Dentures Romanous Final

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emm64
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Dentures Romanous Final
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2013-03-20 23:56:14
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Dentures Romanous Final
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  1. 1. Identify the clinical anatomic landmarks found on the maxillary and mandibular edentulous arch and discuss their clinical significance.
    • Maxillary Anatomical Landmarks
    • • Buccal Vestibule - vestibule-when properly filled with the denture flange greatly enhances stability and retention
    • • Canine eminence - This prominent bone provides denture support. A square arch prevents a denture from rotating and is thus the best for denture stability
    • • Coronoid Process - The width of the distobuccal flange will then be contoured by the anterior border of the coronoid process
    • • Fovea Palatina - usually two, slightly posterior to the junction of the hard and soft palates
    • • Frenum - High frenum attachments will compromise denture retention and may require surgical excision (frenectomy)
    • • Hamular Notch - critical to the design of the maxillary denture. Improper molding of this area could lead to soreness and loss of retention
    • • Hard Palate - consists of the two horizontal palatine processes and appears to resist resorption. For this reason it is a primary support area for the maxillary denture
    • • Incisive Papilla - Pressure in this area will cause a disruption of blood flow and impingement on the nerve in the nasopalatine canal, causing the patient to complain of pain or a burning sensation. The denture should be relieved over this area
    • • Midpalatal Suture - extends from the incisive papilla to the distal end of the hard palate. The overlying mucosa is tightly attached and thin, relief is usually required to prevent soreness.
    • • Major Palatine Foramen - the orifice of the anterior palatine nerve and blood vessels. Relief in this area is usually not required due to the abundant overlying tissues
    • • Minor Salivary Glands - in the posterior third of the hard palate the tissue is very glandular and displaceable
    • • Posterior Palatal Seal Area - distal to the junction of the hard and soft palate at the vibrating line
    • • Rugae - raised areas of dense connective tissue in the anterior 1/3 of the palate that resists anterior displacement of the denture and is a secondary support area
    • • Tuberosity - is an important primary denture support area. It also provides resistance to horizontal movements of the denture
    • • Zygomatico Alveolar Crest - the crest has been likened to the buccal shelf in the mandible as a stress bearing area. However, the mucosal coverage is usually very thin and although the bone is in good position for stress bearing, the mucosa is not considered desirable for this purpose (thin mucosa
    • Mandibular Anatomical Landmarks
    • • Alveolar Ridge - is a secondary support area. High rate of resorption when excessive pressure is applied to this area
    • • Buccal Shelf - bordered externally by the external oblique line and internally by the slope of the residual ridge. This region is a primary stress bearing area in the mandibular arch
    • • Buccal Vestibule -
    • • External Oblique Ridge – Is the attachment site of the buccinator muscle and an anatomic guide for the lateral termination of the buccal flange of the mandibular denture
    • • Frena - High frenum attachments will compromise denture retention and may require surgical excision (frenectomy)
    • • Lingual Sulcus -
    • • Masseter Groove - the action of the masseter muscle reflects the buccinator muscle in a superior and medial direction. The distobuccal flange of the denture should be contoured to allow freedom for this action otherwise the denture will be displaced or the pt. will experience soreness in this area
    • • Mental Foramen - the anterior exit of the mandibular canal and the inferior alveolar nerve. In cases of severe residual ridge resorption, the foramen occupies a more superior position and the denture base must be relieved to prevent nerve compression and pain
    • • Mentalis - elevates the skin of the chin and turns the lower lip outward. dictates the length and thickness of the labial flange extension of the lower denture
    • • Mylohyoid Ridge – palpate to determine its contour, sharpness, and degree of undercut
    • • Retromolar Pad - The bone beneath does not resorb secondary to the pressure associated with denture use. It is one of the primary support areas
    • • Retromylohyoid - very important for denture stability and retention
    • • Sublingual Crescent -
  2. 2. Discuss the influence that muscles such as the buccinator, mylohyoid, masseter and genioglossus have on the flange extensions of a denture.
    • • Buccinator
    • o attaches to the external oblique ridge and serves as an anatomic guide for the lateral termination of the buccal flange of the mandibular denture.
    • • Mylohyoid
    • o forms the muscular floor of the mouth
    • o determines the lingual flange extension of the denture
    • • Masseter
    • o the action of the masseter muscle reflects the buccinator muscle in a superior and medial direction
    •  the distobuccal flange of the denture should be contoured to allow freedom for this action otherwise the denture will be displaced or the pt. will experience soreness in this area
    • • Genioglossus
    • o an extrinsic muscle of the tongue that can move and alter its shape – since it originates outside the tongue, denture flanges must be contoured to allow the action of this muscle so that the tongue can have its normal range of functional movements
  3. 3. Identify and discuss the importance of the primary and secondary support areas on the maxillary and mandibular arches.
    • • Support is the principle that describes how well the underlying mucosa (oral tissues, including gums and the vestibules) keeps the denture from moving vertically towards the arch in question, and thus being excessively depressed and moving deeper into the arch.
    • • Maxillary Arch
    • o Primary Support Areas:
    •  Tuberosity
    •  Hard palate
    • o Secondary Support Area:
    •  Rugae
    • • Mandibular Arch:
    • o Primary Support Areas:
    •  Buccal shelf (prime support area because it is parallel to the occlusal plane and the bone is very dense - these two factors make it relatively resistant to resorption)
    •  Retromolar Pad
    • o Secondary Support Area:
    •  Alveolar process
  4. 4. Describe how and why lip support is lost when a patient becomes edentulated, and how this affects the utilization of the maxillary wax rim.
    The muscles of facial expression, which are responsible for lip support and function, generally do not insert in bone and need support from the teeth and denture flanges for proper support and function. Therefore, the muscles of facial expression have nowhere to insert in edentulous patients and can not support the lip.
