3. FORENSIC OSTEOLOGY
Forensic osteology is a
sub-specialty of forensic
medicine and deals with
examination and
assessment of human
skeleton.
The assessment includes
both — the identification
of the victim’s
characteristics and cause
and manner of death
from skeleton
4. FORENSIC OSTEOLOGY
Whenever whole or partial skeleton or bundle of bones are
submitted by legal authorities for medical examination then
medical examiner should be able to answer following
questions
1. Are they bones?
2. Are they human bones?
3. What is the sex?
4. What would be age at the time of death?
5. What is the stature?
6. What is the race?
7. How identity could be established?
8. What would be time since death?
9. What was the cause of death?
10. What is the manner of separation?
5. FORENSIC OSTEOLOGY
Bone or Not
It is necessary to examine a given article and
opine whether the stated article is bone or not.
The following description will help in evolving the
answer.
• Gross examination of bone: Examination of
bone in respect to shape, size, texture, weight
and morphology with established anatomical
landmark will reveal true nature
• Microscopic examination: Microscopic
examination of bone will reveal true Haversian
system and presence of osteons
7. FORENSIC OSTEOLOGY
• Microscopic examination: Microscopic
examination may provide differentiation feature or at
least helps to exclude a human origin. The Haversian
system is different in animals than human. Haversian
systems and canals are of larger diameter in humans
than animals.
• Serological examination: Precipitin test can be
done by extracting species-specific protein from bone
into solution and tested against specific antisera of
human. The techniques such as electrophoresis or
gel diffusion can now identify human tissue.
8. FORENSIC OSTEOLOGY
Sex of Bone
Sex from bone is determined by
• Morphological examination
• Morphometry or osteometry i.e. by taking various
measurements of bone
• Multivariate discrimination function analysis
According to Krogman, the sexing from skeleton and
individual bones are given in Table 4.1. General sex
difference of skeleton is provided in Table 4.2. Sex
can also be determined from soft parts available with
bones by:
• Demonstration of Y-chromosome
• DNA profiling
14. FORENSIC OSTEOLOGY - AGE
Age at the time of death from bone/skeleton is determined by
noting the:
• Dental status
• Ossification data – the appearance and fusion of
ossification centers
• Age related changes occurring in individual bones
• Radiographic method
• Histological method – it is observed that size and shape of
osteons increases with age. The relation between osteons
and age is presented in table 4.3. Rai had derived a
regression equation for estimation of age. The
equation is – Age = number of osteons + 8.3.
15. FORENSIC OSTEOLOGY -
STATURE
Stature
Determination of stature from bone means estimation of
body height of that person. For estimation of stature, long
bones are widely preferred and are more reliable than flat
or irregular bones. The length of bone is taken with the
help of Hepburn osteometric board (Fig. 4.4).
When stature is estimated from a bone, an allowance of
2.5 to 4 cm is added to the calculated stature in order to
compensate the loss of soft tissues. (The total thickness of
the soft tissues in between the bones at different joint from
heel to vertex is about 2.5 to 4 cm)
17. FORENSIC OSTEOLOGY -
STATURE
Different formulae are used to estimate stature and
includes
• Karl Pearson • Trotter and Glesser
• Dupertuis and Haden • Pan • Nat
• Shah and Siddiqui
If fragmented long bones are submitted for medical
examination, stature can be estimated by following
formulae:
• Muller
• Steele
• Steele and McKern
18. FORENSIC OSTEOLOGY - RACE
Race
• Determination of race is difficult from bones, partly
because racial traits are not so marked and partly
because so much ethnic mixing has taken place
Amongst bones, skull offers better evidence
regarding race and according to Krogman and
Iscan, race can be determined in 90 to 95% of
cases.
19. FORENSIC OSTEOLOGY – TIME
SINCE DEATH
Time Since Death
Time since death is determined by analyzing:
• Gross examination of bones and/with state of soft
tissue available
• Stage of healing in case of fracture
• Physical tests
• Chemical tests
20. FORENSIC OSTEOLOGY – TIME
SINCE DEATH
Gross Examining
• Recent bones will have
soft tissue attached in form
of ligaments and/or
tendons, especially at or
near joints.
