Denture Rationalle Flashcards
Discuss your technique of obtaining posterior palatal seal
I used the T burnisher to palpate the hamular notch areas, asked the patient to say “ah” and see the movement of the soft palate. I marked the line along this line and connected them to the hamular notches. I then transferred the vibrating the line to the record base.(As advocated by Boucher in his textbook)
What are the Adv of PPS:
. Clinical
- To provide retention
- The proximity of the tissue contact prevents food from getting under the denture base
- To make the sunken distal border less noticeable to the tongue
- Firm contact with the tissue of the soft palate reduces the tendency to gag b. Laboratory
- Aids in compensating for dimensional changes in curing
- The thickened area provides added strength across the denture
Why did you use a Hanau Wide-vue articulator?
Most comfortable with the equipment and together with my records, it satisfied the need for this particular treatment situation. Description: The Hanau Wide-Vue 183-2 is a: • Class III • Arcon articulator • Semi-adjustable • Straight line It has: • a fixed inter-condylar distance • a fixed working condyle • adjustable condylar setting • adjustable Bennett angle setting • a straight condylar path • an enclosed track guidance • a wider view! It does NOT have: • kinematic face bow tolerance • ISS/IMLT component • Fischer angle setting • adjustability of inter-condylar distance • rotating condyle path record
Why don’t your anterior teeth touch in centric occlusion?
don’t your anterior teeth touch in centric occlusion?
• Did not want any potential denture tooth fractures or de-bonding caused by the opposing natural teeth.
• The posterior teeth may wear out quicker because of higher forces and then all function would be only on anterior teeth and might lead to a combination syndrome type situation.
• Anterior contact may not add further stability to the denture.
• Would be harder to develop protrusive balance on denture teeth because of their lingual anatomy and the polished surface of the acrylic.
Discuss your philosophy of maxillary impression.
Discuss your philosophy of maxillary impression.
A minimal pressure mucodisplacing (MPMD) impression technique was used. Light body polysulfide material with a self cure acrylic tray was used. The tray did not have vent holes or wax relief. The rational for this selection is based on a study from Masri et al, JPD 2002 where the pressure generated on simulated oral analog by impression materials in custom trays of different designs was done.
What factors affect denture Retention?
What factors affect denture Retention?(Jacobsen and Krol)
- Adhesion (physical attraction of unlike molecules)
- Cohesion (physical attraction of like molecules)
- Interfacial Surface tension (resistance to separation of 2 parallel surfaces that is imparted by a film of liquid between them)
- Gravity (for lower)
- Border Seal
- Atmosphere Pressure (for upper)
- Mechanical Undercuts, Parallel walls and rotational insertion paths
- Neuromuscular Control
- Intimate tissue contact
- Orofacial musculature – correct position of denture teeth must be in the neutral zone
Describe your technique of determining the centric relation.
Describe your technique of determining the centric relation.
I had to record the CR twice during the treatment: once for diagnostic purposes and second time using the occlusion rim for setting the teeth.
All the times, I used the chin point guidance method to guide the patient and feel the hinge and asked the patient to gently close on my Alu-wax recording medium.
Why did you choose lingualized occlusal scheme?
Parr, G.R. and Ivanhoe, J.R.: Lingualized Occlusion. Dent Clin North Amer 40(1):103-112, 1996
1. Aesthetics was the patient’s chief complaint
Excellent stability with the implant retained, mandibular fixed complete denture.
Repeatable CR record.
I found it easier to balance with ortholingual teeth
a. lingualized occlusion uses the maxillary lingual cusp as the dominant functional element, occluding against the corresponding portion of the mandibular tooth.
b. According to Mehringer, the lingual cusp of a maxillary posterior tooth in a lingualized occlusion penetrates the bolus like a cleaver on a butcher’s block, and then operates on the bolus in a holding and grinding fashion similar to the action of a mortar and pestle.
d. The maxillary buccal cusps are raised above the occlusal plane and play no functional role in occlusion. The maxillary buccal cusps are present to improve the esthetic appearance of the prosthesis and to lift the cheek away from the occlusal plane to prevent cheek biting.