  5. 5. Define stability, retention and support and explain how each is achieved relative to the anatomy of an edentulous arch.
    • Retention: Resistance to vertical displacement away from the bearing surfaces
    • Mandible:
    • Primary Factors:
    • • Tongue position (ability to have extended lingual falange)
    • • Floor of mouth posture (ability to have extended lingual falange)
    • • Neuromuscular control
    • Secondary Factors
    • • Peripheral seal
    • • Adhesion
    • • Cohesion
    • Maxilla:
    • • Shape of the palatal vault (peripheral seal)
    • • Drape of the soft palate - House classification (peripheral seal)
    • • Quality and quantity of saliva (peripheral seal – less saliva means less cohesion and adhesion)
    • • Compressibility of posterior palatal seal area (peripheral seal – when tissue glands atrophy, they become less compressible, making it harder to establish a peripheral seal)
    • • Presence of well shaped tuberosities
    • • Height of alveolar ridge (resistance to displacement)
    • Stability: Resistance to lateral displacement
    • Mandible:
    • • Alveolar ridge height (resistance to lateral displacement)
    • • Floor of mouth contour (favorable vs. unfavorable – ability to have extended lingual falange)
    • • Tongue position (anterior vs. retruded – ability to have extended lingual falange)
    • • Neuromuscular control
    • • Presence of flabby, moveable denture bearing surface tissues.
    • Maxilla:
    • • Alveolar ridge height (resistance to lateral displacement)
    • • Presence of well formed maxillary tuberosities
    • • Presence of flabby, moveable denture bearing surface tissue
    • Support: Factors of the bearing surfaces that absorb or resist forces of occlusion
    • Mandible:
    • • Retromolar pad
    • • Alveolar ridge contours (the broader the more support)
    • • Amount of attached
    • • Keratinized mucosa (the more present the better the support because the better it can withstand forces during mastication)
    • • Buccal shelf area (the more access and the greater the surface area the better the support)
    • Maxilla:
    • • Amount of keratinized mucosa
    • • Alveolar ridge contours
    • • Palatal shelf area and contour
  6. 6. Why is an older patient more likely to experience cheek biting than a younger patient?
    As a person ages, tension is lost in the buccinators muscle fibers which provides support and mobility of the soft tissues of the cheek, predisposes older patients to cheek biting
  7. 7. What is the purpose of the posterior palatal seal? What is the depth and width of the bead placed in this area?
    • Purpose of PPS: to enhance retention & maintain the peripheral seal of the maxillary denture base by compensating for :
    • 1) polymerization shrinkage
    • 2) minor denture base functional movements
    • Depth and Width:
    • mimic thickness of displaceable tissues and potential movement of mobile soft palate
    • .75 - 1mm deep
    • 1mm posterior to fovea palatina
  8. 8. What is the cause and the treatment of angular cheilitis? Epulis fissuratum?
    • Angular cheilitis
    • • Cause: secondary to chronic candidiasis, a fungal infection that becomes more common with low salivary rates.
    • • Result: burning and irritation of the denture bearing mucosa, making tolerance of complete dentures difficult. The fungus is keratolytic, further compromising support and tolerance
    • • Treatment: topical antifungal therapy followed by relining of the dentures (Nystatin is the drug of choice. It can be dispensed as a cream, a powder or an oral lozenge).
    • Epulis fissuratum
    • • Cause: continued denture wear of an overextended denture flange
    • • Result: irritation leads to inflammatory fibrous hyperplasia
    • • Treatment: surgical excision
  9. 9. What is the occlusal plane? What are the landmaks of the occlusal plane? Describe the methods used to determine the plane of occlusion in edentulous patients.
    • • Occlusal Plane Definition: imaginary surface which touches the incisal edges of incisors and the cusp tips of the occluding surfaces of the posterior teeth
    • o Regardless of tooth form used the plane of occlusion should be parallel to the plane of the body of the mandible in the 1st molar premolar region (which in almost all patients will be parallel to Camper’s line)
    • • Landmarks used to determine occlusal plane:
    • o adjust the plane of the wax rim so that its parallel to Camper’s line
    •  established by the inferior border of the ala of the nose and the superior border of the tragus of each ear
    • o adjust the plane of the wax rim so that it is parallel to the interpupillary line
    • o retromolar pads - measureable, identifiable, similar to natural teeth
    • o Modiolus - 8 - 9 facial muscles join
    •  approximately at occlusal surface of mandibular first premolar
    •  anterior limit of occlusal table
    •  important in control of bolus
    •  requires proper support from teeth for function
    • o tongue position as it relates to occlusal plane "e" and "ah"
    • o commisure of lips - approximate canine position
  10. 10. What clinical problems are brought about if the plane of occlusion is too low or too high?
    • • Too low
    • o may result in tongue biting
    • • Too high
    • o results in preventing the tongue from being able to control the bolus of food and from easily clearing the vestibule
  11. 11. What is purpose of the condylar settings on your articulator? How is it transferred to the articulator in edentulous patients? How is the Bennett angle set?
    • • condylar settings are important because they represent the maxilla-mandibular relationship of the patient on the articulator and help establish a balanced occlusion
    • o records the orientation of the maxilla to the terminal hinge axis.
    • o provides the same relative opening axis on the articulator as the mandible has to the TMJ.
    • • determination of condylar settings on the articulator for a given patient is established be means of a protrusive record
    • o insert wax dentures in patient
    • o patient closes in protrusive position
    • o thermoplastic compound, plaster or wax is used to make an interocclusal record at this protruded position
    • o dentures and records seated on master casts back on articulator and condylar mechanism rotated until complete seating of dentures into protrusive records is achieved
    • o resultant condylar inclination is recorded
    • • Bennet angle?
