Flashcards in BCSC Plastics Deck (238)
Which muscles are the deep mimetic muscles?
buccinator, mentalis, levator anguli oris
What are the 5 major branches of the facial nerve (CN VII)?
Temporal, zygomatic, buccal, marginal mandibular, cervical
What are the 7 structural layers of the eyelids?
1) skin and subcutaneous tissue; 2) muscles of protraction; 3) orbital septum; 4) orbital fat; 5) muscles of retraction; 6) tarsus; 7) conjunctiva
What defines the upper eyelid crease?
The attachments of the levator aponeurosis to the pretarsal orbicularis bundles and skin
What defines the upper eyelid fold?
the loose preseptal skin and sucutaneous tissues above the confluence of the levator aponeurosis and orbital septum
What are the divisions of the orbicularis oculi muscle?
Orbital, pre-septal, and pre-tarsal
Which divisions of the orbicularis oculi muscle are involved in involuntary movement of the eyelids?
Pre-septal and pre-tarsal
Where does the orbital septum fuse with the levator aponeurosis in the upper eyelid?
2-5 mm above the superior tarsal border in non-Asians
Where does the orbital septum fuse with the capsulopalpebral fascia in the lower eyelid?
At or below the inferior tarsal border
What conditions can lead to anterior herniation of the orbital fat in the aging eyelid?
Thinning of the orbital septum and laxity of the orbicularis
How many orbital fat pockets are there in the upper and lower lids, respectively?
2 in the upper lid and 3 in the lower lid.
Where does the orbital fat lie in the upper and lower lids?
posterior to the orbital septum and anterior to the levator aponeurosis (upper lid) or the capsulopalpebral fascia (lower lid)
What are the retractors of the upper lid?
Levator muscle (with levator aponeurosis) and superior tarsal muscle (Muller muscle)
What are the retractors of the lower lid?
Capsulopalpebral fascia and inferior tarsal muscle
Where is the peripheral arterial arcade found?
between the levator aponeurosis and the Muller muscle, just above the superior tarsal border
How tall are the superior and inferior tarsal plates?
10-12mm (superior) and 4mm (inferior)
How are the tarsal plates connected to the periosteum of the orbit?
Via the medial and lateral canthal tendons
Where is the mucocutaneous junction of the eyelid located?
Just posterior to the meibomian gland orifices on the eyelid margin
When do most congenital anomalies of the eyelids occur?
During the second month of gestation
What are the components of Blepharophimosis Syndrome?
Blepharophimosis, telecanthus, epicanthus inversus, severe ptosis.
What are the common associations of congenital ectropion?
Blepharophimosis syndrome, Down syndrome, and icthyosis
What is euryblepharon?
From the Greek eurus, meaning "wide" -- unilateral or bilateral horizontal widening of the palpebral fissure, sometimes associated with blepharophimosis syndrome
What is ankyloblepharon?
From the Greek prefix ankyl, meaning "stiff, unmovable, adhesion" -- partial or complete fusion of the eyelids by webs of skin
What is epicanthus?
a medial canthal fold that may result from immature midfacial bones or a fold of skin and subcutaneous tissue
What are the 4 types of epicanthus?
tarsalis (upper eyelid), inversus (lower eyelid), palpebralis (equal between upper and lower eyelids), supraciliaris (arising from the eybrow region running to the lacrimal sac
What is epiblepharon?
A condition in which the lower eyelid pretarsal muscle and skin ride above the lower eyelid margin to forma horizontal fold of tissue, causing the lashes to assume a vertical position.
What is congenital distichiasis?
A rare, sometimes hereditary condition in which an extra row of lashes is present in place of meibomian gland orifices
Which skin is usually used for grafting eyelid defects?
Contralateral eyelid or pre-auricular or post-auricular skin
Should hair-bearing skin grafts be used around the eye?
No, they should be avoided if possible