Plastics/Anatomy

Question 1

• Canalicular system anatomy/lengths:

Answer 1

vertical 2 mm, horizontal 8-10 mm, NL sac 12-15 mm, NL duct approx. 12 mm.

Question 2

• Medial canthal trauma

Answer 2

is punctum out of position? Is lid apposed to the globe?

Question 3

medial canthal trauma: lid not apposed

Answer 3

o If no, then anterior and posterior tendon avulsed. For anterior and posterior avulsion, if nasal fracture, repair with metal miniplate and fixate avulsed tendon to plate with sutures. If no nasal fracture, fixate to tendon to posterior lacrimal crest with wire or suture through drill holes.

Question 4

medial canthal trauma: lid apposed

Answer 4

o If lid is apposed to the globe it is an anterior limb avulsion and posterior is still attached. Suture anterior tendon to anterior crest of lacrimal bone.

Question 5

• Anatomy of lateral horn of levator

Answer 5

passes through the lacrimal gland and divides it into the orbital and palpebral lobes. Whitnall’s ligament changes the direction of levator’s force from anterior/posterior to superior/inferior. The lateral horn of levator inserts at whitnall’s tubercle, which is a bony prominence on the zygomatic bone on the lateral orbital wall.

Question 6

• Order of occurrence of cancerous eyelid lesions:

Answer 6

medial/lower > upper > lateral

Question 7

• Superior orbital fissure

Answer 7

superior to annulus of zinn are LFTs (lacrimal, frontal, trochlear, superior ophthalmic vein), within annulus of zinn are “3N3 is 6” (superior and inferior divisions of CN 3, nasocilliary branch of V1, sympathetic roots of the ciliary ganglion, and CN VI

Question 8

• Plastics surgical planes in the face:

Answer 8

deep to SMAS in the upper face and superficial to SMAS in the lower face to avoid damaging the facial nerve

Question 9

• Capsulopalpebral fascia:

Answer 9

originates from inferior rectus

Question 10

• Average distance from posterior globe to optic foramen

Answer 10

18 mm

Question 11

• Length of optic nerve

Answer 11

length of orbital part of nerve is 25-30 (another source states 24) mm; intrascleral 1 mm; 10 mm intracanal segment.

Question 12

• Where CN 5 passes through:

Answer 12

“Standing Room Only” V1 through superior orbital fissure, V2 through foramen Rotundum, V3 through foramen Ovale

Question 13

• Location of Krause glands:

Answer 13

superior/inferior fornices

Question 14

• Location of wolfring glands:

Answer 14

non-marginal tarsal border (superior tarsal border on upper lid and inferior tarsal border of lower lid)

Question 15

• Location of meibomian glands

Answer 15

along eyelid margin

Question 16

• Nasolacrimal duct drains to

Answer 16

the INFERIOR meatus

Question 17

• Muller’s muscle:

Answer 17

typically inserts along the superior border of tarsus, deep to the levator apaneurosis.