  12. 12. What are balancing ramps? How and why are they utilized?
    • • What are Balancing Ramps?
    • o pea-sized ball of soft base plate wax immediately posterior to the mandibular second molar with the intent of making posterior bilateral contact between the balancing cups and the maxillary second molars at the same time the anterior teeth contact during excursive movements
    • • Why?:
    • o purpose is to make balanced occlusion possible with 0 degree teeth
    • o the balancing ramp functions are similar to the compensating curve used with anatomic teeth
    • o result is the posterior bilateral contact between the balancing ramps and the maxillary second molars with simultaneous contact with the anterior teeth during excursive movements
    • o tripod effect in eccentric movements to stabilize the denture
    • • How?
    • o developed in wax posterior to the most distal mandibular tooth
    • o must be large enough to provide adequate balancing contacts throughout the functional range of tooth contact (usually anterior edge to edge contact in protrusive and lateral excursive movements - approximately 3-5 mm in all directions)
    • o steps in making it:
    •  Lute a soften ball of wax posterior to the distal most mandibular tooth and Vaseline the maxillary denture teeth
    •  "Walk" the articulator in all functional eccentric positions to form the balancing ramp
    •  Trim excess wax outside of the functional range and blend into normal denture contours
    •  Balancing ramps contoured to polished surface of denture base
  13. 13. Describe the ridge resorption patterns of the maxillary and mandibular archs.
    • • Residual Ridge Resorption = atrophy of supporting structures
    • o Maxillary loss is in vertical and palatal direction
    • o Mandibular loss is vertical and oriented along cross-sectional shape of mandible
  14. 14. What is combination syndrome? What are its causative factors?
    • • Combination Syndrome – What is it?
    • • It produces a very specific pattern of resorption of the maxilla involving:
    • • Resorption of premaxilla
    • • Hypertrophy (fibrous hyperplasia) of maxillary tuberosity.
    • • Occlusal plane problems.
    • • Causative Factor:
    • • It is caused by edentulous maxilla opposing dentate mandible where anterior dentition has been retained and where the denture has not been properly balanced.
    • • As a result, during the chewing cycle , the denture tips anteriorly, compressing the mucoperiosteum of the premaxilla, leading to resorption of the bone of the premaxillary area.
  15. 15. Define centric relation. Define centric occlusion.
    • • Centric Occlusion (CO):
    • o the occlusion of opposing teeth when the mandible is in centric relation. This may or may not coincide with maximum intercuspation.
    • • Centric Relation (CR):
    • o a maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective discs with the complex in the anterior-superior position against the slopes of the articular eminences.
  16. 16. Describe some of the differences between anatomic and monoplane complete denture occlusion.
    • Anatomic Occlusion
    • Definite point of positive intercuspation may be developed
    • Tooth-to-tooth and cusp-to-cusp balanced occlusion can be achieved
    • Maintains some shearing ability after moderate wear
    • Requires frequent follow-up and may require more frequent relines to maintain proper occlusion
    • Esthetically similar to natural dentition
    • Horizontal force development due to cusp inclinations
    • Less adaptable to arch relation discrepancies
    • Monoplane Occlusion
    • Patients may complain of lack of positive intercuspation position
    • CR can be developed as an area instead of a point
    • No vertical component to aid in shearing during mastication
    • Easy to set and adjust teeth
    • Esthetically limited
    • Reduction of horizontal forces
    • Can develop solid occlusion despite arch alignment discrepancies
    • Occlusal adjustment impairs efficiency unless spillways and cutting edges restored
  17. 17. What is the purpose of flasking a trial denture? Describe the procedures for flasking a denture.
    • Flasking:
    • • a sectional, metal, boxlike case in which a sectional mold of plaster of paris or artificial stone is made for the purpose of compressing and curing dentures or other resinous restorations
    • Steps:
    • • Seal the periphery of the denture flange to the inner edge of the land of the cast
    • • After soaking the master casts and mountings in water for a few minutes, gently remove the casts from the mountings
    • • Place the master casts within the flask – they should fit easily
    • • The denture flasks are partially filled with stone and the casts are then positioned within the flask so that the land of the cast and the plaster is at about the same level as the edge of the flask
    • • The injection funnel is positioned after the stone has set
    • • An appropriate separating medium is applied to the surface of the stone
    • • A thin layer of improved dental stone is applied to the surface of the trial denture - Note that the stone application is below the level of the upper half of the flask
    • • The flask is filled to the brim with stone and the lid is closed into position
    • • The wax and the record bases are then removed by hot water washes - the denture teeth are imbedded in one side of the flask and the master casts are imbedded in the other side
    • • After drying the stone, both sides are covered by a tin foil substitute
  18. 18. What is the purpose of the post-processing laboratory remount and equilibration?
    • Purpose of Laboratory Remount and Equilibration:
    • 1. To correct errors in occlusion that have occurred during processing
    • 2. To return dentures to the correct vertical dimension of occlusion
    • 3. To restore centric and bilateral balanced occlusion
  19. 19. Describe the post-processing laboratory remount and equilibration procedure with non-anatomic posterior denture teeth. What is the function of the incisal pin?
