Development of the face, nose, palate


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Development of the face, nose, palate

  1. 1. Development of Face Nose Prof. Mohamed Autifi
  2. 2. Development of the face     The face develops from 5 mesenchymal prominences (swellings or processes) that appear in the 4th week. One Frontonasal prominence (formed by proliferation of mesenchyme and ectoderm ventral to the forebrain). Two maxillary swellings (from 1st pharyngeal arch). Two mandibular swellings (from 1st pharyngeal arch). Prof. Mohamed Autifi
  3. 3. Development of the face  These 5 prominences surround the stomodeum (primitive mouth) , cranially , laterally and caudally. Prof. Mohamed Autifi
  4. 4. Mouth: Primitive oral cavity: develops from: a)An ectodermal depression between frontonasal prominence and the first pharyngeal arch: the stomodeum. Its floor is closed by the buccopharyngeal membrane. b)An endormal part: is the cranial end of the pharynx. The buccal membrane degenerates during the 4 th week, i.e. the 2 parts continue together. Prof. Mohamed Autifi
  5. 5. Lips & gingivae: They develop as a linear ectodermal thickenings around the stomodeum  labiogingival laminae. They grow into mesenchyme, then degenerate forming labiogingival grooves separating lips from gingivae. A small area of laminae persists in median plane forming frenulum of the lip. Prof. Mohamed Autifi
  6. 6. Salivary glands: Appear as epithelial buds from oral cavity. Parotid gland: The first to appear, early in 6th week, from oral ectoderm, near angle of stomodeum. It forms a tube, extends into cheek’s mesoderm. Its Proximal part forming the parotid duct; Its distal end breaks to form the glandular alveoli. Capsule & connective septae develop from surrounding mesoderm.  The duct opening is carried to open inside the cheek. Submandibular gland: Appear late in 6th week, from an endodermal bud in floor of stomodeum (alveolo- lingual groove). Develops in same way as parotid gland. Sublingual gland: appear in 8th week, from multiple endodermal buds in the alveolo-lingual groove. Prof. Mohamed Autifi
  7. 7. I. Frontonasal process    Bilateral ectodermal thickenings above the lateral angle of stomodeum form the nasal placodes. By the 5th weak, the nasal placodes are invaginated to form the nasal pits, thus the nasal placodes are divided into medial and lateral nasal folds (promeninces). The two medial nasal folds fuse to form median nasal fold. Prof. Mohamed Autifi
  8. 8. Prof. Mohamed Autifi
  9. 9. Fate of the frontonasal process The lateral nasal folds form the alae of the nose.  The nasal pits get deeper and they form the primitive nasal cavities.  The medain nasal fold forms: 1. Forehaed 2. Middle of the nose and nasal septum 3. Filtrum of the upper lip 4. Premaxilla  Prof. Mohamed Autifi
  10. 10. II. Maxillary processes   The maxillary process develops as mesodermal proliferation from the 1st pharyngeal arch. It grows ventrally and medially, compressing the medial nasal folds towards the middle line and converting them into one median nasal fold. Prof. Mohamed Autifi
  11. 11. II. Maxillary processes   The maxillary processes are separated from the lateral nasal folds by the nasolacrimal groove. The lower part of the groove will form the nasolacrimal duct while its upper part will form the lacrimal sac. Prof. Mohamed Autifi
  12. 12. II. Maxillary processes A palatine shelf arises from the medial aspects of each maxillary process.  Both shelves are approximated towards each other and fuse together and with the premaxilla forming the hard and soft palate. Thus the nasal cavity becomes separated from the oral cavity. Prof. Mohamed Autifi
  13. 13. Fate of maxillary processes 1. Cheeks 2. Upper lip except the filtrum 3. Palate except the premaxilla Prof. Mohamed Autifi Frnotnasal process
  14. 14. III. The mandibular processes  Develop from the mesenchyme of the 1st pharyngeal arch.  Fate : 1. Lower jaw 2. Lower lip 3. Floor of the mouth Prof. Mohamed Autifi
  15. 15. Prof. Mohamed Autifi
  16. 16. Development Of Nasal cavities Prof. Mohamed Autifi
