Prosth 2 Flashcards
What muscle attaches to the Mandibular labial frenum? What about maxillary?
Orbicularis oris
There is no muscle that attaches to the maxillary labial frenum
What muscle attaches to the mandibular buccal frenum? What about maxillary buccal frenum?
Orbicularis oris and buccinator
Same for maxillary buccal frenum
The lingual frenum of the mandibular arch attaches to what muscle?
Genioglossus
The mandibular labial vestibule inferior border is the ___ muscle
Mentalis
The mandibular buccal vestibule inferior border is the ___ muscle
Buccinator
The retromolar pad defines the __ boundary of the endentulous ridge. It is ideally covered for support and retention since the ____ in this area is maintained. It contains attachements from what muscles?
Posterior
Integrity of the bone
Temporalis
Buccinator
Superior pharyngeal constrictor
Pterygomandibular raphe
The retromolar pad contains attachments to what 4 muscles?
Temporalis
Buccinator
Superior pharyngeal constrictor
Pterygomandibular raphe
What is the masseteric notch?
Not so much an anatomical landmark but a landmark on the impression of the dentures
Refers to the distobuccal area on the impression/denture
Masseter contracts when mouth closes against resistance - so you want the pt to close against resistance during border molding
Where is the alveololingual sulcus located? What shape does it have?
Between mandibular alveolar ridge and tongue
It has an “s” shape and 3 regions?
The anterior region of the alveololingual sulcus runs from ___ to ___. The ___ sits above the mylohyoid muscle in this region so the flange is [shorter/taller] anteriorly and should touch the mucosa of floor of the mouth
Lingual frenum
Premylohyoid fossa
Sublingual gland
Shorter
The middle region of the alveololingual sulcus goes from ___ to ___
Premylohyoid fossa
Distal end of mylohyoid ridge
In the middle region of the alveololingual sulcus, the flange is deflected ___ away from mandible due to…
Mesially
Prominence of mylohyoid ridge in this area and contraction of mylohyoid medially
The posterior region of the alveololingual sulcus extends into the ___. Although the mylohyoid attaches __ posteriorly, the posterior fibers are directed more ___ so the denture seats ___ and the lingual flange is [shorter/longer]
Retromylohyoid fossa
Higher
Vertically
Deeper
Longer
In the posterior region of the alveololingual sulcus, the flange is directed [medially/laterally] toward the ___ to form the typical S-form of lingual sulcus.
Laterally
Ramus of mandible
The denture extension in the posterior region of the alveololingual sulcus is limited by what two muscles?
Palatoglossus
Superior constrictor
The buccal shelf is located ___ to the ___. It lies ___ to occlusal forces and provides ___ for the denture. The __ muscle attaches here.
Lateral
Posterior mandibular alveolar ridge
Perpendicular
Support
Buccinator
List the order of frenectomies from most common to least common
Labial > buccal > lingual
True or false…. free gingival graft is sometimes necessary for some overdenture teeth
True, it widens the band of keratinized tissue
A hyper mobile ridge is a flabby edentulous ridge that are most commonly seen in which location?
Anterior maxilla
Name some treatment options to treat a hypermobile ridge
Tissue conditioner (if tissue is inflamed)
May use electrosurgery or laser surgery to eliminate tissue if conditioner is ineffective - but this can also eliminate the vestibule
Use large relief in tray or perforate a custom tray when taking impression
What is an epulis fissuratum?
Hyperplastic tissue reaction caused by an i’ll-fitting or overextended flange
What is the treatment for an epulis fissuratum?
Treat with tissue conditioner and by adjusting the flange
May use surgery if there is an inadequate response
A fibrous (pendulous) tuberosity is common when ____ touch ____. This can interfere with ____. How is this corrected?
Large tuberosities touch retromolar pads
Denture construction by limiting interarch space
Surgical excision of fibrous tissue and/or bone
Papillary hyperplasia = multiple papillary projections of ___ caused by local irritation, i’ll-fitting denture, poor oral hygiene, and leaving dentures in all the time. ___ is the main cause. How do you treat this?
Palate
Candidiasis
Treat with OHI, leave dentures out at night, soak dentures in 1% bleach and rinse thoroughly, use tissue conditioner, and brush irritated area lightly with soft brush
Combination syndrome is a specific pattern of ___ in the ____ when it is opposing ___ only
Bone resorption
Anterior edentulous maxilla
Mandibular anterior teeth
Describe what combination syndrome looks like
Overgrowth of tuberosities
Papillary hyperplasia
Extrusion of lower anterior teeth
Loss of bone under the partial denture bases
True or false… residual root tips may be left alone if they have an intact lamina dura and no radiolucency
True
Alveoloplasty is surgical reshaping of alveolar bone. It is useful for __, __, or ___.
