Denture Anatomy, Fit, and Fabrication: Maxillary and Mandibular Principles

which frenum is the largest/ strongest?

labial frenum- this will require the most adjusting of the pt's denture

The max labial frenum is requires trimming of which part of the denture?

labial vestibule

which areas on the max CD could be sensitive and require relief?

incisive papilla

rugae\max tuberosity

hamular notches

palatal suture

which part of the maxilla resorbs quickly?

max anterior

what defines the posterior seal of the max CD?

hamular nothces

what feature of the posterior palatal seal helps with retention?

softer tissue, compression

posterior limit of the denture

where is the vibrating line located?

at the junction of movable and immovable soft palate

what are the primary stress bearing in the max?

-make stops in the CD\

which areas to avoid w/ the max CD?

buccal slops and ridges of vestibule

T/F: mand has a buccal and lingual vestibule

T

area on mand with muscle insertions and requires a relief

masseter muscle

when you move the cheeks, what anatomical location will be marked on the BOMO?

masseteric notches and frenum

which area serves as good retention on the mand?

retromylohyoid fossa

what are the primary, secondary and non-stress bearing areas on mand dentures?

primary- buccal shelves

secondary- ridges

non-stress- buccal and lingual inclines of ridges and vestibules

where do you place stops on the mand denture?

buccal shelves- flat and allows for better support

where should the max denture extend to posteriorly? mand denture posterior extension?

what way does the max resorb? what way does the mand resorb?

Max: lose a lot of lip support, goes up and inward

Mand: down and outward- looks like class III because maxilla has lost bone and resorbs superiorly and posteriorly

what 3 areas could require relief on the mand as it resorbs?

-mental foramen

-mylohyoid line

-buccal shelf

what is done during the start check?

-x-rays

-Comp ex and PDI classification

-Complete denture form

-diagnostic casts

pt comes ready for denture (all teeth are ext) just needs to change denture. when can tx be presented?

same day as comp exam

pt needs FM EXTs and cannot be done in clinic, what happens next?

refer to OMFS, they can see of they need to do or TMD

pt presents w/ exostosis, needs CD, what next?

OS consult, hold off on tx plan until their assessment

pt presents w/ stomatitis, already has dentures, what happens next?

clear up the infection, express home care, may need an interim denture to wear while infection clears

Fungal infections also infect the prosthesis

why cant you deliver a final denture on extraction sites even if it were 2-3 mo prior?

bone needs to remodel and tissue shrinks, final won't fit properly. Will need an interim denture

what are the steps for having a maxillary interim denture after EXTs?

1. impression

2. lab- plans how ridges will look after surgery

3. surgery to ext teeth and deliver interim immediatly after

If DMD level wants to do a mand over denture, what is required?

DMD level (APC consult required)

who does max overdentures or fixed implant dentures?

grad prosth level

anything involving implant retention goes through....

APC

what 3 things provide good adaption?

mucosa, saliva and denture base

what is cohesion?

same molecules in the saliva provide a thin layer between denture base

Effective border seal: __ helps resist denture displacement

atmospheric pressure

Thin saliva film: __ and __ between alike molecules

cohesion and surface tension

what is the best means of retention for the max CD?

Posterior palatal seal- add more pressure to create the seal

what is the best means of retention for the mand denture?

retromylohyoid fossa- the lingual flange has a "S" shape

retention on max vs mand CD?

more area on the max to create a seal and more cohesion/ saliva for retention

how do obtain retention on very flat mand ridges?

implant

how do obtain retention on very flabby mand ridges?

refer to prostho and place additional retention (build up ridges)

what does matte surface mean on impression?

green compound and matte shows when you have a good impression

what can dislodge a denture?

-occlusion, make sure its even/ balanced and adjust occlusion so that when they do certain movements it doesn't get disoldged

-teeth are flat- no cusps so pt can slide with ease

what are the steps for implant overdenture?

