Denture Manual 52-81 (Anterior/Posterior Controlling Factors and occlusal setups) Flashcards
Hanau's Quint, Monoplane vs Lingualized vs Cross tooth cross arch
What is Thielman’s formula?
Which of these are the “posterior controlling factors” on denture occlusion? (3)
K (balance) = CG x IG / CH x CC x O
Cusp height
Compensating curve
Plane of occlusion
Limitations and occlusal errors produced by the use of the Hanau articulator
- Fixed intercondylar distance
- Straight condylar path
- No Fischer angle
- No individual working condylar motion
- Arbritary hinge axis location
What phenomenon aids in compensation for limitations of the articulator?
REALEFF (resiliency and like effects)
Four determinants of esthetics
Shade
Arrangement
Form
Phonetics
Who in 1914 concluded that human teeth could be classified into three principal shapes? What are these shapes?
What did he advocate as the method to select the most pleasing appearance?
J Leon Williams
Rectangular, triangular, ovoid
Take the outline form of a patient’s face and flip it to find the shape that would harmonize their face
Who in 1955 proposed the concept to “art, practice, and technique to achieve the esthetic goal in dentistry”, and what is that concept called?
Frush and Fisher
Dentogenic concept or dynesthetics
Dynesthetics/dentogenic harmonizes what three attributes for tooth selection?
SPA
- Sex (male/female)
- Personality (vigorous, medium, delicate)
- Age (young, middle, elderly)
Labial sounds - What are the sounds?
- What two errors in setup would lead to defective sounds?
P & B
- Insufficient support of lips (thickness of denture flange)
- Incorrect anterior posterior position of anterior teeth
Labiodental sounds - What are the sounds?
- What happens if the incisors are too short?
- What happens if the incisors are too long?
- Who proposed using this method to set the central incisors?
F & V
- If too short - V sounds like F (Vivian sounds like Frank)
- If too tall - F sounds like V (Frank sounds like Vivian)
- Earl Pound
Linguodental sound - Th
- What movement causes linguodental sounds?
- Tongue extends between maxillary and mandibular anterior teeth
- Setup of anteriors too anterior or too posterior
Linguopalatal sounds - What are they?
- What movement creates them?
- T & D
- Tip of tongue contacts anterior part of palate or lingual side of anterior teeth
Sibilants
- What sounds?
- Who proposed using these sounds to help determine vertical dimension?
Ch, J, S
Earl Pound 1977
A whistle sound can result from what two errors?
- Too narrow of an arch
2. Opening two small
What two things did Martone discover?
Hint: think of how he sets the initial “tone” for setting teeth
Maxillary incisors fall approximately 8 to 10 mm anterior of incisive papilla.
Also, a perpendicular line bisecting the incisal papilla should extend outward through the middle of the maxillary canines.
Who determined that men display more mandibular anterior teeth than women?
Cade
Who coined the phrase “speaking centric”, aka “closest speaking level”, aka “closest speaking space”?
Silverman 1950
What three things are Pound known for?
- Max anteriors - evaluating length and anteroposterior via F and V sounds
- Let S Be Your Guide (1977) - Mandibular anterior arrangement
- Originating the term “lingualized occlusion” (1970) based off the work of Payne 1941
What are the five factors of occlusion?
Who developed this?
Condylar guidance Incisal guidance Compensating curve Cusp height Occlusal plane
Hanau (1926)
Fun fact: Hanau is an engineer from Capetown, South Africa. (Harry Page is also an engineer - mucostatic impressions)
Advantages of anatomic teeth (pg 60)
- Permits mechanically and physiologically balanced occlusion
- Penetrates food more easily
- Articulated in harmony with the TMJ and muscles of mastication
- Resists rotation of denture bases through cusp interdigitation in laterotrusion
- Offers better esthetics
- Interdigitate
- Cause “less” trauma to underlying structures
Disadvantages of anatomic teeth (pg 61)
- Little tolerate in their articulation and require exacting technique
- Some claim that it produces lateral torque in eccentric movement, being more traumatic than noncusp teeth
- Adjustment should be done on an articulator rather than intraorally
- Relining and rebasing is more difficult
Definition of semi-anatomic teeth (GPT pg 70)
- What do critics say is the disadvantage of semi-anatomic teeth?
Modified denture tooth occlusal forms with a 20 degree or less cuspal incline
All of the disadvantages of cusp teeth with none of the advantages of flat plane teeth
Who advocated for semi-anatomic teeth (pg 61)
- He argued that by having less step cuspal inclines, you can have functional harmony with what anatomic structure?
Schuyler
Glenoid fossa
What two things are Clyde Schuyler known for?