Sharp, spiny, or extremely irregular ridges
When are tori removed for dentures?
If it creates an undercut or interferes with posterior palatal seal
What is the purpose of a vestibuloplasty?
Increase the relative height of the alveolar process to increase denture base area by apically repositioning the alveolar mucosa and the buccinator, mentalis, and mylohyoid muscles as they insert into the mandible
Lingual vestibuloplasty is more traumatic and rarely indicated
Bone augmentation of edentulous ridges can be done to increase area for denture seat. Bone grafts can include ___ and ___ as well as ___. Which is more common, horizontal or vertical bone augmentation?
Iliac crest of hip
Rib
Hydroxyapatite-biocompatible bone substitute
Horizontal > vertical
What is another name for labiodental sounds? What kinds of sounds do they include?
Fricative
F, V, Ph
Fricative/ labiodental sounds are produced by contact between ___ and ____. Testing for fricative sounds help determine what positioning?
Maxillary incisors
Wet/dry line of lower lip
Helps determine the position of incisal edges of maxillary anterior teeth
What is another name for linguoalveolar sounds? What types of sounds do they include?
Sibilant
S, Z, Sh, Ch, J
Sibilant (linguoalveolar) sounds are produced by contact between ___ and the ____
Tip of tongue
Anterior palate or lingual surface of the teeth
Sibilant sounds help determine the correct ___ and ___
Vertical length
Overlap of anterior teeth
What does it mean if the patient makes a whistling sound when trying to produce sibilant sounds?
Too narrow arch form
What does it mean when the patient makes a lisp where “s” becomes “sh” when trying to produce sibilant sounds.
Too wide arch form
Define closest speaking space
You want to evaluate vertical dimension during pronunciation of “s” sound, the inter incisal separation should be 1-1.5mm
What are linguodental sounds?
It is made by contact between ___ and ___
“Th”
Tip of tongue and upper and lower teeth
Having the patient produce linguodental sounds “th” helps determine the position of…
Helps determine labiolingual position of anterior teeth
When the patient is producing linguodental sounds, what does it mean when the tongue is not visible? What does it mean if the tongue sticks out?
Tongue is not visible = teeth are set too far forward
Tongue sticks out = teeth are set too far back
What sounds are bilabial sounds?
It is made by…
“B” “p” “m”
Contact between both lips
Insufficient lip support by the teeth or labial flange can affect the production of ___ sounds
Bilabial
What are guttural sounds?
“G” and “k”
Produced by contact between back of tongue and throat
What is VDR?
Vertical dimension of rest
It is the distance between nose and chin at rest
Where elevator and depressor muscles are in a state of equilibrium (PRP = physiologic rest position)
In VDR, there is usually __mm of space between upper and lower premolars
3mm
What is VDO?
Vertical dimension of occlusion
It is the distance between nose and chin when biting together
Indicates superior-inferior relationship of the maxilla and the mandible when the teeth are occluded in MI
What is interocclusal space?
Difference between VDR and VDO (ideally 2-4mm)
VDR = VDO +3mm
VDR = VDO + ___
3mm
Excessive VDO means the interocclusal space is < ___mm. Some symptoms are… excessive display of ___ teeth. ____ fatigue. Clicking of the ____ when speaking. ___ appearance of the lips. Pt unable to wear dentures. Discomfort. Excessive ___ to supporting tissues. Gagging.
2mm
Mandibular
Muscles of mastication**
Posterior
Strained
Trauma
Name some symptoms of excessive VDO.
Excessive display of mandibular teeth
Muscles of mastication fatigue
Clicking of posterior teeth when speaking
Strained appearances of the lips
Patient unable to wear dentures
Discomfort
Excessive trauma to supporting tissues
Gagging
Insufficient VDO is when the interocclusal space is >___mm. Name 3 symptoms
4mm
Aging appearance of lower third of face because o thin lips, wrinkles, chin too near the nose, overlapping of corners of the mouth
Diminished occlusal force
Angular cheilitis***
Obtaining the CR record for an edentulous patient provides the ability to increase or decrease the ___ more accurately in the articulator by establishing a radius of the ____
VDO
Mandible’s arc of closure
Facebow transfers the relationship between the hinge axis of maxilla from the patient to the articulator
The protrusive record registers the ____ in the translation movement of the condyles
Anterior-inferior condyle path
What is Christensen’s phenomenon?
