Evolution of posterior tooth forms / dental implant courses by Indian dental academy

EVOLUTION OF POSTERIOR TOOTH FORMSEVOLUTION OF POSTERIOR TOOTH FORMS
INDIAN DENTAL ACADEMYINDIAN DENTAL ACADEMY
Leader in continuing Dental EducationLeader in continuing Dental Education
www.indiandentalacademy.comwww.indiandentalacademy.com

IntroductionIntroduction
History of the development of posterior tooth form.History of the development of posterior tooth form.
Theories and concepts of occlusionTheories and concepts of occlusion
Occlusal schemes used in complete dentureOcclusal schemes used in complete denture
Anatomic and non anatomic teethAnatomic and non anatomic teeth
Selection and arrangement of posterior teethSelection and arrangement of posterior teeth
Monoplane arrangement of posterior teethMonoplane arrangement of posterior teeth
Posterior teeth arrangement of Class II patientsPosterior teeth arrangement of Class II patients
Posterior teeth arrangement of Class III patientsPosterior teeth arrangement of Class III patients
Review of literatureReview of literature
Summary & conclusionSummary & conclusion
ReferencesReferences

1 21 2
33
44
55

66 77
88

99
1010

1111
1212 NON ANATOMIC OR ONON ANATOMIC OR O00
CUSPLESSCUSPLESS
TEETHTEETH

1313
1414

1515
1616

1717
18 1918 19

Occlusal Materials for the denturesOcclusal Materials for the dentures
The materials available for occlusal posterior tooth forms areThe materials available for occlusal posterior tooth forms are
PorcelainPorcelain
Acrylic resinAcrylic resin
GoldGold
Acrylic resin with amalgam stopsAcrylic resin with amalgam stops
I P N(integrated polymer network)I P N(integrated polymer network)

.
There are several schools of thought on the choice of
occlusal forms of posterior teeth for the three
concepts of occlusion which is taken from Heartwell
are,
(1) The balanced occlusion concept,
(2) The neutrocentric concept
(3)The lingualised occlusion concept
Anatomical molds usually are selected for bilateral
balanced articulation; however, nonanatomical teeth
can be used in a balanced concept with the use of
compensating curves.www.indiandentalacademy.comwww.indiandentalacademy.com

Nonanatomical or cusp less teeth are generally the choice in the
nuetrocentric occlusion
lingualised concept utilises anatomic teeth for the maxillary and
monoplane or semianatomic teeth for the mandible

OCCLUSAL SCHEMES FOR COMPLETE DENTURE OCCLUSION
The occlusal scheme or the tooth molds selected for occlusal
rehabilitation will depend on the concept of occlusion that has been
selected to satisfy the needs of the patient.
The posterior teeth, arrangement according to the occlusal concept
selected, should fulfill the dentist's philosophy of occlusion as which
appear esthetically pleasing.
Prosthetic tooth anatomy seems to be more important to dentists than to the
patients who use the teeth.
In the absence of clear evidence of the benefits of one tooth anatomy
compared with others, dentists should use the least complicated procedures
and tooth forms that will satisfy their concepts of occlusion and articulation
of a mucosal supported dentition

The proponents of anatomic teeth seen dedicated to the precision ofThe proponents of anatomic teeth seen dedicated to the precision of
articulation and the infallibility of meticulous maxillomandibulararticulation and the infallibility of meticulous maxillomandibular
records.records.
Many claim it is not the cusps that are the problem but theMany claim it is not the cusps that are the problem but the
management of the cusps.management of the cusps.
The natural tooth forms with its cusp inclines usually functions inThe natural tooth forms with its cusp inclines usually functions in
harmony on the working side with its opposing tooth monitored byharmony on the working side with its opposing tooth monitored by
tooth contacts of incisal guidance, cuspid guidance and grouptooth contacts of incisal guidance, cuspid guidance and group
function of posteriors with proprioceptive information.function of posteriors with proprioceptive information.
Arificial posterior teeth are classified accordinglyArificial posterior teeth are classified accordingly
Anatomic teethAnatomic teeth Non anatomic teethNon anatomic teeth

