L1: extra oral anatomical landmarks

Question 1

what landmarks are observed extra-orally when dealing with teeth loss?

Answer 1

-interpupillary line
-alatragus line
-nasolabial sulcus
-labiomental sulcus
-philtrum
-vermilion border
-commissures
-modulus

Question 2

which extra-oral land mark is used to determine the occlusal plane of ANTERIOR teeth of the denture ?

Answer 2

-interpupillary line (if it is inclined then occlusal plane of anterior teeth will also be inclined )

Question 3

which extraoral landmark is used to determine the occlusal plane of the POSTERIOR teeth of denture ?

Answer 3

Alatragus line ( from ala of the nose to tragus of the ear )

Question 4

which extra-oral landmark gives an indication about the relationship between mandible and maxilla ?

Answer 4

labio-mental sulcus

Question 5

class I:
class II:
class III:

Answer 5

I: normal , ( 6th of upper arch occludes with 6th of lower arch )

II: overjet , retrognathism ( acute concave

III: prognathism (straight )

Question 6

what is the vermilion border and how is it affected by tooth loss?

Answer 6

transitional epithelium between mucus membrane of the lip and the skin

• the ammout shown is reduced following loss of anterior teeth and resorption of supporting alveolar bone

Question 7

how is a lacking vermilion border improved by dentures?

Answer 7

by proper positioning and thickening of labial flanges of the denture

Question 8

which anatomical landmark lies opposite to canines and is used for determination of canine line ?

Answer 8

commissures