Refers to the distal space created between the maxillary and mandibular occlusal surfaces when the mandible is protruded, due to downward and forward movement of condyles down their articular eminences
Define camper’s line
Imaginary line from ala of nose to tragic of ear
Define interpupillary line =
Imaginary line between pupils of the eyes.
The maxillary occlusal wax rim should be parallel to ___ and ___ which can be measured with a ____
Camper’s line
Interpupillary line
Fox plane
define balanced occlusion for complete dentures
Simultaneous anterior and bilateral posterior contacts (tripodization) in centric and eccentric movements to maintain seating of dentures
True or false… it is ideal to have Christensen’s phenomenon with dentures
False.. you want balanced occlusion (tripodization) so the dentures maintain seating
True or false… anterior guidance should be avoided in complete denture occlusion to prevent dislogment of denture bases
True
In balanced occlusion, on the balancing side, maxillary lingual cusps contact __ of ___. On the working side, maxillary lingual cusps contact ___ of ___ AND mandibular buccal cusps contact ___ of ___
Lingual incline of mandibular buccal cusps
Facial incline of mandibular lingual cusps
Lingual incline of maxillary buccal cusps
Define linguallized occlusion (sometimes used in denture fabrication)
Where only the palatal cusps of the maxillary posterior teeth contact the mandibular posterior teeth theoretically eliminating the destabilizing buccal force vectors
Define Bennett angle
Define Bennett shift
Define Bennett movement
Bennet angle = angle obtained after nonworking side condyl has moved anteriorly and medially relative to Sagittal plane (15 degrees)
Bennet shift = lateral movement of mandible toward the working side during lateral excursions
Bennett = lateral movement of both condyles toward the working side, magically “TMJ losseness”
True or false…. for posterior teeth disclusion, you want posterior teeth with short cusps and shallow inclines
True. Because they have less room to be interfered with and can disclude easier
Name two compensating curves
Curve of spee
Curve of Wilson
True or false… for best disclusion of posterior teeth, you want less curve of spee and less curve of Wilson
True
Define curve of spee
Anterior posterior curve to ensure loading into long axis of each tooth
More mesial inclination as you move distally
Define curve of Wilson
Mediolateral curve along posterior cusp tips to ensure loading into long axis of each tooth
More lingual inclination as you move distally
If you want more disclusion, you want the orientation of the occlusal plane to be [more/less] parallel to the orientation of the condylar path
Less
Define support
Resistance to vertical seating forces
What structures in the maxilla provide the most support?
Palate
Alveolar ridge
What structures in the mandible provide the most support?
Buccal shelf***
Retromolar pad
What component of the denture is involved in support
Denture base
Define stability
Resistance to horizontal dislodging forces
What components of upper and lower arches provide stability?
Ridge height
Depth of vestibule
What part of the denture provides stability?
Denture flange
Define retention
Resistance to vertical dislodging forces
What component provides the most retention?
Peripheral seal
Which provides better retention, thick and ropy saliva or thin watery saliva?
Thin watery saliva
Define overextension
Denture flange is too long - The patient would get a sore spot or ulcer after wearing the denture for a while
Or denture extends too far back - denture teeth are set so far back that they go up on the ramus. Occlusal forces dislodge the denture
What is the treatment for a sore spot created by overextension of flange?
Relieve denture and re-evaluate in a few weeks
What are the two main side effects of overextending a denture?
Sore spots
Dislodging
What happens when the denture is underextneded?
Lacks retention
What is the best indicator for success of a denture?
The ridge
A wide broad ridge is the best scenario (square like)
The acrylic used in dentures are ___-cured. The polymer is in __ form. It is called ___. The monomer is in ___ form. It is called ___.
Heat-cured
Powder
PMMA
Liquid
MMA
The liquid component of acrylic contains what four components?
Methyl Methacrylate (MMA) = monomer
Hydroquinone = inhibitor
Glycol dimethacrylate = cross-linking agent
Dimethyl-p-toluidine = activator
The liquid of acrylic contains the monomer, inhibitor, cross-linking agent, and activator. Name each of these.
Monomer = MMA
Inhibitor = hydroquinone
Cross-linking agent = glycol dimethacrylate
Activator = dimethyl-p-toluidine
The powder of acrylic contains what 3 things?
