PROSTHO CD: Recent Episodes
Dr. Mayakha Mariam
GAG REFLEX:
1. Excess thickness of PPS (main reason)
2. Over extension of denture tray
3. Under the extension of denture tray
4. Over post dam
5. Under post dam
SYSTEMIC REASONS OF GAG REFLEX
If the patient had no gag for years after delivery of the new denture, and then recently develops the gag reflex on denture use – then suspect systemic problem & is definitely not due to the denture itself
SYMPTOMS OF OVEREXTENDED MAX DISTO-PALATAL END
1. Ulcer 2. Sure throat 3. Dysphagia
MENTAL ATTITUDE
-By MM Hose
- PHYSIOLOGICAL
- Cooperative
-
Good prognosis
-
EXACTING
- Patient will have previous history of denture wearing
- Needs exactly as their prev denture
-
Demanding attitude
-
INDIFFERENT
-
HYSTERICAL
- Seen in pedo cases
- Temper & tantrum*
- Poor prognosis
- Hand-over-mouth behavior management is to be used here- HOME
MAXILLARY DENTURE
PRIMARY STRESS-BEARING AREA
Posterolateral slopes of the hard palate
PRIMARY RELIEF AREAS
Mid-palatine raphae
Incisive papilla
- Why it needs relief? Contains nasopalatine nerve & not incisive nerve OK!
- When compressed, causes paresthesia of anterior palate
Rugae
- Secondary relief – optional answer for primary relief OK!
PRIMARY RETENTION AREA
Post Palatal Seal area
THE MOST IMPORTANT FACTOR PROVIDING RETENTION OF A CD IS THE PERIPHERAL SEAL.
PP Seal: At the soft palate
SOFT PALATE:
- Supplied by the accessory nerve of the Vagus nerve
- Thus any patient with vagus nerve damage – will not be able to record PPS – thus no retention here
Anterior Vibrating Line:
At the junction of immovable hard palate & slightly movable soft palate (cupid bow shape)
RECORDING ANT. VIBRATING LINE:
- During border-molding – short & vigorous “hah”
- Ask the patient to blow through closed nostrils – Valsavan Maneuver
- Soft palate should be depressed & inferior
- Hold head at 30° flexion
- Fox plane angulation – 30°
- While recording soft palate should fall gradually for easy recording
Posterior Vibrating Line: At the junction of slightly movable soft palate & highly movable soft palate
- PPS recording angulation – 30°
- It is a straight line, from one hamular notch to the other
- Anatomically – the junction between aponeurosis of tensor veli palatini & muscular portion of soft palate
Hamular Notch / Pterygomaxillary notch
- Depression distal to the maxillary tuberosity
- Used as a landmark for posterior extension of the maxillary denture
RECORDS ON THE IMPRESSION – Anatomical Structures
1. Ant. vibrating line
2. Post. Vibrating line important
3. Hamular notch
4. Fovea palatine --------- least important
NB : PPS is marked on cast using – Lecron’s carver*
PARTS OF PPS:
- PPS area
- Pterygomaxillary area
Ant. Vibrating Line Post. Vibrating Line
BORDERS OF PPS:
- Ant vibrating line
- Post vibrating line
- Hamular notch
- Fovea palatine
FUNCTION OF PPS:
- Improves retention
- Completes the border seal of the maxillary denture
- Compensation of polymerization shrinkage
- Prevent food lodgement
NB : If food lodgement is not prevented – causes gag reflex – glossopharyngeal nerve involved here
LIMITING STRUCTURES – MAXILLA
- ANTERIORLY- Labial vestibule which extends from right buccal frenum to to left.
FRENUM
- 1 labia & 2 buccal
- Should reline (2mm)
- If not will lose frenum & cause pain for the patient
NB: If high labial frenum --> Do frenectomy, it is safe as it has no muscle attachment but only
fibrous tissue
- LATERALLY- on either side, buccal vestibule extending from the buccal frenum till hamular notch
POSTERIOR EXTENSION OF TRAY: - Post vibrating line***
- Hamular notch** not hamular process (which is beyond the notch itself OK)
- Approx 2mm anterior to Fovea palatine *
NB: If tray extension crosses & goes beyond hamular notch ie up until the hamular process then the patient will c/o pain.
Therefore it must extend up to hamular notch only OK!
