howMed Know Yourself
Sex of an unidentified skeleton may be determined from the differences in the bones among males and females.
Krogman’s Sex Determination from Skeleton
| Entire skeleton | 100% accuracy |
| Pelvis only | 95% accuracy |
| Skull and pelvis | 98% accuracy |
| Skull only | 92% accuracy |
| Pelvis and long bones | 98% accuracy |
| Long bones only | 80% accuracy |
a. Subjective Sex Determination
e.g. From morphology of bones
b. Objective Sex Determination
e.g. From pelvic indices
Pelvic Sex Differences
| Males | Females | |
| Pelvic cavity | Longer and more conical | Shorter and more cylindrical |
| Dimensions | Greater | Less |
| Markings for muscles and ligaments | More prominent | Less prominent |
| General architecture | Stouter and heavier | Lighter |
| Pelvic brim | Heart shaped | More circular or elliptical |
| Anterior pelvic wall | More in height | Lesser in height |
| Sub pubic arch or angle | More angular (50-60 degrees) | U shaped (80-85 degrees) |
Pelvic Indices
Sacral Index = Sacral breadth/Sacral length x 100
Male = 105%
Female = 115%
Ischium Pubis Index = Pubis length/ Ischium length x 100
In Negroes
- Male < 84
- Female > 88
Caucasians
- Male < 90
- Female > 95
Ilium
| Iliac crest | More rugged and curves medially more acutely at anterior end | Less curved |
| Iliopectineal line | Less vertical | More vertical |
| Pre-auricular sulcus | Less marked | Well marked |
| Pubis | ||
| Body of pubis bearing symphyseal surface | Triangular in shape | Quadrangular in shape |
Ischium
| Ischial spine | In turned | Out turned |
| Ischiopubic rami | Distinctly roughened area for attachment of crus penis | Attachment of clitoris poorly developed |
| Acetabulum | Larger | Smaller |
| Obturator foramen | Ovoid and larger | Triangular |
| Greater sciatic notch | Wider |
Sacrum
| Longer and narrower | Shorter and wider | |
| More massive | Less massive and smooth | |
| Dorsal convexity | Less prominent | More prominent |
| Over 5 segments due to addition of a lumbar or coccygeal vertebra | ||
| Auricular surfaces for articulation with ilium | Longer | Shorter |
| Articular facet | 1/3 of width of base | Less than 1/3 in female |
Femur
| Length | Longer | Shorter |
| Weight | Heavier | Lighter |
| Texture | Rough | Smooth |
| Muscle markings | More developed | Less developed |
| Shaft | Less oblique | More oblique |
| Head of femur | Larger | Smaller |
| Linea aspera | More marked | Less marked |
| Trochanters | More prominent | Less prominent |
| Femoral neck angle | More (>125) | Less (<125) |
Sternum
Generally sternal body is more than twice the length of manubrium in males and less than twice in females.
Skull
Until age of puberty there is little difference.
| Heavier and larger | Lighter and smaller | |
| Capacity | More | 10% less |
| Walls | Thicker | Thinner |
| Muscular ridges | More marked | Less marked |
| Glabella, superciliary arch and mastoid process | Well marked | Less marked |
| Air sinuses | More prominent | Less prominent |
| Upper margin of orbit | Smoother | Sharper |
| Orbital shape | Squarer or rectangular | Round |
| Forehead | Less vertical | More vertical |
| Fronto-nasal angulation | Distinct | Less distinct |
| Cheek bones | Heavier and more laterally arched | Lighter |
Lower Jaw
| More massive | Less massive | |
| Rami | More broad | Less broad |
| Angle region | Everted | |
| Chin | Squarer | More rounded |
