Singh and Gunberg used multiple regression analysis to develop equations that could predict age in adult males based on histologic examination of bone. The age at the time of death could be predicted within 6 years of the true value in 95% of the cases.
Patient population studied: adult males from age 39 to 87 years
Bones examined:
(1) mandible
(2) femur
(3) tibia
Method:
(1) 1 cm x 1 cm fragment of bone was removed from the midshaft of the anterior surface of a long bone or the posterior border of the mandibular ramus.
(2) The bone was either (a) embedded in methacrylate and ground or (b) decalcified and sectioned.
(3) The samples were examined at 100x magnification (10x objective, 10x widefield ocular), with a microscopic field 2 mm in diameter.
Measurements taken:
(1) total number of osteons counted in 2 microscopic fields (number increases with increasing age)
(2) average number of lamellae per osteon (number increases with increasing age), based on counting all osteons in 2 fields
(3) average diameter of Haversian canal in microns (diameter decreases with increasing age)
Equations:
(1) 7 equations were calculated for each bone studied
(2) The 3 equations with the highest R values are included below. Additional equations are given in Table 4 on page 377.
Choice of equations:
(1) The authors favored studying the mandible over the long bones, and preferred the mandibular equation III since the total number of osteons and the diameter of the Haversian canals were better correlated with age than was the average number of lamellae.
(2) The authors developed a nomograph using number of osteons and Haversian canal diameter to predict age (Figure 2, page 378).
Equations for the Mandible
age by mandibular equation I =
= 20.82 + (0.85 * (total number of osteons)) + (0.87 * (average number of lamellae)) – (0.22 * (average diameter of Haversian canal))
age by mandibular equation III =
= 32.23 + (0.92 * (total number of osteons)) – (0.30 * (average diameter of Haversian canal))
age by mandibular equation II =
= (-18.99) + (1.13 * (total number of osteons)) + (1.76 * (average number of lamellae))
|
Equation |
R value |
Standard Error of Estimate |
|
I |
0.979 |
2.55 |
|
III |
0.978 |
2.58 |
|
II |
0.976 |
2.69 |
Equations for the Femur
age by femoral equation I =
= 27.65 + (0.65 * (total number of osteons)) + (0.78 * (average number of lamellae)) – (0.26 * (average diameter of Haversian canal))
age by femoral equation III =
= 29.59 + (0.79 * (total number of osteons)) – (0.28 * (average diameter of Haversian canal))
age by femoral equation IV =
= 61.25 + (1.74 * (average number of lamellae)) – (0.44 * (average diameter of Haversian canal))
|
Equation |
R value |
Standard Error of Estimate |
|
I |
0.958 |
3.24 |
|
III |
0.957 |
3.25 |
|
IV |
0.949 |
3.52 |
Equations for the Tibia
age by tibial equation I =
= 43.52 + (0.291 * (total number of osteons)) + (1.47 * (average number of lamellae)) – (0.34 * (average diameter of Haversian canal))
age by tibial equation IV =
= 54.79 + (2.19 * (average number of lamellae)) – (0.4 * (average diameter of Haversian canal))
age by tibial equation III =
= 48.61 + (0.53 * (total number of osteons)) – (0.38 * (average diameter of Haversian canal))
|
Equation |
R value |
Standard Error of Estimate |
|
I |
0.964 |
3.02 |
|
IV |
0.960 |
3.12 |
|
III |
0.957 |
3.22 |
Limitations:
• A person with a nutritional deficiency or disease affecting bone formation might have an erroneous estimate of age.
• The effect of race was not included.
• A small number of women were included in the study group. The results appeared comparable to the men.
Specialty: Clinical Laboratory
