FORMATION OF THE FORMATION OF THE PALATEPALATE

By: By:

Dr.Carmina GranadoDr.Carmina Granado

Formation of the PalateFormation of the Palate

Initially, during the Initially, during the 66thth week week of of development, there is development, there is a common oronasal a common oronasal cavity bounded cavity bounded anteriorly by the anteriorly by the primary palate and primary palate and occupied mainly by occupied mainly by the developing the developing tonguetongue

palatepalate

The tissue that separates the oral & nasal The tissue that separates the oral & nasal cavities.cavities.

This palate, although thin, is separated by This palate, although thin, is separated by bone, which provides rigiditybone, which provides rigidity

Develops from an anterior wedge-shaped Develops from an anterior wedge-shaped medial part & two lateral palatine processes.medial part & two lateral palatine processes.

The medial part is also known as The medial part is also known as the the primary palate primary palate because it develops first because it develops first and is a floor to the nasal pits.and is a floor to the nasal pits.

Lateral palatine process Lateral palatine process develop from develop from the maxillary tissues laterally & grow to the maxillary tissues laterally & grow to midline.midline.

It has been said that It has been said that the primary palate is the primary palate is formed by the formed by the merging of the two merging of the two median nasal median nasal processesprocesses

Between the Between the 77thth and and 88thth weeks weeks of of development, development, formation of the formation of the secondary palatesecondary palate occursoccurs

Formation of the Formation of the palate involves the palate involves the fusion of two fusion of two processes: processes: the right the right and left maxillaryand left maxillary processesprocesses and the and the medial nasal processmedial nasal process

The The median nasal median nasal processprocess grows grows downward and downward and forward to form the forward to form the nasal septumnasal septum

The growth into the The growth into the stomatodeum from stomatodeum from the inside of the the inside of the maxillary processesmaxillary processes is called the is called the right and right and left lateral palatine left lateral palatine processesprocesses, which at , which at first grows first grows downward to the downward to the elevated tongueelevated tongue

As a result of the As a result of the enlargement of the enlargement of the mandible and a mandible and a change in the degree change in the degree of flexion of the of flexion of the fetus head, the fetus head, the tongue drops to the tongue drops to the floor of the floor of the stomodeumstomodeum

When the tongue is When the tongue is removed from the removed from the path of the growing path of the growing lateral palatine lateral palatine processesprocesses, the , the processes are processes are straightened to a straightened to a horizontal positionhorizontal position

Then the Then the lateral lateral palatine processespalatine processes grows medially at the grows medially at the midline and fuse midline and fuse with each other and with each other and with the lower border with the lower border of the of the nasal septumnasal septum to give rise to the to give rise to the hard and soft palatehard and soft palate

At their anterior At their anterior borders, they meet and borders, they meet and fuse with the posterior fuse with the posterior border of the border of the premaxillary growth premaxillary growth (primary palate)(primary palate)

The structure thus The structure thus formed is at once the formed is at once the roof of the oral cavity roof of the oral cavity and the floor of the and the floor of the nasal cavitynasal cavity

Clinical ConsiderationsClinical Considerations

Cleft palateCleft palate – is the – is the result of the non-result of the non-fusion of the 2 fusion of the 2 palatine processes palatine processes and the inferior and the inferior border of the nasal border of the nasal septumseptum

UranoschisisUranoschisis – cleft – cleft hard palatehard palate

StaphyloschisisStaphyloschisis – cleft soft palate – cleft soft palate

Microstomia Microstomia – – abnormally small mouth abnormally small mouth due to the excessive due to the excessive merging of the merging of the mandibular and mandibular and maxillary processesmaxillary processes

MacrostomiaMacrostomia – big – big mouth resulting from mouth resulting from incomplete union of the incomplete union of the maxillary and maxillary and mandibular processes. mandibular processes. May also be called cleft May also be called cleft of the cheekof the cheek

Cleft jawCleft jaw – non – non fusion of the fusion of the globular processes globular processes with the maxillary with the maxillary processes (for upper) processes (for upper) or non-union of the 2 or non-union of the 2 mandibular mandibular processes forming processes forming the so called the so called true true median cleftmedian cleft

GOOD DAY!GOOD DAY!