alveolar bone. In the earliest stage of periodontal disease â gingivitis â the infection affects the gums. In more severe forms of the disease, all of the tissues are involved. For many years scientists have been trying to figure out what causes periodontal disease. It is now well accepted that various types of bacteria in dental plaque are the major villains. Researchers also are learning more about how an infection in your gums can affect your overall health.
Elephants are large mammals of the family Elephantidae and the order Proboscidea. Three species are recognised, the African bush elephant (Loxodonta africana), the African forest elephant (L. cyclotis), and the Asian elephant (Elephas maximus). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons.
There are two species of elephant. The Asian elephant and the African elephant live on separate continents and have many unique features. There are several subspecies that belong to one or the other of these two main species, though there is disagreement over just how many subspecies there are. Size. African elephants are the larger of the two species. They grow 8.2 to 13 feet (2.5 to 4 meters) from shoulder to toe and weigh 5,000 to 14,000 lbs. (2,268 to 6,350 kilograms), according to the National Geographic. Asian elephants can grow up to 6.6 to 9.8 feet (2 to 3 m) from shoulder to toe and weigh up to 2.25 to 5.5 tons (2,041 to 4,990 kg). Older elephants with larger tusks are becoming rarer due to their ivory.