Part 4 Theories pg 1-17 Flashcards
Findings of Wright and relation of the tongue to denture stability
- Retracted or normal position better for stability
- What percent for both?
- How do the buccinator and tongue work together?
- Normal is superior
- 65% normal, 35% retracted
- They form a food trough to keep food on the occlusal surfaces
Lytle (1959) - How long for the underlying tissues of an ill-fitting denture to recover for CD impression?
- What is the result of impressing extremely abused tissues?
- What is the quantitative difference for healthy vs abused tissue dimensions?
- 12-24 hours for JRR, try-in, and final placement.
48-72 hours for impressions, 72 hours for extremely abused tissues. - Would lead to errors in CD such as ill-fitting record base, prostheses, CR, etc
- 0.7 to 3 mm difference
Who advocated using the patient’s existing dentures to assess patient expectations? How would you do this?
- Sprig - Assessed patient expectations prior to treatment using CD. Polysulfide in existing dentures to demonstrate changes in tooth position/vertical dimension
- Vig - Border molded and impressed with old dentures, used to determine VDO, tooth selection, placement, and base shade
What info can you obtain from the existing dentures?
Incisal length, size, and shape of teeth, patient’s expectations. length of existing flanges/extent of PPS, lip display, VDO
Muscles of mastication (4)
- What innervates them?
- Temporalis
- Masseter
- Lateral pterygoid
- Medial pterygoid
A. Mand. branch of Trigeminal nerve (V3)
Temporalis
- Origin
- Insertion (2)
- Nerve
- Action
O: Side of skull
I: Coronoid process; anterior border of ramus (Medial and anterior surface)
N: V3
A: Elevates mandible
Masseter
- Origin
- Insertion (2)
- Nerve
- Action
O: Zygomatic arch
I: Lateral surface of ramus, coronoid process
N: V3
A: Elevates/protrudes mandible
Lateral pterygoid (superior and inferior belly)
- Origin
- Insertion
- Nerve
- Action
Superior belly O: Sphenoid
Inferior belly O: Lateral pterygoid plate
Superior I: Anterior disc/capsule of TMJ
Inferior I: Pterygoid fovea (neck) of condyle
N: V3
Superior A: Stabilize/protrude disk
Inferior A: Depresses, protrudes, moves mandible side to side
Medial Pterygoid
- O(2) INA
O: Medial surface of the lateral pterygoid plate, the pyramidal process of palatine and tuberosity
I: Medial surface of ramus
N: V3
A: Elevates, protrudes, laterotrusion
Retromolar pad
- Contents (5)
- What is underlying the pad?
- Glandular tissue
- Loose areolar tissue
- Superior constrictor
- Buccinator
- Tendon of temporalis
A. Cortical bone
Soft elevation of mucosa tissue comprising of loose connective tissue and mucous glands
- Bounded laterally by the buccinator
- Posteriorly by the temporalis tendons
- Medially by pterygomandibular raphe and superior constrictor
Contents of retromylohyoid fossa (3)
Posterolateral: Superior constrictor
Posteromedial: Palatoglossus
Medial: Mylohyoid
What muscle produces the “s” curve of the lingual flange?
Mylohyoid
What are the muscles in the floor of the mouth?
- Mylohyoid
- Genioglossus
- Geniohyoid
Hamular notch
- Junction of what structures?
- Origin of what structure
- Junction of max tuberosity and hamular process of medial pterygoid plate
- Origin of pterygomandibular raphe that has mucous membrane covering a thick submucosa of loose areolar CT as well as tendon of tensor veil palatini
Hamular notch
- What tendon wraps around the hamulus?
- Is overextension in the hamular notch tolerated?
- Tendon of tensor velli palatini
2. Not tolerated as the pterygomandibular raphe is pulled forward when the mouth opens wide
Muscles of the soft palate (5)
- Palatoglossus
- Palatopharyngeus
- Levator veli palatini
- Tensor veli palatini
- Uvula muscle
Palatoglossus
- OINA
O: Palatine aponeurosis
I: Tongue
N: Vagus nerve (X) with motor fibers from cranial accessory nerve (XI)
A: Elevate posterior tongue and aids initiation of swallowing
Palatopharyngeus - OINA
O: Palatine aponeurosis and posterior hard palate
I: Thyroid and blends with constrictor fibers
N: Vagus nerve (X) with motor fibers from cranial accessory (XI)
A: Elevate pharynx and larnyx. Closes nasopharyngeal in swallowing
Levator veli palatini - OINA
O: Temporal bone and auditory tube
I: Palatine aponeurosis
N: Vagus nerve (X) with motor from cranial accessory (XI)
A: Raises soft palate. May open auditory tube on swallowing
Tensor veli palatini - OINA
- Note something special about the insertion - the tendon
O: Sphenoid bone and auditory tube
I: Palatine aponeurosis (via pulley of pterygoid hamulus)
N: Nerve to medial pterygoid (mandibular nerve (V3))
A: Tenses soft palate
Uvulae muscle - OINA
O: Posterior border of hard palate
I: Palatine aponeurosis
N: Vagus nerve (X) with motor fibers from cranial accessory nerve (XI)
A: Shapes uvulae
What muscles insert into modiolus?
BORZZLD (8) Buccinator Orbicularis oris Rissorius Zygomaticus major Zygomaticus minor Levator anguli oris Depressor anguli oris
What is the modiolus?
- Nerve?
- Blood supply?
