The face & scalp
The face extend from the hair margin to the chain & from one auricle to the other. The scalp covers the vault of the skull & extends between the left & right temporal lines laterally & the eye brows anteriorlly & the superior nuchal lines posteriorlly .The forehead
Extends between the eye brows & the hair margin ( is common to the face & scalp ).The facial region subdivided into :
1- The forehead. 2- The temporal area. 3- The area of the eye & eyelids. 4-The external nose . 5-The zygomatic area ( the prominence of the cheek). 6-The mouth & lips. 7-The cheeks. 8-The chain. 9- The external ear.Sensory nerves of the face :
The facial cutaneous nerve supply, derived from the trigeminal nerve ( cranial nerve no.5). Within the skull the trigeminal nerve divided into three parts: 1- Ophthalmic N. ------ sensory nerve associated with orbit & its contents. 2-Maxillary N. ------- sensory nerve associated with nasomaxillary complex. 3-Mandibular N. -------- sensory & motor nerve associated with lower jaw & the muscle of mastication .The ophthalmic nerve
The ophthalmic N. contributes several branches to the upper eyelid, the forehead & scalp & the external nose. 1-The supraorbital N. supply portion of the frontal sinus, large portion of the upper eyelid, & large portion of the forehead & scalp.2-Supratrochlear N.
Supply the medial portion of the upper eyelid & adjacent forehead. 3-Infratrochlear N. Supply the medial angle of the upper eyelid & the lacrimal sac. 4-Palpebral N. Supply small lateral portion of the upper eyelid. 5-External nasal N. Supply medial part of the external nose below the nasal bones.Maxillary nerve:
1-Infraorbital N. Emerge into the face through infraorbital foramen. On the face , it divides into three branches : A. Inferior palpebral br. : Convey sensation from the skin & conjunctiva of the lower lid. B. Lateral nasal br.: Convey sensation from the lateral aspect of the external nose.
C. Superior labial br. : Convey sensation from the skin & mucous membrane of the upper lip. 2- Zygomaticofacial N. Emerge into the face through the zygomaticofacial foramen , supply skin of the zygomatic prominence. 3- Zygomaticotemporal N. Ascends to supply skin of the anterior aspect of the temporal fossa & scalp.
Mandibular nerve
1- Auriculotemporal N. Pass between the T.M.J. & the tragus of the ear, supply upper lateral portion of the external ear, the ear canal, the temporal region & the lateral aspect of the scalp.2- Buccal N. Convey sensation from the skin & mucous membrane of the cheek & to the buccal gingiva. 3- Mental N. Termination of the inferior alveolar N. , emerge into the face through mental foramen & divided into three br. :
Mental br. ------ to skin of chin. Inferior labial br. -------to skin & mucous membrane of the lower lip. Gingival br. --------to labial gingiva of the mandibular teeth.
Muacle of the face : The muscle of the face or muscle of the facial expression found within the superficial fascia around the facial orifices, the muscle of the scalp & the platysma muscle of the neck belongs to the same muscle group. They perform two function : 1) As dilators & sphinctors. 2) As movers of overlying skin, they reflect the various facial expressions. Most of facial M. originate from the bone or from fascia & all insertinto the skin of the face.
Orbicularis oris muscle :It’s the sphincter of the oral aperture & lie within the upper & lower lips, encircling the mouth . Its fibers originate mainly from contribution of other facial muscles that converge on the mouth . It closes the oral aperture , presses the lips against the teeth & protrudes the lips.
Buccinator muscle : It arises from three areas : 1- Pterygoid mandibular raphe. 2- Maxillary alveolar process. 3- Mandibular alveolar process. Insertion : The muscle fibers sweep anteriorly through the cheek as a flattend sheet. On approching the angle of the mouth, the upper fibers sweep inferiorly & the lower fibers sweep superiorly to blend with the orbicularis oris muscle.
Function : It helps in mastication by pressing the cheek against the vestibular surface of the molar teeth. Sucking by decrease intraoral pressure, expelling air from oral cavityas in playing wind.