occlusion Flashcards
Name the 2 types of occlusal examinations
- Basic occlusal exam
2. Comprehensive occlusal exam
What is the basic occlusal exam split into
Extra oral exam
Intra oral exam
What do we assess when carrying out the extra oral exam
- Skeletal pattern
- Asymmetry
- TMJ
4, Range of movement - Muscles of mastication
Name the 3 types of skeletal patterns
Class 1
Class 2
Class 3
What is class 1 skeletal pattern
When the lower jaw is proportional to the upper jaw
What is class 2 skeletal pattern
Lower jaw is retruded
What is class 3 skeletal pattern
Lower jaw is protruded
When assessing the TMJ what are we doing
- Trying to locate the condyle
2. Feel/ listen for clicks
When looking at the muscles what do we look at
- Size
- Symmetry
- Tenderness
4, Tonicity
Name the 4 muscles of mastication
- Masseter
- Temporalis
- Lateral pterygoid
- Medial pterygoid
What do we assess when carrying out the intra oral exam
- Soft tissues
- Teeth
- ICP
- Overjet and overbite
- Centre line shifts & cross bites
- RCP
- guidance schemes
What do we look at when assessing the soft tissues
- Sharp cusps on the upper arch
- Check for ridging when the patient bites down on the buccal mucosa
- Tongue scalloping g
What do we look at when assessing the teeth
Look for: 1. Evidence of wear patterns 2. Fractures 3, Mobility 4. Drifting 5. Overeruption
Define overjet
Horizontal disgrace between the cusp tips when teeth are in ICP
Define overbite
Vertical distance between cusp tops when teeth in in ICP
How do we describe overjets and overbites
In classes: Class 1 Class 2 devision 1 Class 2 Devision 2 Class 3
What is a class 1 overjet
A positive over jet that is less than 3mm
What is a Class 2 devision 1 overjet
An increased overjet
What is a Class 2 devision 2 overjet
A normal overjet but increased over bite
What is a class 3 overjet
Edge to edge or reverse overjet
Define centre line shift
When the upper frenum is not in line with the lower frenulum
Define cross bite
When one or multiple teeth are out of normal ICP relationship
If a patient doesn’t have a stable ICP what MUST we record
The RCP
Name the 2 types of occlusal guidance
- Canine guidance
2. Group function
What is cracked cusp syndrome
Pain on releasing on biting that is very well localised
Talk through the stages of cracked tooth syndrome
- Occlusal loading of a cusp associated with a crack opens the crack (microcracks)
- Crack fills with fluid
- Release of occlusal loading causing crack to rapidly close
- Some fluid is expelled to surface of tooth
- Some fluid is forced into D tubules leading to pulp stimulation & pain on release
What does tooth sleuth do
It islets individual cusp so that we can investigate them for cracked
How can we treat cracked tooth syndrome
- Desensitise area with fluoride varnish/ tubule occlusion with bonding agents
- Remove cracked portion of the tooth and place direct restoration
- , Place indirect restoration
What is confirmative treatment
No restoration should affect how teeth meet in ICP
Which muscle aids opening of the jaw
The digastric muscle
What is the digastric muscle made up of
Anterior and posterior belly
How does the digastric muscle work
It depresses and draws the mandible back as it opens
The digastric muscle then elevates the hyoid bone which is used in swallowing and speech
Name the 2 parts of jaw benign
Rotation and translation
Talk through the stages of lateral movement
- Immediate side shift
2. Progressive side shift
List the function of articulators
- To mimic a patients jaw movements
- To allow examination of the occlusion (ICP, RCP, 3. Protrusive and lateral movements)
- To allow fabrication of restorations (Crowns, bridges, dentures, splints)
- To investigate proposed changes to the occlusion (change from CG to GF)
Name the 4 types of articulators
- Simple hinge
- Average valve
- Semi adjustable
- Full adjustable
What does a simple hinge articulate mimic
Opening and closing the mouth by rotation only
When is it useful to use a simple hinge articulator
Useful in seeing if what you’ve made is too high in ICP
What does an average valve articulator mimic
Allows fro lateral excursion and protrusion
What are the average distances on a average value articulator
110 mm between condyles
100 mm from condyle to incisal edge
Condylar guidance angle = 30degrees
What can a semi adjustable articular replicate
ICP, RCP, Lateral movements and position of hinge axis (relationship of condyle)
What must be used alongside a semi adjustable articulator
FACE BOW
What do face bows record
Used to record the position on the hinge axis
How are face bows used
They go into the ear and extend to the top of the teeth
What can a FULLY adjustable articular replicate
Can replicate Position of hinge axis (which can’t be measure on a patient) (& all of above)
We can adjust: surfaces of the glenoid fossa Intercondylar width, Progressive SS, condylar
If we are only interested in ICP which articular should we use
Simple hinge
If we are only interested in making a denture which articular should we use
Average valve
If we are worried about lateral and protrusive interferes which articulator should we use
Semi adjustable with a face bow
What can go wrong if we down take occlusion into consideration when carrying out treatment
- Fractured teeth
- Premature contacts (interferences)
- Lateral forces on posterior teeth
- Strong forces on weak teeth
What is an interfere
A heavy tooth contact tray prevents the jaw moving in its intended path
How might a patient describe an ICP interference
Might feel “high” to the patient