Chiasma of facial muscles held together by fibrous tissue
N: Facial nerve (7)
Blood supply: Facial artery
Innervation of the tongue
- Sensory (2)
- Taste (2)
- Motor
- Blood supply
- Ant 2/3 - Lingual nerve
- Post 1/3 - Glossopharyngeal
- Taste: Ant 2/3 is chorda tympani and Post 1/3 is glossopharyngeal
- Motor: Hypoglossal (XII)
- Blood supply - Lingual artery of facial nerve
Innervation of palate
- Ant 1/3
- Post 2/3
- Nasopalatine
2. Greater palatine
Innervation to TMJ
Auriculotemporal and masseteric branches of V3 (sensory innervation)
Five ligaments that attach to the mandible
- Collateral discal ligaments (2)
- Capsular ligament
- Temporamandibular ligament
- Sphenomandibular ligament
- Stylomandibular ligament
Collateral discal ligaments
- OIA
O: Medial and lateral poles of disc
I: Medial and lateral poles of condyles
A: Restrict movement of disc away from condyle
Which ligament is responsible for hinge movement of TMJ?
Collateral discal ligaments
Capsular ligament (aka articular capsule) - OIA
O: Temporal bone
I: Neck of the condyle
A: Resist forces to dislocate surfaces
Temporomandibular ligament
- Outer oblique portion OIA
- Inner horizontal portion OIA
Outer: O: Articular tubercle and zygomatic process
I: Condylar neck
A: Permits rotation
Inner: O: Articular tubercle and zygomatic process
I: Condyle and articular disk
A: Limits posterior movement and provides bracing for lateral and retruding movements
Sphenomandibular ligament
- OIA
O: Spine of sphenoid
I: Lingula
A: Limit inferior movement of mandible
Stylomandibular ligament
- OIA
O: Styloid process
I: Angle and posterior border of mandible
A: Limit protrusion of mandible
Embryologic origin of cleft lip
Failure of median nasal process and maxillary process to fuse
Embryologic origin of cleft palate
Failure of palatine shelves to fuse and/or with the primary palate (median palatine process)
Embryologic origin of mandible
Mandibular processes
Embryologic origin of forehead
Frontal processes
Palotopharyngeal incompetency
Failure of soft palate/pharynx to close the palatopharyngeal port - required for speech
- Leads to nasal regurgitation and hyper nasal speech
Superior constrictor
- OINA
O: Ptyergoid hamulus, pterygomandibular raphe and posterior end of mylohyoid line on mandible
I: Pharyngeal tubercle and pharyngeal raphe
N: Pharyngeal plexus and Pharyngeal branch X with motor fiber from cranial accessory (XI)
A: Constrict upper pharnyx
Middle constrictor
- OINA
O: Stylohyoid ligament, hyoid bone
I: Median pharyngeal raphe
N: Branch of pharyngeal plexus (X)
A: Constricts mid-portion of pharynx
Inferior constrictor
- OINA
O: Thyroid line of thyroid and cricoid cartilage
I: Median pahryngeal raphe and circular esophageal fibers
N: Pharyngeal plexus (X)
A: Constricts lower portion of pharynx
Salpingopharyneus muscle
- OINA
O: Auditory tube
I: Blends with palato pharyngeus muscle
N: Pharyngeal plexus (X)
A: Elevates pharynx, open auditory tube during swallowing
Stylopharyngeus muscle
- OINA
O: Styloid process
I: Blends with constrictors, thyroid cartilage
N: Glossopharyngeal nerve
A: Elevates pharynx and larynx
Physiology of speaking (Martone)
- Three physiologic valves
- True vocal folds of larynx
- Palatopharyngeal region: Nasal, oral, and laryngeal pharynx
- Mouth
What nerves are involved in the innervation of speech? (5)
- V: Soft palate
- VII: Muscles of the periphery of the mouth
- IX: Pharyngeal muscles
- X: Pharyngeal muscles, laryngeal muscles, soft palate
- XII: Tongue
Physiology of gagging
- Afferent to medula oblongata
- Efferent
- V, IX, X: Innveration of fauces, base of tongue, palate, uvula, posterior pharyngeal wall
- V, VII, X, XII, pharyngeal plexus, various sympathetic and parasympathetic nerves
Causes of gagging
Systemic, psychological, physiological, iatrogenic
Neutral zone - What and who?
Area in the mouth where the force of the tongue pushing out is neutralized by the forces of the cheeks and lips pressing inward
Fish, Cagna, Massad, Beresin, and Schiesser
Wolf’s law
Bone will develop the structure suited to resist the forces acting on it
Four salivary glands and their ducts, % of overall secretion
- Parotid glands - Stenson’s - 26%
- Sublingual glands - Batholin’s - 5%
- Submandibular glands - Wharton’s - 69%
- Palatine glands
If stimulated, the parotid produces more than 50%
Quality of the saliva from salivary glands and their innervation
- Parotid - serous, glossopharyngeal
- Submand - mixed, mostly serous, facial
- Subling - mucous - facial
- Palate - mucous
How much saliva and components?
- 1 to 1.5 L/day
2. Ptyalin (salivary amylase), mucins, and bactericidal components
Neil’s Lateral throat form
- Classes?