  17. 17. In the 6th week, the nasal pits deepen ➪ nasal sacs, grow dorsally, separated from oral cavity by oronasal membrane, which soon ruptures. Both cavities continue together via primitive choanae, dorsal to 1ry palate. Later, choanae lies bet nasal cavity & pharynx. Lateral wall develops 3 shelf-like projections: Superior, middle & inferior conchae Prof. Mohamed Autifi
  18. 18. Development of Nasal cavity 28 day Prof. Mohamed Autifi
  19. 19. Development of Nasal cavity 5 wk 6 wk Prof. Mohamed Autifi
  20. 20. Development of Nasal cavity 7 wk 12 wk Prof. Mohamed Autifi
  21. 21. In the roof of each cavity, the ectoderm shows thickened patch, olfactory epithelium, forming receptor cells, they are ciliated bipolar neurons. Their axons form the olfactory nerves. Paranasal air sinuses: -They develop after birth, except maxillary sinus which appears late in foetal life. -They develop as diverticula of lateral nasal walls, extend into their bones. -They reach mature size during puberty. Prof. Mohamed Autifi
  22. 22. Development Of Palate Prof. Mohamed Autifi
  23. 23. Medial growth of the two maxillary processes leading to fusion of the two medial nasal folds in midline ➪ intermaxillary segment ➪ philtrum of upper lip, 4 incisors & 1ry palate (premaxilla). Prof. Mohamed Autifi
  24. 24. Early in 6th week, Two medial outgrowths from maxillary processes called, palatine shelves, fuse along palatine raphe forming Secondary palate. It fuses with the 1ry palate at the incisive foramen ➪ definitive palate. Anterior part of definitive palate ➪ hard palate, while post part ➪ soft palate Prof. Mohamed Autifi
  25. 25. Nasal septum develops from fronto-nasal prominence & medial nasal folds; fuses with definitive palate. Prof. Mohamed Autifi
  26. 26. Congenital anomalies 1. Anomalies of the mouth :      Microstomia : small mouth opening Macrostomia : large mouth opening Agnathia : absence lower jaw Microstomia and single nostril Micrognathia : small lower jaw Anodontia : absence of the teeth 2. Anomalies of the nose :   Stenosis of nostrils Deviation of the nasal septum Prof. Mohamed Autifi Macrostomia
  27. 27. 3. Anomalies of the face and palate : 1.Fusion dermoid: Cystic swelling developed along line of fusion of face 2. Oblique facial cleft: Due to failure of fusion between maxillary & frontonasal processes (at nasolacrimal groove). May include cleft upper lip. Prof. Mohamed Autifi
  28. 28. 3. Cleft upper lip (harelip): Unilateral or bilateral. The former is most common anomaly of head & neck (1:1000). Due to failure of fusion of maxillary process with medial nasal fold. 4. Cleft lower lip: Usually central 5. Cleft uvula Median cleft of the lower lip Prof. Mohamed A. Autifi
  29. 29. 6. Cleft palate: (1:2500 births) a) Anteriorly: Anterior to incisive Foramen, includes lateral cleft lip, cleft upper jaw & cleft between 1ry & 2ry palates, unilateral (C), bilateral (D) b) Posteriorly: Behind incisive F, includes cleft of 2ry palate & cleft uvula (E) c) Antero-posteriorly: Combination, oblique/median (F) Prof. Mohamed Autifi
  30. 30. Cleft lip Prof. Mohamed Autifi
  31. 31. Unilateral cleft lip and palate Prof. Mohamed Autifi
  32. 32. Prof. Mohamed A. Autifi
  33. 33. Bilateral cleft lip and palate Prof. Mohamed Autifi
  34. 34. Unilateral cleft lip and palate Bilateral cleft lip and palate Prof. Mohamed Autifi
  35. 35. Prof. Mohamed Autifi
  36. 36. Development of Pituitary gland
  37. 37. Development of the pituitary gland The pituitary gland is derived from 2 ectodermal sources:  Anterior Lobe : develops from the ectoderm of the roof of stomodeum ( Rathke’s pouch ).  Posterior Lobe: develops from the floor of the diencephalon ( Infundibulum ).  Prof. Mohamed Autifi
  38. 38. Development of pituitary gland Prof. Mohamed Autifi
  39. 39. Development of pituitary gland Prof. Mohamed Autifi
  40. 40. Development of pituitary gland Prof. Mohamed Autifi
  41. 41. Development of pituitary gland Prof. Mohamed Autifi
  42. 42. Congenital anomalies of pituitary gland  Craniopharyngioma Tumour formed from persistance of a small portion of Rathk’s pouch in the roof of the pharynx. Prof. Mohamed Autifi
  43. 43. Thanks and best of luck Prof. Mohamed Autifi