What are the five main swellings that form the face during development?

The face develops from five mesenchymal swellings around the stomodeum (primitive mouth): a single frontonasal process, paired maxillary processes, and paired mandibular processes.

Which facial structures does the frontonasal process give rise to?

The frontonasal process forms the forehead, external nose, nasal cavity and septum, and the philtrum of the upper lip.

How do the maxillary and mandibular processes contribute to facial formation?

The maxillary processes form the lateral upper lip and upper parts of the cheek. The mandibular processes form the chin, lower lip, and lower parts of the cheek.

What is the role of olfactory placodes in facial development?

Olfactory placodes form on the frontonasal process and invaginate to become nasal pits, which are flanked by medial and lateral nasal processes that help shape the nose.

How is the philtrum of the upper lip formed?

The philtrum is formed by the fusion of the paired globular portions of the medial nasal processes, though its skin is derived from ectoderm of the maxillary process.

What is the innervation pattern of the face based on embryological origin?

Innervation corresponds to the processes: frontonasal process is supplied by the ophthalmic nerve (V1), maxillary processes by the maxillary nerve (V2), and mandibular processes by the mandibular nerve (V3).

Why is the philtrum innervated by the maxillary nerve despite its frontonasal origin?

The philtrum's mesoderm comes from the frontonasal process, but its ectodermal skin coverage is derived from the maxillary process, which explains its innervation by the maxillary nerve (V2).

Face Development – Facial Prominences & Fusion

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