Class I: 8-12 mm extension below mylohyoid
II: 4-6 mm
III: 2-3 mm
House’s palatal throat form
- Classes
- House line reference
- Levin line reference
I: 5-12 mm compressible tissue II: 3-5 mm III: 3-5 mm anterior to line House line: Line between tuberosities Levin: Vibrating line
Describe layers of mucosa in patient’s mouth
Mucous membrane
Mucosa
Submucosa (vessel/nerve)
Periosteum
Frenum composition
Which author says no muscle and which says yes
Non-keratinized, unattached alveolar mucosa with underlying fibrous attachment to bone
Sicher - no muscle
Gartner 1991 - Yes, 35% of maxillary frenum
Most common sites for intraoral cancer
Lip and tongue
Primary and secondary stress-bearing area of maxilla and mandible according to Boucher
Boucher - Max: 1° Residual ridge, 2° Rugae
Mand 1°: Buccal shelf
2°: Residual ridge
Pear-shaped pad
Scar of 3rd molar, attached tissue
Coined by Craddock
Retromolar pad
Alveolar mucosa covering glandular loose alveolar CT
- Contains fibers of buccinator muscle, temporal tendon, pterygomandibular raphe, superior constrictor, and palatal glands
Resorption in mandible vs maxilla
Mandible: 4x as much as maxilla
Mandible resorbs L to B and Max B to L, creates psuedo Class III
Factors affecting denture retention according to Jacobsen and Krol
- Adhesion
- Cohesion
- Interfacial surface tension
- Gravity
- Intimate tissue contact
- Border seal
- Atmospheric pressure
- Neuromuscular control
5 Methods from denture manual to evaluate vertical dimension
8 Ways to evaluate vertical dimension by Turrell
- Boos Bimeter
- Silverman: Closest speaking space
- Pound: Phonetics and Esthetics
- Lytle: Neuromuscular perception
- Pleasure: Pleasure points (tip of nose/chin)
- Pretreatment records (Turrell)
- Physiologic rest (Atwood, Tallgren, Niswonger, Thompson)
- Cephalometrics (Atwood)
- Closing forces (Boos Bimeter)
- Esthetics (Turrell)
- Electromyography
- Facial dimensions
- Phonetics
- Deglutition
- Tactile sense: Lytle (tap, tap tap)
- Wear (Turner)
How does a patient lose vertical dimension? What authors argue it is constant and who argues it changes?
Mechanical/chemical wear and unstable occlusion
Constant: Thompson (dependent on muscles) and Dawson (bone remodeling to supraerupt) and Niswonger
Changes: Atwood (ceph VDR changes), Tallgren (VDR will adapt to VDO), Ramfjord (range of rest is 1.7 mm)
What did Silverman say about closest speaking space?
Ranges from 0-10 mm
Uses existing teeth if possible, otherwise trial and error. Recommend to speak sentences rapidly.
Difference between closest speaking position and centric occlusion
Not the same as resting dimension (normally 3 mm)
(Fun fact: Letter “G” also does closest speaking space)
What did Pound say about S?
S sound produced when upper and lowest incisors are 1 mm apart. Class II patients 3 mm, and Class III patients no movement. For posterior teeth, distances are Class I (1.5-3), Class II (3-6), Class III (1)
Vig and Brundo (1978) - Incisal edge display reduction by sex
By every decade?
What relation does amount of maxillary central display have with mand. central?
What relation does lip length have with maxillary central display?
Male: 1.91
Female: 3.4
Up to 29: 3.37 30-39: 1.58 (-1.8) 40-49: 0.95 (-0.6) 50-59: 0.46 (-0.5) 60+: -.04 (-0.5)
The more maxillary central shown, the less mand central and vice versa.
The longer the lip, the less maxillary central display there is.
Who talked about face form in relation to denture tooth selection?
Williams classification (Square, tapering, ovoid) correlated with teeth of similar shape
Should patient be involved in teeth/mold selection?
Yes, Hirsch, Levin, & Tiber - Increased patient acceptance
Lefer, Pleasure, Rosenthal - Patient involvement had fewer complaints and postop’s
SPA concept of denture esthetics by who?
Frush and Fisher (1955)
Sex, personality, and age
- Curves, eminences, flatter, sharpness, flat incisal edges
Golden proportion’s
- What’s the ratio
- Who discussed this?
1:1.618
Lombardi, Preston
Mashid (2004) disproved
Who talked about fricative sounds?
Pound
- F and V - Maxillary teeth should touch the wet dry line
Who talked about vertical dimension in literature?
Thompson (1943) and Brodie (1941) - VDR is constant and dependent on musculature, not affected by presence or absence of teeth
Atwood (1956) - Cephalometric studies to find that VDR is dynamic and varies within a person
Tallgren - VDR adapts to VDO in edentulous and dentulous patients (she measured pre/post extractions)
Ismail & George (1968) - VDR adapts to VDO
Abduo (2012) - Dentate study, but increases up to 5 mm is tolerable. Symptoms resolve in 2 weeks.
Who said patients would not adapt to changes in vertical dimension?
When patients are very overclosed, they may not adapt to changes. May need to restore at decreased VD.
Why did I choose my articulator?
The Artex CT is a non-arcon semiadjustable articulator so it accepts an arbitrary facebow and allows me to program condylar track inclination. I like the centric quick lock as well as the angled legs.
What is the angle of the protrusion track?
40 degrees.
Celenza classifications of articulators
Class I: Simple, static registration
Class II: Vertical/horizontal movement not associated with TMJ (fixed distance)
Class III - Condylar pathways stimulated by averages; accepts Facebow transfer. Arcon or non-arcon
Class IV: Accepts 3d records and allows joint orientation of casts
Why not use a fully adjustable?