MANDIBULAR DENTURE PRIMARY STRESS BEARING AREA Buccal Shelf Area
- Because it is made of cortical bone
- It is perpendicular to masticatory forces / occlusal plane
TRetromolar pad is Secondary stress-bearing area
- It provides retention, support & stability
- It adds another plane to the movement of the denture
Posterior most extension- 2/3rd height of the retromolar pad
Mandibular dentures do not rely on suction unlike max dentures, they get maximum stability by
covering as much basal bone as possible without impinging on the muscle attachments.
LIMITING STRUCTURES – MUSCLES
-
Mentalis Muscle: The mandibular anterior area from left buccal frenum to right buccal frenum.
-
Buccinator Muscle: The determination of the depth & width of both max & mand denture into the buccal vestibule is the buccinator muscle; thereby preventing food lodgement there.
-
Massetric muscle: Distobuccal flange of denture is limited by this muscle. If over-extended, the patient experiences extreme soreness.
-
Genioglossus Muscle: Denture extension into the lingual vestibule is determined by the genioglossus muscle (1st PM to contralateral side 1st PM).
-
Mylohyoid Muscle: Denture extension in the alveo-lingual sulcus is determined by oral diaphragm / mylohyoid muscle.
-
Retromylohyoid Area :
a. Superior Constrictor Muscle: Disto-lingual aspect of mandibular denture is determined by the superior constrictor muscle of the pharynx.
b. Palatoglossus Muscle: Post most extension is determined by palatoglossus; whereas post most height is determined by 2/3rd of the retromolar pad.
MUSCLES AND POST-INSERTION PROBLEMS ASSOCIATED:
-
If patient c/o pain & dislodgement
o If the anterior lingual sulcus is over-extended
o Genioglossus – ant region - Helps protrusion
o It is the safety muscle of the tongue -
If denture dislodges during mouth opening
o Due to overextended denture at Mylohyoid – PM, M region -
If sore throat, pain, dysphagia
o Due to over extended flange in the post most part – Palatoglossus – 3rd M region
o Or even at the massetric area -
If difficulty in swallowing
o Due to over extended – Superior Constrictor – distolingual part
RESIDUAL RIDGE RESORPTION:
¤ Severe/fast in 6 months (to 1 year)
¤ That’s why the patient complains of the loose denture during this period
¤ Pattern in Max- results in the short maxilla
¤ Pattern in Mand- results in no change
¤ Therefore CD patients have Class 3 ridge which is expected
¤ Mand ridge resorption is 4 times faster than Max
¤ Maxillary – upward & inward direction
¤ Mandibular – outward & downward direction
¤ Alveolar bone function – to hold teeth, therefore alveolar bone resorbs only after teeth loss OK!
FACTORS INCREASING RIDGE RESORPTION:
1. Diabetes
2. Bruxism
3. Osteoporosis ( especially females- during menopause )
NB: Female patients at Menopause (40yrs)
- Pain due to xerostomia
- Loose denture due to ridge resorption related to osteoporosis
IMMEDIATE DENTURE
1. Extract molars only – 1st appointment – leave PMs & anteriors if any
2. Take impression, do border molding, secondary impression
3. Pour cast n send to the lab
4. In the lab, they trim anteriors & PMs in cast
5. Fabricate CD
6. Extract rest teeth – 2nd appointment
7. Do alveoloplasty
8. Suture – interrupted suture
9. Give denture
10. Recall & check-up after 24hrs - 48hrs
NB: EPULIS FISSURATUM may develop in vestibules of denture patients after 6 months or so
Advantages:
- Maintainance of aesthetic condition
- Since PMs are not extracted – VD can be recorded
- Immediate protection of the surgical site
- No speech impairment
Disadvantages:
- No try-in
- Will require religning / rebasing after 3-6 months
IMPRESSION MATERIALS GYPSUM MATERIALS
TYPE I – IMPRESION PLASTER
- To take impression not to pour cast
- Mucostatic type impression technique
TYPE II – DENTAL / MODELING PLASTER
- For flasking procedure
- Orthodontic diagnostic casts
TYPE III – DENTAL STONE
- For making diagnostic cast
- Also called Yellow Stone / Micro stone
TYPE IV – DIE STONE--Low Expansion
- High strength
- Least setting expansion
- For pouring cast, base, for crowns bridges & implants, etc.