    • • Purpose:
    • o to adjust the occlusion to account for distortions that occur during processing
    • • Steps:
    • o With a piece of fine sand paper and a flat glass slab, sand the denture teeth so that both the buccal and lingual surfaces of the posterior teeth and the incisal edges of the central incisors touch the occlusal plane
    • o Attach the maxillary cast and mounting to the articulator (make sure the incisal guide pin is set at zero and lock the condyles) - Close the articulator and note how much vertical opening has occurred as a result of processing
    • o Insert strips of articulating paper between the teeth and lightly tap them together in centric occlusion - premature contacts will usually show up as dark areas with a light center
    • o When restoring the vertical dimension of occlusion of dentures made with nonanatomic teeth make your adjustments on the mandibular arch only - grind on these areas first
    • o Continue with this procedure until the incisal guide pin comes in contact with the incisal guide table. You have now restored the vertical dimension of occlusion
    • o When the exercise is completed, all of the teeth, with the exception of the maxillary laterals and perhaps the cuspids (because of esthetic considerations) will be on the same plane and there will be no vertical overlap of the anterior teeth
    • o When the VDO has been restored, the denture is examined in working, balancing and protrusive
    • o In the posterior region, premature contacts may be seen on the lingual cusps of the mandibular teeth - these contacts must be removed
    • o Upon completion, the articulator should slide easily from working to balancing to protrusive and back - there should be no bumps along the road
    • o If the contacts on the balancing ramps are insufficient they may be supplemented with autopolymerizing acrylic resin
  20. 20. If a tooth was severely malpositioned due to a processing error, describe the solution?
  21. 21. Discuss the method used in equilibration of processed dentures with anatomic teeth. Be specific! Describe the BULL rule.
    • • BULL Rule:
    • o Most occlusal discrepancies found during “working” and “balancing” can be corrected by reducing premature contacts on the buccal cusps of the maxillary teeth and the lingual cusps of the mandibular posterior teeth (non-centric holding cusps) otherwise known as the rule of BULL (buccals of the uppers and linguals of the lowers).
    • • Method of Equilibration:
    • o Equilibration in Working
    •  Begin by the equilibrating the right working side. Slide the articulator through right working with articulating paper between the denture teeth. Begin grinding by removing any contacts that are present on the inclines of the lower right lingual cusps as shown in the diagram (arrows)
    •  Check the contacts on the buccal inclines of the upper buccal cusps. During working, they should all be about equal. If not, make the appropriate adjustments
    • o Equilibration in Balancing
    •  Slide the articulator through working again and observe the contacts on the balancing side, the lingual inclines of the lower buccal cusps. Premature balancing side contacts are reduced by grinding on the lingual inclines of the lower buccal cusps. If there are no balancing side contacts, the working side contacts should be reduced until balancing side contacts appear. Continue until working and balancing contacts are about equal
    •  Repeat the same sequence on the opposite side
    • o Equilibration in Protrusive
    •  This may require grinding of the anterior teeth as shown and selective reduction of the buccal inclines of the posterior teeth
  22. 22. Discuss the method used in equilibration of processed dentures with non-anatomic teeth. Be specific!
    • • Method of Equilibration
    • o Begin by checking the condylar inclination. For the lab exercise it should be 30 degrees. For a clinical patient it will vary
    • o Next, tract the articulator through working, balancing and protrusive. This is the working position.
    • o In the posterior region premature contacts will may be seen on the lingual cusps of the mandibular teeth. These contacts must be removed.
    • o Upon completion the articulator should slide easily from working to balancing to protrusive and back. There should be no bumps along the road. If the contacts on the balancing ramps are insufficient they may be supplemented with autopolymerizing acrylic resin.
    • o A successful result creates a tripod during excursions and should result in maximum stabilization of the denture bases.
  23. 23. Describe the techniques for finishing and polishing denture bases.
    • • Finish borders with an acrylic bur
    • • Remove excess resin beyond the land but be careful to preserve the border width and contour
    • • Remove all plaster or stone
    • o Remove small particles of stone from the proximal areas with a brush wheel
    • • Smooth the denture bases to the proper contour with your acrylic burrs or the Kingsley paper
    • • Bubbles and other irregularities around the denture teeth can be removed with chisels or scrapers.
    • • Use a very wet rag wheel with liberal amounts of wet pumice to polish the palatal, lingual, labial and buccal areas, as well as the periphery of the denture
    • o Do not overpolish and thereby loose the contours that were developed during festooning.
  24. 24. Describe the technical procedures for repairing broken or fractured denture bases.
    • • Place cryanoacrylate on fracture/broken area
    • • Closely approximate the denture bases pieces and piece them together
    • • Create a plaster index of the manually re-assembled denture base
    • • The plaster index should be perfectly adapted to the tissue surface directly below the site of the fracture
    • • Re-break the denture along the fracture line and freshen the edges
    • • Create a long bevel along the fracture
    • • Fill the gap with acrylic
  25. 25. List the purposes served by the clinical remount.
    • Purposes
    • 1. To correct errors in occlusion that have occurred during processing
    • 2. To return dentures to the correct vertical dimension of occlusion
    • 3. To restore centric and bilateral balanced occlusion
  26. 26. Describe three methods used in determining the vertical dimension of rest on a patient.
    • • Vertical Dimension of Rest: the vertical separation of the jaws when the opening & closing muscles of the mandible are at rest in tonic contraction. It is the length of the face when the mandible is in rest position
    • • Methods in Determining VDR*:
    • o Facial Measurements
    •  pt. sits comfortably,looking straight ahead
    •  insert maxillary record base
    •  place point of reference on nose & chin
    •  instruct pt. to lick lips and swallow
    •  mandible comes to rest position
    •  measure the distance between reference points
    • o Tactile Sense
    •  where pt. feels most comfortable
    • o Phonetics
    •  repeat the letter “mm-mm” and relax
    • o Facial Expression
    •  recognize the pts relaxed facial expression when the jaws are at rest
    • o Anatomic landmarks
    •  average measurements, questionable validity
    • (*No one method for determining rest position can be accepted as being valid for all pts.; therefore, it is advisable to use several methods and compare the results)
  27. 27. Describe the speech sounds most useful in determining anterior tooth placement.