- Do clinical remount
2. REALEFF effect (resiliency and like effect) - Articulator is more precise than in the patient’s mouth
Which occlusal scheme and describe it?
Lingualized
Maxillary cusps articulate with mandibular occlusal surfaces in CO and in excursive movements. Maxillary buccal cusps do not contact, creating a mortar and pestle effect with the lingual cusps.
Who described lingualized occlusion?
- Gysi (1914)
- Farmer
- Payne (1941)
- Pound (1971) - Unbalanced lingualized
- Lang
Who advocated balanced denture occlusion?
Woelfel, Hickey, Boucher
Why balance dentures?
During function, dentures aren’t in perfect balance. But they should be balanced so that patients have an unimpeded path back to CR. During parafunction is the only time eccentric balance matters. If not balanced, stability becomes an issue.
Lang: Report by Brewer (1963) reported that tooth contacts during chewing were much less than during non-chewing (10 min vs 2-4 hours).
Can monoplane teeth be balanced?
Yes, Sears balancing ramps or by increasing compensating curve.
Who described neutrocentric occlusion teeth, and what 5 things does it entail?
DeVan
- Position teeth as far lingual as tongue allows
- Proportion - Narrow B-L width 40%
- Pitch - Occlusal plane is parallel to underlying ridges and midway between them; no compensating curve or incisal guidance
- Form - Tooth form is flat with no deflecting inclines
- Number - Three posterior teeth instead of four
How does lingualized occlusion compare to other forms?
No specific tooth form is advantageous, so it matters what the patient can tolerate and use.
Compare CD bite strengths versus natural teeth
35 pounds vs 162 pounds (Gibbs)
What is REALEFF?
Resilience and like effect described by Hanau. Soft tissue under denture base has movement which is less precise than the articulator.
How do you measure intercondylar distance?
Pantograph or cadiax. It can be set with fully adjustable articulators, but most semi-adjustable use 110 mm (Aull and Lundeen)
What muscles form the pterygomasseteric sling?
Medial pterygoid and masseter
What denture teeth did you use, and what occlusal setup?
Phonares II, lingualized
What are the denture teeth made of?
4 layers
- Facial incisal is nano-hybrid composite
- Dentin core also nano-hybrid composite
- Neck is PMMA
- Back incisal is PMMA
Why did you pick these teeth?
High resistance to wear, plaque build-up, opalescence and a highly homogenous nano structure
Compatibility with the denture base, Ivobase.
What is in the nano hybrid composite?
Matrix is UDMA - high degree of cross-linking for stability and resistance to corrosion
Filler’s 1-3 are silicone dioxide to stiffen the matrix, increase hardness and resistance to abrasion as well as reduce polymerization shrinkage
Lastly, PMMA clusters to reduce affinity for plaque and discoloration.
Are you concerned about using composite denture teeth with a fixed denture restoration?
There are advantages and disadvantages to using composite denture teeth in a fixed restoration. There were many factors involved in selection of denture teeth, to include esthetics, patient’s finances,
The denture teeth are nano-hybrid composite, which are UDMA with silicone dioxide fillers. A 2019 study by Esquivel, Lawson, Bruggers, and Blatz in the JPD found that when various denture teeth, to include cross-linked PMMA, CAD/CAM PMMA, and nano hybrid composite were compared to oppose zirconia, nano-hybrid had the least amount of volumetric wear at almost three times less. This result was consistent with other studies.
The wear of a nano-hybrid composite tooth is still higher than the wear of say zirconia or porcelain materials, but the advantages of nano-hybrid composite are that it can be more affordable to replace than a zirconia full arch prostheses or lithium disilicate teeth. Failures can include denture teeth chipping or dislodging, but I’ve tried to minimize that by having a cross tooth bilaterally balanced setup to distribute forces. Additionally since the patient has a maxillary removable prostheses to oppose a mandibular prostheses, occlusal forces should be less than if the patient were to have a maxillary and mandibular fixed prostheses. I had the restorable space to pick from a variety of prostheses, and there are many options. When there are as many options as are available, I think it comes down to a combination of personal philosophy, financial planning for the patient long term.
How are the Ivoclar Phonares II teeth classified?
They kind of follow dentogenics by Frush and Fisher. Dentogenics follows an organization style of sex, personality and age. Phonares combines sex and personality in either a soft or bold style, another for age (youthful, universal, or mature), followed by size (for small, medium, and large)
What is the BULL rule?
It an acronym for buccal upper, lower lingual, and references how the aim is to maintain the functional cusp height and recontour non-functional cusp height.
Schuyler (Also known for CR method of using tip of tongue to roof of mouth)
Maxillary border molding and muscles
- Define labial notch, grasp philtrium close to vermilion border and pull downward.
- For labial vestibule borders, ask patient to purse lips using a sucking action and then to smile widely (orbiculares oris, levator labii superior, levator anguli oris, incisivus labi superior)
- For buccal notches and buccal vestibular borders, grasp cheek with the forefinger and thumb at the corner of the mouth and pull downward and forward (buccinator, risorius, buccal frenum)
- Define coronomaxillary vestibule border and hamular frenum area, ask the patient to open mouth wide which will cause coronoid process to translate through coronomaxillary spaces, bringing the associated muscles to their terminal positions. (coronoid process, medial pterygoid, temporalis tendon/muscle, pterygomandibular notch). Move side to side to stretch pterygomandibular raphe.