Periosteum may be visible
so do the cartilage
especially over articular
surface. Such bones may
emit putrid smell.
The bones will be soft,
moist and greasy to touch
21. FORENSIC OSTEOLOGY – TIME
SINCE DEATH
Gross Examining
•The recent bones, on sawing, will be hard and
uniform through the whole thickness. In old
bones, the bones become lighter due to loss of
organic matter and collagenous stroma. On
sawing, the outer cortex and to a lesser extent,
the zone around marrow cavity will loose stroma
first so a “sandwich” effect may be seen in which
a central ring of hard collagenous bone is layered
on each side by a zone of more porous crumbling
material
Due to wear and tear, the ends of long bone may
be fragile and brittle
24. FORENSIC OSTEOLOGY – TIME
SINCE DEATH
Stage of Fracture Healing (Fig. 4.8)
Examination of stage of fracture healing
offers help in dating time since death. Stages
of healing of fracture are
A. Stage of hematoma formation
B. Stage of Granulation tissue formation
C. Stage of Callus formation
D. Stage of Remodelling
E. Stage of Modelling
26. FORENSIC OSTEOLOGY – TIME
SINCE DEATH
Physical Test
• After sawing, if the cut surface of bone is examined
under ultraviolet light, recent bone will be
fluorescence (shine) with a silvery-blue tint across the
whole cut surface. With advancing age, the outer rim
and rim around the marrow cavity will cease to
fluorescence (due to loss of organic matter) and this
progressively deepens towards center. In older bones,
the surface will be non-fluorescent (Fig. 4.9).
The total time taken for loss of complete fluorescence
was estimated somewhere at 100 to 150 years
28. FORENSIC OSTEOLOGY – TIME
SINCE DEATH
Chemical and Serological Test
• Benzidine test or Kastel-Mayer test may be positive
up to 100 years. These test detects presence of blood
(Fig. 4.10).
• Serological test such as precipitation test, gel
diffusion or Coombs reagent may be positive for 5 to
10 years
• Presence of nitrogen – fresh bones have 4.5%
nitrogen. With bone become older, it progressively
loses nitrogen. If the nitrogen content is about 4%
then the death interval may be up to 100 years. At
about 350 years, the nitrogen content falls to 2.5% or
less.
32. FORENSIC OSTEOLOGY – CAUSE
OF DEATH
Cause of Death
Up to some extent, cause of death can be offered
based on following features:
• Any injury/fracture incompatible with life
• Presence of foreign body – bullet, pellets or any
piece of weapon
• Chemical analysis for poison
• Radiological examination for and
pathology/disease/malignancy/secondaries
33. Osteology: study of skeletal remains
CHE 113 33
Each bone studied INDIVIDUALLY
206 Skeletal Bones (total)
34. Theskull is abony structure
which serves asthe general
framework for the head.The
skull supports the structures
of the face and protects the
head against injury.
The skull can be
subdivided into two parts:
the cranium and the
mandible.
37. SKULL
The features that indicate sex are :
• General appearance
• Supra orbital ridges
• Orbits
• Glabella
• Zygomatic arches
• Mastoid processes
• External occipital protuberance
• Mandible
• Palate
38. FORENSIC OSTEOLOGY – SKULL
SKULL – Sex Determination from Skull
Sex from the skull is determined by morphological
examination and by doing craniometry. Table 4.4
provides differences between male and females
39. FORENSIC OSTEOLOGY – SKULL
SKULL – Sex Determination from Skull
Sex from the skull is determined by morphological
examination and by doing craniometry. Table 4.4
provides differences between male and females
46. Zygomatic arches
In females, the zygomatic arch is less pronounced, and tends
to not extend posteriorly beyond the external auditory meatus.
In males, the zygomatic arch is more pronounced or
robust, and tends to extend posteriorly beyond the external
auditory meatus.
48. MASTOID PROCESSES
The mastoid processes are located on the inferior
portion of the temporal bone, just posterior to the
external auditory meatus.
