Teeth arranging for complete denture /continued dental education

Arranging Teeth For Complete
Denture Occlusion
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

Once the master casts have been mounted
on the articulator, the teeth are set in the occlusion
rims so a more accurate observation can be made
of the jaw relationship recorded and eventually
the occlusion established.

• The incisive papilla is a valuable guide to anterior
tooth placement because it has a constant
relationship to the natural central incisors.
• It also serves to position the midline of the upper
denture or, more specifically, the central incisors in
the dental arch.
• However, the centre of the face must also be kept
into consideration when locating the midline for the
teeth arrangement.

• A line marking the centre of the
incisive papilla can be extended
onto the land area of the cast.
• The central incisors are placed on
either side of this line.

• The incisive papilla also aids in anteroposterior
positioning of the teeth.
• The labial surfaces of the central incisors are usually
8 to 10 mm in front of the papillae.

• However, the distance for obvious reasons, will vary
with the size of the teeth and the labiolingual
thickness of the alveolar process carrying the teeth.
• So it is not an absolute relationship.
• Another guide to position the central incisors is their
relationship to the reflection of soft tissues under the
lip or as recorded in the maxillary impression. the
labial surfaces and incisal edges of the teeth are
anterior to the tissues at the reflection, where the
denture borders will be placed.

• The root of the natural tooth extends into
the alveolar process, with a relatively thin
layer of bone over it labially. This means
that in some situations the residual ridge
can be used as a guide to determine the
proper inclination of anterior teeth.
• However, the accuracy of this guide
decreases as resorption of the residual ridge
progresses.

• The anteroposterior position of the dental arch
should be governed chiefly by consideration of the
orbicularis oris and its attaching muscles and by the
tone of the skin of the lips.

The anterior teeth should be placed to
support the lips to maintain the normal
muscle tonus.
Placing them too far posteriorly,
allows the muscles to go unsupported
and lips to sag.
Placing them too far anteriorly
stretches the muscles and results in a
smaller looking mouth.

Notice the lack of tone in
the skin of the upper lip
Teeth positioned correctly
in an anteroposterior
direction. Notice the
improved skin tone.

• A stretched
appearance of the
lips and philtrum
indicates that teeth
are positioned too
far anteriorly

• Setting teeth over the maxillary anterior ridge may
undermine the esthetic result.
• The greatest harm is done when the maxillary
anterior teeth are set too far back on the ridge or
under the ridge.
• In the resorbed situation, the crest of the ridge is
considerably more posterior than it is in a patient
with recent extractions, if the rule of setting teeth
over the ridge is followed after the ridge has
resorbed, a prematurely aged appearance will result.

The four principal factors that govern the positions of
the teeth for complete dentures are
(1) the horizontal relations to the
residual ridges,
(2) the vertical positions of the occlusal
surfaces and incisal edges between the
residual ridges,
(3) the esthetic requirements, and
(4) the inclinations for occlusion

HORIZONTAL POSITIONS
The horizontal positions of teeth to the residual ridges
involve placing the teeth anteroposteriorly and
mediolaterally
(1)to provide stability,
(2) to direct the forces of mastication to areas most
favorable for support,
(3) to support the lips and cheeks for esthetics, and
(4) to be compatible with the functions of the surrounding
structures. www.indiandentalacademy.com

• Forces directed at right angles to the
supporting tissues are more stabilizing than
forces directed at an inclined plane.
• The artificial teeth must be placed in
suitable horizontal positions to allow the
muscle activity to occur naturally

• The positions of the teeth influence the phonetics as
exemplified by the J, ch, and sh sounds.
•When the maxillary anterior teeth are placed too far
posteriorly as related to the lower lip, the J sound may be
muffled.
•It may be necessary to arrange the mandibular anterior
teeth with more labial version to aid in the correct
enunciations of the ch and sh sounds

• In mastication, the tip of the tongue reaches into the
buccal and labial vestibules, gathers the food, and
places it on the occlusal surfaces.
• When the teeth are placed too far in a lateral or anterior
direction, the vestibular spaces are obstructed to the
tongue.
• When the teeth are placed too far in a medial or
posterior direction, the tongue will dislodge the
mandibular denture in an attempt to reach over the
teeth www.indiandentalacademy.com

The crests of the residual ridges are aids in
positioning the artificial teeth if the natural teeth
were recently extracted and the cortical plates of
bone remain intact. Unfortunately, the crests of the
residual ridges do not remain in the same
anteroposterior or mediolateral positions.

As resorption of alveolar
ridge progresses, the
maxillary arch
becomes narrower and
the mandibular arch
becomes broader.

Guidelines for placing teeth in
original centre of mandibular ridge
• Retromolar fossae
• Retromolar papilla
• Retromolar pad
• Mandibular canine region

LIMITS TO PLACING POSTERIOR TEETH
• The mandibular arch determines the posterior limit
for placing posterior teeth
• Mucosa considered capable of bearing stress
terminates at the retromolar papilla
• Medial extension of the mylohyoid ridge
determines the medial limit in placing mandibular
posterior teeth- if placed more lingually than it,
elevating the tongue may dislodge the denture
• Actions of tongue and cheek, alongwith esthetics
determine the lateral limits of mandibular
posterior teeth

LIMITS TO PLACING ANTERIOR TEETH.
•Involves placing the teeth in an anteroposterior and
mediolateral position in harmony with the action of the
lips and the tongue.
•Establish horizontal overlap sufficient to prevent the
anterior teeth from contacting when the posterior teeth
are in centric occlusion .

