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Development of the lips and palate.
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V1
VII
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V2
V3
Dr. Frank C. T. Voon
13 Apr 2009
Summary
The mandible and lower lip are formed by the fusion
of the paired mandibular processes.
The upper lip develops from the intermaxillary
segment and from fusion of the maxillary process
with the medial nasal process on each side.
The intermaxillary segment gives rise to the philtrum,
incisors and the primary palate.
The secondary palate develops from fusion of the
palatine shelves of the maxillary process.
Medial nasal processes
Maxillary processes
Intermaxillary segment
Lip - lateral part
Palatine shelves
Concept
labial component
philtrum Lip - median part
alveolar component
4 incisors
palatal component
primary palate
secondary palate
Definitive palate
Hard palate
Maxilla &
Palatine bone
Soft palate
muscles
Derivatives of the Germ Layers
Epithelium
Endoderm
Nerve
Ectoderm
Connective tissue
Muscle
Mesoderm
Pharyngeal pouch
Artery
Nerve
1st arch
Cartilage
2nd arch
Pharyngeal cleft
3rd arch
4th arch
Orifice of larynx
The face begins to form in the 4th week.
Brain
The mesenchyme
(mesoderm) of 5
facial primordia
from the 1st
pharyngeal arch
proliferate around
the stomodeum.
1st
rd
2nd 3
Heart
Liver
The 5 facial primordia are the:
single frontonasal
process,
paired maxillary
processes,
Cardiac bulge
and paired
mandibular processes.
Medial and lateral nasal swellings also
form as part of the frontonasal process.
medial nasal swelling
lateral nasal swelling
frontonasal
process
maxillary process
Mns
Mp
mandibular processes
The right and left medial nasal swellings
fuse to form the intermaxillary segment.
The intermaxillary segment
develops into 3 parts, the
philtrum, the alveolar part (4
incisors) and the primary
palate.
The maxillary and medial
nasal process on each side
fuse to form the rest of the
upper lip.
Maxillary process
The right and left mandibular
processes fuse to form the
mandible.
Mandibular processes
The palatine shelves of the
right and left maxillary
processes fuse with the
primary palate to form the
definitive palate.
Philtrum
4 incisors
Primary palate
Secondary palate
The incisive foramen marks
the point of fusion between the
two palatine shelves with the
intermaxillary segment.
Cleft lip & palate
Cleft secondary palate
unilateral
bilateral
In the adult, the definitive palate consists of the hard
palate and soft palate as well.
The palatine process of the maxilla and the horizontal
plate of the palatine bone are the bones of the hard
Incisors
palate.
Definitive palate
Primary palate
Incisive foramen
Secondary palate
The soft palate contains
5 muscles, namely the:
Palatoglossus,
Palatopharyngeus,
Musculus uvulae
Levator veli palatini, &
Tensor veli palatini.
Palatoglossus, palatopharyngeus, musculus uvulae
and levator palati are supplied by the branches of
the vagus nerve in the pharyngeal plexus.
Tensor palati is supplied by the mandibular nerve.
The Palate
The palate consists of the hard palate and soft palate.
The hard palate separates the oral cavity from the nasal cavity.
The soft palate separates the oropharynx from the nasopharynx .
The 3 foramina in the hard palate are the:
incisive foramen which transmits the nasopalatine nerve and artery,
greater palatine foramen which transmits the greater palatine n & a.,
lesser palatine foramen which transmits the lesser palatine n & a.
The mucosa of the hard palate is supplied by the nasopalatine and
greater palatine nerves.
The mucosa of the soft palate is supplied by the lesser palatine nerves.
These are all branches of the maxillary nerve.
The mucous glands are supplied by parasympathetic fibers from the
pterygopalatine ganglion.
There are taste fibers in the soft palate which travel with the lesser palatine nerves, pass
through the pterygopalatine fossa and pterygoid canal, and then travel with the greater
petrosal nerve to join the facial nerve, and their cell bodies are in the geniculate ganglion.