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The idea of a tooth worm is a theory of the cause of dental caries, periodontitis and toothaches. Once widespread, the belief is now obsolete, having been superseded by more scientific rationales. It was supposed that the disease was caused by small worms resident within the tooth, eating it away. [1]
Gongylonema pulchrum was first named and presented with its own species by Molin in 1857. The first reported case was in 1850 by Dr. Joseph Leidy, when he identified a worm "obtained from the mouth of a child" from the Philadelphia Academy (however, an earlier case may have been treated in patient Elizabeth Livingstone in the seventeenth century [2]).
During the European Age of Enlightenment, the belief that a "tooth worm" caused caries was also no longer accepted in the European medical community. [169] Pierre Fauchard, known as the father of modern dentistry, was one of the first to reject the idea that worms caused tooth decay and noted that sugar was detrimental to the teeth and gingiva ...
The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The Annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion.
Familiar worms include the earthworms, members of phylum Annelida. Other invertebrate groups may be called worms, especially colloquially. In particular, many unrelated insect larvae are called "worms", such as the railroad worm, woodworm, glowworm, bloodworm, butterworm, inchworm, mealworm, silkworm, and woolly bear worm.
The cilia allow the worms to glide along in the water between sand grains, although they also use muscles, allowing the body to twist or contract, for movement. They have no body cavity, and no circulatory or respiratory system. The nervous system is simple, and restricted to the outer layers of the body wall.
The majority of freshwater leeches are found in the shallow, vegetated areas on the edges of ponds, lakes and slow-moving streams; very few species tolerate fast-flowing water. In their preferred habitats, they may occur in very high densities; in a favourable environment with water high in organic pollutants, over 10,000 individuals were ...
Tongue worms grow by moulting, which suggests they belong to Ecdysozoa, while other work has identified the arthropod-like nature of their larvae. [12] In general, the two current alternative interpretations are: pentastomids are highly modified and parasitic crustaceans, probably related to fish lice, or they are an ancient group of stem ...