Hard palate
It is a septum which separate nasal cavity from oral cavity.
Formation :
1.
Anterior 2/3 by palatine process of maxilla
2.
Posterior 1/3 by horizontal plates of palatine
bone
Sutures:
There are
three sutures present in hard palate.
1.
Intermaxillary
suture
2.
Interpalatine
suture
3.
Palatomaxillary
suture
Relations:
Anteriorly it is continuous with alveolar arches and gums
Posteriorly it is
attached with soft palate
Superiorly it is formed floor of nasal cavity
Inferiorly it is formed roof of oral cavity. Inferior
surface bears following structures
1.
Incisive fossa : a small pit behind the
incisive teeth , it is the lower opening of two incisive canal (right and left)
. incisive canals transmit terminal part of nasopalatine nerve and greater
palatine vessels
2.
Greater palatine foramen: transmits greater
palatine nerve and vessel
3.
Lesser palatine foramen: transmits lesser
palatine nerve and vessel
Histology of hard
palate :
It
has two surfaces:
Histology
of nasal surface of hard palate:
It is lined by pseudo-stratified ciliated columnar
epithelium.
This epithelium
contains intraepithelial gland.
Sub-endothelial
connective tissue contains glands,
blood vessels and lymph vessels.
The epithelium and the sub-epithelial
connective tissue are collectively known as the mucoperiosteum, which is
firmly attached to the bony shelf of the palate.
Masticatory mucosa :
It is found in the gingival (gums)
and the hard palate
1.
Lining
epithelium: Keratinized stratified squamous epithelium and in some place
parakeratinized .
Keratinized
epithelium of hard palate likes skin but stratum lucidum layer is absent.
Criteria of parakeratinized
stratified squamous epithelium :
·
Superficial
cells have nuclei like keratinized stratified squamous epithelium but nuclei
are pyknotic (highly condensed) remain until the cell is exfoliated and
·
cytoplasm
is not intensely stain by eosin
Rete ridges are
present in epithelium they are deep invagination of epithelium with
subepithelial
connective tissue
2.
Lamina propria is formed by connective tissue
contain dense collagen fibres, blood vessels and nerves. Deep to lamina propria
contain reticular fibre rich dense connective tissue which firmly bind the
palatine mucosa to the periosteum. Hard palate is also containing large
deposits of adipose tissue at its anterior part and mucous gland at its
posterior part.
Blood supply : greater palatine artery (from the
third part of the maxillary artery) which emerges from the greater palatine
foramen and passes forwards around the palate (lateral to nerve) to enter the
incisive canal and pass up into the nose
Vein: corresponding vein drain into
pterygoid venous plexus and pharyngeal plexus.
Lymphatic drainage:
retropharyngeal and deep cervical lymph
nodes
Nerve supply : by branches of maxillary
nerve via pterygopalatine ganglion
1.
Anterior part is supplied by two nasopalatine
nerves
2.
From incisive fossa to rest of the posterior
part is supplied by greater palatine nerve .
Development:
1.
Primary palate
develops from intermaxillary
prominence
2.
Secondary
palate develops from palatine shelves from the maxillay prominence
Two palatine shelves of maxillary prominence unite and fused
with primary palate.
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