Polymethyl methacrylate (PMMA) = polymer
Benzoyl peroxide = initiator
Salts of iron, cadmium, or organic dyes = pigment
The powder of acrylic contains, polymer, initiator, and pigment. What are each of these things?
Polymer = PMMA
Initiator = benzoyl peroxide
Pigment = salts of iron, cadmium, or organic dyes
The activator in the liquid, ____, breaks ____ in the powder, into its radical form
Dimethyltoludine
Benzoyl peroxide
Shrinkage always occurs in denture processing. But more shrinkage occurs if there is excessive ___
Monomer
What is the ideal ratio of monomer to polymer?
1:3
Porosity in denture processing is due to what two things?
Underpacking with resin at time of processing
Or
Being heated too rapidly***
Porosities in dentures have what two negative outcomes?
Less durable
More plaque accumulation
What are the two main types of denture teeth?
Acrylic
Porcelain
What is the main advantage of acrylic denture teeth?
Better retention because they can bond to acrylic resin of denture base
What is the main advantage of porcelain denture teeth?
More esthetic because it is stain and wear resistant
What are 3 drawback to porcelain denture teeth?
Brittle
May wear opposing teeth
Mechanical retention must be achieved to keep teeth in place
With porcelain denture teeth, anterior teeth are retained via ___ and posterior teeth are retained via ___
Pins
Diatorics
Define Kennedy class 1
Bilateral distal extension
Define Kennedy class 2
Unilateral distal extension
Define Kennedy class 3
Unilateral bounded edentulous space
Define Kennedy class 4
Bilateral bounded edentulous space (which means it crosses the midline)
What is applegate’s rule #1?
Kennedy classificaiton should be assigned AFTER any extractions
What is Applegate’s 2nd rule?
Missing third molars are not considered
What is Applegate’s 3rd rule?
Abutment third molars are considered
What is Applegate’s 4th rule?
Missing second molars are not considered
What is Applegate’s 5th rule? (Probably the most important) what is the 6th rule?
The most posterior edentulous area determines the Kennedy classification
Other edentulous areas are referred to as modifications
What is Applegate’s 7th rule?
Extent of modification does not matter, only the number
What is applegate’s 8th rule?
Kennedy class 4 cannot have any modifications, by definition
The major connector of an RPD provides ___. It units all other components. It is not placed on ___
Rigidity***
Movable tissue
What is the primary function of a major connector in an RPD?
Provides rigidity
What is the most rigid type of maxillary major connector? When is it indicated?
Complete palatal plate
Indicated when all posterior teeth are missing bilaterally, periodontally compromised teeth, shallow vault, small mouth, flat or flabby ridges.
What type of maxillary major connector is the least rigid design. When is the only time you should use this?
Horseshoe
Only used if large palatal torus is present
In a palatal strap major connector design, it should cross at the midline at a __ angle
90 degree
Same thing applies for all major connectors
What is beading?
Exclusive for maxillary major connector
Involves scribing a 0.5mm rounded groove in the cast at the borders of the major connector
This adds strength and maintains tissue contact to prevent food impaction, allows for firmer tissue contact
What is the simplest and most common mandibular major connector? It is preferred when the depth of the lingual vestibule is greater than or equal to 7mm
Lingual bar
A lingual bar mandibular major connector should be used when the depth of the lingual vestibule is equal to or greater than ___mm
7mm (measured from gingival margin to wherever the lingual frenum starts)
When is the lingual plat mandibular major connector used?
When depth of lingual vestibule is < 7mm
Additional tooth loss is anticipated
Lingual tori are present
All posterior teeth are missing bilaterally (only canine -canine are present)
When is labial bar (swing lock) mandibular major connector used?
When there is a missing canine
Unfavorable soft tissue contour
Questionable periodontal prognosis
Define minor connectors
Connects major connector to rests, indirect retainers, and clasps
Define RPD rests
Rigid extension of an RPD framework that contacts the occlusal, lingual, or incisal surface of an abutment tooth
Directs forces through long axis = support*
What is the differnce between a rest and a rest seat?
A rest is an extension of an RPD framework
A rest seat is prepared into the occlusal, lingual, or incisal surface of an abutment tooth in order to receive and support a rest
What is the correct shape of an occlusal rest?
Rounded, semicircular outline form (spoon shaped)
One-third MD width of tooth
One-half intercuspal width
1.5mm deep for base metal
Angle formed with vertical minor connector is <90degrees.