51. FORENSIC OSTEOLOGY –
SKULL - Stature Determination
Stature
Stature from skull can be estimated by performing somatometry.
Following are the various formulas for estimating stature
from skull.
1. Height of skull × 8 = stature
• Eight times the height of skull will give approximate height of the
individual
• Height of skull is measured from basion to the bregma Basion is the
point where the anterior margin of foramen magnum meets the mid-
sagittal plane.
2. From regression equation7
• Stature in male = (diameter + circumference of skull) ×
1.35 + 70.6 (S.E. = 6.96 cm)
• Stature in female = Circumference of skull × 1.28 + 87.8
52. FORENSIC OSTEOLOGY –
SKULL - Race Determination
Race
Race can be determined from morphological features
and cephalic index
Cephalic Index
Cephalic index (CI) is measured as follows.
C.I. = Maximum breadth of skull × 100 ÷ Maximum
length of skull.
53. FORENSIC OSTEOLOGY –
SKULL - Age Determination
.Age
Age from the skull can be
determined by studying the:
• Closure of fontanelle
• Fusion of bone
• Suture closure
• Secondary changes occurred
in skull.
54. FORENSIC OSTEOLOGY –
SKULL - Age Determination
.Closure of Fontanelles (Fig. 4.14)
• Lateral and occipital fontanelle
closed within two months
• Posterior fontanelle closes at 6–
8 months after birth
• Anterior fontanelle closes at
1.5–2 years after birth
55. FORENSIC OSTEOLOGY –
SKULL - Age Determination
. Fusion of Bone
• At the end of second year of life,
squamous part of
occipital bone unites with
condylar part
• Squamous portion of occipital
bone fuses with the basilar
part at 6th year
58. FORENSIC OSTEOLOGY –
SKULL - Age Determination
.
Suture Closure
Skull bones are united by sutures and the union is analogous with the
epiphseal-diaphyseal union. Epiphseal-diaphyseal union begins centrally and
proceeds peripherally; similarly suture closure begins endocranially and
precedes ectocranially.
In other words, union begins first endocranially and then ectocranially. Before
proceeding further, some terminology needs attention
• Lapsed union is the incomplete union in the sense that the process of fusion
has begun but has not gone to completion
• Precocious closure is the closure of suture before the age of seven years. At
this age the cranial growth is about 95 percent complete Premature closure is
closure after the age of 7 years but considerably before the usual or normal age
of closure
• Vault sutures are – sagittal, coronal and lambdoid suture
• Circummeatal sutures are – sphenotemporal, parietomastoid, masto-occipital
and squamous suture
• Basal suture is spheno-occipital
60. FORENSIC OSTEOLOGY –
SKULL - Age Determination
.
Pattern of Closure
• Sagittal suture unites evenly from front to back
• Coronal suture fuses from medial to lateral end
• Lambdoid suture fuses from medial to lateral end
• No difference exist between right and left sides of
skull
• No sex difference in fusion of suture
• According to Krogman, vault suture fuses between
17 to 50years whereas circummeatal suture closes
above 50 years
61. FORENSIC OSTEOLOGY –
SKULL - Age Determination
.
Age of Fusion
Here it is important to note that aging an individual solely on
suture closure will be unsafe exercise because the method is
not reliable. McKern and Stewart had concluded that suture
closure has only a general relationship with age. So erratic
is the onset and progress of closure that an adequate series
will provide just about any pattern at any age level.1 The
age provided by this method is in range of decade. Due
to phenomenon of lapsed union, which is found frequently
ectocranially, therefore more reliance should be placed on
endocranial closure. after McKern and Stewart) (Fig. 4.15).
• Metopic suture closes at 2 to 4 years
• Sagittal – 30 to 40 years
• Coronal – 40 to 50 years
• Lambdoid – 40 to 50 years
• Sphenotemporal – 50 to 60 years
• Parietomastoid – 80 to 90 years
• Masto-occipital – 80 to 90 years
• Squamous – above 80 years
65. Themandible together with the maxilla, the
largest and strongest bone of the face . It
forms the lower jaw and holds the lower teeth
in place.
