1 - 3/4: The Trial Placement Flashcards
What relationship must the denture function in?
Harmonious relationship between the mechanical and the biologic
What stage is a critical phase of complete denture care when evaluating the relationship between mechanical and biologic?
The wax trial denture stage
What is a significant appointment for successful complete denture treatment?
Trial placement
What attitude should a dentist approach the trial placement appointment?
Errors may exist in all areas
The steps that convert dentures to acrylic resin may do what?
Limit the possibility of further corrections
What is the trial denture?
A preliminary arrangement of denture teeth that has been prepared for placement into the patient’s mouth to evaluate esthetics and maxillomandibular relationships
What is trial placement?
process of placing a trial denture into the patient’s mouth for evaluation
What are waxs occlusion rims?
Crude approximations of positions of artificial teeth
What are contours?
Arbitrary
How are shapes and size of teeth selected?
Based on anatomic averages (are estimates)
What is important to patient and dentist?
Trial denture evaluation
What question does the trial denture evaluation help answer?
“Do we have the correct teeth in the correct locations?”
What might be necessary during a clinical evaluation?
A checklist for the steps
What should you use inside the trial bases?
Denture adhesive powder
What should you clinically evaluate in trial dentures?
- occlusal vertical dimension
- centric occlusion
- midline, vertical and horizontal overlap
- occlusal plane
- buccal corridor
- phonetics
- overall esthetics
How should you assess occlusal vertical dimension?
- numerous methods suggested
- all methods are unscientific
- should assess using a combination of methods for more accuracy
What is the OVD assessment in physiologic rest position?
Normally 2-4mm space between teeth when mandible is in physiologic rest position
What is the OVD assessment in stretch-relax method?
- dot on nose and chin. Open wide and hold for 20 seconds
- slowly close until lips first touch. Measure distance between dots
- after 10-15 more seconds, close until teeth touch. Measure dots again
What are the difference in measurements in OVD during the stretch-relax method?
“interocclusal distance”
2-4mm average
What is the swallow relax method in OVD assessment?
- Pnt is asked to swallow then relax. Teeth contact while swallowing, then separate upon relaxing
Note: teeth should not be in contact at physiologic rest position
How to determine the closest speaking space?
- rapid speech of sibilant sounds “sixty six, san francisco, kansas city chiefs, salt lake city, cincinnati”
- should be no contact of max. and mandib. teeth when speaking
How should you perform the OVD assessment?
“Just look at it”
What should you verify to determine centric occlusion?
Must verify that the casts are mounted correctly on the articulator
How should you verify centric relation mounting?
- make new interocclusal record in mouth and check it on the articulator
- remember: either record base can move on soft tissue and the resulting occlusion may seem acceptable when its not
- REMOUNT CAST IF NEEDED
How should you check centric position contacts?
- with articulating paper
- stabilize the mandibular denture
- new centric relation record
- minimal amount of recording medium
What does accurate mounting entail?
- teeth interdigitate perfectly (no space around the cusps)
- condylar ball should contact fossae wall
- if either criteria not met, remake record
What is used to confirm inaccurate mounting?
- second record
- mandibular cast removed from mounting ring
- mounting plaster ground thinner
- cast remounted, using the new record
What is the level of occlusal plane in the anterior determined by?
Esthetics/phonetics
How much of the incisor teeth are visible when the upper lip is resting?
1-2mm
What is displayed when smiling?
Most of teeth length, but minimal amount of denture base
“The white things look better than the pink stuff”
What contact must the maxillary incisors have?
Positive contact with lower lip when fricative sounds “F, V, “very funny”, are made
What should be visible at the lower lip?
Mandibular incisors, slightly
What should the occlusal plane be like in the posterior?
- mandibular molars at height 2/3 up RM pads
- plane should be 2-3mm below dorsal surface of resting tongue
- plane should parallel the two residual ridges and (usually) bisects the space between the ridges
What are the maxillary posterior teeth parallel to?
Ala-tragus plane (camper’s plane)
- should not appear to descend posteriorly
What are phonetics?
-easier to assess (Teeth have replaced bulky rims)
- crowded tongue space can adversely affect phonetics
How do specific sounds affect phonetics?
Sibilant sounds - “S”, “CH” –OVD
Fricative sounds - “F”, “V” – incisors hit wet/dry line of lip
What are fricative sounds?
F, V, ‘fifty five’
Ask patient to count from 50-60
Maxillary incisal edges should just touch the posterior one third of the lower lip
What are the five components of speech?
Respiration - lungs
Phonation - vocal cords
Resonance - pharynx, mouth, nasal cavity
Articulation
Neurologic integration - a learned activity
What converts sound into meaningful speech?
Mandible, tongue, lips, soft and hard palates, alveolar ridge and teeth convert sound
What happens if teeth touch when speaking “S” sounds?
OVD is too far open
What happens if the speaking space is excessive?
More than approx. 3mm - OVD likely overclosed
What does it mean if a pnt whistles or lisps on sibilant sounds?
Whistles - contour of anterior palate may be too narrow
Lisps - anterior palate may be too braod
What should the incisors approach in sibilant sounds?
End to end relationship
What is lisping?
- non uniform overjet of the anterior teeth
- diastemas between teeth
- palatal contours
- diamond shaped openings between incisors
What should the incisal plane parallel?
Interpupillary line
What should you evaluate when assessing esthetics/appearance?
Various harmonies of tooth size, form, position, arrangement, shade
Where should posterior teeth be centered?
Mesiolaterally centered over denture-bearing area
What is the checklist when evaluating how dentures fit on a patient?
- centric record verified with recording medium
- vertical dimension verified:
a. 2-3mm between lip closure and teeth touching
b. phonetics tests “50s-60s” or “mississippi” - space between rims
c. lips appear and feel unstrained - tooth form, arrangement and shade verified
- phonetics verified “S”, “F”, and “M” sounds
What does a protrusive record record?
Condylar inclinations of pnt
What is a protrusive record used to adjust?
Articulator condylar angles
- recird is made approx. 6mm protruded
What schemes should a protrusive record be used for?
Balanced occlusion schemes only
- is not needed for non-balanced schemes
What is VERY IMPORTANT?
Patient approval
- pt, family, friends
- look in a large mirror, alone for a few minutes
What do denture base contours affect?
Phonetics, comfort, and retention
Should not be slightly convex in shape
What do denture base contours ensure?
That the denture base is not unduly thick or thin
- excess bulk impair comfort (feel between index finger and thumb)
- base that is too thin will be weakened (should not be able to see through
What should you request in a labaratory prescription?
- processing, finishing and polishing
- lab remount of the dentures
- adjustment of occlusion to compensate for processing changes
