Development and malformations of face and palate Compiled by András Csillag and Andrea D. Székely
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