Age

Age, is defined as the time elapsed from birth to the moment of examination. In determining the age of a person, before the onset of sexual maturity, the following data are used—height, chest circumference, presence of milk teeth, their replacement and eruption of permanent teeth; with the onset of sexual maturity, attention is paid to the development of mammary glands, growth of hair (on the upper lip, chin, pubic region and in the armpits), appearance of menstruation in girls, change of voice in boys, body weight, size of sexual organs and their changes. In later periods of life, in determining age, changes in permanent teeth, condition of the skin and formation of arcus senilis on the cornea play a role. Taking the length of a newborn infant as 50 cm, it is considered that by 5 years of age human height doubles (100 cm), by 15 years it triples (150 cm). By the time of sexual maturity it almost reaches its maximum size, to which only a little is added until growth is completed. Chest circumference is considered approximately equal to half the height. - The weight of a newborn, on average, is 3 kg. By 5-6 months the weight doubles, by 1 year it triples, by 2 years it quadruples. In the subsequent years up to 8, 1 kg is added each year, so that an 8-year-old child weighs 18 kg. In the period from 8 to 14 years, 3 kg is added each year, and at 14 years the child weighs 36 kg; in an adult the weight doubles—70 kg. According to Lacassagne and Martin, the weight of a mature male is almost equal to the last two digits of height expressed in cm, while the weight of a woman is equal to these two digits minus 2.5 kg. English anthropologists also believe that the weight of a mature person is equal to the number of cm of height over 1 m. - The eruption of milk teeth occurs in the following order: a) central lower incisors at 7 months, central upper incisors at 10 months, b) small molars: first lower ones at 24 months, first upper ones by 26 months; second lower ones by 28 months, second upper ones by 30 months, c) canines—in the interval from 30 to 33 months. At 7 years, permanent teeth appear—the first large molars; central incisors by 8 years, lateral incisors by 9 years, first small molars by 10 years, second small molars by 11 years; canines at 12 years; second large molars around 13 years; wisdom teeth between 18 and 25 years. The eruption of milk teeth ends approximately at 2½ years. Milk teeth begin to fall out at 7 years of age. The final eruption of permanent teeth, except for wisdom teeth, in our climate occurs approximately at 14 years. In judging age, the wear of teeth, their decay and loss play a role. The cutting surfaces of lower incisors wear out first, then upper ones, and after that the chewing tubercles of molars. The loss of some molars begins at 45 years. With age, the color of teeth (enamel) also changes, gradually turning dark, yellow, brown and dark gray. The skin gradually, with age, becomes pigmented, becomes dry, rough, loses its elasticity, and as a result wrinkles appear on it. Up to 40 years of age, the skin of the hands is elastic. From 40 years, pigmentation appears, and keratinization begins. From 50 years, dryness of the skin is added. Later all these phenomena intensify. At 55 years, skin pinched transversely on the back of the hand between two fingers straightens well, at 60 years—slowly, at 65—it does not smooth out on its own. Wrinkles appear gradually in the following order: forehead and nasolabial (20 years), at the outer corners of the eyes and behind the ears (25 years), pretragal and infraorbital (around 30 years), neck (35 years), on the earlobes, hands, chin, nose bridge and upper lip (from 55 years of age). According to Lacassagne, by 60 years the cornea becomes dull and whitish at the edge. By 70 years arcus senilis surrounds the entire cornea. After 75 years, the absence of arcus senilis is the exception. According to Nadezhdin, in nervous subjects with early arteriosclerosis, arcus senilis is noted already at 35 years. - Determination of the age of a fetus—see Full-term.