- Also called Densite
TYPE V – DIE STONE – High Expansion
- High strength
- High setting expansion
- For dies for crown & bridge
- Also called DieKeen
NB :
Accelorator:
- Sulphate
- Least amount of sodium chloride
Retarder
- A-Acetate, B-Borate, C-Citrate
- Higher amount of sodium chloride
HYDROCOLLOIDS
- Reversible Agar-agar & Irreversible Alginate
- They both have IMBIBITION (absorbs water) & SYNERGISIS (loss of water);
- Similar reaction to water property makes them under hydrocolloids title
AGAR-AGAR
- Reversible hydrocolloid
- Major composition is water – about 85%
- Contains potassium Sulphate – thus helps accelerate the setting of a gypsum cast
- Tempering at 46°C
- Used in the lab to duplicate master cast
- No sterilization protocol needed – advantage
- Reproduction of surface details even up to 25 microns, therefore excellent
- Impression trays – have water coolant channel
- Triple tray technique
ALGINATE
- Irreversible hydrocolloid
- Content Is sodium or potassium salt of alginic acid –
- Advantages
¤ Economical/cheap
¤ Single use, therefore no cross-infection
¤ Sterilization done here
- Laminate technique ie. alginate (tray) + agar (syringe)
- Trisodium phosphate – setting reaction
- Filler used is - Diatomaceous earth – for strength
ALGINATE IMPRESSION TAKING:
1. Right after alginate impression wash under tap water disinfect with 2% glutaraldehyde (1st choice) / cidex / iodoform – for 10 seconds
2. Pour immediately – within 15mins
3. If not distortion & poor cast due to synergesis
4. When sending the impression directly to lab – store in 100% humidity – up to 45mins only
5. Ie. Cotton dipped in water, drained & kept along with the impression in the plastic cover
6. Do not put soaked cotton directly – will cause imbibition
7. If alginate dries out – will affect the setting of dental stone also – due to absorption of water from cast by alginate – causes rough cast –
8. Anticholinergic drugs are generally used to reduce saliva in patients with excess salivation
ELASTOMERIC / SILICONE MATERIAL
¤ Used for secondary impression generally
¤ Primary impression for knife-edge ridge cases only
¤ Setting reaction is by polymerization type of setting reaction here
POLYSULFIDE
- Hydrophobic
- Catalyst – lead, therefore bad taste, least patient acceptance – disadvantage
- Most biocompatible material due to the sulfide content
- By-products after polymerization – water, which is a large molecule, thus not the best impression material
- Can do electroplating – advantage
- Used in cases with deep undercuts- rubbery consistency
- It has the consistency of thycol rubber, - high tear strength
- Not expensive – advantage
- Must pour the cast within 30 mins
- Not compatible with epoxy resin
CONDENSATION SILICONE
- Hydrophobic
- Poor wetting
- Low stability
- Limited shelf life
- Catalyst – tin
- Byproduct – C2H2O4 (ethyl / methyl alcohol) – large byproduct high polymerization shrinkage
– highest dimensional change, therefore least preferred imp material - Just economical
- Wear vinyl gloves only
- Wait for 20-30mins before pouring - for stress relaxation
ADDITION SILICONE
- Hydrophobic
- Polyvinyl siloxane – another name
- Catalyst – platinum
- By-product – H2 gas – smaller molecule
- Least dimensional change
- Most accurate impression material preferred for onlay cavity
- OSMF patients (less mouth opening)
- Never pour immediately, wait for 30 mins for the release of H2 gas – if not pin-point depression on cast
- Expensive – disadvantage
- Only vinyl gloves – no latex
POLYETHER
- Hydrophilic
- No catalyst
- No dimensional change
- But not the best impression material because it's hydrophilic meaning it gets stuck to the oral mucosa & skin. Can absorb water, therefore least compatible
- Difficult to remove from patients’ mouth
- Highly rigid, with a high modulus of elasticity
- Stiff
- Dimensionally stable
- Most preferred in………
- Can be used in epoxy resin dye-making – advantage
IMPRESSION TECHNIQUES
- MUCOCOMPRESSIVE – Impression compound, Elastomeric Impression material
- MUCOSTATIC – Impression plaster
- SELECTIVE PRESSURE TECHNIQUE
Primary impressions- Gypsum & Hydrocolloids
Secondary impressions - Elastomeric
TYPES OF RIDGES – IMPRESSION
WELL ROUNDED
- Mucocompressive technique
- Alginate
KNIFE EDGED
- Mucostatic technique
- Elastomeric Imp.
- Need maximum extension of the denture to help distribute the occlusal forces over a large area.
