When examining bones any injuries to their structure or other abnormalities should be noted. The skull must be carefully examined for fractures, especially the base, which may be easily overlooked. Injuries to vertebræ should be looked for. The presence of callus will indicate that fracture has occurred at a period before death long enough for its formation.
Age.—There are several data which enable one to form a fairly accurate opinion as to the age of a body, these are especially useful in earlier years and intra-uterine life.
The more general are the size, height, development, the presence or absence of signs of puberty, the state of dentition, the greyness of the hair; in the female the atrophic condition of the uterus after the menopause, and the character of the lower jaw.
In addition are the time of life at which centres of ossification appear and the union of epiphyses to the shafts of bones and bones with each other.
In intra-uterine life centres of ossification appear by the end of the sixth month in the os calcis, manubrium, and the bodies and laminas of the sacral vertebræ; by the seventh, in the first piece of the body of the sternum and the astragalus; by the eighth, in the second piece of the body of the sternum; at full term in the cuboid, third piece of the sternal body, first coccygeal vertebra, and the lower epiphysis of the femur.
All traces of the fontanelles have disappeared by the end of the fourth year. The angle of the jaw in infants and young children is obtuse; as dentition proceeds, the body becomes deeper and the angle alters so that towards adult life it approaches a right angle, the ramus is longer and the body has become well developed with a mental foramen midway between upper and lower borders. In the new-born, the mental foramen is low down as the body of the jaw is practically all alveolar. In old people the angle again becomes obtuse and the alveolus disappears as the teeth are shed, and the mental foramen is at the upper border.
Table of the Eruption
of the Teeth
| Age— | Eruption of teeth. | Temporary. | ||||
| Lower | central | incisors, | 7 | months. | ||
| Upper | “ | “ | 8 | “ | ||
| “ | lateral | incisors, | 7-10 | “ | ||
| Lower | “ | “ | 10-12 | “ | ||
| First molars, | 12-14 | “ | ||||
| Canine teeth, | 18 | “ | ||||
| Second molars, | 22-24 | “ | ||||
| First molars, | 6 | years | Permanent. | |||
| Middle incisors, | 7 | “ | ||||
| Lateral incisors, | 8 | “ | ||||
| First bicuspids, | 9 | “ | ||||
| Second bicuspids, | 10 | “ | ||||
| Canines, | 11-12 | “ | ||||
| Second molars, | 12-13 | “ | ||||
| Wisdom teeth, | 18-25 | “ | ||||
Examine the lower jaw. The ramus forms an obtuse angle in full-grown fœtus, a right angle in adult life, obtuse in old age from loss of teeth.