    • • The anterior teeth and tongue act as a part of the valving mechanism which modify the flow of air to produce speech sounds
    • o Labial sounds: “p” “b”
    •  if the lips are not supported properly by the teeth these sounds may be defective
    • o Labiodental sounds: “f” “v”
    •  are produced by contact between the maxillary incisors and the posterior one-third of the lower lip
    • o Linguodental sounds: “th”
    •  are produced by extending the tip of the tongue 3-6 mm beyond the incisal edges of the upper & lower anterior teeth
  28. 28. List the speech sounds most useful in determining the vertical dimension of occlusion.
    • • “s” sounds
    • • counting from 60-70
  29. 29. List five objectives of master impressions in edentulous patients.
    • • Preservation
    • o with the loss of the stimulation of the natural dentition the alveolar ridge will atrophy or resorb, the process can be hastened or retarded by local factors.
    • o pressure in the impression technique is reflected as pressure in the denture base and results in soft tissue damage and bone resorption.
    • • Support
    • o maximum coverage provides the “snow shoe” effect.
    • • Stability
    • o close adaptation to the underlying mucosa is most important to reduce the horizontal movement of the denture.
    • • Esthetics
    • o border thickness should be varied to restore facial contour and proper lip support.
    • • Retention
    • o atmospheric pressure, adhesion, cohesion (depends on peripheral seal) mechanical locks, muscle control.
  30. 30. List five purposes served by the maxillary wax rim.
    • • 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
    • • Serve as a general aid in selection of teeth
  31. 31. Describe the advantages and disadvantages of autopolymerized and heat polymerized acrylic resin when used for complete denture bases and repairs.
    • Autopolymerized Advantages
    • • Low solubility
    • • Low water uptake
    • • Dimensional stability
    • • Dimensional accuracy
    • Heat Polymerized Advantages
    • • Good appearance
    • • High glass-transition
    • • temperature
    • • Ease of fabrication
    • • Low capital costs
    • • Good surface finish
    • Autopolymerized Disadvantages
    • • Not cheaper over long term
    • • Increased creep
    • • Increased free-monomer
    • • Color instability
    • • Reduced stiffness
    • • Tooth adhesion failure
    • Heat Polymerized Disadvantages
    • • Free-monomer & formaldehyde can cause sensitization
    • • Low impact strength
    • • Flexural strength low
    • • Fatigue life too short
    • • Radiolucency
  32. 32. Describe the indications and problems associated with complete denture relines?
  33. 33. What is the purpose of the facebow transfer record?
    • • creates an analogue (or representation) of the patient’s jaw relationship on the articulator
    • o this analogue enables the establishment of proper maxillary to mandibular prostheses relationships (proper denture occlusion) for your specific patient
    • o orients the maxilla to the transverse axis of the mandible in three dimensions and allows the transfer of this orientation to the articulator
  34. 34. What is a clinical remount cast?
    con­sists of remounting finished dentures on an ar­ticulator by using inter-occlusal records made in the patient's mouth. The occlusion is then adjusted on the articulator to eliminate discrepancies and interferences­. Should be accomplished when the dentures are delivered, and they find it to be the most accurate procedure for occlusal adjust­ment after insertion. The clinical remount procedure­, also known as the patient remount procedure, is one way to redefine occlusion and thereby reduce occlusal interferences and pre­serve soft tissues and residual ridges.
  35. 35. Describe the processes used to determine hinge axis location (arbitrary vs. true) and facebow transfer.
    • • Hinge Axis: a hypothetical line through the two mandibular condyles around which the mandible may rotate
    • o True Hinge Axis:
    •  Is difficult to determine especially in edentulous pts. and requires special armamentarium.
    • o Arbitrary Hinge Axis:
    •  Is an estimated axis location, using any of the current techniques will place the position within +6mm of the true hinge axis.
    •  Earbows use the external auditory meatus reference point as the arbitrary hinge axis location.
  36. 36. What are the clinical consequences if the occlusal plane is too high? too low? tipped?
    • • Too High:
    • o results in preventing the tongue from being able to control the bolus of food and from easily clearing the vestibule
    • • Too Low:
    • o may result in tongue biting
    • • Occlusal Plane Inclination (Tipping):
    • o reverse plane (lower in posterior than in anterior) results in anterior dislodgement of mandibular denture
    • o too great an inclination results in inclined plane forces on residual alveolus
  37. 37. What histologic structures lie beneath the palatal epithelium in the posterior palatal seal area?
    • Posterior palatine glands
  38. 38. Of the five factors in Hanau's Quint, which two factors are under greatest control of the dentist?
    • • Cuspal Inclination
    • • Compensating Curve
  39. 39. Once the proper incisal pin position is determined and set, why must incisal pin to incisal table contact be maintained throughout the denture fabrication procedures?
    To make sure that the vertical dimension of speech/occlusion is maintained and kept constant
  40. 40. What are the clinical consequences of the following errors in posterior tooth placement?
    • • Too lingual
    • o impingement on tongue function, destabilization of the denture base and potential speech problems
    • • Too buccal
    • o can result in cheek biting and excessive tipping of the denture bases, as well as cosmetic deficiencies
  41. 41. List five indications for the use of anatomic denture teeth.
    •  Good Residual Ridges
    •  Well Coordinated Patient
    •  Previously successful with anatomic dentures
    •  Denture opposes natural dentition
    •  When “Lingualized” occlusion is desired
  42. 42 List five indications for the use of monoplane denture teeth.
    •  Poor Residual Ridges
    •  Poor Neuromuscular control (Bruxers, CP etc.)
    •  Previously successful with Monoplane Dentures or Severely worn occlusion on previous denture
    •  Arch discrepancies
    • – Class II or III or Cross-bite
    •  Immediate Dentures
    • – except when opposing natural dentition
    •  Potential poor follow-up
  43. 43. Describe the purpose served by the placement of finger rests onto the mandibular custom impression tray.