FLAT RIDGE
- Selective pressure technique
- Imp. Compound
FLABBY RIDGE
- Full muscular tissues and less bone structure
- Impression Plaster - type 1 Gypsum
IMPRESSSION TRAYS
Primary impression – perforated trays
Border molding – special/custom trays
- Major function is to provide even thickness of impression material to the structures
- To provide support for green stick for border molding
- Should trim 2-4 mm from the sulcus depth
OCCLUSAL RIMS
Maxillary
Height
- Anterior – 22mm
- Posterior – 18mm
Width
- Anterior – 5mm
- Posterior – 8 to 10mm
Mandibular
Height
- Anterior – 18mm
- Posterior – 2/3rd of retromolar pad
Width
- Anterior – 5mm
- Posterior – 8 to 10mm
Temporary Denture Base
- Function – to hold the occlusal rims
- Materials – acrylic or shellac
JAW RELATION & OCCLUSSION
- Correct the occlusal plane using fox plane
- Occlusal rim with base or record base
Maxillary Plane
a) Ant occlusal plane
o Parallel to interpupilary line
o Strabismus (malaligned pupils ) – parallel to the line of lower lip at rest
b) Post occlusal plane
o Ala-tragus line / Camper’s line
o Parallel with the inferior border of posterior occlusal plane run in anteroposterior direction
Mandibular Plane
Parellel to the maxillary occlusal plane
Orientation Jaw relation
- Records the hinge axis of a body
- It is the relation of maxillary / mandibular bone to the cranial base
- Not the relation between maxilla & mandible OK!
- FACE BOW – used to record the hinge axis
- 3 points of face bow – 2 ears. Nose tip / root
Centric Occlusion
- Maximum intercuspation of opposing teeth
- It is independent of condylar position
- Maximum intercuspal position
Centric Relation
- It is the maxilla-mandibular relation
- Condylar head of the mandibular articulates with the thinnest avascular position of their respective disc
- Terminal hinge position
- Anterior & superior position ( condylar disc complex )
- Against the slope of the articular eminence
Interocclusal Record Materials (bite registration materials)
- Polyvinyl siloxane – fast-setting material
- Alu wax
- Polyether
Balanced Occlusion
- It is the simultaneous contact of teeth in a centric and eccentric position
- Relation between maxillary and mandibular teeth
- Working side & non-working side relation
- Mandatory for CD only
-
But not possible in natural occlusion, FPD, RPD
-
Hanau’s Quint
1) Incisal Guidance
2) Condylar Guidance
3) Compensatory Curves
4) Plane of Occlusion
5) Cuspal Angulation
Incisal Guidance
- Angle - 0°
- Also known as Anterior Guidance
- Incisal Pin in the articulator
- Upper & lower anteriors shouldn’t touch
- If not proper – lateral extrusive movement, separation of posterior teeth, class 3 appearance ie. protrusive movement
- In occlusal appliances – Bionator, Activator, Frankel Appliance
Condylar Guidance
- Protrusive Condylar Guidance – 70° – it is best recorded during protrusive movt by the patient itself only
- Lateral Condylar Guidance – 0° – in CDs only
Bennet's Angle L= H/8 + 12
Compensatory Curves
1) Curve of Spee
o Anteroposterior curve
o Concave
2) Curve of Wilson
o Lateral curve
o From right to left
3) Curve of Monsoon
o A sphere drawn by taking Glabella as the center
o Periphery
Plane of Occlusion
- Ala-tragus line
- Interpupillary line
Cuspal Angulation
- 33° - anatomic cusp
- 20° - semi-anatomic cusp
- 0° - non-anatomic cusp / flat cusp (given in neuromuscular disease cases such as parkinsonism, myasthenia gravis )
Q. Why do we need balanced occlusion?
For stability of occlusion only OK!
STABILITY – Balanced occlusion
SUPPORT – Oral mucosal tissues
Retention – PPS & flanges
VERTICAL DIMENSION
- Will’s gauge
- If VD error happens – then the only option is new denture!