66. FORENSIC OSTEOLOGY –
SKULL - Age Determination
.
Secondary Changes in Skull
• Texture – (after Todd 1939 and Cobb 1952) the texture of a young adult
skull is smooth and ivorine on both surfaces. At about 40 ± 5 years, the
skull surface begins to assume “matted, granular and rough appearance”.
• Markings on skull – after the age of 25 year onwards the muscular
markings become increasingly evident. The markings are – temporal line,
nuchal lines, and masseteric attachment on side of mandible.
• After 50 years, the diploe becomes less vascular with increasing
replacement by bone.
• The grooves for middle meningeal artery becomes deeper
• Thickness of skull – (after Todd 1924) the thickness of skull increases
with age. The increase in thickness is more after 50 years up to 60 years
with no decrease thereafter.
• Increase in skull size – (after Israel 1967 and 1968) on
lateral skull radiograph, Israel noted increase in skull size with increase in
skull thickness and skull diameter with advancing age.
67. FORENSIC OSTEOLOGY –
MANDIBLE SEX DETERMINATION
.
Sex
The differences between male and female in mandible are
described in the table below
68. FORENSIC OSTEOLOGY –
MANDIBLE STATURE & RACE
DETERMINATION
Stature
The distance between symphysis menti and angle of mandible is
taken and is multiplied by 16, which will give stature.
Stature = length from mandibulr angle to symphysis menti × 16.
Race
According to Schultz (1933) mandible in white people have
• Larger breadth,
• Higher and narrower ramus
• Greater gonial angle
• Ramal surface more parallel to the median sagittal plane
• Protrusive chin
• Mental tubercles placed more lateral in position
69. FORENSIC OSTEOLOGY –
MANDIBLE RACE
DETERMINATION
RACE:-
According to Schultz (1933) mandible in black
people have
• Lower, wider and more vertical ramus
• Greater dental arch length i.e. a long “U” shaped
dental arch
• Small breadth
• Less prominent chin
• Mental tubercles are placed more medial in
position and are smaller
70. FORENSIC OSTEOLOGY –
MANDIBLE AGE
DETERMINATION
Age
The mandible shows remarkable changes with age.
Following
are the age related changes in mandible (Fig. 4.18).
At Birth
• Two halves of mandible are united by fibrous symphysis
menti
• Body is shell like with imperfectly separated sockets of
deciduous teeth
• Mandibular canal is near the lower border
• Mental foramen opens below the first deciduous molar
• Mental foramen is directed forwards
• Coronoid process projects above the condyle.
71. FORENSIC OSTEOLOGY –
MANDIBLE AGE
DETERMINATION
At 1-3 Years
• At first year, two halves joins at symphysis from below upwards with separation
at alveolar margin – may persist into second year
• Body elongates behind mental foramen
• During first and second years, chin develops
• Condylar cartilage is covered on articular aspect by fibrous tissue
• Body height increases, alveolar growth make place for root of teeth
• The sub-alveolar region (area) becomes thicker and deeper
At 6 Years
• Mandible increase in size
• Remodelling continuous with bone added at posterior border of ramus.
Adults
• Alveolar and sub-alveolar areas are about equal in depth (size)
• Mental foramen midway between upper and lower border
• Mandibular canal nearly parallels the mylohyoid line
• Ramal height increase
• The condyloid process is at a higher level than the coronoid
process.
72. FORENSIC OSTEOLOGY –
MANDIBLE AGE
DETERMINATION
Old Age
• Bone is reduced in size
• Alveolar region is absorbed. Absorption affects mainly
the thinner alveolar part and after completion of
absorption, a linear alveolar ridge is left at the superior
border of mandible
• Mandibular canal near to superior border
• Mental foramen near to superior border
• Ramus become oblique, the angle is about 140 degree
• Neck is inclined backwards
73. Themale mandible
tends to have a
“square” shape.
Mandible of female
tends to have a
pointed chin.
