Age Estimation from Examination of the Pubic Symphysis

 

Patient selection:

(1) The scores are valid only for adults between ages 18 and 38.

(2) After the age of 40 years the changes in the symphysial surface show large variations, making age estimates inaccurate.

(3) The study was performed using skeletons from Japanese adults.

 

Examination:

(1) The external surface of bones cleaned of attached soft tissue are examined grossly for 7 external features.

(2) Reference photographs are shown on page 239, Hanihara (1978).

 

Features relative to age:

(1) horizontal ridges and furrows: Under 20 years of age, the ridges and furrows are distinct. Between 20 and 23 the furrows become shallow and the ridges dull. After 28 these features almost always disappear completely.

(2) pubic tubercle: Under 23 years, the tubercle is attached through cartilage. After 24 years this is fused bone.

(3) lower end: Before 22-23 years, the lower end of the symphysial surface is indistinguishable from the upper end of the inferior pubic ramus. From 23-30 years, the lower end of the symphysial surface is bordered by a narrow ridge. After 30 years the ridge is broadened, with some showing a triangular swelling.

(4) dorsal margin: Before 19 years of age no marginal ridge borders the symphysial surface. At 20 years a trace of a ridge appears along the dorsal surface. After 27 years there is a nearly complete ridge formed over the dorsal surface, but this is relatively narrow. After 33-34 years this ridge may broaden, but it also may remain narrow.

(5) superior ossific nodule: This nodule appears at the upper part of the pubic surface for a limited period in the early and late twenties, then disappears.

(6) ventral bevelling: Before 22 years the ventral surface coincides with the ventral surface of the pubic bones. Afterwards a narrow surface appears between the 2 surfaces, which was called ventral bevelling by Todd. It is not complete until age 27. From 28-33, it is complete along the full length of the pubic symphysis. After age 33 the upper part may disappear, but the changes show wide variation.

(7) symphysial rim: Some older individuals may have a relatively broad and dull rim around the symphysial surface. If a distinct rim is present, then the person is in the mid-thirties or older. Absence of the rim does not correlate with age.

Morphologic Feature	Morphologic Change	Points	Normalized Score
horizontal ridges and furrows	distinct	1	18.08
	furrows become shallow	2	19.36
	trace	3	21.46
	no longer visible	4	21.74
pubic tubercle	attached by cartilage	1	0.00
	united (fused)	2	0.95
lower end	indistinct	1	0.00
	narrow ridge	2	-0.33
	broad ridge	3	3.52
dorsal margin	none	1	0.00
	interrupted narrow ridge	2	0.86
	narrow ridge over full length	3	2.72
	broad ridge	4	5.25
superior ossific nodule	none	1	0.00
	present	2	1.95
	no longer visible	3	2.88
ventral bevelling	none	1	0.00
	incomplete	2	0.77
	completed over full length	3	0.37
	upper part no longer visible	4	2.82
symphysial rim	incomplete	1	0.00
	whole symphysis surface bordered by a broad rim	2	-0.85

 

age in years from multiple regression analysis (MRA) =

= (1.40 * (points for horizontal ridges and furrows)) + (0.48 * (points for pubic tubercle)) + (2.11 * (points for lower end)) + (1.91 * (points for dorsal margin)) - (0.27 * (points for superior ossific nodule)) + (1.45 * (points for ventral bevelling)) + (0.14 * (points for symphysial rim)) + 10.14

 

age in years from quantification theory model I (QMI) using normalized scores =

= SUM(normalized scores for all morphologic features)