**Complete Dentures**
**Preclinical**
**Posterior Tooth**
**Arrangement &**
**Trial Insertion**
**Complete Denture Overview**
**Treatment Schedule**
| Visit | Operator | Procedure |
| :------- | :----------- | :------------------------------------------------------ |
| Visit 1 | Clinician | Patient evaluation & primary impressions |
| | Laboratory | Diagnostic casts & special trays |
| Visit 2 | Clinician | Secondary impressions |
| | Laboratory | Bead & box, master casts, base & rims |
| Visit 3 | Clinician | Contour rims, OVD, MMR, shade & mould selection |
| | Laboratory | **Articulation & tooth setting** |
| Visit 4 | Clinician | **Wax try-in** |
| | Laboratory | Finalisation & processing |
| Visit 5 | Clinician | Assessment & issue |
| | | Instructions for care |
| Visit 6 | Clinician | Post operative review, post insertion instructions |
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
Classification
* Bilateral Balanced
* Lingualised
* Canine Guidance
* Group Function
* Monoplane
THE UNIVERSITY OF
WESTERN
AUSTRALIA
Oral Health Centre
of Western Australia
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
* **Bilateral Balanced**
* **Lingualised**
* **Canine Guidance**
* **Group Function**
* **Monoplane**
R L
the bilateral, simultaneous posterior occlusal contact of teeth
in maximal intercuspal position and eccentric positions;
# <span style="color: #6699CC;">Posterior Tooth Arrangement</span>
# <span style="color: #FF9900;">Complete Denture Occlusal Schemes</span>
* **Bilateral Balanced**
* **Lingualised**
* **Canine Guidance**
* **Group Function**
* **Monoplane**
**Factors Affecting Balanced Occlusion**
* Incisal Guide Angle
* Condylar Guidance
* Compensating curves (antero-posterior & transverse)
* Orientation of occlusal plane
* Cuspal Inclination
<p align="left">
Incisal guide angle<br>
<img src="https://i.imgur.com/example-incisal-guide-angle.png" alt="Incisal Guide Angle Diagram" width="300"/><br>
Posterior tooth contact in intercuspal position
</p>
<p align="center">
Compensating Curve<br>
Condylar guidance<br>
<img src="https://i.imgur.com/example-compensating-curve.png" alt="Compensating Curve Diagram" width="300"/><br>
Both anterior & posterior teeth in contact
</p>
<p align="right">
Curve of Wilson<br>
<img src="https://i.imgur.com/example-curve-of-wilson.png" alt="Curve of Wilson Diagram" width="300"/><br>
Contact on both working & balancing sides during lateral excursions
</p>
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
- **Bilateral Balanced**
- **Lingualised**
- **Canine Guidance**
- **Group Function**
- **Monoplane**
**ANTERO-POSTERIOR BALANCE**
**THE UNIVERSITY OF**
**WESTERN**
**AUSTRALIA**
**Oral Health Centre**
**of Western Australia**
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
* **Bilateral Balanced**
* **Lingualised**
this form of denture occlusion articulates the maxillary lingual
cusps with the mandibular occlusal surfaces in centric occlusion,
working and nonworking mandibular positions;
Balancing side
Working side
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
* Bilateral Balanced
* Lingualised
* **Canine Guidance**
* Group Function
* Monoplane
a form of mutually protected articulation in which the vertical and horizontal overlap of the canine teeth disclude the posterior teeth in the excursive movements of the mandible
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
* Bilateral Balanced
* Lingualised
* Canine Guidance
* Group Function
* Monoplane
** Working contacts**
multiple contact relations between the maxillary and mandibular
teeth in lateral movements on the working-side whereby
simultaneous contact of several teeth acts as a group to distribute
occlusal forces
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
* Bilateral Balanced
* Lingualised
* Canine Guidance
* Group Function
* **Monoplane**
THE UNIVERSITY OF
WESTERN
AUSTRALIA
Oral Health Centre
of Western Australia
an occlusal arrangement wherein the posterior teeth have
masticatory surfaces that lack any cuspal height
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
**Significance of the Occlusal Plane**
**ORIENTATION OF OCCLUSAL**
**PLANE**
**The occlusal plane is defined as imaginary plane**
**established by the incisal and occlusal surfaces of the**
**teeth".**
**Interpupillary Line**
**Camper's Line**
**Occlusal Plane**
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
Significance of the Occlusal Plane
* The orientation of the occlusal plane is important as slight variations will lead to occlusal instability
* It should be in harmony with the other components of the masticatory system
* It forms the basis by which occlusal surfaces of teeth can be related to one another and to other structures of the head
* The height of the occlusal plane of the lower teeth should be at the level of the resting tongue
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
Completing Curves
The compensating curves are artificial curves introduced into the complete
denture occlusion. They are so-called because they compensate for the space
(Christensen’s Phenomenon) formed between the posterior occlusal surfaces
during eccentric (translatory) mandibular movements.