POSITIONING OF THE TEETH ACCORDING TO THE
HORIZONTAL RELATION OF THE JAWS .
Maxillary arch is broader Using larger teeth buccolingually may
than the mandibular arch be required.
Maxillary arch is smaller The buccolingual relations of the teeth
than the mandibular arch are reversed
Place the buccal cusps of the
mandibular teeth lateral to the buccal
cusps of the maxillary teeth

The mediolateral and anteroposterior positions of the
anterior teeth influence sounds in speech.
f – incisal edges of maxillary centrals should barely
contact the vermillion border of the lower lip.
s- mandibular anterior teeth affect the s sound .
th – the tip of the tongue should make contact with
the palatal surface of maxillary anterior teeth

•The artificial maxillary central incisors should be
placed anterior to the incisal papilla regardless of he
relation of the papilla to the existing residual ridge
•When natural teeth are present, the inclinations of the
anterior teeth, as related to the crest of the alveolar
ridge, are downward and forward. Usually this
relationship is accentuated as resorption takes place.

• The upper lip is supported in the area of the
philtrum by labial surfaces of the maxillary
anterior teeth and at the corners of the mouth by
the canines.
• In normally related jaws, the border of the lower
lip is supported by the labial incisal third of the
maxillary anterior teeth.

Definite anatomic landmarks to be used
as guides in arranging the anterior teeth
are
(1)the incisal papilla
(2)the midsagittal suture, and
(3)the canine lines.
By locating these landmarks and recording
their positions on the cast, one establishes
points of reference indispensable to the correct arranging
of the teeth www.indiandentalacademy.com

In the absence of other more definite information,
the arch form is used as a guide for the initial
arrangement of the teeth
The anterior teeth for the tapered arch places the central
incisors farther forward than the canines .
The anterior teeth for the square arch places the central
incisors nearly horizontal with the canines.
The anterior teeth for the ovoid arch places the six anterior
teeth in gentle curve.

A-SQUARE , B- TAPERING, C- OVOID

•The size and shape of the head are reliable factors in
determining arch form.
•Round heads are associated with square arches and a
broad flat arrangement of the anterior teeth. The labial
surfaces of the central incisors are in full view, and the
canines are prominent.
•Long narrow heads are associated with long narrow,
palates, tapered arches, and a tapered anterior tooth
arrangement.

VERTICAL POSITIONS
The arrangement of artificial teeth in the correct vertical
positions involves placing the anterior and posterior
teeth in an acceptable position between the two residual
ridges in a vertical direction. As in correct horizontal
positioning, correct vertical positioning of the teeth
should provide (1) denture stability, (2) favorable forces,
(3) support for the lips and cheeks, and (4)
compatibility.

•Natural teeth lose contact and migrate; they assume
abnormal relations and positions when subjected to forces
beyond the physiologic limits. Natural teeth extrude when
their antagonists are removed, and at times the teeth and
bone extrude as a unit. They can also be intruded.
•To place the artificial teeth in the exact positions
occupied by the natural teeth may not be tolerated during
functions involving mandibular movements even though
the teeth appear natural.
•A compromise between appearance and function may
have to be reached for a favourable prognosis.

•When the mandibular teeth extend too high, the tongue
cannot reach the labial or buccal vestibules to retrieve
the food.
•When the mandibular teeth are too low, the tongue will
not be supported at the lateral margins and will
therefore enlarge in a lateral direction.
•The tongue apparently accommodates more readily for
anteroposterior changes in position than for vertical
changes in position.

•The length and horizontal position of the central incisors
should be such that when an individual says "five" or
"valve" the teeth should come into slight end-to-end
contact with the center of the lower lip.
•The anteroposterior occlusal plane is established when
the mandibular posterior teeth are placed at their correct
vertical length and the maxillary anterior teeth are placed
at their correct vertical length on a plane .

VERTICAL POSITIONS OF MANDIBULAR POSTERIOR
TEETH.
Two anatomic guides to establish the vertical position of
the occlusal surfaces of the posterior teeth are
(1) the orifice of the duct of the parotid gland (Stensen's
duct) and
(2) the retromolar pad.
1. The occlusal surface of the maxillary first molar is
measured approximately ¼ inch below the orifice of the
duct from the parotid gland (Stensen's duct).

2. The occlusal surface of the last mandibular natural
molars is on a plane approximately at the bottom of
the upper third of the retromolar pad. This vertical
position is usually compatible with the activities of the
tongue and the cheeks.
The occlusal groove, on the inner surface of the cheek,
is located opposite the occlusal plane of the natural
mandibular posterior teeth.
When this groove is present, it is a reliable guide to
the position occupied by the occlusal surfaces of the
natural mandibular posterior teeth and can be used as a
guide to positioning the posterior artificial teeth in a
vertical direction . www.indiandentalacademy.com

VERTICAL POSITIONS OF MAXILLARY ANTERIOR TEETH.
Esthetics and phonetics are used to establish the vertical position of
the incisal edges of the maxillary anterior teeth.
The following are aids to establishing the vertical positions of the
artificial teeth by using occlusion rims:
1. Attach hard wax occlusion rims to accurate, stable record
bases.
2. Properly contour the occlusion rims in an anteroposterior
and mediolateral direction.

