Maxillary process

Maxillary process is a term used in embryology to refer to the two processes that grow out from the sides of the developing face and eventually form the upper jaw or maxilla. The maxillary processes also contribute to the formation of the zygomatic bone, the lower part of the orbit, and parts of the temporal bone.

Etymology

The term "maxillary" is derived from the Latin "maxilla" which means "jawbone". The term "process" in this context is derived from the Latin "processus" which means "going forward". Thus, "maxillary process" can be translated as "the forward growth of the jawbone".

Development

The maxillary processes develop during the fourth week of embryogenesis. They grow out from the sides of the frontonasal process, which is the embryonic structure that will form the nose and the middle part of the upper lip. The maxillary processes grow around the sides of the stomodeum, the primitive mouth, and meet in the middle to form the upper jaw.

The maxillary processes also give rise to the palatine shelves, which grow inward from the sides of the oral cavity and eventually fuse in the middle to form the hard palate. The fusion of the palatine shelves occurs during the sixth week of embryogenesis.

Clinical significance

Abnormal development of the maxillary processes can lead to a number of congenital anomalies, including cleft lip and cleft palate. These conditions occur when the maxillary processes fail to meet in the middle and fuse properly.

Related terms

• Frontonasal process
• Mandibular process
• Palatine shelves
• Stomodeum

See also

• Embryology
• Maxilla
• Zygomatic bone
• Orbit
• Temporal bone
• Cleft lip
• Cleft palate