    • • Finger rests in the 1st molar and 2nd premolar region so that even pressure can be placed on the mandibular tray to attain a fully seated impression with even pressure distribution
    • • The finger rests also provide something to grab onto to make removal of the tray easier
  44. 44. What are some of the advantages and disadvantages of acrylic vs. porcelain teeth?
    • Acrylic Resin Teeth ( Plastic Teeth)
    • Advantages
    • useful with reduced space between residual ridges
    • chemically bonds to denture base - increased fracture resistance
    • useful opposing natural teeth and metal restorations
    • shock absorber effect?
    • ease of adjustment
    • ease of restoration of surface polish
    • break and chip resistant
    • contact sound reduction
    • insolubile in mouth fluids
    • Plastic Disadvantages
    • less wear resistance
    • dull in appearance after loss of surface luster
    • careful polishing required
    • crazing and blanching if not cross linked
    • Porcelain Teeth:
    • Advantages
    • resists abrasion
    • maintains cuting edge
    • less wear - maintains VDO
    • polishing is facilitated
    • inert in mouth - no dimensional changes
    • natural appearance
    • force and temperature distortion resistance
    • Disadvantages
    • chip and fracture - brittle
    • relies on mechanical retention for attachment
    • difficulty in resotring surface polish after grinding
    • may weaken denture since they do not bond to denture base chemically
    • harder sound "click" in function
    • can acumulate stain at gingival margin
    • abrade opposing natural teeth and resin or metal restorations
  45. 45. Describe the differences between anterior guidance, group function and bilateral balance.
    • -Anterior Guidance: the anterior (front) teeth guide the posterior (back) teeth into position or centric Occlusion
    • -Group Function: the simultaneous contacting of opposing teeth in a segment or a unit, used to stabilize a full maxillary and mandibular denture
    • -Bilateral Balance: is the simultaneous contacting of the maxillary and mandibular teeth in the R and L and in the anterior and posterior occlusal areas when the jaws are either in centric or eccentric relations
  46. 46. What is the difference between Centric Occlusion and Centric Relation.
    • • Centric Occlusion (CO):
    • o the occlusion of opposing teeth when the mandible is in centric relation. This may or may not coincide with maximum intercuspation.
    • • Centric Relation (CR):
    • o a maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective discs with the complex in the anterior-superior position against the slopes of the articular eminences.
    • • Difference/Comparison
    • o Centric occlusion with teeth present is a tooth-to-tooth relation, whereas centric relation, is a static position, is a bone to bone relation.
  47. 47. Describe the clinical problems that may be precipitated when a denture is fabricated in which the vertical dimension of occlusion exceeds the vertical dimension of rest.
    • • Excessive VDO = Inadequate Interocclusal Rest Space – which results in:
    • o clicking of the teeth
    • o facial distortion, tense strained appearance
    • o difficulty closing lips
    • o difficulty swallowing
    • o soreness and discomfort under the denture
    • o increased ridge resorption due to trauma
  48. 48. Describe some of the clinical problems created when the vertical dimension of occlusion is closed excessively in relation to the vertical dimension of rest.
    • • Inadequate VDO = Excessive Interocclusal Rest Space – which results in:
    • o reduced interarch distance when the teeth are in occlusion
    • o overclosure is potentially damaging to the TMJ
    • o normal tongue space is limited
    • o facial distortion, chin is closer to nose, commissure of the lips turns down , lips lose their fullness
    • o muscles of facial expression loose their tonicity, face appears flabby
    • o angular cheilitis is sometimes attributed to overclosure
  49. 49. In a denture that has been fabricated with non-anatomic denture teeth, which teeth should be in contact when the patient is in the protrusive position?
  50. 50. What are the 5 factors that comprise Hanau’s Quint? Please write down the formula and explain how it is used.
    •  Inter-relationship of Hanau’s five factors may be described by Theilman’s Formula
    •  In order to maintain a balanced occlusion:
    • Constant = (Condylar Inclination * $Incisal Guidance$) / (Occlusal Plane * $Compensating Curve$ * $Cuspal Inclination$)
  51. 51. What is the vibrating line? What muscles associated with the velopharyngeal complex most affect the position of the vibrating line?
    • • Vibrating Line:
    • o Junction of the hard and soft palate (this is what she says in her lecture slides, even though last quarter we learned that it was the junction of the mobile and non-mobile parts of the soft palate)
    • • Musles associated with the velopharyngeal closure:
    • o Muscles of the soft palate:
    •  Tensor veli palatini
    •  Levator veli palatini
    •  Musculus uvulae
    •  Palatoglossus
    •  Palatopharyngeous
  52. 52. Why do we use centric relation when making complete dentures?
    • • CR is a reference point in recording maxillomandibular relations. It is independent of tooth contact. It allows us to record the anterior-posterior position of the mandible.
    • • It can be verified and repeated
    • • It is a starting point for developing occlusion. In denture occlusion CR=CO
    • • It’s a functional position, although fleeting in nature.
  53. 53. What is meant by the term “polished surfaces” as it pertains to complete dentures? Why is it important to develop proper contour of the “polished surfaces”?
    • • Polished surfaces
    • o are those surfaces of the denture that do not rest on the denture bearing surfaces and that interact with the mobile tissues adjacent to the denture such as the tongue, the tissues associated with the vestibule, the lips and the buccal mucosa.
    • • Why its important:
    • o Improved esthetics particularly for patients with a high smile line who display a significant amount of gingiva.
    • o Proper contours improve tolerance and comfort of the dentures.
    • o Proper contours improve neuromuscular control and the stability of lower denture.
    • o Proper contours limit biting of the lip or cheek.
    • o Proper contours provide appropriate tongue space permitting normal speech articulation.
  54. 54. What are the clinical consequences if the palatal portion of a maxillary denture is excessively thick?
    • • Excessive thickness reduces space for the tongue which results in:
    • o Gagging in some patients.
