Tooth Selection Flashcards
tooth selection is part of what patient visit?
intermaxillary records (3rd)
lines on rim that serve as rx for the lab? in terms of teeth?
- midline
- high smile line
- canine lines
- interpupillary line
is labial frenum a good indicator of pt midline? what about lower anterior teeth?
no
and
no
best thing to determine midline for teeth?
look at pt. FACE
plus incooporate patient – what they really want
relationship of incisal edge to teeth/ lip line?
it should MIMICK THE patients lip line
- the incisal edges of the maxillary anteriors should follow the contours of the lower lip during the smile
most people have incisal edges that are contouring the lower lip
reversed smile?
when the centrals and laterals are lifted up slightly more than the canines
what is the guide for tooth selecton and set-up?
the rim
we also built the rim to form the arches of the bone
what are the rim guidleines for tooth selection
- midline- comes from the face
- high smile line - determines the length of maxillary centrals
- canine lines
high smile line indicates?
length of the maxillary centrals
what helps determine the position of the maxillary canines?
- 1/2 the ala-modiolus
- mid-pupillary line
- canine -eminence on cast – if it is prominent
canine eminence line should also extend where? what does this represent and what are the implications
onto the land of the cast – determining the height of contour of the cuspids
since this is the height of countor – we see this when we look at a patient straight on but there is still part of canine tooth distal to this point and need to account for this as well
in many people width of 6 anterior teeth = what?
width of the nose - these are about the same distance
what to keep in mind for canine lines
- consider each side separately – not always symmetrical
2. lines represent the M-D height of contour – so will need more space distal
what is your prescription??
YOUR RIM
do we add the centric lines to rim?
YES – so we know position is reproducible and lines on the rim are where they should be
what do we measure with the rulers on the rim?
- high smile line – from base of wax to the beginning of the land
- Midline to each canine on either side (2 measurements) – we can have some assymmtry here
- distal of one canine – distal to the other
this gives you a range
range numbers on rulers correspond to what?
range between 42-58 mm?
different letters – which indicate molds of teeth
represent different molds of teeth we can choose from
patients face falls into what 4 major categories?
what does this suggest?
- square face
- the swuare tapering face
- tapering face
- the ovoid face
follows the arches of persons teeth – square face? – probably a square arch of patient – square tooth
describe square face
+ incisal aspect of teeth
Sides of the face from the hairline to the levels of the condyles to the angles of the jaw are straight and parallel
+ incisal aspect of teeth– central incisors are set practically straight across with the laterals also having full labial aspect
describe square tapering face
+ incisal aspect of teeth
sides of the head are parallel from the condyles upward – from condyles downward along the sides of the face – outline tapers in to the angle of the jaw
+ incisal aspect of teeth– centrals are more prominent than the laterals and canines- which are slightly elevated – but set at softer arrangement than a typical square taper
describe tapering face
+ incisal aspect of teeth
tapered face is widest at teh hairlien and most narrow at the angles of the haw – lines converge towards the jaw
+ incisal aspect of teeth– tapering arch converges to a point midline between the two centrals – centrals start to curve even
describe ovoid face
+ incisal aspect of teeth
widest through the center at the level of the condyles it curves upward and downwards to form an oval outline
+ incisal aspect of teeth— teeth set to full curve and demonstrate the ovoid characteristics
long face = what in terms of tooth selection
long tooth
mold guide comes with?
mold chart –
mold chart
lists sizes
first column in mold chart gives you what?
height/length of tooth / centrals
second column in mold chart gives you what?
width width of centrals
third column in mold chart gives you what?
canine to canine distance – distance of anteriors ON A CURVE
once you pick maybe two different styles of teeth what do you do?
first, compare your mold choices with the guidelines you have on your occlusion rim
- then can evaluate intra-orally via a rim selector kit
if first number is different but second letter is the same what is the same/ different for the tooth?
height is different
width is the same
underneath the upper anterior molds are?
recommended mandibular anterior molds
usually come in cards – 6 teeth for
mold chart articulations for what type of typical patient?
Class I patient
with different degrees of tapering, etc.
mold chart for class II or class III patient
II– pick a smaller mold
III- pick a larger mold
Types of posterior molds?
indicating what?