3. Instruct the patient to say "fifty-five" and establish the
vertical length of the occlusion rims in the anterior section of
the maxillary arch.
4. Reduce the posterior occlusal surfaces until the surface is
parallel to a line drawn from the ala of the nose to the tragus of
the ear .
5. Make a face-bow transfer and a centric relation record and
attach the casts to the articulator.
6. Record the top of the retromolar pad on the cast.
7. Alter the occlusion rims so the posterior vertical positions of
the mandibular rim are on a plane at the same level as the top of
the retromolar pads and the anterior vertical position is in
contact with the maxillary occlusion rims.www.indiandentalacademy.com

• Remember that the use of the ala
– tragus line is an expediency
and is not a reliable indication
for the occlusal surfaces of the
teeth.
• The plane is not used unless it
coincides with the other guiding
factors.
• Establish the plane , using the
retromolar pad for the posterior
and the incisal edge or low lip
line for the anterior points ofwww.indiandentalacademy.com

Arranging the maxillary teeth
• After selecting the anterior molds for the
maxillary and mandibular teeth, the
arrangement is left to the discretion of the
individual dentist to achieve the esthetic
needs of the patient.
• Remove the maxillary wax occlusal rim on
one side from the midline around the arch
for a distance of approximately 1 inch

• To set the maxillary anterior teeth with the
appropriate labial orientation, it may be necessary to
grind the acrylic resin to reduce the thickness of the
record base.
• This is a common occurrence in clinical practice,
and should always be performed before grinding the
neck of the tooth.
• A longer tooth clinically will provide a better
esthetic result.

Maxillary Central Incisor:
•The long axis of the tooth is perpendicular to the horizontal
(labiolingual inclination)
•Its long axis slopes towards the vertical axis
( mesiodistal inclination)
•Slopes labially about 15 degrees when viewed from the side.
•Incisal edge is in contact with the occlusal plane.

Maxillary Lateral Incisor:
• Long axis slopes rather more towards the midline
• Inclined labially about 20 degrees when viewed from
the side
• The neck is slightly depressed
• The incisal edge is about 1mm short of the occlusal plane.

Maxillary Canine :
•Its long axis is parallel to the vertical axis when
viewed from both the front and side or it may be
slightly to the distal.
•The bulbous cervical half of the tooth provides its prominence.
•Its cusp is in contact with the horizontal plane.
.
•The neck of the tooth must be prominent

• Remaining maxillary teeth are arranged on the other side of
the arch to complete the anterior set up.
• To maintain the set teeth in position, the wax supporting the
teeth must be heated and sealed both to the teeth and to the
record base.

First premolar:
• Long axis is parallel to the
vertical axis when viewed from
the front or the side.
• Its palatal cusp is about 1mm
short of, and its buccal cusp in
contact with, the occlusal plane.

Second premolar:
• Its long axis is parallel with
the vertical axis when viewed
from the front or the side.
• Both buccal and palatal cusps
are in contact with the
occlusal plane.

First molar:
• Long axis slopes buccally when
viewed from the front, and
distally when viewed from the side.
• Only mesiopalatal cusp is in contact
with the occlusal plane.

Second molar:
• Long axis slopes buccally more steeply
than the first molar when viewed from
the front, and distally more steeply
when viewed from the side.
• All four cusps are clear of the occlusal
plane, but the mesiopalatal cusp is
nearest to it.

Arranging the Mandibular
Teeth

Mandibular central incisor:
• Long axis slopes slightly
towards the vertical axis
when viewed from the front.
• Slopes labially when viewed
from the side.
• Incisal edge is about 2mm
above occlusal plane

Mandibular lateral incisor:
• Long axis inclines to vertical axis
when viewed from the front
• Slopes labially when viewed from
side but not so steeply as the central
incisor.
• Incisal edge is about 2mm above
occlusal plane

Mandibular canine:
• Long axis leans very slightly towards
the midline when viewed from the
front.
• Leans very slightly lingually when
viewed from the side
• Neck is slightly prominent and the
tooth is tilted to the distal
• Tip at same level as incisors.

First premolar:
• Long axis is parallel to the vertical plane when
viewed from the front and the side.
• Its lingual cusp is below the horizontal plane
• Its buccal cusp about 2mm above it as it contacts the
mesial marginal ridge of the upper first premolar.

Second premolar:
• Long axis is parallel to the vertical plane when viewed from
both the front and the side.
• Both cusps are about 2mm above the occlusal plane.
• The buccal cusp contacts the fossa between the two upper
premolars.

First molar:
• Long axis leans lingually when viewed from the front and
mesially when viewed from the side.
• All cusps are at a higher level above the occlusal plane than
those of the second premolar.
• The buccal and distal cusps are higher than the mesial and
lingual.
• The mesiobuccal cusp occludes in the fossa between upper
second premolar and first molar.www.indiandentalacademy.com

Second molar:
• Lingual and mesial inclination of the long axis is more
pronounced than in the case of the first molar.
• All the cusps are at a higher level above the occlusal plane
than those of the first molar, the distal and buccal cusps
more so than the mesial and lingual.
• The mesiobuccal cusp contacts the fossa between the two
upper molars.

