Transcript
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
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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
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