Anatomy of Impression and Posterior Palatal Seal Flashcards
Support of maxillary denture
Palate
zygomatic shelf
crest of ridge line
Support for mandibular denture
note major ones
Buccal shelf
retromolar pads
crest of ridge lines
more support in buccal shelf and RMP
because more bone support
border seal/ atmospheric pressure
the contact of the denture border with the underlying or adjacent tissues to prevent the passage of airs or other substances
general vertical height and width of border
vertical height – all the way to the depth of the border
width = full width of the border
horizontal component of impression limited by?
anatomical limitations
list of muscles (general) that are involved with creating a denture
Masseter - muscle of mastication
orbicularis oris and buccinator – muscles of facial expression
mylohyoid and genioglossus – muscles of the floor of the mouth
superior constrictor, tensor veli palatini, levator palatini - muscles of oropharynx
obicularis oris captures what border? how to produce?
anterior border of both maxillary and mandibular – ask patient to pretend sucking on straw, puckering lips, whisteling, smiling
buccinator captures what border? how to produce?
lateral aspects of the border on maxilla and mandible
can produce by asking patient to pretend sucking on straw, puckering lips, whisteling, smiling
muscles on the floor of the mouth contributing to border molding on mandible
what part of border
how produce
Mylohyoid
Genioglossus
on the inner aspect (ligual side of the mandibular border - closer to the tongue)
produce during function of movements of the tongue and swallowing
- stick tongue out and move tongue side to side / to the roof of mouth
if create lingual border too long - cannot move tongue as would
muscles of oropharynx contributing to border
superior constrictor
tensor veli palatini
levator paltini
borders of the retromylohyoid space lateral- medial- posteriorly anteriorly-
Lateral - retromolar pad
Medial - tongue
Posterior - superior constrictor
Anterior - mylohyoid
what compromises the mandibular sling?
Masseter and medial pterygoid
Masseteric notch and how to replicate this during function
masseter on buccinator
when patient says OO-EE
open wide and move side to side as well
creating the reverse S shape
shape and characteristics of the Masseteric Notch
this is NOT an anatomical position but occurs when the massater slides on the buccinator – interaction of these two muscles
results in a CONCAVITY
this is a FUNCTIONAL FEATURE
what happens if you do not capture the Masseteric notch?
denture will POP FORWARD during these sounds
purpose of edentulous impression
provide support of denture and retention
if dont border mold the retromylohyoid space well? too long?
Difficulty in swallowing and the patient may present with a sore throat
reverse S curve in posterior aspect of mandibular border?
by the massateric notch
creates a reverse S and if not accounted for could catch on the corners of the cheeks
frenal attachments
lip out and down – want to see these cut through the border molding and PVS allows this
dont want a straight border mold
coronoid process trims a border on where?
Maxillary aspect
DISTO-BUCCAL
open wide and then close half way and move side to side
want this to be about 3mm wide in the posterior and uniform all the wall around
if not – too thick they will get stuck or denture will pop out
hamular notches AKA
pterygo-maxillary notches
hamular notch importance
locate how?
POSTERIOR LIMIT OF THE DENTURE
- will take a t-ball burnisher and rub along area until drops into the notch
two muscles of oropharynx in addition to superior constrictor that encompass the posterior palatal border
tensor veli palatini
levator veli palatini
anterior vibrating line
unction between moveable and non-moveable tissue on the soft palate
need to locate this because cannot fabricate denture onto moveable tissue
how to determine moveable vs. non-moveable tissue
“aah, aa, aah..
but not continuous like day ah ah ah not ahhhhh
are the fovea palatini reliable in locating posterior border of the maxillary denture?
