Dentures Flashcards
Neurocentric
Position: closest to the tongue as possible
Proportion: reduce Occlusal table by 40%
Pitch: parallel between ridges
Form: non-anatomic
Number: reduce posterior teeth from 8 to 6
Devan
Neil’s Lateral Throat form
Class I: 8-12mm of extension below the mylohyoid ridge (long, wide flange)
Class II: 4-6mm of extension below the mylohyoid ridge
Class III: 2-3mm of extension below the mylohyoid ridge; RARE
Kelly Combination syndrome
Papillary Hyperplasia
Max ant ridge resorption
Extrusion of mand ant teeth
Downgrowth of tuburosities
Resorption of mand post ridge
House palatal throat form
Class I: 5-12 mm post from hard palate
Class II: 3-5 mm post to hard palate
Class III: anterior to hard palate
The area in the mouth where the force of the tongue pushing out is neutralized by the forces of the cheeks and lips pressing inward so that normal muscle activity retains dentures rather than dislodges them.
Neutral Zone
Berersin Scheiser
Dentogentics
Frush and Fisher
Sex
Age
Personality
Balancing ramps
Nepola and Sears
PDI for edentulism
1) residual bone height
2) residual bone morphology
3) muscle attachments
4) maxillo-mandibular relationship
Pear shaped pad
Cradock
-6 factors of retention
adhesion: the physical attraction of unlike molecules
-cohesion: the physical attraction between like molecules
-interfacial surface tension: resistance to separation by the film of liquid between
the denture base and the supporting tissues (combines cohesion and adhesion).
-mechanical locking into undercuts
-peripheral seal and atmospheric pressure: *the most important factor
-orofacial musculature: correct position of denture teeth must be in the neutral zone
The quality of a prosthesis to resist displacement by functional horizontal or rotational stress. THIS IS THE MOST IMPT FACTOR. Occlusion that is not balanced in excursive movements will create instability of the denture, loss of retention and eventually frustration to the patient.
Stability
The quality inherent in the prosthesis that resists dislodgement along the path of insertion
Retention
6 purposes of posterior palatal seal
1. retention of max denture
2. firm contact with the palatal tissue reduces the gag reflex
3. it reduces food accumulation
4. the pressure on the tissue makes the distal border of the denture less noticeable to the dorsum of the tongue.
5. it compensates for dimensional change
6. the thickened area provides added strength across the denture
the arbitrary terminal hinge axis: measured out from the posterior margin of the tragus of the ear – 13mm on a line between the tragus of the ear and the outer canthus of the eye.
Beyrons point
Hanau’s formula
L = H/8 + 12
-H is the horizontal condylar inclination established by the protrusive record
-L is the lateral condylar inclination
Theilman’s formula
K(balance) = IG x CG / CH x OP x CC
Foundation area on which a dental prosthesis rests
Denture support
5 ways to improve denture support
1. surgical removal of pendulous tissue
2. use of tissue conditioning materials
3. surgical reduction of sharp/bony ridges
4. surgical enlargement of ridge
5. implants
6 advantages of a anatomic teeth
-1. Can establish mechanical and physiologic occlusion.
-2. Penetrates food more easily.
-3. Articulate in harmony with TMJ and masticatory muscles.
-4. Resists rotation of denture base through interdigitation with cusps.
-5. Better esthetics.
-6. Less trauma to underlying tissues.
What is Frenum composed of?
Non keratinized, unattached alveolar mucosa with an underlying fibrous attachment to bone. 35% of max frenum have small striated muscle; Gartner, 1991
Muscles of Mastication
●Temporalis
Origin: lateral surface of the skull (temporal fossa)
Insertion: Coronoid process, anterior border of ramus
Action: elevates mandible, posterior part retrudes jaw
●Masseter
Origin: zygomatic arch (process)
Insertion: lateral surface of ramus, coronoid process
Action: elevates mandible
●Medial Pterygoid
Origin: medial surface of lat pterygoid plate, pyramidal process of palatine and tuberosity
Insertion: medial surface of ramus
Action: elevated mandible
●Lateral Pterygoid:
Origin: lateral surface of lateral pterygoid plate
Insertion: neck of condyle and Disc and capsule of TMJ
Action: depresses, protrudes, moves mandible side to side
What is in retromolar pad?
•glandular tissue
•loose areolar tissue
•pterygomandibular raphe
Superior pharyngeal constrictor
Buccinator
•Tendon of the Temporalis
•Most impt: cortical bone underlying these structures
How long leave denture out?
48-72 hours
How to balance monoplane setup
Balancing ramp
Nepola and Sears