Harold R Ortman 1971Harold R Ortman 1971 The role of occlusion in the preservation andThe role of occlusion in the preservation and
prevention in complete denture Prosthodonticsprevention in complete denture Prosthodontics
Becker et al 1977 Lingualised occlusion for removable prosthesisBecker et al 1977 Lingualised occlusion for removable prosthesis
Anatomic occlusionAnatomic occlusion
AdvantagesAdvantages
Penetrates food more easilyPenetrates food more easily
Resists the rotation of denture bases through cusp interdigitationResists the rotation of denture bases through cusp interdigitation
Provides better estheticsProvides better esthetics
Acts as a guide for proper jaw closureActs as a guide for proper jaw closure
DisadvantagesDisadvantages
More occlusal disharmony during settling and difficult to correct byMore occlusal disharmony during settling and difficult to correct by
adjustmentadjustment
Precise jaw closure and base stability required for interdigitationPrecise jaw closure and base stability required for interdigitation
Increased horizontal forcesIncreased horizontal forces
Difficult to adapt to abnormal jaw relationshipsDifficult to adapt to abnormal jaw relationships

Nonanatomic occlusionNonanatomic occlusion
AdvantagesAdvantages
Does not lock the mandible in one positionDoes not lock the mandible in one position
Permits the use of less time consuming techniques.Permits the use of less time consuming techniques.
Minimizes horizontal stress because of the absence of inclinedMinimizes horizontal stress because of the absence of inclined
planesplanes
Adapts easily to Classes II and III jaw relationsAdapts easily to Classes II and III jaw relations
More easily adjusted after changes in vertical and horizontalMore easily adjusted after changes in vertical and horizontal
relationsrelations
Easier to arrange in cross biteEasier to arrange in cross bite
DisadvantagesDisadvantages
Poor estheticsPoor esthetics
Decreased masticatory efficiencyDecreased masticatory efficiency
More difficult to obtained balanced occlusionMore difficult to obtained balanced occlusion
PsychologicalPsychological

Harold R. Ortman (1971) ….Harold R. Ortman (1971) ….
Evaluation of the occlusal formsEvaluation of the occlusal forms
Payne and Trapozzano and Lazzari ……Payne and Trapozzano and Lazzari ……
Kydd…..Kydd…..
Sauser and Yurkstas……..Sauser and Yurkstas……..
Brewer and co-workers……..Brewer and co-workers……..
Julian B. Woelfel, Chester M. Winter and Takayashi Igarashi
(1976) conducted a five year cephalometric study of mandibular ridge
resorption with different posterior occlusal forms. Three groups of
patients were selected,
one group of patient flat-cusped rational posterior teeth were used.
Second group, semianatomic 20° posterior teeth were set with a
buccolingual reverse curve.
Third group of patient given anatomic 33° posterior teeth….

Payne, discussed the selection of artificial posterior tooth forms.Payne, discussed the selection of artificial posterior tooth forms.
““The dentist must be versatile and capable of making intelligentThe dentist must be versatile and capable of making intelligent
compromises”.compromises”.
There are three basic schemes of posterior occlusionThere are three basic schemes of posterior occlusion
The sphericalThe spherical
The flatThe flat
The reverseThe reverse

Factors influencing function of anatomic and non-anatomic teethFactors influencing function of anatomic and non-anatomic teeth
Efficiency…Efficiency…
Directional forces…Directional forces…
Horizontal stress…Horizontal stress…
Stability..Stability..