    • o Impaired speech articulation of most oral sounds
  55. 55. What is a facebow transfer jig? How is it used?
    • • What is it?:
    • o A facebow transfer jig orients the maxilla to the transverse axis of the mandible in three dimensions and allows the transfer of this orientation to the articulator
    • • Steps:
    • o Place the maxillary record base and wax rim in the pts. mouth and begin to
    • o contour it for proper phonetics, esthetics lip support and occlusal plane
    • o Place four notches on the wax rim.
    • o Place compound on the bitefork and line it up to the midline
    • o Mark the third point of reference. Using the Denar facebow, this point is 43 mm above the level of the lateral incisor (in edentulous patients this point is represented by the wax rim)
    • o Place the facebow in position. Have the patient position the ear pieces while you support the apparatus with your left hand.
    • o The bow is parallel to the interpupillary line.
    • o Position the 3rd point of reference.
    • o Tighten the bolts in sequence (1-2)
    • o Carefully remove the facebow from pts. face.
    • o Remove the facebow from the patient. Insert the maxillary cast into the record on the bite fork and attach the cast and face bow to the articulator with the jig.
  56. 56. Be capable of identifying the following anatomical landmarks, either on a clinical photo, or a master cast.
    • -Get with it and just identify it
    • a) External oblique ridge
    • b) Buccal shelf
    • c) Masseter groove
    • d) Genial tubercle
    • e) Alveolar ridge
    • f) Maxillary tuberosity
    • g) Hamular notch
    • h) Palatal tori
    • i) Rugae
    • j) Retromylohyoid space
    • k) Palatal vault
    • l) Posterior palatal seal area
    • m) Retromolar pad
    • n) Sublingual folds
    • o) Stenson’s duct
    • p) Wharton’s duct
    • q) Palatine glands
  57. 57. You will be asked to identify the specific muscles associated with specific areas of the denture borders.
    Go through Lecture 1 Slides to view images and identify them
  58. 58. Three different salivary glands interface with either the denture bearing surfaces or the denture periphery. Name them.
    • Sublingual Glands
    • Submandibular Glands
    • Palatal Glands?
  59. 59. What is the linear expansion of acrylic resin secondary to water resorption?
  60. 60. What anatomic structure affects the thickness and contour of the denture flange in the posterior buccal flange space? What are the consequences of a thick flange in this area?
    The posterior buccal flange space is affected by the masseteric groove, which enables the the masseter muscle to reflect the buccinator muscle in a superior and medial direction. The distobuccal flange of the denture should be contoured to allow freedom for this action otherwise the denture will be displaced or the pt. will experience soreness in this area
  61. 61. What is the purpose of custom impression trays in edentulous patients. How far short of the vestibule must the tray extend?
    • • Purpose:
    • o a properly extended custom tray is created to expedite border molding and facilitate a quality final impression
    • • Tray Extent:
    • o Try in custom impression tray and adjust the length of the flanges 2-3 mm short of the vestibule depth
  62. 62. Name the four extrinsic muscles of the tongue? What is their function?
    • • originate in structures outside the tongue and their function is to move the tongue and alter its shape
    • o Genioglossus
    • o Styloglossus
    • o Hyoglossus
    • o Palatoglossus
  63. 63. What is the difference histologically between the attached and the unattached oral mucosa.
    Attached oral mucosa is firmly attached to underlying periosteum and also exhibits a higher degree of keratinization more often?
  64. 64. What is the thickness of the maxillary wax rim?
    Molar region ____8?____Premolar region ____6?____ Anterior region ___3?____
  65. 65. List the limitations associated with the repair of a fractured mandibular denture base with autopolymerizing methyl methacrylate?
    • • Not cheaper over long term
    • • Increased creep
    • • Increased free-monomer
    • • Color instability, Reduced stiffness
    • • Tooth adhesion failure
    • • About half the strength of heat polymerized methyl methacrylate
  66. 66. List four disadvantages of porcelain denture teeth.
    • • Porcelain Teeth - Disadvantages
    • o chip and fracture - brittle
    • o relies on mechanical retention for attachment
    • o difficulty in resotring surface polish after grinding
    • o may weaken denture since they do not bond to denture base chemically
    • o harder sound "click" in function
    • o can acumulate stain at gingival margin
    • o abrade opposing natural teeth and resin or metal restorations
  67. 67. List five indications for the use of monoplane denture teeth.
    •  Poor Residual Ridges
    •  Poor Neuromuscular control (Bruxers, CP etc.)
    •  Previously successful with Monoplane Dentures or Severely worn occlusion on previous denture
    •  Arch discrepancies
    • – Class II or III or Cross-bite
    •  Immediate Dentures
    • – except when opposing natural dentition
    •  Potential poor follow-up
  68. 68. Discuss the current trends in tooth loss and adult edentulism. Is the number of edentulous patients in the United States increasing or decreasing?
    • • Since the 1960’s there has been a dramatic decrease in the rate of tooth loss in our population
    • • However, due to the exponential growth of our population the actual number of edentulous patients is slightly increasing over time.
    • • By the year 2020 approx. 30 million elderly adults will be edentulous in one or both arches.
  69. 69. What % of the adult population is either partially or completely edentulous?
    In 1996: 21.4% of adult population wore some type of dentures (not sure if theres a more recent date)
  70. 70. What % of patients wearing upper and lower dentures are satisfied, moderately satisfied, moderately dissatisfied or dissatisfied with their complete dentures. Be specific.
    • • Fully satisfied: 66.7%
    • • Moderately satisfied: 25.6%
    • • Not satisfied: 7.7%
  71. 71. Relative to mastication efficiency, compare edentulous patients wearing complete dentures with fully dentate individuals. Be specific.
