POSTNATAL GROWTH AND
DEVELOPMENT OF CRANIAL AND
FACIAL REGION
DR. ZUBER AHAMED NAQVI
Preclinical orthodontics
OBJECTIVES
 GROWTH OF CRANIAL BASE
 CORTICAL DRIFT AND REMODELLING
 SYNCHONDROSIS
 POST NATAL GROWTH OF NASO MAXILLARY COMPLEX
 POST NATAL GROWTH OF MANDIBLE
• Cranial base grows post- natally by complex
interaction between three growth processes– Cortical drift and remodelling
– Elongation at synchondrosis
– Sutural growth
CORTICAL DRIFT AND REMODELLING
• It is a process where
bone deposition and
resorption occurs so as
to bring about change
in size, shape and
relationship of the
bone.
ELONGATION AT SYNCHONDROSIS
• Remnants of primary cartilage
at the junctions of the bones
of cranial base are known as
synchondrosis.
• Spheno - occipital
synchondrosis
• Inter - sphenoid
synchondrosis.
• Spheno – ethmoid
synchondrosis.
• Intra - occipital synchondrosis.
SYNCHONDROSIS
• Spheno - occipital synchondrosis
• Cartilaginous junction between
the sphenoid and the occipital
bone.
• Closure of synchondrosis occurs
on an average at 13-15 years of
age.
• Spheno – ethmoid
synchondrosis.
• Cartilaginous junction between
the sphenoid and the ethmoid
bone.
• It ossify by 5- 25 years of age.
SYNCHONDROSIS
• Inter - sphenoid
synchondrosis.
• Cartilaginous band
between the 2 parts of
sphenoid bone.
• It ossifies at birth.
• Intra - occipital
synchondrosis.
• cartilaginous union
between the squamous
and lateral parts of the
occipital bone in the
newborn.
• It ossifies at the age of
3- 5 years.
SUTURAL GROWTH
• As the brain enlarges
during the growth, bone
formation occurs at the
ends of bone ( at either
ends of the suture)
• Spheno - frontal suture
• Fronto - temporal suture
• Spheno - ethmoid suture
• Fronto – ethmoid suture
• Fronto – zygomatic suture
POST NATAL GROWTH OF NASO MAXILLARY
COMPLEX
Mechanism
1. Displacement
2. Growth at suture
3. Surface remodelling
DISPLACEMENT
• Maxilla is attached to cranial base
by a means of number of sutures.
Hence growth of cranial base has a
direct effect on nasomaxillary
growth.
• Primary displacement- this occurs
by growth of maxillary tuberosity in
posterior direction.
• This results in whole maxilla being
carried anteriorly.
• Secondary displacement• It occurs in forward and downward
direction as the cranial base grows.
• The actual enlargement of these
parts is not directly involved.
SURFACE REMODELLING
• Bone deposition and
resorption occurs which
cause• Increase in size.
• Change in shape of
bone.
• Change in functional
relationship.
GROWTH AT SUTURE
• Fronto nasal suture
• Fronto maxillary suture
• Zygomatico temporal suture
• Zygomatico maxillary suture
• Pterygo palatine suture
POST NATAL GROWTH OF MANDIBLE
• Of the facial bones, the mandible undergoes
the largest amount of growth post - natally.
RAMUS OF MANDIBLE
• It moves progressively posterior by a combination of
bone deposition and resorption.
• Resorption- anterior part of ramus.
• Deposition- posterior region.
Function of remodelling of ramus
To accommodate the increasing mass of
masticatory muscles inserted into it.
To accommodate the enlarged breadth of the
pharyngeal space.
To facilitate the lengthening of the mandibular
body which accommodates the erupting
teeth.
CORPUS OR BODY OF MANDIBLE
• Bone remodelling
results in displacement
of ramus which results
in conversion of formal
ramal bone into the
posterior part of body
of mandible.
ANGLE OF MANDIBLE
• Bone remodelling results in flaring of the
angle of the mandible as age advances.
THE ALVEOLAR PROCESS
• It develops in response
to the presence of
tooth buds.
• As the teeth erupts
alveolar process
develops and increases
in height by bone
deposition at the
margins.
THE CHIN
• The mental
protuberance forms by
bone deposition during
childhood.
• Its prominence is
accentuated by bone
resorption that occurs
in alveolar region.
THE CONDYLE
• Growth of soft tissues
including the muscles
and connective tissues
carries the mandible
forward away from
cranial base. Bone
growth follows
secondarily at the
condyle to maintain
constant contact with
the cranial base.
THE CORONOID PROCESS
It follows the enlarging V principle of growth.