CUSP height
0 degree - monoplane
10 degree
20 degree
22 degree
30 degree
33 degree
40 degree
posterior molds available in cards of_____
1X8 “cards”
12 degree means?
Functional – anatoline posteriors
next level up
how do we select posterior tooth width m-d?
measure from DISTAL of cuspid to RISE OF THE RAMUS on mandible
available from 29-36 mm
available height/ length of posterior teeth?
short, medium, long, or L/S (long buccal - short lingual)
rule of thumb for posterior teeth selection?
the flatter the ridge the flatter the cusp
monoplane posterior cusp height an rational
0 degrees
resorbed ridge
semi-anatomical posterior cusp height an rational and what is it called?
used when?
12 degree, 20 degree, and 22 degree
(10-20)
rational – LINGUALIZED – lingual contact occlusion – most often used for implant overdenture
contains aesthetics of anatomical – somewhat of a cusp but reduces lateral sheer forces
anatomical posterior cusp height an rational
30, 33, and 40 degree
rational – excellent rdige– you have enough ridge
class II or III patient what plane tooth?
monoplane
list the 8 major rationals for choosing monplane posterior tooth height
- resorbed rigde
- class II or class III patient
- bruxism patient
- cross-bite
- debilitation –pt. weak
- interum U/L
- when in doubt
- when CR is difficult
list the 6 major rationals for choosing anatomical posterior set ups
- excellent ridges
- natural opposing teeth
- bilateral balance
- severe overbite – so need to accomodate for anterior guidance
- improve aesthetics
- chewing efficiency
resorption on lower but upper is okay?
always resort to the lower – so we choose what teeth will match most efficiently with the ridge
so severe resorption on lower = monoplane
10 major analysis in the anterior for tooth selection? when should this start?
DURING INTAKE – understand the patients expectations from the start
- face shape
- smile line - length
- canine distance - width
- gender -
- complexio - shade
- old dentures (likes/dislikes)
- old photos
- old x-rays
- old casts
- PATIENT OPINION /SIGNIFICANT OTHER
9 major patient analysis for posterior tooth selection
- ridge status
- arch relatonship - what class is pt.
- cross-bites?
- bruxism
- coordination
- health
- old dentures
- anterior overbites
- canine- to pad distance
denture tooth material?
- acrylic
- IPN
- Porcelain
porcelain drawbacks?
brittle
what is does to ridge over long term wearing
can porcelain teeth chemically bond to denture base?
NO
- they need tooth retention deviced for denture base acrylic
retention for acrylic, IPN, and porcelain teeth? - general
Acrylic and IPN teeth are CHEMICALLY retained in denture bases
Porcelain teeth must be MECHANICALLY retained in denture bases
porcelain anterior teeth have what for retention?
porcelain posterior teeth have?
PINS = anterior
Diatoric = posterior
- holes in undersurface
opposing dentition consideration?
important because over time can ware down natural teeth
example - porcelain can cause ware on the enamel
opposing dentition for acrylic?
best / okay / not good
acrylic and enamel are good
IPN is okay –but acrylic would ware because the IPN is harder
against polished porcelain – porcelain would ware the acrylic
plastic = acrylic
yeah, basically
long term effects of porcelain anteriors and plastic posteriors?
acrylci waring at a different rate than the porcelain
eventually leaving occlusion in the anterior – and anterior would increase in pressure and increase in bone resorption
effects of long term use of porcelain denture tooth misuse
severe mandibular and anterior maxillary resorption
pre- maxilla like gone
mental foramen coming up to the occlusal table
loss of the flange
no premaxilla
loss of pre-maxilla?
bad combination of materials used
denture base coloring?
basic ones
- fibered dark, light
- lucitone 199
- custom blends and custom shading
- custom staining
sequence of monoplant tooth set up
A-B-C-D
set anterior teeth first
2/3 height of pad – because do not use curves
two techniques to setting teeth?
which do we use?
- setting one side at a time
- setting 2 pairs at a time
- - we will use this one
what touches occlusal plane in anterior set up?
centrals and cuspids touch
laterals are a little above table - about 1-2 mm above
canine points?
towards chin with neck outwards
for upper anterior set up where do we align incisal edges? where will roots diverge?
