Download The skull

The skull
Forensic anthropology
The Skull

Total # - 22





8 paired, 6 unpaired
Cranium – skull without mandible
Calvarium – cranium without face
Sutures: serrated and interdigitated
The only moveable (synovial) joints


Occipital condyles and C1
TMJ
The Frontal Bone



Unpaired
Recognizable by the sinuses
Articulations?

Individual identification: unfused frontal
(called metopic suture), variable sinuses

2 growth centers (R&L)
Is the frontal useful?

Yes!

Age – the metopic suture fuses ~2-4 years

Sex determination



Supercilliary arch / frontal boss
Supraorbital margin
Temporal line
The Parietals

Paired
Rectangular shaped

Articulations?

Individual ID: variable sutures and foramen
placement


Growth – single growth center
Are the parietals useful?

Mostly for age

General thickness becomes more uniform with
adulthood

Fuses with parietal only with advanced age
The occipital

Unpaired
Ovoid with a big hole in it…
Articulations?

Individual ID: Inca bone p. 50




(usually triangular or rectangular)
Growth - 4 parts: squamous, 2 laterals, basial
(pars basilaris usually survives)
Is the occipital useful?

Yes!!!

Age

Pars basilaris




Fuses to squamous portion at 1-3 years
Fuses to the rest at 5-7 years
Fuses to sphenoid during mid teens
Sex


External occipital protuberance
Superior and inferior nuchal lines
The temporals

Paired
Circular (with a large process for ear canal)
Articulations?

Individual ID: suture variation



Growth – 3 parts: petrous, squamousal,
tympanic ring)
Are the temporal useful?

Age


The 3 parts are joined by ~5 years old
Sex

Mastoid process
The sphenoid




Unpaired
Butterfly shaped
Articulations?
Growth – many centers fuse by birth into 3
parts (wings separated by body) which fuse by
1 year old
The zygomatics

Paired facial bones
Triangular with maxillary, frontal, and temporal
processes
Forms lateral wall of orbit
Articulations?

Individual ID: variable sutures

Growth – 1 center,



Are the zygomatics useful?

Age


Zygomatics fully formed by 2-3 years old
Race

Suture pattern of the zygomaxillary junction
generally related to race
The ethmoid

Found at the base of the frontal, anterior to the
sphenoid
Very uniquely shaped
Forms part of the orbit (medial wall)

Need to know




Crista galli
Perpendicular plate
Other bones of the face

Not typically found, not
particularly useful in ID



The NASALS

The inferior nasal
conchae (found in nasal
aperture internally,
posterior to the nasal
bones

The lacrimals –tear ducts
The palatines – at back of
mouth, found behind
palatine process of
maxillae
Vomer – small wedge of
bone btw pterygoid
processes of sphenoid
(bisects nasal cavity)
The teeth
The Maxillae





Paired, facial
Contribute to structure of eyes, nose, mouth
3 processes; frontal, zygomatic, palatine
Articulations?
Individual ID: dental arch, teeth, prominence
of mouth and nose
Are the maxillae useful?

Yes!

Age – TEETH!!!

Race:



Width of nasal aperature
Projection of nose and mouth
Dental arch shape
The Maxillae





Paired, facial
Contribute to
structure of eyes,
nose, mouth
3 processes; frontal,
zygomatic, palatine
Articulations?
Individual ID:
dental arch, teeth,
prominence of
mouth and nose
Are the maxillae useful?

Yes!

Age – TEETH!!!

Race:



Width of nasal aperature
Projection of nose and mouth
Dental arch shape
The mandible

Single bone
U-shaped with vertical processes
Contains teeth: functions largely as muscle
attachments (chewing muscles and tongue) and
holds teeth

Individual ID: variable shape of jaw, teeth

Growth – 2 centers


Is the mandible useful?

YES!!

Age


2 halves fuse by 6-8 months
Sex


Mental protuberance
Gonial angle
The mandible



Single bone
U-shaped with vertical processes
Contains teeth: functions largely as muscle
attachments (chewing muscles and tongue) and
holds teeth
Is the mandible useful?

YES!!
Individual ID: variable shape of jaw, teeth

Growth – 2 centers

Age


2 halves fuse by 6-8 months
Sex


Mental protuberance
Gonial angle
Teeth!!!!!

Directional terminology





Labial: toward lips
Buccal: toward cheek
Lingual: toward tongue
Mesial: toward midline
Distal: toward back of mouth, away from midline
Teeth


We talk about teeth in
quadrants (RU, RL, LU,
LL), 8 in each
Short hand examples…


Upper, lower, left, right
4 types




Incisors (2)
Canines (1)
Premolars (2)
Molars (3)
http://en.wikipedia.org/wiki/Incisor
4 types
Incisor, Canine, Premolar, Molar
www.dkimages.com
Incisors

8 total

Anterior teeth
Single straight edge with no cusps
Single root


http://www.nature.com/bdj/journal/v203/n10/thumbs/bdj.2007.1059-f1.jpg
Canines

4 total

Distal to incisors
Single cusp
Single root


www.uic.edu/classes/orla/orla312/
CanMand.gif
Premolars

8 total

2 cusps


Distal to canine
http://www.uic.edu/classes/orla/orla312/
PreMandTwo.gif

Buccal root larger
1-2 roots
Molars

12 total


Multiple cusps
Multiple roots

Complex morphology for chewing and grinding

Upper molars generally have more roots
www.uic.edu/classes/orla/orla312/MolarDownOne.gif
http://www.uic.edu/classes/orla/orla312/MOLARS%20up
per.htm
www.tpub.com