    A denture wearer’s ability to comminute food during mastication is markedly reduced to 1/4 or 1/7 of that of adults with natural dentitions depending on the ages of the subjects and type of food
  72. 72. What factors most influence denture satisfaction?
    • • Denture satisfaction is influenced by various factors, including:
    • o denture quality
    • o the denture bearing area available
    • o the quality of dentist-pt. interaction
    • o previous denture experience
    • o the pt’s personality & psychologic well being
  73. 73. In patients with retruded tongue positions and unfavorable floor of mouth contours what improvements can be expected from the addition of two implants in the anterior mandible? Be specific!!
    • • Patients with unfavorable floor of mouth posture and tongue, the length of lingual flange of the denture will be limited, compromising stability, retention, and the ability of the patient to control the lower denture.
    • • Implant Result:
    • o Improved retention. Note denture snaps onto retention bar.
    • o Improved stability (from the implants and the retention bar).
    • o Improved support (anteriorly).
    • o Improved control of the bolus (tongue no longer must position denture and control bolus simultaneously).
    • o Improved mastication efficiency
  74. 74. Is leukoplakia a premalignant lesion? Explain!
    Yes. It has the potential to transform into a squamous cell carcinoma
  75. 75. How does lichen planus affect a patient’s ability to function with complete dentures?
    • • Oral Lichen Planus Erosive lesions and subsequent scarring in the buccal shelf area limit denture extension in this region and make it difficult for some patients to tolerate their dentures.
    • o This results in compromised support and tolerance of the mandibular denture.
  76. 76. What impact does xerostomia have on a patient’s ability to function with and tolerate complete dentures?
    • • Less saliva results in more friction at the mucosal-denture interface as the mandibular denture slips and slides over the mucosal surface during function.
    • o Difficult to achieve and maintain peripheral seal and atmospheric pressure.
    • o Compromised adhesion and cohesion
    • • Xerostomia also leads to increased numbers of fungal organisms
    • o Leads to high incidence of oral candidiasis, which leads to burning and irritation of the denture bearing mucosa, making tolerance of complete dentures difficult
  77. 77. What is Christensen’s phenomenon?
    The creation of a space between the posterior teeth bilaterally during protrusion or on the balancing side during lateral excursions. Protrusive and laterotrusive interocclusal records register the gap produced by Christensen's Phenomenon
  78. 78. What is the “Neutrocentric concept of occlusion? How is it different from bilateral balanced occlusion?
    • • In neutrocentric occlusion there is separation of the denture teeth in the posterior regions during balancing and protrusive positions, leading to tipping of the dentures, which is disadvantageous in the patients exhibiting parafunctional grinding habits. This is different than balanced occlusion where all posterior teeth are in contact, providing stability during parafunctional movements.
    • • Additional Info on Neutrocentric Occlusion for Further Understanding:
    • o non-balanced occlusion in excursions
    • o flat occlusal surfaces should have flat planes in all directions with no inclination at all with respect ot the underlying denture foundation
    • o balanced occlusion in excursions is unnecessary and undesirable as resulting inclines causes horizontal forces
    • o contact in centric only, no eccentric balance
    • o theory is to modify the muscular pattern to centric only, so that patient chews with a vertical pattern only, no horizontal component
    • o forces of occlusion on posterior teeth as lingually as possible with a decreased buccal lingual width of teeth, decreased numbers of teeth resulting indecreased force
    • o denture is made to "flip out" if patient attempts to incise
    • o no vertical overlap of anteriors
  79. 79. Why is bilateral balanced occlusion preferred in most patients when designing and occlusal arrangement for complete dentures?
    Balanced occlusion is preferred because it provides stability during parafunctional movements. In bilateral balanced occlusion, all posterior teeth are in contact, with no anterior contact, when in centric relation. Also, during excursions, there are at least 3 stable contacts widely distributed around the arch. This is preferable over other forms of occlusion where in balancing and protrusive positions there would be separation of the denture teeth in the posterior regions leading to tipping of the dentures, which would be disadvantageous in the patients exhibiting parafunctional grinding habits
  80. 80. Name two means of minimizing the resorption of edentulous mandible? Explain why they are effective!
    • • Well adapted and properly extended dentures with properly designed and executed occlusion
    • • Retention of residual tooth roots in key locations*
    • • Use of osseointegrated implants*
    • o *Retained roots and osseointegrated implants are useful because they absorb much of the occlusal load locally, thereby preventing compression of the periosteum and in turn preventing resorption of the adjacent bone*
  81. 81. There are four distinct layers associated with the attached keratinized epithelium found on the denture bearing surface. Name these layers from the surface inward.
    • 1) stratum corneum
    • 2) stratum granulosum
    • 3) stratum spinosum
    • 4) basal layer
    • 5) lamina propria
    • (not sure about this one)
  82. 82. It is very difficult for patients with a history of lichen planus to wear mandibular complete dentures. Please explain.
    • • Oral Lichen Planus Erosive lesions and subsequent scarring in the buccal shelf area limit denture extension in this region and make it difficult for some patients to tolerate their dentures.
    • o This results in compromised support and tolerance of the mandibular denture.
  83. 83. It is difficult for patients with a long history of insulin dependent diabetes to wear mandibular dentures. Please explain.
    • • Patients with a history of diabetes have epithelium that is thinner and less keratinized
    • o This results in compromised support and tolerance of complete dentures
  84. 84. Speech is an important tool when determining the proper vertical dimension of occlusion (VDO). In order to produce normal speech velopharyngeal closure must be accomplished. What muscles are responsible for velopharyngeal closure?
    • • Musles associated with the velopharyngeal closure:
    • o Muscles of the soft palate:
    •  Tensor veli palatini
    •  Levator veli palatini
    •  Musculus uvulae
    •  Palatoglossus
    •  Palatopharyngeous

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