- For posterior border, patient performs Valsalva’s maneuvers. Palate will valve downward, forming VPS along post palatal seal (tensor veil palatini, levator veil palatini, palatopharyngeus, palatoglossus, and uvula muscles)
Mandibular border molding and muscles
- Lingual and retromylohyoid flange borders, patient puts tip of tongue forward out of the mouth and have the patient move the tongue side to side. Then patient retracts tip of the tongue to touch the posterior palate. (lingual frenum, and mylohyoid)
- Patient pushes tongue against fingers (activates palatoglossus and superior constrictor muscles to mold distal-lingual border)
- For labial notch, grasp lower lip at the vermillion and pull outward and upward.
- For labial and buccal borders, stabilize tray and have patient purse the lips using a sucking action and then to smile widely (stretch labial/buccal frenum and actives modiolus)
- Patient tries to close against resistance (activate masseter and temporal muscles to mold lateral shelf and masseteric notch)
- For buccal notches, grasp cheek with forefinger and thumb at the corner and pull upward and forward.
Who wrote about the different impression techniques?
Selective pressure (Boucher, Halperin) Mucostatic (Page) Functional (Pound)
Who discussed how deep to make posterior palatal seal?
What shape is commonly generated?
Who discussed purpose of PPS? What are two most important purposes?
Neil 1932 - 2/3rd’s of depth
Hardy and Kapur 1958 - One half
Cupid’s bow shape
Hardy and Kapur 1958 - Increase maxillary retention and compensate for polymerization shrinkage
What actions and movements for distal-lingual border of mandibular denture?
Place fingers at vermillion border and have patient push tongue against fingers
- Activates palatoglossus and superior constrictor
How to border mold lingual borders of mandibular denture?
What muscles?
Place fingers on top of tongue and attempt to raise tongue
Activates mylohyoid
How to border mold mesio-lingual border of mandibular denture?
What muscles?
How to border mold mesio-lingual border of mandibular denture?
What muscles?
How to border mold lateral aspect of buccal shelf / masseteric notch?
What muscles?
Hold tray down and have patient attempt to close against resistance
Activates masseter to push against buccinator (which runs parallel) to form masseteric notch
How to border mold anterior border of mandibular denture?
What muscles?
Create suction around finger, puck lips, smile, pronounce Christmas, Q, U, and pull lower lip and cheek superiorly over impression tray
Stretch frena, activate cheek and lip muscles, refine mentolabial angle
(Buccinator, depressor anguli oris, depressor labii inferioris, mentalis, orbicular oris, incisivus labii inferioris)
Who wrote about the denture occlusal schemes?
Bilateral balanced (Boucher)
Lingualized (Payne/Pound)
Monoplane (Jones)
Neutrocentric (De Van)
Who wrote about remount procedures?
Firtell 1987 - Incidence of soreness is reduced if occlusion is optimized by a remount procedure
What reference plane did you choose for your occlusal plane?
Camper’s plane aka ala-tragus line
Line from inferior border of the Ala of the nose to the trigs of the ear
How do you demarcate the posterior palatal seal?
How do you demarcate the hard palate - soft palate junction?
Are the fovea palatini normally ahead of or before this demarcation?
PPS Patient says “ah” to denote the vibrating line which I cover with the tray as the posterior extent.
Hard palate soft palate junction via valslva maneuver
Normally fovea palatini are posterior to vibrating line (75% - 1980 Chen - Also he had some patients with three or four fovea palatini)
How to border mold anterior maxillary denture?
What muscles?
Suction around finger, smile, and pull upper lip and cheek inferiorly over tray
Activates cheek and lip muscles and stretches frena
How to border mold lateral aspect of maxillary denture?
What muscles?
Open mouth wide and close and then move mandible side to side
Coronoid process moves and also stretches pterygomandibular raphe
How to border mold posterior aspect?
What muscles?
Pinch nostrils closed and blow air through nose (valsalva maneuver)
Palatoglossus, tensor veli palatini, levator veli palatini, uvula, palatopharyngeus
MRONJ - Patients can be diagnosed with it if they have what three situations?
- Receiving or have received antiresorptive or antiangiogenic meds
- Have exposed necrotic bone in maxillofacial region for 8+ weeks
- Have no hx of radiation therapy or dx metastatic jaw disease
MRONJ - How long does it take for oral bp’s to cause issues?
- What other comorbidities can compound the risk?
How long is the BP drug holiday, and how long to wait to restart?
4 years (unless you have comorbidity in which it is less than 4)
Rheumatoid arthritis, glucocorticoid exposure, diabetes, smoking
2 to 3 month drug holiday, and do not restart until osseous healing has occurred
MRONJ
- Does a denture increase MRONJ risk?
- Which area of a denture needs special care and consideration?
Yes, two fold risk for MRONJ for denture wearers receiving IV antiresorptive therapy for cancer
Mandibular lingual flange (mylohyoid region and midpalatal ridge)
MRONJ
- Antiangiogenic and antiresorptive medications - What are they used for?
Osteoporotic patient or cancer (such as bone cancer)
Osseo - Describe four stages of wound healing
- Hemostasis - Within minutes - Blood contacts implant, platelets start to form thrombus, beginning the signaling cascade for a fibrin clot.
- Inflammation - hours to days - Vasodilation occurs, and neutrophils, monocytes, leukocytes, and inflammatory mediators arrive to remove cells, pathogens, and bacteria and stimulate angiogenesis and fibrogenesis.