Chin (anterior mandible)
74. Mandible in the
male is closer to a
right angle than
the female. In the
female, the ramus
is an obtuse
angle to the lower
jaw bone, i.e.,
greater than 90
degrees. The
ramus in the male
is wider and
larger.
RAMUS (rear of the mandible)
MALE FEMALE
78. FORENSIC OSTEOLOGY –
FEMUR AGE DETERMINATION
Age
Age estimation from femur
can be done by noting
following changes.
• Ossification events
• Radiographic changes
79. FORENSIC OSTEOLOGY –
FEMUR AGE DETERMINATION
Ossification Event
Table 4.9 provides ossification centers with their appearance
and fusion in male and female
80. FORENSIC OSTEOLOGY –
FEMUR AGE DETERMINATION
Ossification Event
Table 4.9 provides ossification centers with their appearance
and fusion in male and female
81. FORENSIC OSTEOLOGY –
FEMUR AGE DETERMINATION
Radiographic age determination from the proximal epiphyses of femur –
radiographs of the proximal end of femur show the progressive proximal-ward
extension of medullary cavity as age advances and the features are more obvious
in age ranges of 31.4 to 67.8 year. Acsadi and Nemeskeri (1970) divided the
changes into five phases. The phases are described below and the correlation with
age is presented in Table 4.10.
82. FORENSIC OSTEOLOGY –
FEMUR AGE DETERMINATION
• Phase 1: Apex of the medullary cavity below the lesser trochanter. Texture of
trabeculae is thick.
• Phase 2: Apex of medullary cavity reaches or surpasses the lower limit of lesser
trochanter
• Phase 3: Apex of medullary cavity reaches the upper limit of the lesser trochanter
• Phase 4: Apex of the medullary cavity extends above the upper limit of lesser
trochanter
• Phase 5: Apex of medullary cavity extends beyond the upper limit of lesser
trochanter. A cavity of 3 mm diameter is formed in the greater trochanter. Cavity
appears in the head beneath fovea capitis and at the medial and later border
• Phase 6: Cavities in medial part of neck merges with medullary cavity. Cavities
formed in neck and greater trochanter gets enlarged.
83. FORENSIC OSTEOLOGY –
FEMUR RACE DETERMINATION
Race
Race from femur can be determined from
• Morphological features
• Bone length
• Index
Morphological Features
Stewart (1962) and Walensky (1965) studied the femur in
respect with the anterior curvature and they have noted that:
• In Black people the femur are much straighter
• In White people the femur are bowed forward
• In American Indians, the femur has greater anterior
curvature and a more distal positioning of the point of
maximum curvature.
84. FORENSIC OSTEOLOGY –
FEMUR RACE DETERMINATION
Race
Bone Length
Table 4.11 shows racial variation in femur bone length in
American blacks and whites (after Krogman 1955). Male
bones are longer than female bones and slightly longer in
Blacks than in Whites.
85. FORENSIC OSTEOLOGY –
FEMUR RACE DETERMINATION
Race
Index
Following are the indices frequently used to determine race.Table 4.12 provides information
regarding indices and Table 4.13 provides value of indices in various races.
• Crural index
• Intermembral index
• Humoro-femoral index
86. FORENSIC OSTEOLOGY –
FEMUR STATURE DETERMINATION
Stature
Stature of an individual can be estimated from femur. The
length of bone is taken and is multiplied with multiplication
factor i.e. length of femur × multiplication factor = stature.
Different formulas and multiplication factors are available such as Karl Pearson
formula for Europeans, Trotter and
Glesser formula for American persons. In India, various
researchers of different states have evolved multiplication
factor to estimate stature. Table 4.14 presents multiplication
factor. Following account shows the authors and study
states.
• Pan – for residents of Bengal, Bihar and Orissa
• Nat – for residents of Uttar Pradesh
• Shah and Siddiqui – for residents of Punjab
• Singh and Shoha – for residents of East Punjab
• Mehta and Thomas – for residents of Mysore
90. FORENSIC OSTEOLOGY –
TIBIA RACE DETERMINATION
Race
Race is determined from Crural and Intermembral index.
Age
Table 4.17 provides ossification centers with their appearance
and fusion in male and female