UNIT 4 - Palate and Oral Cavity development

When is the palate formed ?

By the End of 4th week and beginning of 5th week (embryonic period) —> pharyngeal arches

What reliefs of the face does first pharyngeal arch form ?

• 2 maxillary prominences

• 2 mandibular prominences

How is the definitive palate formed ?

It is formed by the fusion of :

• primary palate (intermaxillary segment)

• secondary palate

• nasal septum

How is the primary palate formed ?

• medial growth of the maxillary prominence and medial nasal prominence (intermaxillary segment)

• intermaxillary segment will grow and develop (part of the maxilla, 4 incisor teeth and triangular primary palate)

How is the secondary palate formed ?

• PALATINE PLATES (process) of the maxillary prominence, begin to grow medially (4-6 weeks)

• PALATINE PLATES fuse together, once the tongue leaves the space, forming the SECONDARY PALATE (6-8 weeks)

• THE SECONDARY PALATE is fused with the PRIMARY TRIANGULAR PALATE, with the INCISIVE HOLE being THE UNION BETWEEN THEM (10 weeks)

How is the nasal septum formed ?

JOINS THE TRIANGULAR PRIMARY PALATE AND THE SECONDARY PALATE SUPERIORLY TO THEM

Where does tongue development occur ?

Oral cavity floor

How is tongue developing ? (origin)

cells of mesodermal origin (muscle)

Which nerves innervate the tongue ?

Nerves from first (Trigeminal V), third (Glossopharyngeal IX) and fourth (Vagus X) pharyngeal arches

Which nerves is innervating the root of tongue and epiglottis ?

Vagus nerve (X)

Which nerve is innervating 1/3 POST of tongue ?

Glossopharyngeal nerve (IX)

Which nerve is innervating 2/3 ANT of tongue for taste ?

Facial nerve (VII)

Which nerves is innervating 2/3 ANT of tongue for sensitivity ?

Lingual nerve of mandibular branch of trigeminal nerve (V3)

Which nerves is innervating the tongue for motor movement ?

Hypoglossal nerve (XII)