Balanced occlusionBalanced occlusion
Is the stable simultaneous contact of the opposing upper and lowerIs the stable simultaneous contact of the opposing upper and lower
teeth in centric relation position and a continuous smooth bilateralteeth in centric relation position and a continuous smooth bilateral
gliding from this position to any eccentric position within the normalgliding from this position to any eccentric position within the normal
range of mandibular functionrange of mandibular function
Furthermore,this balance must be in harmony with theFurthermore,this balance must be in harmony with the
temporomandibular joints and with the neuromuscular activity.temporomandibular joints and with the neuromuscular activity.
Ellsworth Kelly 1977 Centric relation,centric occlusion and posteriorEllsworth Kelly 1977 Centric relation,centric occlusion and posterior
tooth forms and arrangementtooth forms and arrangement

Bilateral balance in cusped teeth depends on the hanau’s quint-Bilateral balance in cusped teeth depends on the hanau’s quint-
The condylar inclinationThe condylar inclination
The incisal guidanceThe incisal guidance
The compensatory curveThe compensatory curve
The cuspal inclinationThe cuspal inclination
The occlusal planeThe occlusal plane

BALANCE CAN BE ATTAINED IN NON ANATOMICAL TEETH ASBALANCE CAN BE ATTAINED IN NON ANATOMICAL TEETH AS
WELLWELL
Chastain et al 1955 The Cuspless Centralised Occlusal Pattern…Chastain et al 1955 The Cuspless Centralised Occlusal Pattern…
Balancing ramps or elements are provided by inclining the occlusalBalancing ramps or elements are provided by inclining the occlusal
plane and an flat incisal guidanceplane and an flat incisal guidance
This form of occlusion tends to magnify the stresses created, because theThis form of occlusion tends to magnify the stresses created, because the
forces delivered somewhat at right angles to the occlusal surface are offorces delivered somewhat at right angles to the occlusal surface are of
butting action.butting action.
The forces against the lower denture are not only exerted, such a directionThe forces against the lower denture are not only exerted, such a direction
as to tip it, but will drive it to one side against the poorly formed andas to tip it, but will drive it to one side against the poorly formed and
sensitive tissues of the mylohyoid ridge.sensitive tissues of the mylohyoid ridge.

Theories of occlusionTheories of occlusion
Spherical theory,…
Conical theory…
Bonvill triangle theory…

Spherical theory of occlusionSpherical theory of occlusion
Edgar et al 2002Edgar et al 2002 The history of articulators:A clinical history ofThe history of articulators:A clinical history of
articulators based on geometric theories of mandibular movementarticulators based on geometric theories of mandibular movement
This was given by Monson and the concept was derived from an ideaThis was given by Monson and the concept was derived from an idea
by Vonspee.by Vonspee.
Positioning of teeth with anterioposterior and medio-lateral inclines inPositioning of teeth with anterioposterior and medio-lateral inclines in
harmony with a spherical surface. Some times referred to as havingharmony with a spherical surface. Some times referred to as having
Monson curve.Monson curve.

The effect of Bonwills equilateral triangle theoryThe effect of Bonwills equilateral triangle theory
Finn Tenges Christensen (1959) The Effect Of Bonvill’s Triangle OnFinn Tenges Christensen (1959) The Effect Of Bonvill’s Triangle On
Complete DenturesComplete Dentures
The construction of average articulators is generally inThe construction of average articulators is generally in
accordance with Bonwill’s theory, and Monson’s pyramid isaccordance with Bonwill’s theory, and Monson’s pyramid is
based also on Bonwill’s triangle.based also on Bonwill’s triangle.
The sides are assumed to be 100mm in length. The height of theThe sides are assumed to be 100mm in length. The height of the
triangle is consequently equal to 100mm X sine 60 degrees.triangle is consequently equal to 100mm X sine 60 degrees.