- VD at rest – VD at occlusion = 2-4mm ( freeway space )
- Mandible should be at a physiologic position
- Errors are noted on VD at – occlusion
Increased VD
- Reduced inter-occlusal space ⸫ TMJ pain
- Tenderness of muscle ⸫ difficulty in swallowing
- Increase in lower facial height
- Erythema at denture-bearing sight, which occurs within a week
- Cheek bite ( due to decreased horizontal overlap between the teeth ⸫ to manage – trim buccal cusp of mandibular teeth
- Clicking of teeth during speech ( also seen in ceramic crowns, no retention of dentures )
Decreased VD
1. Increase in Freeway space
drooping of corners of the mouth
angular cheilitis
other reasons
----Candidiasis
----iron deficiency anemia
----riboflavin deficiency
2. Decreased lower facial height--> thinning of lips
3. TMJ pain
PRE-PROSTHETIC SURGERY
-
Epulis Fissuratum
Pedunculated growth at vestibule due to overextension of the denture
Management- incision by BP blade
Allis forceps- used to hold the tissue -
Papillary hyperplasia
Modular growth at the palate
Raspberry appearance
Duty ill-fitting denture and poor oral hygiene
Management- reline and rebase, change denture, tissue conditioning agents
Surface of a denture:
1. Tissue to face- exactly same in impression
2. Surface facing tongue- should be very smooth and polished
Patient complaints of the ulcer within 1 or 2 days of delivery
irregularity indenture
indenture treatment correct and polish
Patient complaints of ulcer after 2 or 3 years of post-insertion
Due to ResidualRidge resorption
Treatment - educate the patient not to wear the denture for or next 48 hours
conditioning of the tissue surface
Either change the denture or reline or rebasing
OVERDENTURE
Main advantage- no Ridge resorption
the second advantage- proprioceptive reception
increase to stability
easy to repair
Disadvantage - long term retention of denture uh is poor
most preferred canine
secondary molars
IMPLANT SUPPORTED DENTURE
maxillary minimum- 4, optimum- 6
mandibular minimum- 2, optimum
TEETH ARRANGEMENT SELECT
Called as setting-up
select size shape shade of the tooth
Size
By anthropometric method, bizygomatic width is taken using Wills gauge
Bii-zygomatic width / 3.3 = maxillary anterior tooth width
Bi zygomatic width / 16 = CI width
Shape
Endogenic concept
S - sex
P - personality
A - age
Arrangement
Incisal edge of maxillary anterior - covered Lower lip
maxillary Incisor edge - 0.5 mm above occlusal Rim
SHADE SELECTION
Use shade guide
never use extracted teeth / photograph
instead, take shade prior to extraction
Colour
Hue
Dominant colour of object that is red, yellow, Grey
Vita guide A red, B yellow, C Grey, D r y z equal mix
Chroma
Degree of saturation
that is intensity example less intensity at incisal third whereas high Chroma at
cervical 3rd
Value
Lightness and darkness
most important parameter
Eg. A1,A2, A3, etc
SEQUENCE OF SHADE SELECTION
Value >>>> Chroma >>>>>> Hue
Q. When new colour other than red, yellow, grey are added - change in hue
Q. When any of these three above colours are added - change in Chroma
Cusps
-
Functional / working / supporting / stump
Maxillary palatal mandibular buccal -
Non-functional / non-working / balancing cusp
maxillary buckle mandibular lingual
Buccal upper lingual lower BULL
POST INSERTION
After 48 hours- record for occlusion correction
most common complaint - overextension causing laceration
after 6-8 months - recall and 2 relining / rebasing, this is due to high chances
of ridge resorption
if occlusion correction required
--- at the time of insertion
--- or then rearticulate the denture with new jaw relation then make necessary
corrections
speech problems are commonly seen - advise patient that it will correct
automatically
increased salivation is due to increased parasympathetic activity - convince patient - recall and review after 1 week ok
Candidiasis - opportunistic infection, due to the improper oral hygiene of both denture and oral cavity, continuous wearing of denture even at night
Treatment
1. Mouth only - topical nystatin gel/solution, stop denture wearing for few days
2. oral plus systemic - amphotericin B
3. Oral + systemic + immunosuppressants + broad-spectrum antibiotics
- fluconazole ( because nystatin I won’t work here)
Q. Wax used in fluid wax technique of PPS placement
1. Korrecta wax number 4
2. Iowa wax
3. H-L Physiologic paste
SURVEYOR
Q. Function of survey to identify path of insertion.
It is a mechanical device to mark, analyze, and record favourable undercuts — function
Parts —
1. Horizontal arm
2. Vertical arm
3. Platform
4. Surveying arm
5. Mandrel
6. Cast holder/surveying table
Tools
1. Analyzing rod
2. Undercut gauge
3. Carbon marker
4. Wax knife
Tripoding
- (select 3 points) It is the transfer of 3 points from primary to master cast
- Role : transfer of orientation
COMBINATION SYNDROME: -
Also known as Paterson- Kelly Syndrome
Maxillary CD, lower class I RPD
Lower anterior teeth — mobility
Maxillary anterior part — ridge resorption — papillary hyperplasia
Flabby tissue on pre-maxilla !
Q. Over tissue in mandibular with wearing denture epulis fisssurment.
Prognathic facial appearance
Decreased VD
Relining add acrylic to the base of denture to increase vertical dimension
Maxillary tuberosity — downward growth
Re – CD impression — passive position impression
o (due to flabby tissue remember !)