researchers from the United States showed that the time of the appearance of molars in humans is determined by the relationship between the increasing jaws and the change in the position of the chewing muscles and the jaw joints. Calling the cause of the late appearance of the teeth of wisdom. Article of scientists is published in the journal Science Advances.
Three molar meters – employees for eating a large fundamental teeth – grow up in 6, 12 and 18 years. The so-called wisdom teeth appear in humans relatively late compared to other primates: for comparison, our closest relatives, chimpanzees, they grow up in 3, 6 and 12 years, respectively.
Researchers from the University of Arizona created 3D models of 21 Primates skulls throughout the entire period of their growth. Taking into account the growth rate of the jaws, the researchers showed that the appearance of each molar is determined by the extremely accurate relationship of the place and time – it should appear so as not to interfere with the work of parallel to the growing temporomandibular joints. If the tooth grows “not on schedule”, then when chewing it will apply damage to the jaw joint and thereby breaking the work of the entire chewing device. In addition, it turned out that the appearance of molars depends on the beginning and duration of the growth of jaws, which in primates depends on the life expectancy.
Later, the appearance of molars in humans, thus, is the result of slow growing, short jaws and a flexible face. Types with longer jaws need less time to develop a suitable teeth structure.