Bones of calvaria are 8 in number
1. 2 parietal
2. 2 temporal
3. 1 occipital
4. 1 frontal
5. 1 sphenoid
6. 1 ethmoid
Bones of face and jaws are 14 in number
1. 2 maxilla
2. 2 zygomatic
3. 2 nasal
4. 2 lacrimal
5. 2 palatine
6. 2 inferior nasal concha
7. 1 mandible
8. 1 vomer
Age from the skull can be determined by
1. Closure of fontanelle
2. Fusion of bone
3. Suture closure
4. Secondary changes in skull
Closure of fontanelles –
Lateral fontanelle closed within 2 month
Posterior fontanelle closes at 6-8 mnths after
birth
Anterior fontanelle closes at 1.5-2 yrs after birth
Fusion of bone –
Squamous part unites with condylar part – end of
2nd yr
Squamous part fuses with basilar at end of 6th year
Suture closure –
Skull bones are united by sutures
Suture closure begins endocranially and precedes
ectocranially.
Lapsed union is incomplete union in which the
process of fusion has begun but has not been
completed
Precocious closure is closure before the age of 7
yrs. At this age the cranial growth is 95% complete
Premature closure is closure after 7y but
considerably before normal yr of closure
Age of fusion of skull suture –
Metopic suture – 2 to 4 yrs
Sphenotemporal – 50 – 60 yrs
Parietomastoid – 80-90 yrs
Masto occipital – 80-90 yrs
Bassiociput and basisphenoid junction fuses at
18-20 yrs
Coronal , sagittal and lambdoid sutures fusion are
mentioned accordingly in next page
Secondary changes in skull –
Muscular markings of skull are more evident after
25 yrs like the nuchal line
After 50 yrs the diploe becomes less vascular and
is replaced by bone
The grooves for middle meningeal artery becomes
deeper.
Suture closure occurs late in females than in
males
Suture to best estimate the age of skull – sagittal >
lambdoid > coronal
Parts of sagittal suture –
1. pars begmatica
2. Pars vertica
3. Pars obelica
4. Pars lambdica
Parts of coronal suture
1. Pars bregmatica
2. Pars complicata
3. Pars stephanica
4. Pars pterica
Parts of lambdoid suture –
1. pars lambdica
2. Pars intermedia
3. Pars asterica
Vault sutures are –
1. Sagittal
2. Coronal
3. Lambdoid
Circummeatal sutures –
1. Sphenotemporal
2. Parietomastoid
3. Masto occipital
Basal suture –
1. Spheno occipital
SEX DETERMINATION
FEATURES MALE FEMALE
SURFACE RAGGED SMOOTH
FOREHEAD STEEP MORE
ROUNDED
GLABELLA MORE LESS
PROMINENT PROMINENT
FRONTAL AND LESS PROMINENT MORE PROMINENT
PARIETAL
EMINENCES
SUPRA ORBITAL PROMINENT LESS PROMINENT
RIDGE
SUPRAORBITAL ROUNDED SHARP
MARGIN
ORBIT RECTANGULAR ROUNDED
ZYGOMA THICKER , THIN
PROJECTED
OUTWARDS
FRONTO NASAL DISTINT SMOOTH CURVE
ANGLE ANGULATION
PALATE U SHAPED PARABOLA
OCCIPITAL CONDYLES MORE LARGE LESS
FORAMEN MAGNUM LARGE AND OVAL SMALL AND ROUNDED
MASTOID PROCESS HUGE WITH APEX SMALL WITH
DIRECTED MEDIALLY DIRECTED
VERTICALLY DOWN APEX
WITH CONCAVITY
JUST ABOVE BASE
DIGASTRIC GROOVE DEEP SHALLOW
NUCHAL LINES MORE PROMINENT LESS PROMINENT
Pterion takes 25 yrs to close
Asterion closes at 50 yrs
STATURE ESTIMATION –
Height of skull * 8
Height of skull is determined from basion to
bregma.
Basion is the point where the anterior margin of
foramen magnum meets the sagittal plane.