Describe Lingualized occlusion (Gysi)
Maxillary lingual cusps articulate with mandibular occlusal surfaces in CO and eccentric movements. Maxillary buccal cusp contacts are eliminated and the mandibular occlusal fossae are equilibrated to create a mortar and pestle effect with maxillary lingual cusps.
Who was the first to mention this
1 Gysi-(1914)Balanced lingualized
2 Farmer-Lingualized
3 S. Howard Payne(1941)-published and article describing Farmer’s work, popularized the concept
4 Pound-(1971) coined the term “lingualized occlusion” (note: Pound used and unbalanced lingualized concept)
5 Lang
Why do you need to balance teeth?
Then Why do we balance dentures?
For a stable CR and eccentrics should be balanced so that the patient has an unimpeded path back to CR. The only time that patients will actually use eccentric balance is during parafunction and if they do then balancing will be less wear and tear on the ridge.
Lang: There is little scientific support to select an occlusal concept, however, a report by Brewer (1963) found in a 24 hour test period that tooth contacts during chewing (10 minutes) were much less than tooth contacts during nonchewing (2-4hours). This suggests a need for balanced articulation, especially during parafunction and refutes the statement “enter bolus, exit balance.”
How does lingualized occlusion compare in chewing efficiency to other tooth forms?
How does lingualized occlusion compare in chewing efficiency to other tooth forms? (Lang)
•The available research fails to identify a superior tooth form or arrangement; therefore, it appears logical to use the least complicated approach that fulfills the requirements of the patient. International Workshop on Complete Denture Occlusion (1972).
(Sutton, McCord) JPD May 2007
45 patients wore 3 sets of dentures for 8 weeks each. Participants provided with complete dentures having lingualized or anatomic posterior occlusal forms exhibited significantly higher levels of self-perceived satisfaction compared to those with 0-degree posterior occlusal forms.
(Kimoto et al IJP 2006.)
Lingualized was better in satisfaction ratings compared to bilateral balanced occlusion. 28 patients. Subjective ratings on a questionnaire.
( Trapozzano) More pts preferred 20 degree teeth vs 0 degree and 20 degree teeth had greater efficiency. Noteonly 8 subjects. Teeth inserts.
(Clough) Nonanatomic vs Lingualized, 20 of 30 patients preferred lingualized because of perceived improvement in masticatory ability, comfort, and esthetics. Note: this data was gathered by questionaire
(Brewer) 0degree teeth vs Anatomic. Two sets of dentures. 2 preferred anatomic, 11 preferred the zero degree teeth, 10 had no preference
Whose philosophies do you use for esthetics of your denture?
- Vig and Brundo for concepts of lip-teeth relationships
- Frush and Fisher for concepts of teeth selection and arrangement
- Lombardi’s principles for teeth display over-all esthetic guidelines.
Where did lingualized occlusion concept come from?
In 1927, Gysi [11] of Switzerland introduced the concept of lingualized
articulation, and this initial article was followed by a number of articles
presenting several modifications of the original concept. In 1941, Payne [12]
reported on Farmer’s posterior setup that used 30( cusp teeth that were
selectively reshaped to fulfill the concept of lingualized articulation and meet
Why lingualized?
( Gysi, Payne, Pound, Lang,) There are many advantages to lingualized occlusion including :
- improved comfort,
- function, elimination of lateral interferences,
- Appearance,
- Esthetics- as maxillary buccal cusps are not ground down and no need for any diastemas
- Simple as you are only aiming for cross arch balance and not cross tooth balance
- Function - Marked reduction of lateral thrust against the upper buccal cusps and a centralization of chewing forces (Mortar and Pestle effect)
- Provides more freedom of movement in complex jaw relationships like class II such as in my patient.
Disadvantages:
- The VDO is dependent on only one cusp!
- Easier to lose balance when wear occurs
- Some patients may tend to trap food along the buccal vestibule
- Some advocate cross tooth balance over cross arch balance
WHAT are the factors in good dentures
Jacobsen and Krol
stated that there are 3 key principal factors (retention,
stability, and support) in the prescription and provision
of successful complete dentures.