NO – just area of complex nerve endings and cannot see in all patients
focea palatinae
anatomical element in the posterior border
two small depressions in the posterior aspect of the palate, one on each side of the midline, at or near the attachment of the soft palate to the hard palate
pterygomaxillary raphe
patient open wides
fibrotic band
if dont capture - denture will come out
primary stress bearing areas on maxilla
palate
zygomatic shelf
primary stress bearing areas on mandible
buccal shelf
- laterally = external oblique ridge
medially = alveolar ridge
border molding
border molding customizes your impression tray to the desired anatomy, thus enables the clinician to take the impression material all teh way to the borders of the denture
implications of denture adhesive
note that the patient had to wear this with last denture
want to take final impressions when all tissue is healed- maybe tell them to not wear denture for at least 24 hours before taking final impression
do trays move in function
NO -
border molding material
mucodynamic
impression compound
PVS heavy body
cut back treys?
yes 3mm for the purpose of border molding - we orginally made the treys into the full depth of the folds
*not done in our SLC sessions but will be done clinically
anything horizontal?
in the moving state– and need to cut these back
border molding maxilla actions to capture
Anterior- obicularis oris
Lateral - buccinator
Disto-buccal - by cornoid process of mandible
Roll lip over pull lip downward smile big pucker your lips suck on a straw
open wide then close half way move side to side to get the disto-buccal fold on maxillary from the coronoid process from the mandible
border molding posterior palatal seal
note if there is a Pterygomandibular raphe - capture this
then place material across the back and adapt it in a butterfly shape - getting the levator veli palatini and tensor veli palatini
upon removal of maxillary need to have?
SIGNIFICANT retention due to atmospheric pressure .. if not something is wrong
final mucostatic impression captures what 4 border muscles
- obicularis oris
- buccinator
- tensor veli
- levator palatini
also gets cornoid proccess for D-B fold and Pterygomandibular raphe in posterior if present
Hamular notch line
an arbitrary line connecting R and L hamular notches
AVL - anterior vibrating line
demarcates the movable from non movable tissues in the soft palate and also represents the posterior limit of the denture
Compressive Tissue Line
junction of compressible and non-compressible tissue
PPS/ posterior palatal seal
aka post dam
a bead located posteriorly on the INTERNAL SURFACE OF THE UPPER DENTURE - which completes the border seal
-this is inside denture
compressible tissue is what shape/ size and how to locate
always triangular shaped and can locate this type of tissue with the t-ball burnisher - need to note how deep you are compressing the tissue
4-6mm at its deepest/highest point
HALFWAY B/W midline suture and the hamular notch - if do more too much and wont sit
trying to create a V for a suction
how much do you scrape (+where) for depth of tissue displacement?
along the anterior vibrating line
scrape HALF the depth of tissue displacement
but should be customized for each patient based on the amount of displacebale tissue
where is the Compressive tissue line deepest?
along the anterior vibrating line
where is the Compressive tissue line most shallow?
0mm at the compressive tissue line
at the peak of it
purpose of PPS
- maintains the border seal by displacing the posterior border
2, prevents food from getting underneath the denture - diminshes/ eliminates gagging
- provides sunken distal borders which are less conspicuous to the tongue
- compensates for volumetric shrinkage of the acrylic resin
place a perpindicular line where?
along the midline suture
PPS extends where?
PAST hamular notches and blended into the DB fold
posterior nasal spine
should be exactly midline/center in the posterior of the PPS
very shallow
T/F border molding mandibular of Masseteric notch can also be achieved by trying to resist while patient tries to close
Yes
two S curves on mandibular
Massateric notch
and on lingual side to capture lingual muscles
Border molding and shape of lingual of mandible +
how to produce?
Superior constrictor
mylohyoid
Genioglossus
S shaped
tongue forward/out/up
move tongue to left and right
lick upper lip
swallow
6 muscles in border mold of mandible
Obicularis oris - anterior buccinator - lateral mylohyoid genioglossus superior constrictor masseter on buccinator - notch
T/F cut record base back to AVL?
TRUE
after locating AVL line what do?
this is the perpindicular line and after located - scribe with pencil then insert record base and transfer this onto it
after transferring AVL line?
Cut record base back to AVL and palpate outline of compressible tissue and pencil this in
- then insert record base and trasnfer these lines
when can you create the PPS?
developed functionally at the impression stage or mechanically at the cast stage
