LAB PRACTICUM

Figures A, B, C:  Cranial Suture Scoring Sites.

(Scanned from Buikstra and Ubelaker, eds. 1994).

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 Figure D:  Composite Scores (S-values)

(Scanned from Buikstra and Ubelaker, eds. 1994).

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Cranial Suture Closure

Ectocranial sutures are scored at a 1-cm section of suture surrounding the following points, as illustrated in Figure A (the Figures are shown above). Each section is a region comprised of all sutures within a 1-cm circle around the defined point.  Use the left side of the skull in instances of bilateral segments. 

1. Midlambdoid.  Midpoint of left half of the lambdoid suture (pars intermedia).

2. Lambda.  At lambda (pars lambdica) of lambdoid and sagittal sutures.

3. Obelion.  At obelion (pars obelica) of the sagittal suture.

4. Anterior Sagittal.  Point on the sagittal suture1/3 distance from bregma to lambda (at juncture of pars bregmatica and pars verticis).

5. Bregma.  At bregma (pars bregmatica of the coronal and sagittal sutures).

6. Midcoronal.  Midpoint of left coronal suture (within pars complicata).

7. Pterion.  At pterion, within the region of the upper portion of The left greater wing of the sphenoid, usually at the point at which the parietosphenoid suture meets the frontal bone.

8. Sphenofrontal.  Midpoint of the left spheno-frontal suture.

9. Inferior Sphenotemporal.  Point of intersection between the left sphenotemporal suture and a line connecting both articular tubercles of the temporomandibular joint.

10. Superior Sphenotemporal.  Point on the left sphenotemporal suture lying 2 cm below juncture with the parietal bone.

Composite scores are obtained by summing scores for five “vault” sites and five “lateral-anterior” sites. 

See Figure D.  If scores are not available for all sites used to obtain a composite score, then a composite score cannot be determined.

TABLE 1:  Composite Score Sites (after Meindl and Lovejoy 1985). 

TABLE 2:  Composite Scores Obtained from Cranial Sutures

According to Meindl and Lovejoy (1985), the lateral-anterior region proved to be a better predictor of chronological age than the vault sites. 

Obtaining An Age Estimate From The Hard Palate

Sutures of the hard palate should be scored across their entire length.  The left incisive suture should be scored rather than the right, if both segments are observable.  Figure B (above) illustrates the location of each suture segment. 

11. Incisive Suture.  (IN)  Separates maxilla (with canines, premolars and molars) from premaxilla (incisors only).

12. Anterior Median Palatine Suture.  (AMP)  Score entire length on paired maxillae between incisive foramen and palatine bone.

13. Posterior Median Palatine Suture.  (PMP)  Score entire length on paired palatine bones.

14. Transverse Palatine Suture.  (TP)  Score entire length between maxillae and palatine bones.

Mann (et al. 1987) outlines the technique for obtaining an age estimate from the palate.  By young adulthood, the incisive (IN) suture has already closed, with activity evident within the transverse palatine (TP) and posterior median palatine (PMP) segments.  Closure of IN, TP, and PMP, with the anterior median palatine (AMP) remaining at least partially open, are characteristic of middle adulthood.  Complete fusion is typical of older adults. 

Endocranial Suture Closure

Endocranial sutures should be scored across the following segments.  If the skull is complete, anterior sutures can be observed indirectly by use of a small flashlight and a dental mirror (a less expensive alternative is a good 1-inch automotive "mirror-on-a-stick").  Locations are indicated in Figure C (above).

15. Sagittal.  Full sagittal suture.

16. Left Lambdoid.  Pars lambdica and pars intermedia of the left lambdoid suture.

17. Left Coronal.  Pars bregmatica and pars complicata of the left coronal suture.      

Endocranial suture closures for the coronal, sagittal, and lambdoid sutures begin during young adulthood.  Advanced but incomplete closure stages are characteristic of middle adults, while fully fused are typically found in older adults (Krogman and Isçan 1986).

*Nota Bene

For The most part, assessing age on the human skull alone has fallen into disfavor.  Whenever possible, other skeletal elements and assessment methodology should be added to the overall age estimations.  The following URL leas to an excellent overview of The various researchers and their findings in a coherent historical summary of assessing age at death from the human cranium. http://www.geocities.com/xerexes/Cranial_sutures.html

TABLE 1: Iliac Crest Union

(Adapted from Bass 1987).

Iliac Crest: The iliac crest of the coxa fuses in stages, with the corresponding range of ages listed in the table below.  Stage 1 represents nonunion.  At Stage 2, the epiphysis is not fused and remains separate from the metaphysis.  Stage 3 is partial union, and Stage 4 is complete union.

TABLE 2:  Medial Clavicle Union

(Adapted from Bass 1987).

Medial Clavicle:  The medial epiphysis of the clavicle fuses in stages, with the corresponding range of ages listed in the table below.  Stage 1 represents nonunion.  At Stage 2 the epiphysis is not fused and remains separate from the metaphysis.  Stage 3 is partial union, and Stage 4 is complete union.

Table 3:  Brothwell’s System for Scoring Surface Wear in Molars. 

(Bass 1995; after Brothwell 1965)

Estimating Age from Ribs

Sternal rib end changes:  Osteological, histological, and radiographical studies have demonstrated that age-related changes occur in the sternal extremity of the rib.  Accordingly, the rib may provide a useful agent for the estimation of age in forensic anthropology.  Use the right 4th rib if possible.

Figure 1:  Summary of Sternal End Changes.

(Scanned from Burns 1999; after Isçan et al. 1985).

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