Course in facial development for European Course in Neuroradiology in Tarragona, Spain, originally on 12 octobre 2008. Revised for November, 2010. For questions, e-mail to etchevers at free dot fr. Download for the animations to take place, as some pictures are covered by others.

1. Development of the branchial arches Heather Etchevers, Ph.D. INSERM

2. Relation of face to pharynx frontonasal bud maxillary process mandibular process

3. Pharyngeal arches are also known as branchial or aortic The embryonic dorsal aortae are paired before later fusing at the midline

5. The first aortic arch is the precursor to all pharyngeal arches Ventral view, human embryonic heart

6. Rostrocaudal maturation of arches Detrait and Etchevers, 2005

7. All pharyngeal arch arteries are never present at once Constant remodeling during embryonic life Growth factor guidance of endothelial cells Immature mural coverage Flow pressures and hemodynamics Obliterated 1st PA Maxillary artery Right dorsal aorta Left dorsal aorta 1st PA 2nd PA 3rd PA 4th PA

8. Craniofacial evolution MOUTH MOUTH r e t i n a s e l e c t i o n o f N C C G n a t h o s t o m e M O U T H p r o s m e s

10. Pouches and grooves 1 2 Persists as tympanic membrane endoderm ectoderm Persists as intratonsillar cleft bpm midbrain 3

11. Endoderm and vascular development Dorsal aorta Arterial vitelline plexus Endoderm 1 st pharyngeal pouch Vitelline arteries Pharyngeal arch arteries Internal carotid Umbilical arteries

13. Endodermal derivatives of pouches Pharyngeal endoderm Derivative 1 Epithelium of tympanic cavity and auditory tube 2 Epithelium of tonsil 3 Inferior parathyroid glands and epithelium of thymus 4 Superior parathyroid glands

16. Structural derivatives Pharyngeal Arch Cranial Nerve Muscle derivative Skeletal Derivative 1 Maxillary Trigeminal nerve (V) Superior oblique Abducens Oculomotor muscles Maxillary, palatine, jugal trabecula cranii 1 Mandibular Trigeminal nerve (V) Muscles of mastication Tensor tympanis Digastric (anterior belly) Incus, ant. lig of malleus palatoquadrate Meckel’s cartilage 2 Hyoid Facial nerve (VII) Muscles of facial expression, digastric (posterior belly), styloid Stapes, hyoid bone Reichert’s cartilage 3 Glossopharyngeal nerve (IX) stylopharyngeas Horns of hyoid Thyroid cartilage 4 and 6 Laryngeal branches of vagus nerve (X) Striated muscles of oesophagus Cricoid cartilage

17. Cartilage derivatives of arches in 24 wk foetus

18. Hox segment identity genes are incompatible with facial skeleton Creuzet et al. (2002) Couly et al. 1993

19. Human embryo aortic arches Courtesy of Next Generation Embryology http://ngembryo.ncl.ac.uk/ngembryo.php

20. Chicken head vessels are in two sectors

21. Vascular derivatives Internal/ external jugular Brachiocephalic Subclavian Sinus venosus? Pharyngeal arch Arteries Veins- tentative 1 st maxillary (shared artery with mandibular) Ophthalmic, ethmoid, ramus superior of stapedial 1 st mandibular Maxillary, mandibular 2 nd hyoid Stapedial 3rd Common and internal carotids 4th Right subclavian (R) Aorta (L) 6th Right proximal pulmonary Left proximal pulmonary Ductus arteriosis

22. The “cardiac” neural crest is a subpopulation of the cephalic crest

23. Heart participation of NCC is necessary but transitory © K Sulik and coll.

25. Goldenhar, First arch, hemifacial microsomia, oculo-auriculo-vertebral spectrum (MIM 164210) Axial 1-mm 3D FT-CISS MR image through temporal bones. Lemmerling et al., AJNR 2000. Universitätsklinikum Jena semi- circular canals (L) enlarged vestibular aqueduct (R)

26. Cardiovascular defects in DGS