Christensens phenomenonChristensens phenomenon
The supposition for the calculation of the christensen’s angle is aThe supposition for the calculation of the christensen’s angle is a
straight condylar path with a common inclination on each sidestraight condylar path with a common inclination on each side
The incisal point in protrution is assumed to be displaced into orThe incisal point in protrution is assumed to be displaced into or
parellel with the maxillary occlusal rim with flat occluding surfacesparellel with the maxillary occlusal rim with flat occluding surfaces
when there is no inclination of the incisal guidance and nowhen there is no inclination of the incisal guidance and no
compensating curve of occlusioncompensating curve of occlusion
The size of the christensens angle decreases if the height of theThe size of the christensens angle decreases if the height of the
bonvill’s triangle increasesbonvill’s triangle increases

Organic occlusionOrganic occlusion
It is that concept where in any jaw movement away from centricIt is that concept where in any jaw movement away from centric
occlusion will result in separation of all posterior teeth.occlusion will result in separation of all posterior teeth.
The ridge and groove directions of the posterior teeth areThe ridge and groove directions of the posterior teeth are
determined as result of the movements of the condyles. The cuspdetermined as result of the movements of the condyles. The cusp
height, fossa depth of posterior teeth and the proper concavity at theheight, fossa depth of posterior teeth and the proper concavity at the
lingual surfaces of the maxillary anterior teeth are determined as alingual surfaces of the maxillary anterior teeth are determined as a
result of mandibular movements.result of mandibular movements.
The aim of this occlusion is to relate the occlusal elements of teethThe aim of this occlusion is to relate the occlusal elements of teeth
so that the teeth will be in harmony with the muscles and joints inso that the teeth will be in harmony with the muscles and joints in
function.function.

In organic occlusion three phases of mutually interdependentIn organic occlusion three phases of mutually interdependent
protection are present.protection are present.
The posterior teeth should protect the anterior in the centricThe posterior teeth should protect the anterior in the centric
occlusal position.occlusal position.
The maxillary incisors should have vertical overlap sufficient toThe maxillary incisors should have vertical overlap sufficient to
provide separation of the posterior teeth when the incisors are inprovide separation of the posterior teeth when the incisors are in
edge to edge contact.edge to edge contact.
In lateral mandibular position outside the masticatoryIn lateral mandibular position outside the masticatory
movements, the cuspids should prevent contact of all othermovements, the cuspids should prevent contact of all other
teeth.teeth.

Lineal occlusionLineal occlusion
Donald G. Gronas (1974) Lineal Occlusal Concepts For CompleteDonald G. Gronas (1974) Lineal Occlusal Concepts For Complete
DenturesDentures
Straight line of points or knife-edge contacts on artificial teeth in oneStraight line of points or knife-edge contacts on artificial teeth in one
arch occluding with flat nonanatomic teeth in the opposing arch hasarch occluding with flat nonanatomic teeth in the opposing arch has
been suggested as a means of reducing unfavourable occlusalbeen suggested as a means of reducing unfavourable occlusal
forces and simplifying occlusal adjustment in complete denture.forces and simplifying occlusal adjustment in complete denture.

His literature has supported the use of linear (also known as
lineal) occlusion to enhance the stability of complete denture
prosthesis
Noninterceptive occlusion (linear occlusion) requires that there
should be no interference or interception with mandibular
movement in protrusive or lateral excursions.
Richard A. Williamson,DDS, 2004 Maximizing MandibularRichard A. Williamson,DDS, 2004 Maximizing Mandibular
Prosthesis Stability Utilizing Linear Occlusion, Occlusal PlaneProsthesis Stability Utilizing Linear Occlusion, Occlusal Plane
Selection, and Centric RecordingSelection, and Centric Recording

Combinations of occlusal forms used for lineal occlusionCombinations of occlusal forms used for lineal occlusion
Nonanatomic maxillary porcelain teeth opposing mandibularNonanatomic maxillary porcelain teeth opposing mandibular
porcelain lineal teeth. …porcelain lineal teeth. …
Nonanatomic maxillary plastic teeth (modified)opposingNonanatomic maxillary plastic teeth (modified)opposing
mandibular plastic lineal teeth (modified)….mandibular plastic lineal teeth (modified)….
Nonanatomic maxillary plastic teeth (modified)opposingNonanatomic maxillary plastic teeth (modified)opposing
mandibular porcelain lineal teeth….mandibular porcelain lineal teeth….
Anatomic maxillary porcelain teeth opposing nonanatomicAnatomic maxillary porcelain teeth opposing nonanatomic
mandibular plastic teeth…mandibular plastic teeth…

