Articulators Flashcards
What is an articulator?
mechanical device representing the jaw members and the TMJ to which the maxillary and mandibular casts are attached to simulate different mandibular movements
What are the mandibular movements?
- opening and closing
- protrusive
- right and left
What is the sagittal (horizontal) condylar path?
path travelled by the condyles during protrusive movement (downward + forward)
What is the lateral condylar path?
path travelled by the condyles during lateral movement (downward + forward + medial)
What are the articulator movements?
- opening and closing
- protrusive
- right and left
What are the functions of the articulator?
- act as a patient in the absence of the patient
- simulate, but not duplicate, all possible mandibular movements
- diagnosis and treatment planning (to observe all possible movements)
- arrangement of artificial teeth for complete dentures and removable partial dentures
- fabrication of occlusal surface for dental restorations
What are the advantages of articulators?
- visualisation of occlusion (lingual aspect)
- no need for patient cooperation
- decrease chair time and patient appointment
- patient’s saliva, tongue and cheek are not factors when using an articulator
According to records accepted, articulators are classified into…
- simple hinge articulators
- mean value (fixed condylar path) articulators
- adjustable articulators (semi and fully adjustable)
Is Bonwill triangle accurate?
No
Is maxillary facebow accurate?
Yes
What does Arcon stand for?
Articulator condyle on normal
What are the movements and records taken from the patient for a simple hinge articulator?
movements
- opening and closing
records taken from patient
- centric occluding relation
What is centric occluding relation?
centric relation + proper vertical occlusal dimension
What is the movement of articulator on protrusive movement?
Upward and backward
Does the mandible move in the articulator?
No
What are the movements of mean value articulators?
- opening and closing
- protrusive (fixed 30-40 degrees)
- lateral (fixed 12-20 degrees)
What are the records taken for mean value articulators?
to mount the upper cast
- Bonwill triangle (ASA)
- facebow record )AlMahdy articulators only)
to mount the lower cast
- centric relation
Is the incisal angle and table fixed in mean value articulators?
Yes, 30 degrees incisal angle
Are all mean value articulators Arcon?
No
Is the intercondylar distance fixed in mean value articulators?
Yes
What are the two types of semi-adjustable articulators?
- Hanau
- Whip mix
What are the movements of semi-adjustable articulators?
- opening and closing
- protrusive (taken from patient)
- lateral (Hanau’s equation with Hanau’s articulator or taken from patient with Whip mix articulator)
What are the records taken using semi-adjustable articulators?
to mount the upper cast
- Bonwill triangle (unlikely)
- maxillary facebow for all designs
to mount lower cast
- centric relation
How to record protrusive movement of semi-adjustable articulators?
taken from patient and adjusting horizontal condylar guidance
How to record lateral movement of semi-adjustable articulators?
adjusting lateral condylar guidance using either Hanau’s equation or taken from the patient using Whip mix articulator
What is Hanau’s equation?
L = H/8 + 12
How to record lateral movement through Whip mix articulator?
taken from patient
- right record to adjust left lateral condylar guidance
- left record to adjust right condylar guidance
Is Hanau articulator Arcon?
no
Is Whip mix articulator Arcon?
yes
Is the incisal table and angle fixed in semi-adjustable articulators?
no
Is the intercondylar distance fixed in semi-adjustable articulators?
yes
What are the movements of fully-adjustable articulator?
- opening and closing
- protrusive (obtained from patient)
- lateral (taken from patient)
What is the name of a fully-adjustable articulator?
Denar
What are the records taken for a fully-adjustable articulator?
to mount upper cast
- facebow
to mount the lower cast
- centric relation
How is protrusive records taken for fully-adjustable articulator?
from patient to adjust horizontal condylar guidance
How is lateral records taken for fully-adjustable articulator?
taken from patient
- right record to adjust left lateral condylar guidance
- left record to adjust right condylar guidance
it records path of condyle from the beginning of movement to the end of the movement
Is the incisal angle and table fixed in fully-adjustable articulators?
no
Are fully-adjustable articulators all Arcon?
yes
Is the intercondylar distance of fully-adjustable articulators fixed?
no
What are the minimal requirements of articulators?
- maintain correct horizontal and vertical relationships of patient’s cast
- casts must be easily removed and attached to the articulator
- have an incisal guide pin with a positive stop to preserve patient’s vertical dimensions
- open and close in a hinge-like fashion
- accurate, rigid and of non-corrosive materials
- moving parts resist water
- adjustment should be able to move freely and be definitely secured
What are some additional requirements for articulators?
if the denture is fabricated with balanced occlusion (3 points of contact in centric and eccentric), the articulator should…
- accept facebow
- allow protrusive and lateral movements
- have adjustable incisal guidance
Do all semi-adjustable articulators accept facebow records?
yes
Can fully-adjustable articulators be linked to a computer using a software?
yes
