PROSTHODONTICS & OCCLUSION Flashcards
Define the following denture terms
Saddle Abutment Teeth Pontic Flange Retainer Connector Occlusal Rest
Saddle - space in the arch where teeth are missing and will be replaced - edentulous areas
Abutment Teeth - teeth adjacent to the saddle, teeth that will have retainers
Pontic - artificial/denture teeth
Flange - the acrylic component that is replacing soft tissue
Retainer - clasps on abutment or other supporting teeth
Connector - major and minor components which connect the denture to smaller components and/or itself
Occlusal Rest - denture component that is placed on occlusal surfaces to resist forces towards the gingiva
What steps do you need to take in clinically making a denture?
Primary impressions
Facebow and MMR
Complete any other dental treatment needed
Secondary impressions (with special tray)
Facebow, MMR and tooth shade selection
Wax rim try in
Primary denture issue
Secondary denture issue (if adjustments needed to be made based on primary)
A patient attends your clinic and is missing teeth 14-22
What would be the kennedy classification of this denture
Kennedy class IV
Describe a Kennedy class II
Kennedy class two is a unilateral edentulous area posterior to the remaining teeth
A patient attends the clinic with the following teeth missing;
(NB; 37 present)
36, 35, 44, 45, 46, 47
What would be the kennedy classification of this denture
Kennedy class II modification I
The most posterior saddle is in Q4 as all posterior teeth are missing, and there is only one additional saddle in Q3 –> 1 modification
Which of the following statements is correct;
A. You can have a modification on Kennedy class IV B. If there is only one tooth missing, there is no kennedy classification C. Kennedy class III is a unilateral edentulous area bounded by natural teeth D. If you have a bilateral edentulous area posterior to remaining teeth this is a Kennedy class II
C is correct
What are some of the pros and cons of a CoCR denture
Pro’s
Strong, less bulky than acrylic, fracture resistance, tooth support with occlusal rests
Con’s
High thermal conductivity, complex and more expensive to make, difficult to repair
Which of the following statements is incorrect
A. The setting reaction of gypsum is hemihydrate –> dihydrate
B. The setting reaction of gypsum is an exothermic reaction
C. Die stone is the most dense material relative to plaster and stone
D. If you add more water to your mix the setting time is faster and the material is weaker
D - partially correct, more water:powder will result in a weaker cast BUT this will slow the setting time rather than increasing it
Discuss why you would need a clean bowl and spatula when mixing gypsum
Any gypsum slurry or set gympsum remaining in the bowel/on the spatula provides nucleation sites for the new mix and will therefore speed up the setting reaction
Also infection control
Which of the following materials is NOT an elastic material
A. Alginate
B. Polyether
C. Agar
D. Wax
D - wax in a non-elastic material
Differentiate between the mucostatic and mucocompressive impression techniques
Mucostatic
- An impression recording the undisplaced mucosa, retention without load is excellent but distribution to tissues under load may be uneven
Mucocompressive
- An impression recording the mucosa under load. Even distribution under load but fit when not under load may be compromised
What is the chemical formula of alginate
CaSO4 + 2H2O + Na-Alginate
The calcium, sulfate and alginate salt (alginate-Na) are all soluble in water
calcium binds to alginate to move the reaction from a sol–>gel
retarders are added to preferentially bind the calcium to slow the setting reaction
What is the chemical formula of Gypsum
Di-Hydrate - CaSO4+2H2O (stone)
Hemi-Hydrate - CaSO4+1/2H2O (powder)
What is the official definition of occlusion
From Pros Lectures:
The static relationship between the incising masticating surfaces of maxillary or mandibular teeth or tooth analogues
From Occlusion Lectures:
Occlusion is the dynamic, biological relationship of the teeth, jaw muscles and TMJ that determines tooth contact relationships for function
Which of the following are the correct measurements of the condyle
A. lateral-medial 20mm, anterior-posterior 15mm
B. lateral-medial 15mm, anterior-posterior 20mm
C. lateral-medial 10mm, anterior-posterior 15mm
D. lateral-medial 15mm, anterior-posterior 15mm
A
I know this a pain in the ass Q but he mentioned we NEED to know these average values
What are the disc ligaments in the TMJ and where do they attach
Discal; lateral and medial
- attach the disc to the condyle
TMJ; lateral and medial
- attaching the condyle to the skull
Define centric relation, centric occlusion, ICP and RCP
CR - operator guided position, where the condyle is in the most anterior superior position
CO - how the teeth come togerther in a F/F (complete edentulous case). A reproducible, designed occlusal position
ICP - functional tooth contacts in dentate/partially dentate patient. The complete intercuspation regardless of condyle position
RCP - natural tooth contacts when the jaw is guided into CR
Which of the following statements is incorrect
A. The condyle has a functional relationship with the articular eminence
B. Force is always applied along the thinnest most avascular portion of the disc
C. The medial pterygoid attaches to the articular disc
D. The articular disc has three regions; anterior, posterior and intermediate
C is incorrect, its the lateral pterygoid that inserts into the disc of the TMJ
What jaw muscles are involved in chewing
Masseter Medial & lateral pterygoid Buccinator Temporalis Inframandibular muscles
Describe the difference between a mediotrusive contact and a mediotrusive interferance
A mediotrusive contact occurs when a patient is moving the jaw laterally (laterotrusion) from ICP to a chewing side and the contralateral teeth are still in contact.
Where these contacts interfere with the lateral movement they are called interferences
In the denar face bow system the third point of reference is measured;
A. 40mm above the incisal edge of the maxillary incisors on the lip/cheek
B. 43mm above the incisal edge of the maxillary incisors on the side of the nose
C. 42mm above the incisal edge of the maxillary incisors on the side of the nose
C is correct
In the verification of jaw transfer you are taking a transfer of the jaw/teeth in CR
What wax do you use?
Do you want perforation?
Which teeth are you trying to record?
Moyco Wax
The goal is to get an impression WITHOUT perforation, as once there is perforation the recording you have is ICP not CR
You are trying to record contacts on the molars and pre-molars
Which of the following is correct
A. Splints are used for treating bruxism
B. Splints can be given as an initial management of TMD and myofascial pain where regular pain management has failed
C. Splints only have physiological affects
D. Splints create an “loading” effect of the TMJ via increasing the OVD
B is correct
A - this was a gimme
C - splints have psychological and physiological effects
D - they create an “unloading” effect on the TMJ
What are the four most important components in occlusal splint design?
- Full arch coverage of occlusal surfaces (maxillary OR mandibular)
- Flat plane contact with opposing cusp tips at RCP
- Anterior tooth guidance for lateral and protrusive movements
- Bilateral and simultaneous contacts around the arch, anterior and posterior teeth at median occlusal position
