Hygiene Atlas

Atlas · Plate III · Histology and Embryology · 07

Face and palate development

The face forms between the fourth and eighth weeks from five swellings: the frontonasal process and the paired maxillary and mandibular processes. The primary palate comes from the fused medial nasal processes, and the secondary palate from palatal shelves that fuse around weeks 7-12. When these fusions fail, the result is cleft lip or cleft palate. The first pharyngeal arch builds the jaws and chewing muscles.

High-yield facts · 6

  1. The face develops from 5 primordia: frontonasal process, paired maxillary processes, paired mandibular processes, between the 4th and 8th weeks.S52
  2. The primary palate (premaxilla) comes from the fused medial nasal processes; the secondary palate comes from the palatal shelves of the maxillary processes.S52
  3. Palatal shelves fuse between about weeks 7 and 12 in utero.S52
  4. Cleft lip is more common in males and unilateral on the left; isolated cleft palate is more common in females.T5
  5. First pharyngeal arch: mastication muscles, mandible/maxilla, malleus and incus; nerve V3. Second arch: facial expression muscles, stapes, hyoid parts; nerve VII.S52
  6. Third arch: stylopharyngeus; nerve IX. The thyroid begins at the foramen cecum and descends via the thyroglossal duct.S52

Facts are written in our own words; each tag links to its source. Values marked "sources vary" differ between references, so check the one your program uses.