3. Age Estimation Flashcards Preview

BMS 352 - Forensic Anatomy > 3. Age Estimation > Flashcards

Flashcards in 3. Age Estimation Deck (27)
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1
Q

What 2 principles is estimation of age based on?

A
  • Growth and development in immature skeletons

- Degenerative changes in adult skeletons

2
Q

What environmental variables may potentially influence skeletal age changes?

A
  • Diet
  • Physical activity
  • Disease
  • Trauma
3
Q

How does the uncertainty of age estimation change with increasing age?

A

Uncertainty (error) increases with increasing age

4
Q

What are the different ageing methods for adults?

A
  • Dental occlusal wear
  • Pubic symphysis metamorphosis
  • Auricular surface metamorphosis
  • Cranial suture closure
  • Rib sternal-end metamorphosis
  • Changes in trabecular bone density (in proximal ends of humerus and femur)
5
Q

What is dental wear caused by?

A
  • Attrition from inter-tooth contact (between upper and lower teeth)
  • Abrasion from hard particulates
  • Erosion from acidic fluids in oral cavity
6
Q

What does wear rates of teeth depend on?

A
  • Diet
  • Dental disease
  • Non-dietary usage of teeth
7
Q

Break down of enamel by occlusal wear exposes what?

A

Dentine (dark) and pulp cavity

8
Q

What can ante-mortem tooth loss be recognised by?

A
  • Remodelling and eventual obliteration of tooth socket
  • Movement of tooth crowns adjacent to lost tooth
  • Hyper-eruption of corresponding tooth on opposite jaw
9
Q

When do the following teeth erupt?

  • M1
  • M2
  • M3
A
  • M1 = 6 years
  • M2 = 12-14 years
  • M3 = 18-21 years
10
Q

How does the pubic symphysis change with age?

A
  • In young adults, the symphyseal surface consists of horizontal grooves and ridges (billowing)
  • With increasing age, the grooves are infilled and margins are thickened to develop a rim around joint surface
  • In old age, the surface is pitted and porous with an irregular margin
11
Q

What are the auricular surface of ileum stages characterised by?

A
  • Transverse organisation
  • Granularity
  • Porosity
  • Margins of joint surface
12
Q

How does the sternal ends of ribs 4-6 change with age?

A
  • In young adults, joint surface is smooth straight-walled and slightly indented
  • With increasing age, surface becomes deeper and wider with scalloping of the walls
13
Q

What are the age-related changes in the head of the Humerus and Femur?

A
  • Thinning and cavitation of the trabeculae
  • Increased height of the apex of the medullary cavity
  • Thinning of the cortex of the diaphysis
14
Q

How does root dentine transparency change with age?

A

Microscopic tubules in dentine are progressively infilled, starting at the root apex

15
Q

How does cementum growth change with age?

A

Cementum accumulates in thin layers on the surface of tooth roots - can count layers and add to age of tooth eruption to estimate age

16
Q

What are the growth standards based on for estimation of age at death in immatures?

A
  • Increase with age in linear bone dimensions
  • Appearance and fusion of centres of ossification
  • Calcification, eruption and subsequent loss of deciduous teeth and their replacement by permanent teeth
17
Q

How can immature bones be recognised?

A
  • Texture and density of metaphyseal surfaces

- Size and proportion of bones

18
Q

When does midline fusion occur?

A

Early in postnatal life

19
Q

When does epiphyseal fusion occur?

A

Adolescence

20
Q

What are late-fusing centres and when are they completed?

A
  • Medial clavicle and sacral bodies

- Early adult life

21
Q

What best described foetal and neonatal stages of development?

A

Early development of occipital bone

22
Q

What are the features of deciduous teeth?

A
  • Smaller
  • Cemento-enamel junction is less sinuous
  • Roots of anterior teeth narrow
  • Roots of posterior teeth flared to accommodate premolar crowns
  • Pulp chambers are large with thinner primary dentine
23
Q

What happens during exfoliation of primary teeth?

A

Root of primary tooth resorbs as the permanent tooth erupts from beneath until primary crown is lost

24
Q

How many roots do primary maxillary and mandibular roots have?

A
  • Maxillary have 3 roots

- Mandibular have 2 roots

25
Q

When do the first primary teeth erupt?

When do most children have all primary teeth?

A
  • 6 months

- 2.5 years

26
Q

What stages of dental development are growth standards available for?

A
  • Calcification and emergence of primary teeth
  • Root resorption and exfoliation of primary teeth
  • Calcification and emergence of permanent teeth
27
Q

Why are pictorial charts of dental development not sufficiently accurate for age estimation?

A

Individuals vary in sequence and timing of dental development