Tooth positioning for lineal occlusionTooth positioning for lineal occlusion
The mandibular incisors establish the anterior end of theThe mandibular incisors establish the anterior end of the
occlusal plane.occlusal plane.
The posterior landmark is usually the top one third of theThe posterior landmark is usually the top one third of the
retromolar pad.retromolar pad.
The occlusal plane should be kept as high posteriorly asThe occlusal plane should be kept as high posteriorly as
practical to aid in developing protrusive balancing contacts withpractical to aid in developing protrusive balancing contacts with
a flat plane of occlusion.a flat plane of occlusion.

Lingualized occlusionLingualized occlusion
Curtis M. Becker 1977 Lingualised Occlusion For RemovableCurtis M. Becker 1977 Lingualised Occlusion For Removable
ProsthodonticsProsthodontics
stated that occlusal forms can be classified into three major groups:stated that occlusal forms can be classified into three major groups:
Anatomic – 30 degree cuspsAnatomic – 30 degree cusps
Semianatomic – 20 degree cuspsSemianatomic – 20 degree cusps
Nonanatomic or cuspless – 0 degree cuspNonanatomic or cuspless – 0 degree cusp
The basic concepts of lingualized occlusion were first suggested byThe basic concepts of lingualized occlusion were first suggested by
Payne.Payne.
Pound discussed a similar occlusal concept and used the termPound discussed a similar occlusal concept and used the term
“lingualized occlusion“lingualized occlusion..

Indications for lingualized occlusionIndications for lingualized occlusion
Lingualized occlusion can be used in most denture combinations.Lingualized occlusion can be used in most denture combinations.
It is particularly helpful when the patient places high priority onIt is particularly helpful when the patient places high priority on
esthetics but nonanatomic occlusal scheme is indicated by oralesthetics but nonanatomic occlusal scheme is indicated by oral
conditions such as severe alveolar resorption, a Class II jawconditions such as severe alveolar resorption, a Class II jaw
relationship, or displaceable supporting tissue.relationship, or displaceable supporting tissue.
If the nonanatomic occlusal scheme is used, esthetics in theIf the nonanatomic occlusal scheme is used, esthetics in the
premolar region are compromised.premolar region are compromised.
With lingualized occlusion, the esthetic result is greatly improvedWith lingualized occlusion, the esthetic result is greatly improved
while still maintaining the advantages of a nonanatomic system.while still maintaining the advantages of a nonanatomic system.
Lingualized occlusion also can be used effectively when a completeLingualized occlusion also can be used effectively when a complete
denture opposes a removable partial denture.denture opposes a removable partial denture.

Principles of lingualized occlusionPrinciples of lingualized occlusion
Anatomic posterior (30 or 33°) teeth are used for the maxillaryAnatomic posterior (30 or 33°) teeth are used for the maxillary
denture. Tooth forms with prominent lingual cusps are helpful.denture. Tooth forms with prominent lingual cusps are helpful.
Nonanatomic or semianatomic teeth are used for the mandibularNonanatomic or semianatomic teeth are used for the mandibular
denture. Either a shallow or flat cusp form is used. A narrowdenture. Either a shallow or flat cusp form is used. A narrow
occlusal table is preferred wherever resorption of the residual ridgesocclusal table is preferred wherever resorption of the residual ridges
has occurred.has occurred.
Modification of the mandibular posterior teeth is accomplished byModification of the mandibular posterior teeth is accomplished by
selective grinding which is always necessary regardless of specificselective grinding which is always necessary regardless of specific
tooth or material.tooth or material.
Maxillary lingual cusps should contact mandibular teeth in centricMaxillary lingual cusps should contact mandibular teeth in centric
occlusion.occlusion.
Balancing and working contacts should occur only on the maxillaryBalancing and working contacts should occur only on the maxillary
lingual cusps.lingual cusps.
Protrusive balancing contacts should occur only between theProtrusive balancing contacts should occur only between the
maxillary lingual cusps and the lower teeth.maxillary lingual cusps and the lower teeth.