Arranging the Posterior Teeth
.
The anatomical guides most often used in developing the anterior
plane of occlusion are the comers of the mouth.
The posterior plane of occlusion is an extension of this
anterior plane level with the junction between the middle and upper
third of the retromolar pads bilaterally.
The height of the occlusal plane is not simply a matter of
dividing the maxillomandibular denture space equally. This space is
governed by the relative amount of bone lost from the two ridges.
More bone may have been lost from the maxilla than from the
mandible and the occlusal plane should not be placed an equal
distance between the two ridges. It also should not be at a level that
would favor the weaker of the two ridges (basal seats). The most
reliable guides are esthetics or anterior tooth placement and the
retromolar pads www.indiandentalacademy.com

The solution to the problem is to position the teeth along a line
extending from the tip of the canine to the middle of the
retromolar pad this arbitary line should pass through the central
fossa of the mandibular premolars and molars
The basic principle for the buccolingual positioning of posterior
teeth is that they should positioned over the residual ridge. The
canine retromolar pad should provide guides for arrangement.

Compensating curves
• From the foregoing descriptions of the orientation
of the teeth it will be seen that they are arranged
so that the posterior teeth, when considered as a
whole unit, form two curves, an antero-posterior
and a lateral curve.
• Are the artificial curves introduced into dentures
in order to facilitate the production of balanced
articulation.
• Are the artificial counterparts of curves of Spee
and monsoon which are found in the natural
dentition.

Anteroposterior curve
• Follows an imaginary line touching the buccal cusps of all
the lower teeth from the lower canine backwards, and
approximates to the arc of a circle.
• A continuation of this curve backwards in the natural
dentition (curve of Spee), will nearly always pass through
the head of the condyle.

• The arrangement of posterior
teeth in this anteroposterior
curved manner is best
appreciated by the following
references and description.
• If the path followed by the
condyles is horizontal, then the
teeth could be set to conform to
a horizontal plane.when the
mandible moves forwards the
teeth will remain in contact.

• If the path travelled by the
condyles is at an angle from the
horizontal plane (as it always is to
some extent), then as soon as the
mandible moves forwards the
condyles commence to descend,
and the posterior teeth will lose
contact if they have been set to
conform to a horizontal plane.

• If the posterior teeth,
instead of being set on a
horizontal plane, are set to
an anteroposterior curve,
then as the mandible moves
forwards and the condyles
travel downwards, all the
teeth can remain in contact

The lateral curves:
• In the natural dentition there are two lateral curves, one
involving the molar teeth ( the curve of monsoon), and the
other involving the teeth anterior to the second premolars
• The posterior curve has its concavity facing upwards and
increases in steepness from before backwards, the occlusal
surfaces of the upper molars facing outwards and
downwards.
• The anterior curve is a reverse of the posterior curve.

• When the mandible is moved laterally the rotating condyle
on the working side (i.e. the side towards which the
mandible is moved) remains in the glenoid fossa and moves
very slightly outwards and backwards ( Bennet movement).
• The orbiting condyle on the other side ( balancing or non-
working side) travels downwards and forwards.
• If the teeth are set on a horizontal plane, those on the non-
working side will lose contact, due to the downward
movement of the condyle on that side.

• If the teeth are set on a
horizontal plane, those on
the non-working side will
lose contact, due to the
downward movement of
the condyle on that side.

• If however, the teeth are set to
conform to a curve, then
steepness of which relates to
the steepness of the condylar
path, then the teeth will remain
in contact during the lateral
and downward movements.

WAXING AND CARVING
OF THE WAXED UP
DENTURE

Armamentarium required
1. Wax spatula
2. Le Cron carver
3. Chip blower
4. Bowl of chilled water
5. Cotton

• The form of the polished surface of a denture influences its
retentive quality.
• In addition, it influences the esthetic values of the denture.
• The upper part of the polished surface, known as the
“anatomical portion” should be formed in such a way as to
lose none of the original border width of the impression.

• Generally speaking, fullness on the buccal and labial
surfaces is desirable; and the opposite is true on the palatal
surface of the maxillary denture, to provide all possible
space for the tongue.
• The lingual flange of mandibular denture should have the
least amount of bulk, except at the border. This thickness at
border is under the narrowest portion of tongue and it
greatly enhances the seal by contacting the mucolingual
fold.

• An excess of base plate wax is added on the buccal
surfaces of mandibular and maxillary trial dentures.
• The bulk of this cut back to the outer border of the cast.www.indiandentalacademy.com

• The small end of a Le Cron
carver is held at a 45 degree
angle to the tooth surface to
form the wax gingival margin.
• The common tendency is to
cut this line too straight from
the interproximal to
interproximal, not leaving
enough wax. It is well to have
a surplus of wax along the
gingival line and then to
retrim.

• Triangular markings can be
placed as a guide to the
length and position of the
root.
• Root of maxillary canine is
longest, lateral incisor
shortest and central incisor
root is in between of the
two.
• Root of mandibular canine
is longest, central incisor
shortest, and lateral incisor
root is in between the two.

