Medicine and Health related Information

The face develops from the 5 processes:

1) one from frontonasal process

2) two maxillary processes which are given from mandibular arches

3) two mandibular processes

FRONTONASAL PROCESS — It is a single process which divides into two process with the development of nasal pits. A lateral nasal process and a medial nasal process, which give rise to the forehead, the nose, the philtrum (or) the middle part of upper lip.

MAXILLARY PROCESS — These are two in number which are given off from the mandibular arch which gives rise to upper lip, the cheek.

MANDIBULAR PROCESS — These are two in number which give rise to the lower jaw, whole of the lower lip and the chin.
The muscles of the face develops from the second pharyngeal arch hence all are supplied by branches of facial nerve and the skin develops nasal, maxillary and mandibular processes.Hence supplied by mandibular nerve branches.

LOWER LIP — The mandibular process of the two sides grow towards each other and fuse in the midline. They form the lower margin from the stomatodaeum. This fused mandibular processes gives rise to the lower lip and the lower jaw.

UPPER LIP — a) Each maxiallary process grows medially and fuses first with the lateral nasal process and then with the medial nasal process. The medial and lateral nasal process also fuse with each other. In this way the nasal pits (called anterior nares) are cut of from the stomatodaeum.

b) The maxillary process undergo considerable growth. At the same time the frontonasal process becomes much narrower from side to side so that the two anterior nases come closer together.

c) The stomatodaeum is bounded above by the upper which is derived as follows:-
1) The mesodermal basis of the lateral part of the lip is formed from the maxillary process of the lip is formed from the maxillary process. The overlying skin is derived from the ectoderm covering this process.
2) The mesodermal basis of the median part of the lip ( called philtrum) is formed from the frontonasal process. The ectoderm of the maxillary process however over grows this mesoderm to meet that of the opposite maxillary process in the midline. The skin of the entire upper lip is innervated by the maxillary nerves.
3) The muscles of the face (including the lips) are derived from the mesoderm of the second branchial arch and are therefore supplied by facial nerve.