**Posterior Tooth Arrangement**
**Complete Denture Occlusal Schemes**
Factors Affecting Compensating Curves
1. Condylar Guidance
A steep condylar path needs a steep compensating curve for occlusal balance.
2. Incisal Guidance
3. Occlusal Plane
4. Cuspal inclination
A steep incisal guidance requires posterior teeth with high (steep) cuspal inclines, a steep occlusal plane and a steep compensating curve in order to attain occlusal balance.
Ideally the incisal guidance should be kept as low as aesthetics and phonetics permit.
<p style="text-align: left;"><span style="color: #4a6c8e;"><b>Posterior Tooth Arrangement</b></span></p>
<p style="text-align: left;"><span style="color: #e59d28;"><b>Complete Denture Occlusal Schemes</b></span></p>
<p style="text-align: left;">Consensus Statement</p>
<ul>
<li style="text-align: left;">There is strong support that the average denture patient, with good residual ridges</li>
</ul>
<p style="text-align: left;">and no neuromuscular problems, will function adequately with a properly fabricated</p>
<p style="text-align: left;">complete denture <mark style="background-color: yellow;">regardless</mark> of the occlusal scheme.</p>
<ul>
<li style="text-align: left;">There is neither strong support for or against bilateral occlusal schemes as it relates to</li>
</ul>
<p style="text-align: left;">patient satisfaction, preference or chewing ability.</p>
<ul>
<li style="text-align: left;">There is some support for increased alveolar bone loss with complete dentures that</li>
</ul>
<p style="text-align: left;">have a non-balanced occlusion.</p>
<ul>
<li style="text-align: left;">There is a <mark style="background-color: yellow;">need</mark> for bilateral balanced schemes for patients presenting with loss of</li>
</ul>
<p style="text-align: left;">stability and retention as a result of their presenting conditions (<mark style="background-color: yellow;">PDI III and IV</mark>)</p>
<div style="text-align: left;">[for additional information on PDI see "Complete Denture Screening" in week 32 LMS]<br /><br /></div>
<p style="text-align: right;">Goldstein et al, J Prosthodont. 2021 Apr,30(S1): 72-77</p>
**Posterior Tooth Selection**
**Anteriorly**
Aesthetics is the most important factor
**Posteriorly**
Function is the most important factor
**Posterior Tooth Arrangement**
**Factors Affecting Tooth Selection**
Alveolar Ridge Anatomy
**THE UNIVERSITY OF**
**WESTERN**
**AUSTRALIA**
Oral Health Centre
of Western Australia
**EFFICIENCY OF POSTERIOR TOOTH FORMS**
**Cusped occlusal surface**
**Flat occlusal surface**
**More efficient**
**Less efficient**
# Posterior Tooth Arrangement
## Factors Affecting Tooth Selection
**Occluso-gingival length**
available inter-ridge space
**Mesiodistal width**
governed by length and slope of mandibular ridge
**Shade**
same as for the anterior teeth
**Form of the occlusal surface** (cuspal inclination)
Anatomical (30°, **33**°, 40°)
Semi-anatomical (**10**°, 20°, 22°)
Non-anatomical (**0**°)
**Material**
acrylic resin
composite resin
porcelain
From distal of canine to anterior of retromolar pad
**<font color="#996600">Posterior Tooth Arrangement</font>**
**<font color="#FF9900">Factors Affecting Tooth Selection</font>**
**<font color="#000000">Tooth Availability</font>**
**<font color="#000000">IPN 10° Posteriors</font>**
330 Portrait - Bioform
