Week 3- Ageing the human skeleton

Question 1

Estimation of age is based on:

Answer 1

• growth and development
• degeneration changes in adult skeletons
• Only estimate age range not a specific age

Question 2

What are factors in age changes?

Answer 2

• environmental variables= diet, physical activity, trauma and disease

Question 3

Several ageing methods

Answer 3

1. Dental occlusal wear- Wearing down dental enamel, closely tied with diet (hard and abrasive diet wears faster)
2. Pubic symphysis metamorphosis- changes on articular surface. Easy and straight forward. pubic bones tend to degrade in burial situations
3. cranial suture closure
4. auricular surface metamorphosis (ilium)- similar to pubic symphysis
5. Rib eternal metamorphosis
6. changes in trabecular bone density- humeral and femoral proximal ends

Question 4

Dental occlusal wear cause

Answer 4

attrition from inner tooth contact
Abrasion from hard particulates (food that you are eating)
Cumulative
* we know how much time the teeth have been in occlusion and age progressive

Question 5

When does M1 come into occlusion- start of permanent teeth eruption

Answer 5

6 years

Question 6

M2 into occlusion

Answer 6

12 years

Question 7

M3 into occlusion

Answer 7

18-20 years

Question 8

The permanent teeth complete eruption

Answer 8

13 years

Question 9

the exception of the 3rd molar ‘wisdom’ teeth, which usually erupt by the age of

Answer 9

21 years

Question 10

Why might the wear be different and why was it different in the past?

Answer 10

• if you lose a maxillary or mandibular molar than it wont have anything to wear against
• past people used their teeth more usually affecting the anterior teeth

Question 11

Age of individual years based on the condition of the M1

Answer 11

• polished enamel= 6
• dentine= 30
• secondary dentine= 42

Question 12

Functional age of M2- condition of tooth

Answer 12

• polished enamel= 6
• dentine= 26
• secondary dentine= 45

Question 13

Functional age of M3- condition of tooth

Answer 13

• polished enamel= 7
• dentine= 21-28
• secondary dentine= 49

Question 14

What is the highest category age you can research

Answer 14

When you are old, you probably have no dentine left, so you reach a category where you cannot estimate age (Over 65)

Question 15

Age changes in the pubic symphysis

Answer 15

• young adults= symphysial surface consists of horizontal grooves and ridges
• increase age= grooves are infilled and the margins are thickened to develop a rim around the joint surface
• old age= surface is pitted and porous with an irregular margin

Question 16

There is a rippling effect over the surface

Answer 16

The rippling of the bones begins to wear away

• body responds by laying down bone
• late stages= small holes which can coalesce and become larger, edges build up to provide more support to articular surfaces

Question 17

Suchy and brooks 1990 method

Answer 17

• 6 sequential stages of development from early to late
  -separate age standard for male and female due to differences in rate of metamorphosis
  early= good rippling, no edging
  late= pitting and wear down of rim

Question 18

Anterior surface of ilium

Answer 18

• Stages catergorized by changes in transverse organization
• becomes pitted and extra bone is laid on top of articular surface
• successive non overlapping 5 or 10 year age intervals

Question 19

Cranial suture closure

Answer 19

• recorded at defined locations on the superior and lateral anterior cranial vault
• sutures present as you age
• closure observed over a stretch of 1cm of suture and scored from 0 (open)to 3 (closed)= scores are summed and evaluated
• most sutures fuse between 30-50

Question 20

Changes in sternal ribs 4 to 6

Answer 20

• young adult= joint is smooth, straight walled and slightly indented
• articular surface changes with age
• increase age= increase in depth and width

Question 21

Changes in head of humerus and femur

Answer 21

Thinning and cavitation of the trabeculae
increased height of the apex of
thinning of cortex of the diaphysis

Question 22

Microscopic age estimation

Answer 22

1. Root denting transparency- microscopic tubules in dentine are progressively infilled, starting at the root
2. Cementum growth- accumulates in thin layers on the surface of the tooth roots.
3. Osteon accumulation- bone areas in compact bones, long bones- continue to grow in adult life

Question 23

Layers of the tooth

Answer 23

Enamel 
Dentine 
Secondary dentine 
cementum layers 
pulp cavity 
cement on tooth root

Question 24

Growth standards based on

Answer 24

• increase with age in linear bone dimensions
• appearance and fusion of centres of ossification
• calcification, eruption and loss of deciduous teeth `

Question 25

How to recognise immature bones?

Answer 25

- texture and density- Epiphyses are no fused on the shaft, smooth - size and proportions- using shafts of long bones - younger children are easier to age

Question 26

Age estimation based on epiphyseal fusion

Answer 26

- fusion of growth centres and epiphyses occur at defined stage of growth - fusion takes during adolescence - end of long bone was initially separated from shaft-cartilage ossifies so they can fuse

Question 27

The timings of proximal and distal end of the long bone, and the clavicle and sacral bodies

Answer 27

clavicle- completed early adult life | long bones-fuse at different times, timing may vary and the order is consistent

Question 28

Foetal or young children indicators

Answer 28

vertebrae are as good as age indicators | - body and 2 neural arches

Question 29

The 2 neural arches

Answer 29

1. first neural arches will fuse together and then the body | fuse at different rates

Question 30

Deciduous teeth- general characteristics

Answer 30

- smaller size, prominent bulge to crown above the cervical margin - cemento-enamel junction is less sinuous - roots of anterior teeth narrow - roosts posterior teeth flared to accommodate premolar crowns - pulp chambers are large with thinner primary dentine - enamel wears quickly and prone to decay - roots reabsorbed prior to exfoliation of crowns - mandibular first molar does not look distinguishable, second more obvious

Question 31

How do you evaluate age based on dental development?

Answer 31

pictorial charts of dental developmet- not sufficiently accurate - can look at how much of the crown is formed and how much of the root is formed - permanent first molar at the stage of 5.1 years - canine crown estimated 4 years

Question 32

Which is more reliable- dental eruption or calcification?

Answer 32

Calcification is much more reliable | crowns and roots estimate age

Question 33

Growth standards are available for the following stages of dental development:

Answer 33

- calcification and emerge of the deciduous teeth - root reabsorption and exfoliation of deciduous teeth - calcification and emerge of permanent teeth

Question 34

Pubic symphysis stages

Answer 34

1- billowing surface composed of ridges and furrows, well marked 2- retain some billowing, extremities show early stages of delamination with possible ossific nodules 3- smooth , retains some evidence of ridges, nodules, extremities show 4- fine grained, oval outline with distinctive rim, pubic tubercle not part of symphyseal surface. bony outgrowths may occur 5- depression of face of completed rim, outgrowths of ventral border 6- depression in rim erodes. Bony outgrowths. face pitted or porous