Advantages of lingualizedAdvantages of lingualized
occlusionocclusion
– Most of the advantages attributed to bothMost of the advantages attributed to both
the anatomic and nonanatomic forms arethe anatomic and nonanatomic forms are
retained.retained.
– Cusp form is more natural in appearanceCusp form is more natural in appearance
compared to nonanatomic tooth form.compared to nonanatomic tooth form.
– Good penetration of the food bolus isGood penetration of the food bolus is
possible.possible.
– Bilateral mechanical balanced occlusionBilateral mechanical balanced occlusion
is readily obtained for a region aroundis readily obtained for a region around
centric relation.centric relation.
– Vertical forces are centralized on theVertical forces are centralized on the
mandibular teeth.mandibular teeth.

Lingualized occlusion with cutter barsLingualized occlusion with cutter bars
– The use of posterior teeth with metal blades has been advocatedThe use of posterior teeth with metal blades has been advocated
by numerous authors.by numerous authors.
– The procedure usually recommended is to place the metalThe procedure usually recommended is to place the metal
bladed teeth on the maxillary denture and porcelainbladed teeth on the maxillary denture and porcelain
nonanatomic teeth on the mandibular denture.nonanatomic teeth on the mandibular denture.
– The principles of lingualized occlusion can be applied whenThe principles of lingualized occlusion can be applied when
maxillary anatomic teeth oppose that mandibular teeth withmaxillary anatomic teeth oppose that mandibular teeth with
metal blades.metal blades.

Arranging Anatomical Teeth
to a Balanced Articulation

Honorato Villa (1959)Honorato Villa (1959) described a technique for arrangingdescribed a technique for arranging
posterior teeth according to the elliptical principle.posterior teeth according to the elliptical principle.
A path tracer was designed which not only traces the paths that willA path tracer was designed which not only traces the paths that will
determine the exact position of each posterior tooth but also bringsdetermine the exact position of each posterior tooth but also brings
out the deficiencies in incorrectly designed posterior teeth.out the deficiencies in incorrectly designed posterior teeth.

.

2 Arranging nonanatomical mandibular
Posterior Teeth to Balanced Articulation
Anteroposterior and mediolateral compensating curves
permits the establishment of a balanced articulation. …
In such arrangements, the mandibular teeth usually are
arranged first followed by the maxillary teeth. ……..
The use of the several reference lines and guides
developed for the anatomical arrangement also are used with
the nonanatomical teeth…….
The major difference is in the positioning of the mandibular
posterior teeth to develop the compensating curves…..

3 Arranging Nonanatomical Teeth to Monoplane
Articulation
With this concept of occlusion, there is no attempt to
eliminate deflective occlusal contacts in lateral or protrusive
excursions.
However, some deflective occlusal contacts of the posterior
teeth will be experienced

Arranging Mandibular Posterior Teeth to Lingualized Articulation
.
Myerson Lingualized, Integration (MLI) molds represent an
occlusion scheme designed for this concept.
It has been suggested that these molds will provide maximum
intercuspation, an absence of deflective occlusion contacts,
adequate cusp height for selective occlusal reshaping, and a
natural and pleasing appearance
.
The MLI teeth are available in two posterior tooth molds: (1) controlled
contact (CC) and (2) maximum contact MC molds

Arranging the Maximum Contact Mold
In the arrangement of the MC mold, the maxillary teeth are
positioned with the incisal pin slightly open when the lingual cusps are in
contact with their mandibular antagonists.
The prominence of the maxillary lingual cusps will require some
occlusal reshaping of the central fossae and marginal ridges of the lower
teeth to establish maximum intercuspation.
After each maxillary tooth is positioned, a thin sheet of articulating
paper is interposed between the tooth and its mandibular antagonist.
The articulator is closed, marking the first contact point.
The contact point on the occlusal surface of the mandibular tooth is
enlarged by grinding with a round bur to permit the lingual cusp to obtain
positive seating with the lower tooth.
This process is continued until maximum interdigitation is achieved and
the incisal pin is in contact with the incisal table.