• The wax is scraped out of these
triangular areas, after which the
root indications will become
manifest.
• The sharp and rough indications
are now rounded with a Le Cron
carver and the wax spatula. They
should not be over-emphasized.

• The lingual surface of the
mandibular denture may be made
slightly concave without
extending the concavity under
the lingual surface of the teeth.
• A projection of tooth beyond
their polished surface acts as an
undercut into which the patient’s
tongue will slip, thereby causing
the denture to be unseated.
(correct adjustment shown in
diagram) www.indiandentalacademy.com

• The palatal surface of the
maxillary denture should be
waxed to a uniform thickness of
2.5 mm (sufficient for adequate
strength and yet thin)
• Lingual festooning restores part
of the lingual surface of the tooth.
• Wax is added and carved on the
lingual side of the artificial teeth
to imitate the normal lingual
contours of each tooth.www.indiandentalacademy.com

• Polishing of the set up
– Pass the waxed up denture slowly over the
flame or use a chip blower to smoothen the
surface.
– Dip the setup immediately in the bowl of
chilled water or use a wet cotton to gently rub
over the flamed surfaces

Try-in Of The Waxed Up
Denture

Purposes of the try in:
• There is a good deal more to be checked about the dentures
at the try in stage, than just appearance.
• Two main objectives should be to compare the general tooth
and arch position with the way the teeth might have grown.
• We are used to hearing the expression, “ set the teeth on the
ridge”, but this expression should be changed to say “ set
the teeth as nearly as possible to where they grew!”
• Physiologically the mouth and all its functions have
matured in a certain pattern of conditioned reflexes and
proprioceptive guidances. The more we deviate from this
pattern, more the adaptation required by the patient.

Since so many points require checking, it is sound practice
to get into the habit of working to a definite plan during
the trial stage, and the following order is suggested.
1. The lower denture by itself
(a) Peripheral outline
(i) Buccal and labial
(ii) Lingual
(iii) Posterior extension
(iv) Underextension
(b) Stability to occlusal stresses
(c) Tongue space
(d) Height of the occlusal plane

2. The upper denture by itself.
(a) Peripheral outline
(i) Buccal and labial
(ii) Posterior border
(b) Stability to occlusal stresses
(c) Retention.

3. Both dentures together
(a) Position of occlusion
(i) Horizontal relationship
(ii) Vertical dimension (occlusal face height)
(b) Evenness of occlusal contact
(c) Appearance
(i) Centre line
(ii) Anterior plane

(iii) Profile and lip form
(iv) Amount of tooth visible
(vii) Phonetics
(vii) Freeway space
(e) Approval of appearance by the patient.

• Before carrying out these checks, remove the dentures
from the articulator and place them in a bowl of cold
water.
• It is important that the waxed dentures should be
frequently placed in cold water as wax softens
appreciably at mouth temperature and, if left in the
mouth too long, the teeth may be displaced and the
bases may distort.
• The method of carrying out these checks is as follows.

Trying the lower denture by itself:
•Place the denture in the mouth and seat it on the
ridge.
Peripheral outline
•The entire periphery should be checked to ensure
that it is not over-, or under-extended
The buccal and labial periphery
•Hold the denture in place with light pressure on
the occlusal surfaces of the teeth and move the
cheek on one side upwards and inwards, thus
simulating the action it makes when chewing.
.

• Now relax the pressure on the teeth and observe if the
denture rises from the ridge.
• If it does, trim the periphery where it is seen to be over-
extended until little or no movement occurs.
• Pay particular attention to the buccal frena and ensure that
they have adequate clearance.
• Repeat for the opposite side and for the lip.
• Note the bulk and shape of the buccal aspect of the
denture. It should take the form of a gentle convexity in
the molar region but concave in the premolar region
• Such a contour will aid the muscular control of the
denture as the cheek will tend to fit against the surface
and hold the denture down.

The lingual periphery
• Hold the denture in place with light pressure and ask the
patient to protrude his tongue sufficiently to moisten his
lips
• if the denture lifts at the back, it is over-extended in the
region of the lingual pouch.
• Next, ask the patient to put the tip of his tongue up to the
back of his palate;
• if the denture lifts in the front, it is over-extended
anteriorly, probably in the region of the lingual frenum.www.indiandentalacademy.com

• Such over-extension must be relieved, but care should be
taken to avoid over-trimming, which occurs very easily
owing to the difficulty of seeing the functional depth of
the lingual sulcus when the denture is in place
• Final adjustments are more easily and more accurately
made after the finished denture has been worn for a few
days, when areas of slight inflammation will indicate the
precise location of over-extension.

Posterior extension
Ensure that the heels of the lower denture are extended as
high up the ascending ramus of the mandible as is
practicable; the purpose of this is to buttress, the denture
against the backward pressure of the lower lip

Under-extension
• Though of less common occurrence than over-
extension, it is equally important that the periphery
should not be under-extended since dentures must
cover the greatest possible area if maximum retention
and support are to be obtained.
• If the denture is found to be under-extended in any part
of the periphery as shown by the presence of a gap
between it and the functional position of the
surrounding mucosa, replace the denture on the cast
and check whether the base has been carried to the full
extent of the impression at this point.