*U = 7.70*
*L = 8.25*
*X = 30.00*
*Y = 32.00*
332 Portrait - Bioform
*U = 8.50*
*L = 9.25*
*X = 32.00*
*Y = 34.50*
334 Portrait - Bioform
*U = 9.10*
*L = 9.40*
*X = 34.00*
*Y = 36.50*
336 Portrait
*U = 9.50*
*L = 10.50*
*X = 36.00*
*Y = 38.50*
**<font color="#000000">IPN 33° Posteriors</font>**
30M Portrait - Bioform
*U = 8.10*
*L = 8.50*
*X = 30.00*
*Y = 32.50*
30L Portrait - Bioform
*Bioform U = 8.00*
*Portrait U = 7.90*
*Bioform L = 9.25*
*Portrait L = 8.25*
*Bioform X = 30.00*
*Portrait X = 30.00*
*Bioform Y = 33.00 Portrait Y = 32.50*
32M Portrait - Bioform
*U = 8.50*
*L = 9.00*
*X = 32.00*
*Y = 34.50*
32L Portrait - Bioform
*U = 8.50*
*L = 8.75*
*X = 32.00*
*Y = 35.00*
34M Portrait - Bioform
*U = 9.10*
*L = 9.50*
*X = 34.00*
*Y = 36.50*
34L Portrait - Bioform
*Bioform U = 9.00*
*Portrait U = 8.90*
*Bioform L = 9.75*
*Portrait L = 9.30*
*Bioform X = 34.00 Portrait X = 34.00*
*Bioform Y = 36.50 Portrait Y = 36.75*
THE UNIVERSITY OF
**<font color="#336699">WESTERN</font>**
**<font color="#336699">AUSTRALIA</font>**
Oral Health Centre
of Western Australia
THE UNIVERSITY OF
WESTERN
AUSTRALIA
Oral Health Centre
of Western Australia
**Tooth Positioning**
Posterior Tooth Arrangement
**Tooth Positioning**
Neutral Zone
TRANSVERSE SECTION
DENTURE SPACE
THE UNIVERSITY OF
WESTERN
AUSTRALIA
Oral Health Centre
of Western Australia
UPPER AND LOWER DENTURES
IN NEUTRAL ZONE
Posterior Tooth Arrangement
**Tooth Positioning**
Maxillary Posteriors
Place Mesio-lingual Cusp of First Molar
on Plane.
Articulation Should Permit Straight Edge to
Align Buccal Surfaces of the Cuspids and
Bicuspids and of the Two Molars.
Molars Curve Lingual
Distal View of Posterior Teeth As They Appear
With Relation to the Occlusal Plane.
**Posterior Tooth Arrangement**
**Tooth Positioning**
Maxillary Posteriors
THE UNIVERSITY OF
WESTERN
AUSTRALIA
Oral Health Centre
of Western Australia
**Posterior Tooth Arrangement**
**Tooth Positioning**
Maxillary Posteriors
**THE UNIVERSITY OF**
**WESTERN**
**AUSTRALIA**
**Oral Health Centre**
**of Western Australia**
**Posterior Tooth Arrangement**
**Tooth Positioning**
Completed Tooth Arrangement
**Posterior Tooth Arrangement**
**Tooth Positioning**
Completed Tooth Arrangement
THE UNIVERSITY OF
WESTERN
AUSTRALIA
Oral Health Centre
of Western Australia
**Complete Denture Overview**
**Treatment Schedule**
<br>
| Visit | Operator | Procedure |
|---|---|---|
| Visit 1 | Clinician | Patient evaluation & primary impressions |
| | Laboratory | Diagnostic casts & special trays |
| Visit 2 | Clinician | Secondary impressions |
| | Laboratory | Bead & box, master casts, base & rims |
| Visit 3 | Clinician | Contour rims, OVD, MMR, shade & mould selection |
| | Laboratory | Articulation & tooth setting |
| Visit 4 | Clinician | **Wax try-in** |
| | Laboratory | Finalisation & processing |
| Visit 5 | Clinician | Assessment & issue <br> Instructions for care |
| Visit 6 | Clinician | Post operative review, post insertion instructions |
**Trial Insertion**
**Clinical Check**
- **Occlusion**
- Lip support
- Midline and facial midline
- Occlusal plane
- Buccal corridor
- Teeth
✓ Shade
✓ Shape
✓ Embrasure
✓ Position
✓ Inclination
- Teeth display (smiling and rest position)
- Extension posterior
- Phonetics
