Development of the face and palate Dr Gallatz Katalin

Development of the face and pharyngeal arches 4-5.week Pharyngeal arches begin to develop in the 4th week as the neural crest cells migrate into the future head and neck region.

The pharyngeal apparatus consist of: - pharyngeal arches - pharyngeal pouches - pharyngeal grooves - pharyngeal mebranes

Each pharyngeal arch contain: - cartilage - nerve - artery - myoblast - mesenchyme

MIGRATION OF THE NEURAL CREST CELLS

Stomodeum stomodeum: a wide shallow depression in the face, limited in its depth by the buccopharyngeal membrane

Frontal prominence from the mesenchyme covering the forebrain Maxillary prominence from mesenchyme of the I. pharyngeal arch Mandibular prominence From the mesenchyme of the I. pharyngeal arch

4. week The stomodeum is surrounded by facial prominences 1 frontonasal prominence 2 maxillary prominence 2 mandibular prominence On both sides of the frontonasal prominences thickenings of surface ectoderm form the nasal placods

5. week 1.The nasal placods invaginate to form the nasal pits 2.Medial and lateral nasal processes are formed around the nasal pits 3.Maxillary and lateral nasal processes are separated by the nasolacrimal groove nasolacrimal duct

NASAL PLACODS MEDIAL AND LATERAL NASAL PROMINENCES

7-10. week intermaxillary segment Maxillary prominences grow and press the medial nasal processes, they unite and fuse with the maxillary prominences. Maxillary prominences fuse with the lateral nasal prominences and with the mandibular prominences The fused medial nasal prominences form the intermaxillary segment 7-10. week

1. labial component philtrum of the lip Intermaxillary segment is composed of 1. labial component philtrum of the lip 2. upper jaw component alveolar process of the incisor teeth 3. palatine component primary palate

- The ectodermal thickening betwen the lateral nasal and maxillary invaginates into the underlying mesoderm, the nasolacrimal groove and cord is formed later it canalicularises and it becomes nasolacrimal duct. - The maxillary prominences unite with the medial and lateral nasal processes and also with the mandibular prominences.

Palatogenesis 5-12th week Critical period 6-9th week The palate develops from two primordia: - the primary palate - the secondary palate

Development of the palate Primary palate develops from the palatine portion of the intermaxillary segment Secondary palate develops from the palatine process of the maxillary prominence

- Palatine processes (or palatal shelves) project inferolaterally on each side of the tongue. - As the jaws develop he tongue moves inferiorly, the palaine processes elongate and ascend to the horizontal position. They fuse in the median plane and also fuse with the nasal septum and with the primary palate Nasal septum develops as a downgrowth from the internal part of the merged medial nasal prominences

Derivates of the facial prominences Frontonasal prominence frontal part: forehead, root of the nose medial nasal process: - dorsum and tip of the nose, nasal septum intermaxillary segmentum: philtrum, alveolar process of the incisor teeth, primary palate lateral nasal process: alae (wings) of the nose Maxillary prominences: maxilla, lateral part of the upper lip, upper part of the cheek secondary palate Mandibular prominence: lower lip, inferior part of the cheek

Development of the nasal cavity - oronasal membrane - primitive choana primary and secundary palate - nasal conchas - olfactory region - paranasal sinuses

Summary of the development of the face 1. Development of the stomodeum and the facial prominences, 2. appearence of the nasal placods nasal pits 3. development of the medial and lateral nasal prominences 5.week 4. growth of the maxillary prominences, 5. fusion of the medial nasal processes, 6. formation of the intermaxillary segment, 7. development ot the primary palate 6-7. week, 8. formation of the nasolacrimal sulcus and duct, 9. fusion of the maxillary prominence with the and medial and lateral nasal prominences, 10. secondary palate, separation of the nasal and oral cavity

Development of the Face MOVIE v

Malformations Median cleft lip Lateral cleft lip (cheiloschisis) Cleft of the upper jaw (gnatoschisis) Cleft palate (palatoschisis) Oblique facial cleft Transverse facial cleft Macrostomy, microstomy Cleft uvula

Malformations

Malformations Median cleft Cleft of inferior lip Obligue facial cleft Macrostomia Microstomia Bifid nose and incomplete median cleft

Congenital anomalies of the face 1.Lateral cleft lip ( hare lip): Due to failure of fusion between the maxillary process with the intermaxillary segment, unilateral or bilateral . 2. Median cleft lip : Due to incomplete union of the 2 medial nasal swelling in the middle line .

Bilateral cleft lip

3. Oblique facial cleft : Due to failure of union of the maxillary processes with lateral nasal processes.

Thank you for your attention! Development of the Face and Palate www.indiana.edu/~anat550/hnanim/face/face.html Face And Palate - YouTube ► 4:07► 4:07 www.youtube.com/watch?v=DgZ_tqucdI4