• If it has, it implies an inaccuracy in the impression which
must be retaken before proceeding further. An alternative
is to proceed to the finish stage and then rebase the
denture to rectify the peripheral error.
Stability under occlusal load
• This test is used to determine if occlusal stresses will be
transmitted unfavourably.
• Apply pressure with the ball of the finger in the premolar
and molar regions of each side alternately; this pressure
must be directed at right angles to the occlusal surface. If
pressure on one side causes the denture to tilt and

• If pressure on one side causes the denture to tilt and rise
from the ridge on the other side, it indicates that the teeth
on the side on which pressure is applied are set too far
outside the ridge.
• It may also indicate lack of adaptation of the base on the
side being loaded or under-extended flanges on the side
which rises.

Tongue space
• Natural teeth occupy a position in the mouth where the
inward pressure of the cheeks and lips is equalled by the
outward pressure of the tongue, and it is into this zone of
neutral pressure that the artificial teeth must be placed.
• The tongue, being more mobile than the cheeks, will cause
greater instability of the lower denture if the teeth are set
on the lingual side of the neutral zone than if they are set
on the buccal side.
• If the tongue is cramped by the denture, lateral pressure
will be exerted, producing instability when the tongue
moves.

You can test for lack of tongue space as follows:
• Ask the patient to relax the tongue, making sure that the
denture is seated on the ridge, and then request him to
raise the tongue.
• If the tongue is cramped, the denture will begin to rise
immediately the tongue moves.
• This immediate reaction of the denture tends to
differentiate the movement caused by a cramped tongue
from the movement caused by lingual flange over-
extension; movement due to the latter cause does not
occur until the tongue has risen some distance.www.indiandentalacademy.com

The causes of lack of tongue space are:
1. Posterior teeth set inside the ridge.
2. Molar teeth which are too broad buccolingually. Such
teeth should be replaced by smaller ones or their
width reduced by grinding the lingual aspect (if the
teeth are porcelain take care not to damage the
retentive diatoric hole; if they are acrylic they should
be polished before being finally set).

3. Molar teeth leaning inwards. This will not
always cause cramping of the tongue, but should
never be allowed to occur as it interferes with
the free vertical movements of the tongue.
4. Setting the upper teeth over the ridge almost
invariably leads to the occluding lower teeth
lying too far lingually.

Height of the occlusal plane
• To obtain maximum stability of a lower denture, the
occlusal plane of the lower teeth should be very slightly
below the bulk of the tongue, so that the tongue performs
the majority of its movements above the denture and thus
tends to keep the denture down .
• The denture must therefore be examined to see if the
tongue, when relaxed, lies above or below the occlusal
plane.

• Ask the patient to relax and place the tip of the tongue
comfortably and without strain behind the lower front teeth,
which is the normal relaxed position of the tongue, and then
open his mouth without moving his tongue. If the height of
the occlusal plane is correct, the tongue will be seen to lie
on top of the lingual cusps.
• If the lower denture still tends to rise unduly after the
lingual periphery has been checked, and as much lateral
space as possible for the tongue has been allowed, it may be
necessary to reset the teeth completely, lowering the
occlusal plane. This may be especially necessary in those
patients who have a low tongue position

• The height of the occlusal plane is also of importance for
the following reason: the greater the height of the lower
denture, the longer will be the lower front teeth and the
greater the surface exposed to the unfavourable pressure of
the lower lip. This concludes the examination of the lower
denture alone, and it should be removed from the mouth
and placed in a bowl of cold water.
• This concludes the examination of the lower denture
alone, and it should be removed from the mouth and
placed in a bowl of cold water.

Trying the upper denture by itself
Place the upper denture in the mouth and examine in the
following manner.
Peripheral outline
1.The buccal and labial periphery is checked as for the
lower denture.
2. The position of the posterior border is verified to check
that the posterior edge is situated on the soft palate and
that the postdam area on the cast has been placed correctlywww.indiandentalacademy.com

Stability
Stability under occlusal load may be carried out as for the
lower denture, but is intended to check the closeness of
adaptation of the base against the mucosa and the future
support of the denture in those cases where the mucosa is
unevenly displaceable.

Retention
Retention is checked by seating the denture with a finger on
the vault of the palate and then attempting to remove the
denture at right angles to the occlusal plane. Load is then
applied upwards and outwards in one canine region to check
the retentive force in the contralateral corner of the denture,
i.e. in the region of the tuberosity vestibular space and
pterygomaxillary notch. Then check the other side in the
same way.

Both dentures together
Remove the upper denture from the mouth, replace on its
cast to confirm the fit, and chill in cold water for a few
seconds. Then place both dentures in the mouth. If it is
found necessary to improve the retention of the dentures
when using a shellac type of base-plate, adhesive powder
may be sprinkled on their fitting surfaces.

Position of occlusion
Horizontal relation
• Hold the lower denture in position on the ridge
and ask the patient to relax, then to 'close on your
back teeth' gently and maintain them in occlusion
while the examination is carried out.
• If the registration is accurate, the teeth will
interdigitate in the mouth in exactly the same
manner as they do on the articulator, but if the
registration is wrong, the teeth will not
interdigitate correctly and may even occlude cusp
to cusp on one or both sides.