- Occlusal vertical dimension
interocclusal clearance = **2 – 5 mm**
- Maximum intercuspation
should occur on posterior path of closure
- Centric and eccentric interferences
- Overjet - horizontal overlap
- Overbite - vertical overlap
**Trial Insertion**
**Clinical Check**
* **Occlusion**
* Lip support
* Midline and facial midline
* Occlusal plane
* Buccal corridor
* Teeth
✓ Shade
✓ Shape
✓ Embrasure
✓ Position
✓ Inclination
* Teeth display (smiling and rest position)
* Extension posterior
* Phonetics
* Occlusal vertical dimension
interocclusal clearance = 2 – 5 mm
* **Maximum intercuspation**
**should occur on posterior path of closure**
* Centric and eccentric interferences
* Overjet - horizontal overlap
* Overbite - vertical overlap
**Trial Insertion**
**Clinical Check**
- **Occlusion**
- Lip support
- Midline and facial midline
- Occlusal plane
- Buccal corridor
- Teeth
✓ Shade
✓ Shape
✓ Embrasure
✓ Position
✓ Inclination
- Occlusal vertical dimension
interocclusal clearance = 2 – 5 mm
- Maximum intercuspation
should occur on posterior path of closure
- **Centric and eccentric interferences**
- Overjet - horizontal overlap
- Overbite - vertical overlap
working
balancing
protrusive
**Trial Insertion**
**Clinical Check**
- **Occlusion**
- Lip support
- Midline and facial midline
- Occlusal plane
- Buccal corridor
- Teeth
✓ Shade
✓ Shape
✓ Embrasure
✓ Position
✓ Inclination
- Teeth display (smiling and rest position)
- Extension posterior
- Phonetics
- Occlusal vertical dimension
interocclusal clearance = 2 – 5 mm
- Maximum intercuspation
should occur on posterior path of closure
- Centric and eccentric interferences
- **Overjet - horizontal overlap**
- **Overbite - vertical overlap**
**Incisal Guidance:**
Inversely related to
denture stability
**Trial Insertion**
**Clinical Check**
- Occlusion
- **Lip support**
- Midline and facial midline
- Occlusal plane
- Buccal corridor
- Teeth
✓ Shade
✓ Shape
✓ Embrasure
✓ Position
✓ Inclination
- Teeth display (smiling and rest position)
- Extension posterior
- Phonetics
Relationship of upper lip to nasal columella
Relationship of lower lip to chin
**Anteroposterior lip position**
- Esthetic line (E-line).⁹ Joins the nasal tip to soft tissue pogonion. The upper lip should be 4 mm and the lower lip 2 mm behind this line in adults. This is very dependent on nasal and chin projection.
- Steiner line (S-line).¹⁰ Joins soft tissue pogonion to the midpoint between subnasale and nasal tip. The lips should touch this line.
- Harmony line (H-line).¹¹ A line from soft tissue pogonion touching the upper lip should bisect the nose.
- Profile line (of Merrifield).¹² A tangent to the chin and vermilion border of both lips should ideally bisect the nose.
- Nasolabial angle is formed between the nasal columella and the upper lip slope. Average value: 85–120°. Depends on anteroposterior position of maxillary incisors and anterior maxilla, the morphology of the upper lip, as well as the vertical position of the nasal tip.
- Labiomental angle is formed between the lower lip and chin, and depends on the lower incisor inclination and anterior lower face height. Average value: 110–130°.
- Excessively proclined lower incisor teeth, a prominent chin and a reduced lower anterior facial height may lead to an acute labiomental angle.