POSTERIOR TEETH ARRANGEMENT FOR CLASS II
RELATION SHIP

The lower ridge is small and markedly inside the upper ridge .
The anterior teeth exhibit a pronounced horizontal overlap
when they are arranged properly for esthetics .
The vertical overlap should be kept as small as esthetics and
phonetics will allow in order to establish an incisal guidance
as shallow as possible .
In most of these cases, the horizontal overlap is great enough
to accommodate for mastication without the anterior teeth
interfering during the function of mastication on the posterior
teeth.

The small arch of the lower ridge retruded to a position inside
the upper makes it impossible to obtain the correct upper and
lower canine relationship.
The lower canine is inside the upper arch of teeth and is
more distal in its relationship to the upper canine than in class
I .
This gives a tooth-on-tooth vertical relationship to the
posterior teeth that can be articulated to establish a stable
centric and eccentric occlusion after special grinding
procedures

Setting the Mandibular Posterior TeethSetting the Mandibular Posterior Teeth
The same criteria described for setting lower teeth are appliedThe same criteria described for setting lower teeth are applied
to this case.to this case.
The lower anteriors were set for lip support and the first premolarThe lower anteriors were set for lip support and the first premolar
follows the arch contour established by them so that the modiolus isfollows the arch contour established by them so that the modiolus is
supported.supported.
Any attempt to set the lower anterior or posterior teeth to anAny attempt to set the lower anterior or posterior teeth to an
exaggerated labial or buccal position in relation to the lower ridge isexaggerated labial or buccal position in relation to the lower ridge is
contraindicated because it will create an unfavorable lever action oncontraindicated because it will create an unfavorable lever action on
the lower denture base during functionthe lower denture base during function..

Either anatomic, modified anatomic, or nonanatomic teeth
can be used for these retrusive cases.
The selection of the occlusal form is based on the same factors
of ridge strength, form, and interridge space as for the normal
ridge relation.
Because the lower ridge in these patients is usually small
and weak in relation to the upper, the buccolingual inclines
are modified to a shallow angulation, or nonanatomic teeth
are selected.
After the lower premolars are initially set, the upper first
premolar is temporarily set to evaluate its position. It will have
a marked buccal overlap with the upper lingual cusp usually
opposing the lower buccal cusp.

Grinding Modifications for Upper Posterior Teeth
The upper anatomic or modified anatomic teeth are initially ground to
eliminate all mesiodistal interlocking transverse ridges and cusp heights.
The buccal cusps are shortened progressively from the premolars to the
molars
The maxillary premolars need additional special grinding on the
lingual cusp to create a flat stable platform for centric occlusal contact with
the lower premolars
Setting the Upper Posterior Teeth
Before the upper posterior teeth are set the incisal guide pin must be
checked for the proper occluding vertical dimension.
The condylar locks are opened so that eccentric excursions can be made
into right lateral, left lateral, and protrusive positions.
The incisal guidance should be set for most patients so that the anterior
teeth just clear during these excursions.

POSTERIOR ARRANGEMENT FOR CLASS III RELATIONSHIP
The usual approach to the arrangement of the anterior teeth for the
class III is to set the upper anteriors as far forward as esthetics requires for
the support of the upper lip and to set the lower anteriors as far lingual on
the ridge as possible without interfering with the tongue .
The patient treated with this basic approach looks less prognathic
and the anterior teeth, except for the very pronounced class III relationship,
can be set edge-to-edge .
This procedure creates no particular problem in establishing the
proper relationship between the upper and lower canines. It permits an
anatomically normal ,vertical interdigitated relationship for the posterior
teeth.