- Proliferation - Days to weeks - Woven bone (weak) formation via mesenchymal cell differentiation. Contact and distance osteogeuenesis begins.
- Remodeling - Weeks to months - Random collagen fibers of woven bone are remodeled into lamellar bone.
ACP PDI categories?
What ACP PDI is your patient?
Mandibular ridge height
Residual Ridge morphology - Maxilla
Muscle attachments - Mandibular
Maxillomandibular relationship
Conditions requiring preposthetic surgery
Interarch space, tongue anatomy, modifiers
ACP PDI Class III
What is the sensory limb and nerves for pharyngeal reflex? What is the motor cranial nerve limb?
What are the stimuli?
What is the actual action as a result of the reflex arc?
Sensory limb receives stimulus (CN IX - glossopharyngeal nerve or CN V) Motor limb (CN X)
Stimulus: Posterior pharyngeal wall, posterior soft palate, back of tongue
Brisk and brief elevation of soft palate and bilateral contraction of pharyngeal muscles.
Titanium - How is cp Titanium classified?
Which is the strongest?
cp 1-4 according to purity and processing oxygen contact.
Grade 1 cp-Ti is processed with the least oxygen (.18%) with highest purity, best corrosion resistance ability, and formability, but lowest mechanical strength (170 strength/MPa)
Grade 4 cp-Ti (processed with.4% oxygen) has highest strength (480 strength/Mpa) and moderate formability (15% elongation at failure/%)
Titanium - Most common titanium alloy in the world?
Most common grade in medical industry?
Four classifications of titanium?
Besides dental implants, is titanium used in other fields of dentistry?
Ti-6Al-4V. (Grade V titanium alloy) - Composed of 6% Al and 4% V, .25% iron, .2% oxygen.
Grade 23 is Ti6Al4V ELI (extra low interstitial) - They reduce interstitial elements of oxygen and iron to improve ductility and fracture toughness. Most common medical implant-grade alloy. (.13 oxygen, less than .25% iron)
Excellent yield strength (850 strength/Mpa) and fatigue properties, excellent corrosion resistance and lower elastic modulus (10 elongation at failure/%)
Titanium is a transition metal with α and β forms. Al and V stabilize titanium in a way that increases corrosion resistance and yield strength.
Titanium is classified in four: unalloyed, alpha structure, alpha-beta, and beta. Grade 5 is an alpha-beta alloy. Accounts for 50% of all titanium usage in the world.
Beta-Titanium - Used in orthodontics (high ductility) whereas alpha is stronger less ductile
Titanium - How thick is the oxide layer?
What grade Titanium is Zimmer biomet? How do they treat their surface?
TiO2 is 4-6 nm thick.
Ti Grade CP4 (.50% Fe, .40% O2) - Zimmer Biomet implant osseotite surface is double acid etched and then treated with calcium phosphate particles (20-100 nm size)
Compare traditional hierarchy of evidence to Bidra’s evidence based prosthodontics model.
- What’s the hierarchy for each?
- Why does pros need a new hierarchy?
2014 article by Bidra compares the five levels of evidence pyramid to three stages of evidence.
RCT/ SR’s, single cohort/SR’s, single case-control/SR’s, 4. Case report (case series, cross sectional), and 5. Opinion, lab study, animal study
Preliminary evidence (opinion, lab/animal, case report), Substantive (cross-sectional, case-control, cohort), and Progressive (RCT, SR/MA of RCT, and SR/MA of all clinical)
Pros needs new hierarchy due to lack of RCT - pros treatment is difficult to blind patient, have large population, expensive, patient has large level of control in treating conditions, difficult to define: survival vs success, prostheses outcomes vs patient centered outcomes.
Rads for background in a year, bitewing/PA, pano, Cephalometric, CBCT
Background: 3 mSv/year BW/PA: 1-8 uSv Pano: 4-30 uSv Cephalometric: 2-3 uSv CBCT: 50 to 100 uSv
At what ISQ is it okay to one stage a single implant?
At what ISQ to single stage a full arch?
65
60
GPT definition of osseointegration
The apparent direct attachment of connection of osseous tissue to an inert, alloplastic material without intervening fibrous connective tissue
Describe how mechanical stress promotes bone formation and inhibits bone resorption
Primary through mechanosensory function of osteocytes. Mechanical loading can reduce sclerotin (negative bone formation regulator) express in osteocytes and increase prostaglandin production (positive bone formation regulator).
In addition, osteocytes send signals to inhibit osteoclast activation in response to mechanical loading.
Describe Kelly’s Combination Syndrome (1972 in JPD)
- Resorption of anterior maxilla
- Papillary hyperplasia
- Supraeruption of mand anteriors
- Downgrowth of max tuberosities
- Posterior ridge resorption
What are the six additional associated changes to Kelly’s combination syndrome?
Who wrote about these?
- Loss of OVD
- Occlusal plane discrepancy
- Anterior repositioning of mandible
- Epulis fissuratum
- Poor adaption of prostheses
- Periodontal changes
A: Saunders
Boucher - Eight principles of denture retention
- Adhesion
- Cohesion
- Atmospheric pressure
- Interfacial surface tension
- Undercuts
- Gravity
- Posterior palatal seal
- Border seal
Tak Hydroplastic
- Melting point
- 136-140
Resin based polymer that is not brittle, can be re-softened, no odor or taste
Palatogram sounds and areas (6). - Goodacre cad/cam
- Y, g, ng - posterior hard palate, soft palate, most posterior teeth
- R and y - palate and posterior teeth, no anterior
- N - Palate and all teeth
- t, d, ch, and j - palate and all teeth, followed by anterior release
- I - tongue tip to anterior palate
- S, z - tongue to palatal mucosa and teeth except for narrow central area of anterior palate
- Sh and zh - Tongue to palate and posterior teeth, no central area of anterior palate
Frankfort horizontal plane?
