1/22: Posterior Palatal Seal; Record Bases; Facebow transfer Flashcards
What is the average distance between the upper and lower labial sulci adjacent to the labial frenula when teeth are in occlusion?
40 mm
The distance from the upper sulcus to the incisal edge of the upper central incisor is an average of
22 mm
the distance from the lower sulcus to the incisal edge of the lower central incisor is an average of
18 mm
What is a record base?
An interim denture base used to support the record rim material for recording maxillomandibular records.
What does interim mean?
Discarded during denture processing (resin, triad)
What does permanent mean?
Actually become part of the completed denture (processed resin, metal)
What is a trial base?
A material or device representing the base of a denture
- It is used for making maxillomandibular relationship records and for the arrangement of teeth
What is the postpalatal seal?
The soft tissue area at or beyond the junction of the hard and soft palates on which pressure, within physiologic limits, can be applied by a denture to aid its retention
Where is the posterior palatal seal?
Posterior border of a maxillary prosthesis
How do you establish the posterior palatal seal?
- Saying “ah” makes the soft palate go up
- Pinching the nose and trying to blow through it makes the soft palate go down (Valsalva maneuver)
- Transfer the marked posterior palatal seal line from the mouth to the final impression
When should you carve the transferred posterior palatal seal into the master case?
Before making the record base
What is the record base fabrication?
- Autopolymerized resin: sprinkle-on
- Visible-light-cured material
- Vacuum-formed
- Heat-processed resin
- Cast metal
What is the role of record bases/wax rims?
- Establish Rest Vertical Dimension
- Establish Occlusal Vertical Dimension
- Establish adequate interocc. Distance
- Establish tentative occlusal plane
- Determine & record centric relation
- Transfer jaw relationship to articulator
- Enable “Trial denture” arrangement
Record bases must be:
- Rigid
- Stable
- Smooth, contoured, comfortable
- Accurately fitting for retention & stability
What contributes to the most common errors of CD fabrication?
Faulty bases
What does the wax occ. rim establish?
Jaw relationships and to arrange artificial teeth to form the “trial denture”
What is the purpose of wax occlusion rims?
Serve as a means of transfer of face bow transfer records
Aid in orientation of the incisors and the occlusal plane when properly contoured
Aid in developing contours of the lips and cheek when properly contoured
Used in developing the vertical dimension of occlusion
Used in making tentative centric relation records
Sere as a general ad in selection of teeth
According to Zarbs text, what is a wax occlusion rim known as?
“An analogue for the mouth’s neutral zone”
What does analogue mean?
A part that is similar or comparable in some respects
What is a camper’s plane?
A plane established by the inferior border of the ala of the nose
What does the facebow orient?
Maxillary case to the axis of opening/articulator