- Semi-anatomic teeth
2. BULL rule - adjusting those cusps not in occlusal contact at MI/CO
Define non anatomic teeth (pg 61)
Who first introduced them and who else has advocated for them? (GPT pg 61)
All teeth with occlusal forms that have no resemblance to anatomic teeth and offer occlusion without intercuspation
Hardy introduced in 1942
Sears, DeVan, Brudvick and Wormley
Fun fact: Neutrocentric not in GPT
Advantages of non anatomic teeth (7)
- Does not lock mandible in one position and permits use of simple, less time-consuming techniques and articulators
- Minimize horizontal pressures due to absence of inclined planes
- Permit closure in more than one position (CR becomes an area rather than a point)
- Adapts easily to Class II and Class III jaw relations
- Accommodate changes to vertical and horizontal relations
- Make relining and rebasing simpler
- Improve denture stability by permitting proper centralization of occlusal plane in relation to residual ridges
Disadvantages of non anatomic teeth (6)
- Less efficient for mastication because they do not penetrate food effectively
- Inadequate food escape ways
- Esthetically inferior to anatomic forms
- Encourage a higher component of lateral or diagonal jaw movement during chewing and increase rather than decrease horizontal forces on denture bases
- Nonanatomic forms may introduce a negative psychological influence in terms of food-penetrating ability
- When set on a curved plane for balanced occlusion the inclined plane may cause skidding of the denture base
Buccolingual placement of posterior teeth in mechanical positions (instead of anatomical) was advocated by who? (pg 63)
- Advantages?
Sears (1948, 1957) and De Van (1956)
- Maximum stability, forces of mastication are at right angles to residual ridge
Buccolingual placement of posterior teeth in mechanical positions (instead of anatomical) (pg 63)
- Who was critical of mechanical positioning?
- Disadvantages
Pound 1951 (and others)
Argued that clinical residual ridge is often lingual to the bony ridge in mandibles with extreme alveolar ridge resorption
Buccolingual placement of posterior teeth - anatomical positions (instead of mechanical) (pg 63)
- Who advocated it?
- Advantages and disadvantages
Pound, Roberts, Fish, Lamie, Neufield, Carlsson, Persson
Disadvantage: Creates leverage leading to extensive denture movement (leading to resorption of the residual ridge)
Superoinferior positioning of posterior teeth - Mechanical
- Advantages
- Disadvantages
- Proponents
ADV: Keep occlusal plane closer to the denture base with less favourable ridge size and contour
DADV: Increases leverage of the mandibular denture and exerts greater pressure on supporting tissues
Proponents: Sears (1957) and Pleasure (1937)
Superoinferior positioning of posterior teeth - Anatomic
- Advantages
- Proponents
ADV: Denture stability and masticatory function
Proponents: Wright, Pound
Payne advocated for what kind of tooth form for occlusal schemes?
Anatomic teeth (slightly more efficient) 1951-52
But many other studies say no evidence of superiority
Define Christensen phenomenon
The space that occurs between posterior occlusal surfaces during mandibular protrusion
Carl Christensen 1905 - Denmark dentist/professor
Indications for non anatomic tooth forms
Who advocated for non anatomic tooth forms
- Class II or III malocclusion
- Severe residual ridge resorption
- Excessive inter arch distance
- Poor neuromuscular skills
- Poor patient adaptability
- Reverse occlusal (Pleasure) curve in existing dentures
Who first described lingualized occlusion? (pg 73)
Four advantages?
Payne 1941
- Better adapted to different types of ridges
- Greater masticatory efficiency
- Eliminates lateral interferences
- Allows for settling without unbalancing articulation by cuspal inclination
Three disadvantages of lingualized occlusion (pg 73)
- Decreased masticatory efficiency
- Does not resist rotation as well as cross-tooth cross-arch
- May result in increased lateral forces
Payne and Ortman; Becker - Indications for lingualized
Payne/Ortman - Use on virtually all cases, except flat ridges, cases with excessive interring distance
Becker - Severe alveolar resorption, class II jaw relationship, displaceable supporting tissue
Lingualized - contraindications (3)
- Repeatable CR records not possible
- 0-degree teeth set in monoplane are indicated (Parkinson, pathologic joint, some CII patients)
- Flat ridges unable to resist lateral force
Pound and Murrell recommend what degree teeth for lingualized?
Are facebow and protrusive records essential? If not, what condylar inclination do you set your semi-adjustable articulator to?
33 degree maxillary versus 20 or 0 degree mandibular
Not essential but advised. If not obtained, use 30-degree condylar inclination for Class I or III and 20 for Class II patients
Payne and Ortman recommend what degree teeth for lingualized? (pg 76)
Difference between Payne/Ortman and Pound/Murrell
33 degree versus 33 degree
Identical to Pound/Murrell except:
- They grind lingual cusp of mandibular posteriors and turn the tooth buccal lingually
- Protrusive balance exists between maxillary second molar and mandibular second molar
Which posterior teeth are not in contact for lingualized at laterotrusive and mediotrusive?
How about which posteriors are in contact at protrusive?
- First premolars not in contact at all excursives
2. In protrusive, second molars in contact in protrusive (Payne/Ortman)
Cross tooth cross arch aka Anatomic setup - Advantages (3)
- Disadvantages (3) (pg 78)
- Esthetics
- Better penetration of food, requiring less force and decreased vertical stresses on ridges
- Anatomic occlusion arranged in harmony with muscles of mastication and TMJ during functional/non-functional movements
DADV: 1. Precise technique required with exact JRR
- Incline of cusps leads to greater lateral forces (considered more destructive to underlying ridges)
- Requires more time and results not long-lasting (once slight ridge resorption occurs, adjustments needed)