Superior border of tragus of ear to the infraorbital rim
What factors affect denture support? (2)
Who spoke about this?
Extension to maximum surface area and border extensions
Jacobsen and Krol
What factors affect denture stability? (3)
Who spoke about this?
Which of these three factors did Fish think was most important?
- Tissue surfaces (lingual flange, residual ridges shape and contour)
- Polished surfaces (muscles must not be interfered with by denture base / muscles help seat and stabilize denture base)
- Occlusal surfaces (free of interferences)
Jacobsen and Krol
Fish thought polished surfaces was most important
What did Driscoll think was the most important factor out of retention, support and stability?
Stability - the ability to resist horizontal or rotational stress
Difference between Closest Speaking Space and Speaking Space
Silverman: Closest speaking space
Pound: Speaking space
Silverman - Difference from closest speaking position and centric occlusion
Pound - Anterior speaking space for Class I is 1-1.5 and at posterior 1.5 to 3
Which of the five factors in Hanau’s Quint are most important?
Trapozzano - Three important ones (condylar guidance, incisal guidance, and cusp angle). - Argues compensating curve is determined by the above three and that occlusal plane is variable. Also that cusp angle more important than cusp height. Occlusal plane is variable.
Boucher though CG, IG, and OP are most important. CC lets you change cusp height, so cusp angle more important. Also occlusal plane is determined by esthetics and soft tissue harmony.
What muscles originate from the genial tubercles (aka mental spines)? What are their actions?
Genioglossus - Protrudes tongue and raises tip of tongue
Geniohyoid - Pulls hyoid bone and larynx upwards and forwards during swallowing
Average nasiolabial angle?
Men: ~95°
Women: ~97°
Four categories of House classifications?
Philosophical
Exacting
Indifferent
Hysterical
Average condylar guidance angle?
Average Bennet angle?
CG: 33°
Bennett: 15°. (Also known as the “L” in Hanau formula: L=H/8 +12)
Difference between soft liner and tissue conditioner
Viscosity is the difference: Tissue conditioners have a greater percent of alcohol and plasticizers than soft liners and you will see more flow, change and adaptation to the tissue in a less viscous material.
Coe-soft, Viscogel and Lynal have the highest viscosity and are recommended for use as resilient liners (short-term soft denture liners). Their setting time is much longer, but a snap set can be achieved by placing in hot water.
Coe-Comfort and Softone are recommended for use as tissue conditioners.
Anatomically, what is the posterior vibrating line?
Junction of aponeurosis of tensor veli palatini and muscular part of soft palate
Anatomically, what is the anterior vibrating line?
Junction of attached tissues over hard palate and soft palate
Which authors believed that physiologic rest / OVD changes over time?
Tallgren - Changes in face height due to aging, wear, and loss of teeth
Atwood - Cephalometric study
Which authors believed that physiologic rest / OVD stays the same?
Niswonger - 3 mm
Thompson (muscular determinant)
Problems if OVD too great or lack of physiologic rest space? (9)
- TMJ discomfort
- Muscle trismus
- Clacking teeth when speaking or eating
- Rapid ridge resorption
- Chronic tissue soreness
- Difficulty in phonetics
- Insufficient tongue space
- Difficult to close lips
- Difficult to swallow
Problems if OVD insufficient? (3)
- Angular chelitis
- Inability to chew tough foods
- Cheek biting
Muscles involved in depressing the mandible? (6)
- Platysma
- Mylohyoid
- Geniohyoid
- Digastric
- Stylohyoid
- Lateral pterygoid (inferior belly)
How much force do denture patients generate in comparison to natural teeth when chewing?
Natural teeth ~80 according to Gibbs
Denture teeth: 11.7 lbs
6 times less according to Kapur
How does alendronic acid work?
What is its trade name?
Risk %? Is it riskier than others?
It inhibits osteoclast-mediated bone-resorption
Fosamax
Risk of MRONJ was 0.004% (Not as high as Reclast/denosumab which is .0014%)
How does denosumab work?
What is its trade name?
Risk of MRONJ? More or less than Fosamax (alendronic acid)?
RANKL inhibitor - which prevents development of osteoclasts - antiresorptive agent
Osteoclasts have a RANKL surface receptor which denosumab binds to, preventing maturation.
Risk of MRONJ was 0.7-1.9%. More than oledronic acid (which was 0.004%).
What two medication classes are we worried about for MRONJ?
- Antiresorptives (IV bisphophonates, oral bisphophonates, RANKL inhibitors)
- Antiangiogenic
How does sunitinib work? What is its trade name?
Tyrosine kinase inhibitor (anti-cancer drug) - Reduces tumor vascularization and triggers tumor cell death
Sutent
What is Trapozzano’s triad of occlusion?
CG, IG, and Cusp Angle
Eliminated plane of occlusion due to high variability of the plane.
Eliminated compensating curves as an alteration in cusp angles will result in balanced occlusion.
What is Boucher’s three fixed factors?
CG, IG, and occlusal plane
Angulation of cusp more important than height
Compensating curve enables increase in height of cusps without changing form.