**Trial Insertion**
**Clinical Check**
- Occlusion
- Lip support
- **Midline and facial midline**
- **Occlusal plane**
- **Buccal corridor**
- Teeth
✓ Shade
✓ Shape
✓ Embrasure
✓ Position
✓ Inclination
- Teeth display (smiling and rest position)
- Extension posterior
- Phonetics
**Trial Insertion**
**Clinical Check**
- Occlusion
- Lip support
- Midline and facial midline
- Occlusal plane
- Buccal corridor
- Teeth
✓ **Shade**
✓ **Shape**
✓ **Embrasure**
✓ **Position**
✓ **Inclination**
- Teeth display (smiling and rest position)
- Extension posterior
- Phonetics
**Trial Insertion**
**Clinical Check**
* Occlusion
* Lip support
* Midline and facial midline
* Occlusal plane
* Buccal corridor
* Teeth
✓ Shade
✓ Shape
✓ Embrasure
✓ Position
✓ Inclination
* **Teeth display (smiling and rest position)**
* Extension posterior
* Phonetics
**With patient**:
▪ Assess aesthetics
▪ Seek patient input
▪ Gain patient acceptance
THE UNIVERSITY OF
**WESTERN**
**AUSTRALIA**
Oral Health Centre
of Western Australia
rest
posed
spontaneous
Trial Insertion
**Clinical Check**
* Occlusion
* Lip support
* Midline and facial midline
* Occlusal plane
* Buccal corridor
* Teeth
✓Shade
✓Shape
✓Embrasure
✓Position
✓Inclination
* Teeth display (smiling and rest position)
* **Extension posteriorly**
* Phonetics
**Correct extension**
**Under-extended**
**Trial Insertion**
**Clinical Check**
- Occlusion
- Lip support
- Midline and facial midline
- Occlusal plane
- Buccal corridor
- Teeth
✓ Shade
✓ Shape
✓ Embrasure
✓ Position
✓ Inclination
- Teeth display (smiling and rest position)
- Extension posterior
- **Phonetics**
To produce the sounds **f, v and ph**:
- the lower lip is brought into contact with the incisal edges of the upper anterior teeth
- these labiodental sounds serve as an excellent test for determining the proper plane of occlusion and placement of the anterior teeth
To produce the sounds of **s, z and c**:
- the tip of the tongue is in slight contact with the hard palate's most anterior portion
- the lateral margins of the tongue are in minimal contact with the lingual surfaces of the posterior teeth
- the mandible is in a protruded position
- a narrow slit like channel is formed between the tongue and palate
- shape variations of the channel will affect clarity of speech
**Trial Insertion**
**Clinical Check**
- Occlusion
- Lip support
- Midline and facial midline
- Occlusal plane
- Buccal corridor
- Teeth
✓Shade
✓Shape
✓Embrasure
✓Position
✓Inclination
- Teeth display (smiling and rest position)
- Extension posterior
- **Phonetics**
**THE UNIVERSITY OF**
**WESTERN**
**AUSTRALIA**
Oral Health Centre
of Western Australia
Sue is missing one piece. (s sound)
Zelma is busy. (z sound)
"s" & "z"
Tongue contacts the
palatal mucosa and
teeth except for a nar-
row central area of the
anterior palate
She is washing the dish. (sh sound)
Measure the garage. (zh sound)
"sh" & "zh"
Tongue contacts the
palate and posterior
teeth but does not con-
tact the central area of
the anterior palate
Lee will allow it. (l sound)
"l"
Tongue tip contacts
anterior palate
Tom wanted a bite. (t sound)
Did Eddy lead. (d sound)
"t" & "d"
Tongue contacts
the palate and
teeth all around
the arch followed
by anterior
release with sus-
tained posterior
contact
Chuck is watching Butch. (ch sound)
Jane enjoyed the fudge. (j sound)
"ch" & "j"
Tongue contacts
the palate and
teeth all around
the arch followed
by anterior release
with sustained
posterior contact
Ned won many prizes. (n sound)
"n"
Tongue main-
tains continuous
contact with the
palate and teeth all
around the arch
Ralph arrived after everyone else.
(r sound)
"r"
Tongue contacts
the posterior palatal
mucosa and teeth but
does not contact the
anterior palate
Young men like yellow kayaks.
(y as in yellow)
"y"
Tongue contacts the
palate and posterior
teeth but does not
contact the central
area of the anterior
palate
King Gregory was gagging.
(k, g, and ng sounds)
"k", "g", "ng"
Tongue contacts the poste-
rior hard palate, soft palate,
and most posterior teeth fol-
lowed by release in the center
of the soft palate
**Thank
You**
Any questions? Contact me
Dr Ian Lander
**ian.lander@uwa.edu.au**
