DESCRIBE THE PALATE FORMATION & ITS DEVELOPMENTAL ANOMALIES Amjad Al-bleahid

Introduction The palate is the tissue between the oral

& nasal cavities. It develops from two parts: 1-The primary palate. 2-The secondary palate.

The primary palate appears earlier than the secondary palate

Primary palate The primary palate is also called the

median palatine process or the premaxillary bone

Develop at the beginning of the 6th Week of IUL

It is a wedge shaped tissue occupying the anterior area of the hard palate anterior to the incisive fossa

It carries the 4 maxillary incisors

Primary palate

-Primary palate develops from MNP or the intermaxillary segment

-It develops during the development of the nasal cavity towards the oral cavity

Development of the Secondary Palate

The secondary palate is that part of the palate posterior to incisive papilla.

- It forms the remaining part of the hard palate and soft palate.

Development of Secondary Palate

1. Palatal shelf formation.

2. Palatal shelf elevation.

3. Fusion of primary and secondary palates.

4. Hard palate and soft palate

I. Palatal Shelf Formation At the end of the 6th week, 2 lateral

palatine processes develop from the inferio-medial edges of the maxillary processes

At first, they grow medially & downward on either side of the tongue

II. Palatal Shelf Elevation From 8-9 weeks of IUL, the lateral

palatine shelves slide or roll over the tongue & acquire a horizontal position (shelf elevation)

III. Fusion of the Primary & Secondary Palates The palatine closure begins from the 9th

to the 12th Week of IUL The fusion occurs by contact of the 2

processes, loss of intervening epithelium & growth of connective tissue across the midline

Developmental Anomalies-Cleft Palate

Cleft palate is less common than cleft lip. Clefts of the palate may be unilateral or bilateral & are classified into three groups

Causes It may be due to lack of growth It may also be due to interference with palatal

shelves elevation Failure of fusion between the median & lateral

palatine processes & the nasal septum It may be due to initial fusion with interruption of

growth at any point along its course

1 .Cleft of Primary Palate Clefts anterior to the incisive foramen These result from failure of the lateral palatine

processes to meet & fuse with the primary palate Clefts of the primary palate are usually

associated with missing or malformed teeth adjacent to the clefts such as lateral incisors & canines

2 .Clefts of the Secondary Palate Clefts posterior to the incisive foramen They are due to partial or complete

failure of the lateral palatine processes to meet, fuse with each other & with the nasal septum

Thanks for listening..

Note : that cleft palate must be accompanied by cleft lip While cleft lip can be alone without cleft palate or it is not accompanied by cleft palate