1. make CD/ CD

2. use denture you made to make a surgical guide

3. place implants

4. clear implants for restoration

5. select locator abutments- blue/ metal cap goes inside the denture

6. Insterta (blue) can be changed

what are the parts of an implant that supports an mand CD?

what are types of hybrids? Who does this?

zygomatic arch implants

refer to APC

referred to grad prostho

$20-40K

1st step of denture making

1. primary impressions- select correct size- key chain w/ all size options

2. apply ropewax w/ border if needed

3. alginate impressions w/ stock tray

4. pour w/ quickstone

What is the criteria for stock tray selection?

tuberosities, hamular notches and ridges are covered + space for the material you are using

why would rope wax be added?

capture the base of the ridges upto the vestibule, helps the alginate reach these areas

What is the primary purpose of a preliminary impression?

obtain diagnostic cast and provide info to make a custom tray

when should you repeat an impression?

any errors in the 1st impression, impacts the future steps

what requires an impression to be repeated?

-voids

-metal / tray showing through

-important anatomy is missing, distorted or poorly recorded

-poor extension- bubble/ thin surface where not all of the vestibule was extended

--could indicate that rope wax needs to be added--

good features of a primary cast?

-land area 4mm wide to protect vestibule and see extension of custom tray

whats the purpose of a land area?

protect anatomy

2-3mm

13-15 mm at the THINNEST SPOT

13mm

where is the thinnest spot on the mand cast?

retromylohyoid fossa (at least 13 mm)

where do we want to increase thickness on the mand cast?

retromolar pad

What is the purpose of marking primary casts?

to show how far the tray should extend and where relief/ stops should go

mand stops?

max stops?

buccal shelves

hard palate

red- depth of the vestibule

black- limits of custom tray; 2-3 mm shorter

What is the purpose of blocking undercuts?

tray can get stuck and break cast, undercuts prevents

-undercuts can also hurt

What is the purpose of adding wax reliefs?

to create space for impression material; tight on ridges = no space for impression material- only show tray

where should we place tissue stops? purpose?

hard palate

buccal shelves

maintain a consistent space for impression material

What is the purpose of making custom trays?

better adaptation

-something closer/ tighter making better impressions and thinner impression material = LESS distortion

-also fits better in pt's mouth

-uniform thickness

-accurate border molding and final impression making

its overextended and leaving insufficient space for border molding

what are the steps to custom tray try in?

1. put trays in mouth

2. hold at stops (hard plate)

3. move pt's cheeks and lips around

-trays should stay in place, if any movement this means the tray is over extended

When trying in a custom tray, what should be evaluated?

make sure the 2-3 mm clearance inside the pt's mouth

no displacement for lip, cheek and tongue movements

What is the main consequence of an overextended border on a complete denture impression?

1. can cause ulcers from pinching tissue

2. denture will not stay in place

What is the purpose of border molding?

record depth of vestibule DURING functional movements

What material is used at ULSD for border molding?

Green compound

what materials are needed for BOMO? what is the process?

-bunsen burner

-green stick compound

-heat and place in sm sections

-water bath (130-140 degrees for 4-5 sec)- DOES NOT HEAT COMPOUND- tempers it and more comfortable for the pt

If there's a fold, line or bubble in the compound, what should you do?

use flame torch to smooth

DO NOT HAVE TO TAKE COMPUND OUT OF THE TRAY

repeat until you get a soft rounded surface

What can happen if excess compound is not removed from the intaglio surface of the custom tray?

less space for impression material and interfere with the seating and accuracy of the final impression

What should be observed when border molding is finished?

Should stay in place- created a seal - should have retention

What material is used for CD master impression at ULSD?

PVS- Aquasil

What characterizes an acceptable master impression?

-have to cover all anatomical landmarks

-smooth surface- no voids/ bubbles

-no major distortions

-all BOMO covered with impression material

Compound is showing through the impression material, isthat a problem?

sm areas acceptable and large show throughs are unacceptable

What is the purpose of boxing the master impression?

-preserve full depth of vestibule

-guarantee you get the land area

-correct width and depth

consequences of not boxing?

-boxing allows for an easier cast to work w/

process of boxing? where to place the rope wax?

1. sticky wax- reheat before placing rope wax over it; 3mm from the border

2. rope wax over sticky wax

3. 15mm of pink base plate wax around

placing rope wax at the vestibule (not 3mm under) would result in what?

would eliminate the land area

where should wax sheet be placed on mand impression?

where should you spatulate the waxes?

the rope wax to the boxing wax- hold to light to make sure there is no gaps

rope wax forms the __ area

baseplate wax forms the __

land area

cast thickness