Development of Face and Palate

Development of Face and Palate

• Face develops from structures around the stomodeum (4th week)
• Structures involved: fronto-nasal process, 1st pharyngeal (mandibular) arch of each side, maxillary process, and mandibular process

Formation of Mandibular and Maxillary Processes

• Single fronto-nasal prominence ventral to the forebrain
• Paired maxillary prominences develop from the cranial part of the 1st branchial arch
• Paired mandibular prominences develop from the caudal part of the 1st branchial arch
• Five facial primordia appear as prominences around the stomodeum

Further Development of Face

• Formation of nasal placodes and lens placodes (4th week)
• Nasal placodes sink below to form nasal pits (5th week)
• Elevations of the nasal pits form the medial and lateral nasal processes
• Nasal placodes are primordia of the nose and nasal cavities

Derivatives of Facial Components

• Fronto-nasal prominence forms the forehead, bridge of the nose, frontal and nasal bones
• Maxillary prominences form the upper cheek regions, most of the upper lip, maxilla, zygomatic bone, and secondary palate
• Mandibular prominences fuse and form the chin, lower lip, lower cheek regions, and mandible
• Lateral nasal prominences form the alae of the nose
• Medial nasal prominences fuse and form the intermaxillary segment

Development of Palate

• Medial nasal swellings enlarge, grow medially, and merge with each other in the midline to form the intermaxillary segment
• Intermaxillary segment gives rise to the philtrum of lip, premaxillary part of the maxilla, primary palate, and palatogenesis
• Palatogenesis begins at the end of the 5th week and gets completed by the end of the 12th week
• The most critical period for the development of palate is from the end of 6th week to the beginning of 9th week
• The palate develops from two primordia: primary palate and secondary palate

Primary Palate

• Begins to develop early in the 6th week
• Develops from the deep part of the intermaxillary segment as a median palatine process
• Lies behind the premaxillary part of the maxilla
• Fuses with the developing secondary palate
• Represents only a small part lying anterior to the incisive fossa of the adult hard palate

Secondary Palate

• Is the primordia of hard and soft palate posterior to the incisive fossa
• Begins to develop early in the 6th week
• Develops from the lateral palatine processes, which grow medially and fuse in the median plane

Development of Tongue

• Formation of tongue: median and lateral tongue buds arise from the floor of the 1st pharyngeal arch and grow rostrally
• Formation of tongue: fusion of tuberculum impar, two lingual swellings, and caudal medial swelling (hypobranchial eminence)
• Anterior 2/3 of the tongue is formed by fusion of median and lateral tongue buds
• Posterior 1/3 of the tongue is supplied by glossopharyngeal nerve (nerve of 3rd arch)
• Musculature of tongue is derived from occipital myotomes, explaining nerve supply by hypoglossal nerve, nerve of these myotomes

Learn about the formation of the face and palate during embryonic development, including the structures involved and the processes that shape them.