Growth of Maxilla 3 phases to growth

• Period of ovum • Period of embryo • Period of foetus • By the end of the 2nd week of development an endodermal thickening known as the prochordal plate is seen at the cephalic (head) end of the now oval‐ shaped embryonic disc. This plate is firmly attached to the overlying ectodermal germ layer and the whole becomes the future bucco‐ pharyngeal membrane. • During the 3rd week of development a narrow groove, called the primitive streak, appears at the caudal (tail) end of theectoderm layer facing the amniotic cavity. Cells of this layer then migrate along the surface of the embryonic disc towards the primitive streak, which they invaginate. •

• The entrance of the newly formed stomodeum is a wide opening bounded cranially by the frontal prominence of the bulging forebrain and caudally by the pericardial swelling. Thebuccopharyngeal membrane, forming the floor of the stomodeum, ruptures at the end of the 3rd week of development and disappears during week 4. In this way communication is established between the stomodeum and the cranial end of the forgut, the pharynx. At about the same time astream of migrating neural crest cells is responsible for the formation of thefrontonasal process, a swelling of tissue in front of the forebrain. Another stream of neural crest cells migrates towards the lateral aspect of the head where they surround the mesodermal cores in the arising branchial arches. Both the frontonasal process and the branchial arches play a large part in the formation of the face and the oral cavity.

• n the fifth week, the lateral and medial nasal swellings enlarge rapidly, with the medials advancing toward one another and eventually fusing. • The maxillary prominence is dimensionally not impressive early in development. With medial growth of its terminals and broadening of its other borders, the maxillary prominence presses onto the nasal swellings forcing their medial and lateral arms closer together.

Post Natal Growth

• Displacement • Sutures • Surface remodelling Displacement Sutures Surface Remodelling