PARALLEL to the plan so the roots will all DIVERGE DISTALLY – by desgin and canines point towards the chin
and the incisal edges will give the illusion of a curved plane – aka smile
steps to make room for teeth - height
- 1st grind record base
- make window in base (placing foil)
- grind tooth (last resort – we WILL NOT DO THIS IN OUR LAB)
ridge lapping?
reduce from lingual at SAME CURVE AS THE RIDGE
- we will not do this
in which direction do you NOT cut to reduce height of teeth
do NOT cut horizontally – so do not cut top or bottom
which lower anteriors touch plane in monoplane set up?
roots diverge?
canines point?
ALL touch the plane
roots diverge distally and cuspids now point TOWARDS THE FOREHEAD
Tilt and angulation of canines?
uppers — angle towards chine
lowers – angle towards forehead
both roots diverge distally with prominent necks and distal tilt
do anterior teeth touch in centric?
NO – no anterior contact
what is holding VDO?
wax and pin – teeth should not touch
C+D+ pin
cuspid lines indicate what
anterior or mesial half
with a completed anterior set up of monoplane posteriors what is the: tilt axes appearance roots incisals
tilt -- M-D tilt axes-- they converge appearance-- curved appearance roots -- diverge distally incisals -- these align
slight a-p tilt
what is the a-p tilt in anterior set up?
slight proclination
slight a-p tilt
so each tooth is individually angles away from the plane to reflect light and give a natural appearance
T/F we should treat each side of the rim separately?
YES
asymmetry exists in patients
– influence on tooth arrangement
creating natural looks to dentures can include doiong what?
including staining, restorations, overlapping (vertical overlap), stippling, diastemas
*4 Major BASIC rules of denture occlusion.
Include reasons for each…
If change to more anatomical set up what is the big difference?
- NO ANTERIOR CONTACT IN CO
- decreases pressure - NO CANINE GUIDANCE IN LATERAL
- decreases movement - NO ANTERIOR GUIDANCE IN
PROTRUSION
- decreases movement - CO=CR
- decreases movement
ANATOMICAL SET-UPS HAVE BALANCE
Bone loss will come from?
- tooth loss
- pressure
- movement
guidance definition and implication?
any contact in anterior alone and will result in increased movement and pressure
group function definition and implication?
unilateral posterior contact and results in increased movement
balance definition and implication?
bilateral posterior contact and will DECREASE movement
if unsupported posterior in dentures?
resorption in the maxilla and mandible
pressure in anterior so no anterior contact in CO
only time there can be contact in the anterior in dentures?
if there is SIMULTANEOUS CONTACT in the posterior DURING PROTRUSION
NO ANTERIOR CONTACT IN OCCLUSION ALONE
two main denture goals
- prevent guidance
2. promote balance
fixed factors (things we cannot change on patient)
- HINGE POSITION of condyle (CR)
- Protrusive path of condyel — HORIZONTAL condylar inclination
- Lateral path of condyel — lateral inclinations of condyle
what can we alter in dentures?
4 MAIN THINGS
- HORIZONTAL OVERLAP OF ANTERIORS (H)
- VERTICAL OVERLAP OF ANTERIORS (V)
- CUSP HEIGHT OF POSTERIORS
- CURVE OF POSTERIOR PLANES
How to manipulate anteriors for monoplane occlusion in terms of overlap to not get contact
increase horizontal
decrease vertical
combination of both
2 main objectives of anterior denture setup in terms of occlusion
- PREVENT anterior contact as long as possible
2. MAINTAIN posterior contact as long as possible
aspects of the a-p tilt
Labial - incisal
- root location
- lip support
- light reflection
ridge lap? will we do this?
how you can fix the vertical height if tooth too tall BY REDUCING FROM THE LINGUAL AT SAME CURVE AS THE RIDGE
after base is thinned and window is made
N0 – WE WILL NOT GRIND, ADJUST, OR RIDGE LAP ANY TEETH IN EITHER SET UP
overlap allowed in class III patient
horizontal – up to 3-5 mm (usually only 1-2)