An occlusal rest is ___ the MD width. It is ___ the intercuspal width. It is made ___ deep for base metal. The floor should incline apically towards the ____. The angle formed with vertical minor connector is ___ degrees.
1/3rd
1/2
1.5mm
Center
<90
A cingulum rest has what shape?
Inverted V or U
A cingulum rest should be __ in MD length, and ___ in labiolingual width. It should be ___ deep.
2.5 - 3mm
2mm
1.5mm
Cingulum rests are contraindicated in ___ teeth
Mandibular incisors
What are the benefits of a cingulum rest?
Good distribution of occlusal load, esthetics, strength from closeness to major connector
What is the shape of an incisal rest? It should be ___ in MD length. It should be ___ deep. It can be used as an ____. It is less favorable because…
Rounded notch at incisal angle
- 5mm
- 5mm
Indirect retainer
Less favorable leverage than lingual rest. Not often used because of esthetic compromise
What is the proximal plate?
Metal plate that contacts the proximal surfaces of abutment teeth (guide planes)
What are guide planes?
Flat parallel surfaces of abutment teeth that provide path of insertion and removal
Guide planes should be ___ the BL width. It extends ___ vertically down from the marginal ridge.
1/3
2-3mm
When are indirect retainers used?
When a distal extension area of a partial is “loose” and not anchored posteriorly
This is because there is rotational movement centered around an imaginary line drawn through the most distal rests
An indirect retainer should be placed directly ___ and ___ to the fulcrum line which provides bracing to resist rotational movement of distal extension area
Perpendicular
Anterior
A direct retainer is also called a ___. It is made up of what 3 components?
Clasp assembly
Rest
Minor connector
Clasp arms
What do the components of a direct retainer (clas assembly) provide?
Rest = support
Minor connector = stability
Clasp arms….
Retentive clasp arm = retention
Reciprocal clasp arm = stability
What are the two types of direct retainers?
Extracoronal (more common, conventional “clasp” design.
Intracoronal (a precision attachment with key and key way pattern. More esthetic because no clasps)
Clasps should encircle a tooth at least ____ degrees.
180
The retentive clasp originates from ___ and ___. It contacts tooth ___ the height of contour/survey line
Minor connector
Rest
Below
The shoulder and middle of the retentive clasp should be ___, only the tip should be ___
Above the height of contour
Below the height of contour
The tip of the retentive clasp is designed to engage in the ___ and resist ___ forces - only active when dislodging forces are applied to them, otherwise they should seat ____
Undercut
Dislodging
Passively
The retentive clasp is generally located on the __ surface
Buccal
The reciprocal clasp (AKA ___) originates from minor connector and rest. It contacts the tooth ____. It functions to…
Stabilizing clasp
Above the height of contour (survey line) only
Braces abutment tooth so it is not torqued by retentive clasp
What is the suprabulge clasp design?
What is the infrabulge clasp design?
Originates above the survey line
Originates below survey line
Name 4 suprabulge clasp designs
Circumferential (Akers)
Ring
Combination
Embrasure
Name 4 types of infrabulge clasp designs
I bar
T bar
Bar type
Y type
When is the ring clasp used?
When the undercut is adjacent to the bounded edentulous space
What is an embrasure clasp?
Essentially a pair of Akers clasps facing away from each other (both teeth need rest preps)
Why don’t we use I bar on everything?
You need to have sufficient vestibular depth and you can’t have a soft tissue undercut.
What is the RPI clasp assembly? What is it used for?
Rest
Proximal plate
I bar
(Ideal for class 2 lever system)
What is the RPA clasp assembly?
Rest
Proximal plate
Akers clasp
What is the RPC clasp assembly?
Rest
Proximal plate
Circumferential clasp
____ is used for periodontally compromised and endo-treated teeth. Why?
Wrought wire
It puts less torque on teeth
For bounded edentulosu spaces, use ___ with rest seats located ___ to edentulous space
Akers clasps
Adjacent
For distal extension use __, ___, and __ in order of preference
RPI
RPA
Wrought wire
Cobalt-chromium has ___% shrinkage which causes some irregularity and porosity, but its very strong.
2.3%
What is cold-working?
Involves manipulating the metal while at ambient temperature
Clasp assembly is cold-worked everytime it is seated and dislodged
Main reason why clasps break***
What is the main reason why clasps on an RPD break?
Cold-working (taking the RPD in and out)
