Chapter 4: Study of dental arches Flashcards
Functions of anterior teeth
- Aesthetics
- Phonetics
- Initiates the mastication
- Anterior, incisal and canine guidance
Functions of posterior teeth
- Elevations: cusps, ridges, and planes (slopes)
- Depressions: fossa and pits, fissures
What is a pit?
It is a sharp pinpoint depression on the surface of the enamel
What is a fossa?
An irregular depression or concavity on the surface of the tooth
What are functional pits and fossa?
They are the pits and fossa that receive the active cusp
- Upper: mesial pit
- Lower: distal fossa
What is an inclined plane?
It is the sloping area found between 2 cusp ridges
Each cusp has 2 inclined planes. True or False
False, each cusp has 4 inclined planes
What cusps are working cusps?
The upper palatal and the lower buccal cusps
What do active cusps do?
They support the VDO and stabilise the arch
Other names for working cusps
active, cutting, functional, centric, supporting cusps
Other names for non-working cusps
non-active, protecting, non-functional, non-centric, guiding cusps
What cusps are the non-working cusps?
Upper buccal and lower lingual cusps
The active cusps function correctly when following the vertical axis. True or False
True
Match the letters with the numbers:
- Marginal ridges
- Central ridges
- Triangular ridges
A. form the cusp
B. in the mesial and distal areas of the occlusal surface of premolars and molars
C. towards the major fissure and buccally
- B
- C
- A
Each cusp has _____ cusp ridges extending in different directions from its tip
4
Normally the cusp ridge that extends towards the central portion of the occlusal surface is also a _____ _____
Triangular ridge
What is the line going from the first tooth to the last one called?
The main groove