• The clinician must make quite certain that the occlusion he
sees in the mouth is not due to movement of the dentures on
the ridges, tilting of either denture or dropping of the upper
denture.
• This is best tested by asking the patient to keep the teeth
together and then trying to separate the posterior teeth by
means of a thin spatula or Le Cron blade.
• This test should be carried out on each side of the mouth
alternately. The teeth should be brought into occlusion
several times, using any of the registration aids, in order to
make certain that the position of occlusion is correct or, ifit
is incorrect, to ascertain the type of error.

• i.e. whether the mandible can be retruded from the
previously recorded jaw relationship, whether a lateral
deviation has occurred, or whether there is a premature
contact on one side before the other.
• Observation of the upper and lower centre lines in relation
to each other, with the dentures on the articulator and then
in the mouth, will indicate a lateral deviation, if present.

• When the lower centre line is seen to be to one side of
the upper centre line, with the dentures in the mouth, in
contrast to the coincidence of these lines when viewed on
the articulator, it is possible that the original registration
was incorrect and that a lateral position has been
recorded; this may be checked by the occlusion of the
posterior teeth.
• If the original position was incorrect, the lower cusps
will be slightly farther back on one side indicating a
greater retrusion of the condyle on that side. Should the
lower cusps be slightly forward on one side, it indicates
that the original recording of the occlusion was correct
and the patient is now giving a lateral positionwww.indiandentalacademy.com

Major errors in the position of occlusion are easily detected,
but minor errors may pass un-noticed; therefore it is
extremely important to watch for any slight movement of
the dentures on their respective ridges from the time the
teeth first make contact until they reach the position of
complete interdigitation

• the reason being that the cusp inclines of the teeth guide
the dentures into occlusion and will move the dentures in
relation to the ridges when only a slight error of jaw
relationship exists from that which was obtained when
taking the records. Care is needed when holding the lower
denture in place on the ridge to avoid pushing it
backwards.
• When errors of occlusion are noted at this trial stage they
must be corrected by re-recording the position of
occlusion as follows

• The dentures are seated on the casts on the articulator
and the posterior teeth removed from one of the dentures
and replaced by wax which should be trimmed to
occlude with the posterior teeth of the other denture
without altering the vertical dimension as set on the
articulator.
• In this way considerable time may be saved in trimming
the blocks in the mouth, as then only minor adjustments
are necessary to produce even-ness of occlusal contact.

• The position of occlusion is recorded by adding a little
softened base-plate wax to the chilled blocks, placing the
dentures in the mouth and asking the patient 'to close on
the back teeth, thus impressing the cusps of the opposing
teeth into the wax without effecting any alteration in the
vertical height.
• Care must be taken to see that the new position of
occlusion gives the necessary correction. Points which
may help in this are observations of overlap, overjet, and
the relation of the centre lines.

• When correcting a lateral deviation care must be
taken to see that the lower anterior teeth do not impinge
on the upper teeth, as this may cause the mandible to be
guided into another incorrect position, or the dentures to
tilt.
• If any contact of the anterior teeth occurs the
offending lower teeth should be removed and the
position retaken.

• The advantage of removing posterior teeth from the
upper trial denture is that in the re-recording the softened
wax on the occlusal surface of the blocks is not interfered
with by the operator's index fingers which are being used
to control the lower denture.
• The disadvantage is that the orientation of the occlusal
plane, as determined by the upper posterior teeth, is
temporarily lost.

• Removal of lower posterior teeth, on the other hand,
means that the softened wax replacing the teeth is
almost bound to be displaced or disturbed by the
controlling index fingers.
• It is better, therefore, to remove the upper teeth rather
than the lower when rectifying an occlusal error

Check the vertical height
• Ask the patient to relax with the lips closed. Watch the
point of the chin and then ask the patient to close the teeth
together; the chin should move upwards a small but
definite amount.
• If it is impossible to obtain this movement in spite of
repeated attempts, it can be assumed that the vertical
height is too great and, if this is excessive, there will also
be a strained appearance when the lips are brought into
contact with each other.

• It should be remembered that patients who are mouth
breathers relax with their lips parted, and frequently have
a large freeway space.
• An over-closed vertical height will be associated with a
large freeway space, and when the teeth are in occlusion
the lips will be seen to be pressed too firmly together
with some loss of the vermilion border.
• In order to correct the vertical height the posterior teeth
are removed from one of the dentures and replaced by
wax blocks.

• The articulator should be closed or opened
approximately the amount assessed to establish a suitable
freeway space, and the blocks then trimmed to occlude with
the opposing teeth at the new vertical height.
• Final adjustments for evenness of occlusal contact, and
for the production of the correct freeway space, are carried
out in the mouth.
• Once these are satisfactory, the record blocks should be
chilled in cold water, and a little registration paste added to
their occlusal surfaces to record the impressions of the
opposing teeth when registering the retruded contact
position.

Evenness of occlusal contact
• Provided the horizontal and vertical relationships are
correct, the evenness of the occlusion is next checked
• As the teeth close, they should occlude evenly and with
equally distributed pressure all round.
• It frequently occurs that the teeth on one side of the
mouth occlude slightly before those on the other, or the
molars before the premolars.

This may be due to:
1. Pressure on the blocks being heavier on one side than the
other when the records were taken.
2. A slight error when sealing the casts and blocks together
or when mounting them on the articulator.
3. Warpage of the base-plates.

