Development and

malformations

of face and palate

Compiled by

András Csillag and

Andrea D. Székely

ECTODERM contributing to the formation of the face appears by the 4th week.

The oropharyngeal membrane (interface between ECTODERM and ENDODERM)

is located in front of the later palatine tonsils. Ectodermal structures limiting the stomodeum participate in the formation of the face, as well as of the nasal and oral cavities.

MESENCHYME that fills the pharyngeal arches derives from the neural crest

GERMINAL LAYER DERIVATIVES

ECTOMESENCHYME

DEVELOPMENT OF THE FACE

WEEK 6The face is formed by 5 processes

Frontonasal prominence (1)

Maxillary prominence (2)Mandibular prominence (2)

nasal (olfactory) pits formsurrounded by the medial and lateral nasal processes

nasolacrimal groove separates the lateral nasal process from the maxillary process

maxillary processes fuse with the medial nasal processes

lateral nasal processes fuse with the maxillary processes, thus obliterating the nasolacrimal groove.

approximately 24 days

1st arch

5-week embryo 6-week embryo 7-week embryo. 10-week embryo

DEVELOPMENT OF THE FACE

Maxillary prominences have fused with the medial nasal prominences.

The nasal prominences are gradually separated from the maxillary prominence by deep furrows.

Olfactory placode

Stomodeum”Pharyngeal arches

CEPHALIC PRIMORDIA - PLACODES

Nasal placodes - thickenings of the surface ectoderm (later differentiate into the olfactory epithelium)

DEVELOPMENT OF THE NASAL CAVITIES AND THE HARD PALATE

By week 5 the placodes form the nasal pits. They further invaginate and the pits approach the primitive oral cavity.

A thin oronasal membrane separates the two cavities.

By its rupture the primitive choanae will form

The primary palate - the anterior aspect derives from the intermaxillary segment (or median palatine process, formed by the medial nasal processes).

DEVELOPMENT OF THE NASAL CAVITIES AND THE HARD PALATE

The secondary palate – the posterolateral aspectderives from the lateral palatine processes (a medial growth of the maxillary process).

By week 8, a partition forms between the primitive nasal chambers and the oral cavity

As the secondary palate is formed, the nasal septum grows inferiorly toward it.

The nasal septum and the two palatine shelves unite to form separate right and left nasal chambers, an oral cavity, and the definitive choanae.

DEVELOPMENT OF THE NASAL CAVITIES AND THE HARD PALATE

The tongue occupies the center of the stomodeum. The lateral palatine processes (palatal shelves) are located at the lateral borders of the tongue. The Meckel's cartilage, providing a

template for the development of the mandible, is located at the base of the tongue.

M

T

T

Lpp

Lpp

T

Pns

Lpp

Secondary palate

Pns

hyaConcha

Concha

SeptumThe primitive nasal septum descends. By fusion the

palate separates the nasal cavity from the oral cavity.

DEVELOPMENT OF THE NASAL CAVITIES AND THE HARD PALATE

Facial Primordia Adult Derivatives

Frontonasal prominence(unpaired)

forehead, nose, philtrum, primary palate

Maxillary prominence(paired)

upper cheek, maxilla, zygomatic, lateral portion of upper lip, secondary palate

Mandibular prominence(paired)

lower lip, lower cheek, mandible

SUMMARY TABLE OF FACE DEVELOPMENT

Buccopharyngeal m.

stomodeum

pharynx

Head and neck

Week 5

Week 5

Week 5

Week 5 - 6

Week 6

Week 6

Week 6 - 7

Week 7 - 8

Week 10

unilateral cleft lip involving jaw and

primary palate

bilateral cleft lip involving jaw and

primary palate

cleft secondary palate

DEVELOPMENTAL MALFORMATIONS

Supernumerary nostril

DEVELOPMENTAL MALFORMATIONS

Primary

palate

Upper jawLip

Philtrum

Primary palate

Median cleft lip lower cleft lip oblique fissure

macrostomia microstomia

ANTERIOR FACE DEFORMITIES

Cleft lip or palate: the medial nasal processes fail to fuse with the maxillary processes. May occur separately or in combined deformities.

ANTERIOR FACE DEFORMITIES

Cleft palate and/or uvula: the palatine shelves fail to fuse with each other and/or with the primary palate.

Processus globularis (bilateral cleft lip associated with bilateral cleft palate)

MEDIAN CLEFT LIP

BILATERAL CLEFT LIP COMBINED WITH CLEFT PALATE

A cleft lip (cheiloschizis)

B bilateral cheilo-gnato-palatoschizis (processus globularis = intermaxillary segment)

C unilateral cheilognatopalatoschizis

Oblique facial cleft: the nasolacrimal duct remains exposed due to the lateral nasal process failing to fuse with the maxillary process. It may be combined with cleft lip.

LATERAL FACE DEFORMITIES

Lateral cleft lip: macrostomiathe maxillary and mandibular processes fail to fuse at the angle of the mouth.

OBLIQUE FACIAL CLEFT

Congenital craniofacial abnormalities

Macrocephaly• Proportionate

• Disproportionate

Microcephaly

Craniosynostosis• Sagittal

• Coronal

Eye anomalies• Hypertelorism

• Hypotelorism

• Coloboma

• Microphthalmia

• Anophthalmia

Cleft palate and cleft lip• Syndromic (30 %)

• Nonsyndromic (70 %)

Micrognathia (small mandible)• Pierre-Robin sequence

Agnathia

Congenital ear malformations

Pierre-Robin

sequence

THERAPY

Cleft lip

Before surgery After surgery

DEVELOPMENT OF THE EXTERNAL EAR

First pharyngeal cleft

pouch 1

cleft 1

cervical

operculum

cervical

sinus

DERIVATIVES OF THE PHARYNGEAL ARCHESAND CLEFTS (ECTODERM)

DERIVATIVES OF THE PHARYNGEAL ARCHESAND POUCHES (ENDODERM)

thyroid gland

thymus (3rd pouch)

inferior parathyroid (3rd pouch)

superior parathyroid (4th pouch)

DERIVATIVES OF THE PHARYNGEAL ARCHESAND POUCHES (ENDODERM)

DEVELOPMENT OF THE THYROID GLAND

anterior 2/3 of the

tongue

4th week

foramen caecum

thyroglossal duct

thyroid

thyroid diverticulum

5th week

DEVELOPMENTAL MALFORMATIONS

median cervical cyst

persisting thyreoglossal duct

lateral cervical cyst lateral cervical fistule

DEVELOPMENTAL MALFORMATIONS