Five factors of monoplane occlusion by De Van
- Position: Artificial teeth positioned in central position to ridge
- Proportion: Reduce B-L dimension by 40%
- Pitch: Compensating curve should not be employed, and denture plane parallel to base
- Form: Cuspless teeth
- # of teeth: Reduce from 8 to 6 posterior teeth
How did you prepare the framework for processing?
- Aluminum oxide abrasion to improve mechanical bond.
- Applied Ivoclar SR Link and SR Nexco Opaquer. The SR Link bonding system contains a phosphoric acid group coupled with a methacrylate group. The phosphate bonds with the metal oxides at the alloy. The methacrylate bonds with the opaque layer.
SR Link - Dimethacrylate, phosphate ester, solvents, and benzol peroxide
- Metal/composite bonding agent
SR Nexco opaquer - Dimethacrylate
Why titanium over chrome cobalt?
How does Ti Cp4, Ti6AlV4 and CoCr compare for HRC?
Improved tissue response - 2011 Swedish article that found
Cobalt ion leakage
Fit similar, biocompatibility, corrosion resistance, like on like materials. Ti CP4 has Rockwell hardness C of ~23, Ti6AlV4: 34 whereas Chrome cobalt has HRC of 40-50
Definition of AP spread?
Sound guideline of the ratio?
What factors in addition to AP spread need to be considered?
Distance between a fulcrum line through most posterior-most implants and through most anterior implants
1.5x AP spread by English
AP spread not linearly applied. Other factors include prosthetic materials, # and distribution of implants, beam theory, framework design, cantilever size differences in max/mand.
What type of mill do we have?
5 axis mill - 350i Sharp Mill with 20 tools
Oral cancer 5-year survival rate
Majority of oral cancers are what type of disease? What virus is also attributed?
What % greater risk of oral cancer if ill fitting denture?
Warning signs of oral cancer? (12)
57%
94% are squamous cell carcinoma. HPV-16.
400% greater risk
- Ulceration in mouth that doesn’t heal
- Area of leukoplakia or erythoplakia on gingiva, tongue, tonsil, or oral mucosa that persists
- Lump or thickening in cheek
- Sore throat or globus sensation
- Difficulty chewing with or without dysphagia
- Increasing trismus and/or decreasing tongue mobility
- Sensory changes in tongue or oral oral structures
- Swelling of edentulous area that causes dentures to fit poorly or become uncomfortable
- Increasing tooth mobility or pain associated with the teeth or jaw
- Voice changes
- A lump or mass in the neck
- Weight loss
Smokeless tobacco effects (2)
- High concentrations of what chemical in the tobacco?
For smokers, what sites are most common for oral cancer?
- Gingival recession
- Keratosis and acanthosis of buccal or labial mucosa depending on type of tobacco and where used
- Higher concentration of nitrosamines in the processed tobacco
- Floor of mouth, ventrolateral tongue, and soft palate
Interarch space needed for:
- PFM / monolithic zirconia
- PFM / zr with soft tissue
- Hybrid prosthesis / framework with crowns
- Overdenture
- Locator on mandibular denture
Break down space requirement for hybrid
- 10-12
- 12-15
- 15-18
- 12+
- 11.5 (8.5 minimum w/o teeth= 2 (soft tissue), 2 (acrylic), 4.5 (locator)
3 mm teeth, 2 mm soft tissue, 5 mm for milled framework
According to ACP Position Statement - Maintenance schedule for fixed prostheses
- How often for x-rays?
Do we need to remove the prosthesis regularly?
- In-office implant maintenance appointments at 2 to 6 months intervals
- Radiographs every 1 to 2 years
- No, regular removal only necessary if signs of peri-implantitis, inability to maintain oral hygiene, or mechanical complications
Peri-implantitis definition
Peri-implantitis risks
Is BOP alone sufficient for dx?
Loss of supporting bone and clinical signs of inflammation (bleeding and/or suppuration)
Risks: Poor oral hygiene, unhygienic prosthesis, tobacco use, periodontal disease, systemic diseases
- BOP alone is not. Range is 7-58%.
Peri-implantitis treatment
- Is there one standard approach?
Lay out some of the steps of one approach.
Recent International Team for Implantology and Cochrane said no clear superiority for any one approach.
- Surgical debridement of granulation tissue
- Cleaning with plastic / teflon coated ultrasonic
- Phosphoric acid to implant surface
- Irrigation with saline and glycine powder
- Tetracycline powder, graft with bovine xenograft, collagen membrane.
- Antibiotics (Amox and metronidazole) and vitamin supplements.
What authors discussed the posterior palatal seal?
Who proposed functional impression for the PPS?
Which technique did you use?
Millsap, Boucher, Pound, Silverman
Weintraub
Empirical technique advocated by Hardy and Kapur. Depth is greatest in center and tapers to anterior/posterior
Korecta wax composition
Developed by?
Beeswax and paraffin - Flows at 37°
Dr. Applegate
Describe what kind of lever system the mandible is
Class 3 lever
Fulcrum: Condyle
Effort: Muscles of mastication
Load: Occlusal plane
Hanau’s Formula?
- Purpose
Swenson’s Formula?
- Purpose?
L = H/8 + 12
- Can set lateral guidance based on protrusive (H) records
Cusp Height = IG + 1/2(CG-IG)
- Can select posterior cusp inclinations
Difference between Boucher’s selective pressure technique and mine?
He puts a layer of baseplate wax everywhere except PPS