• To test for evenness of occlusal pressure, place two
pieces of thin mylar tape between the teeth in the molar
region, one on each side.
• Request the patient to close and then endeavour to
remove the tapes simultaneously, holding one with each
hand, by pulling them out between the closed teeth.
• Any difference in the force required to remove the
strips will be readily appreciated, and if this force is
interpreted in terms of occlusal pressure, an assessment
may be made of whether or not it is even.
• Repeat the test in the premolar regions.

Remember at all times to
hold the dentures in
place with the index
fingers until final contact

Appearance
• This aspect of the trial stage is a matter more for
individual judgement, and sometimes the patient's ideas,
than for set rules. However, certain factors need to be
checked as routine
Centre line.
Stand in front of the patient, some distance away. A
wrong centre line will be obvious. Minor errors may
be corrected by adjusting the maxillary anterior
teeth at the chairside but if the error is more than 1
mm the whole case may have to be reset

Anterior plane
• This may be observed
from the same position
and any tendency for this
plane to slope markedly
up or down should be
noted and corrected

• It is important to ask the patient to smile and if one
side of the face rises more than the other it is good
practice to set the anterior plane to run slightly up towards
the elevated side.
• This has the effect of making the smile less crooked
and harmonizes the lip-tooth relationship.
• Thought should also be given to the smile curve, i.e.
the incisal edges of the maxillary incisors lying parallel to
the smiling lower lip, as in most faces this produces a
pleasing appearance.

Profile and lip form
• Observe the patient's profile and note if the lips are either
excessively distended or unduly sunken
• In the first case, remove some wax from the labial
flange and try the dentures again.
• If this produces insufficient improvement, examine
the denture to see if the teeth should be set farther in, or if
smaller teeth can be used.
• If the lips are sunken and inverted consider the need
to set the anterior teeth further forward.

Amount of tooth visible.
• Note how much tooth shows.
• In this connection remember that a smiling person
usually only shows the upper teeth.
• If much of the lower incisors are visible, or only these
teeth show, examine the amount of overlap and, if
excessive, reduce it by altering the lower teeth.
• If this does not effect an improvement, the position of
the occlusal plane may require to be altered
• Usually 1 to 2 mm of upper teeth should be visible at
phonation.

phonetics
• tooth positions are sometimes critical for sound
production
• An analysis of these sounds may be an indirect guide to
correct placement of teeth.
• Clinical experience suggests that s and t can cause most
problems in a prosthodontic context.
• The s sound and its relationship to the vertical dimension
has been advocated to be used in denture construction,
both for correct tooth positioning and for correct
physiological VDO determination.

• If the there is too little space, the VDO is too large and
speech distortions will occur.
• Sounds such as s, sh , and th may be affected negatively.
• During the pronunciation of the s sound, the interincisal
seperation should average 1 to 1.5 mm.
• Vertical length of anterior teeth
during production of s

• Horizontal relation of anterior
teeth during production of s

• Other sounds like f and v are also used as guides.
• Are made between the upper incisors and the
labiolingual centre to the posterior third of
lower lip.
• If the upper anterior teeth are too short
( set too high up),the v sound will be more
like an f
• If they are too long( set too far down), the f
Will sound more like a v

Freeway space
The teeth do not contact in the premolar region when the
patient enunciates the sound m and s
Usually 2 to 4 mm of space should be present in the
premolar region.
This also provides an indirect view of the correct
positioning of the teeth.

Approval of appearance by the patient
• It is always wise for the dentist to obtain the patient's
approval of the appearance of the trial dentures before
they are returned to the laboratory for finishing, as this
allows for any mild adjustments.
• Some patients are quite prepared to leave the question of
appearance to the dentist,while others are extremely fussy
over the smallest detail.
• When dealing with the former, the dentist should still
insist that they consider the matter of their appearance,
otherwise when the dentures are finished the patient may
react unfavourably.

• In the case of the fussy patient, much time and trouble
must be spent on getting the shade, shape and setting of
the teeth just as the patient wishes, but it is very
important to obtain final approval before finishing the
dentures.
• In this connection the dentist often needs to use his
restraining influence to avoid extremely bad errors of
aesthetics and much waste of time.

Anterior try in
• Sometimes only the anterior teeth may be arranged and
the patient called for an anterior try in.
• This helps in knowing the exact relationship of the teeth
to the surrounding musculature, phonetics and also
esthetics.
• Patients views may also be obtained regarding the
esthetical value and accordingly adjustments may be
made.
• Phonetics is also used as a guide to know the correct
placement of teeth at the anterior try in stage.
• Later the patient is recalled for a posterior try in when the
posteriors have been arranged in accordance with the
anterior try in done earlier.www.indiandentalacademy.com

• It should be remembered that other people will see more
of a patient's dentures than the patient will, and if the
dentures are not aesthetically pleasing in the opinion of
his relations and friends he will usually become
dissatisfied.
• It is, therefore, advisable to ask the patient to bring a
relation or candid friend with him at the trial denture stage
and the approval or criticism of this second individual
should be sought as well as that of the patient himself.

Thank you
For more details please visit

Teeth arranging for complete denture /continued dental education

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