…
The crossing point of this occlusion depends on the buccolingual vertical
relationship of each case.
The crossing over of the upper posterior tooth occurs when a conventional
occlusal relationship would position the upper tooth too far to the buccal
In this errant position, the tooth would create unfavorable displacing
leverage on the upper base during function. It would also impinge on the
buccal mucosa, which would result in additional displacing forces acting
on the teeth and denture base.
Cheek biting is also common with teeth positioned too far to the buccal

Selection of Posterior Teeth
The same indications for the selection of the size and the
modification of the occlusal form for the conventional case hold for this
type of ridge relationship.
However, it is the upper ridge that is primarily considered since it is
always the smaller and usually the weaker ridge.
When the lower ridge is markedly resorbed a nonanatomic teeth is
indicated .
The buccolingual and mesiodistal relation of the upper and lower
posteriors is not as critical with this type of occlusion .

Grinding Modifications for Upper Posterior Teeth
Each upper posterior tooth is modified before it is set. The transverse
ridges are flattened to eliminate the mesiodistal interlocking potential of
the anatomic tooth.
Special additional individual tooth grinding is necessary as the teeth are
set. It depends on the tooth that initiates the crossing over of the occlusion.
When this occurs, the upper tooth is flattened both on buccal and
lingual cusps to establish a static centric occlusal contact with the lower
tooth .
The teeth in cross-bite relation need additional modification by
grinding on the upper buccal cusps. They must be rounded to occlude in
the modified central fossa of the lower.

Setting the Upper Posterior Teeth
• The upper first premolar can usually be set in conventional relationship to
the lower premolars. The upper lingual cusp is set in the common central
fossa of the modified lower premolars .
• It should be in a complimentary esthetic position in relation to the upper
canine and should establish a normal arch form.
• The second premolar usually requires special consideration because it
starts the crossover to the cross-bite occlusal relation.
• The upper buccal and lingual cusps are flattened. When it is properly set
in relation to the upper ridge, the articulator is closed to evaluate its
occluding position with the lower teeth.
• The lower teeth must now be flattened on the buccal and lingual cusp
inclines so that a stable occlusal contact is established when the articulator
is closed to the occluding vertical dimension .

The upper first and second molars are set in a cross-bite relation,
which puts the rounded upper buccal cusps in the lower central fossa.
This position of the upper molar teeth provides for a compatible arch form
of teeth in relation to the maxilla and provides a favorable leverage system
during function.
The crossing point can vary from case to case, depending on the
degree of prognathism and the residual ridge relationship. It may not be
bilaterally symmetric.
When the basic concepts of acceptable arch form, biomechanical
principles, and tooth modification are applied intelligently, any degree of
prognathism and aberrant ridge relation can be successfully managed either
with modified anatomic or nonanatomic teeth.

Arrangement of posterior teeth in abnormal jawArrangement of posterior teeth in abnormal jaw
relationsrelations
Various methods of correction may be employedVarious methods of correction may be employed

SUMMARY AND CONCLUSIONSUMMARY AND CONCLUSION
The nature of the supporting structures for complete dentues andThe nature of the supporting structures for complete dentues and
the forces directed to to them by the occlusion creates a specialthe forces directed to to them by the occlusion creates a special
biomechanical problembiomechanical problem
Biologic,physiologic,and mechanical principles need to beBiologic,physiologic,and mechanical principles need to be
considered and carefully coordinated in this new man madeconsidered and carefully coordinated in this new man made
occlusionocclusion
The first concern is the health and preservation of the supportingThe first concern is the health and preservation of the supporting
tissuestissues
Apply all the factors that favour the stability of the base and designApply all the factors that favour the stability of the base and design
the occlusion to function optimally in relation to the forces ofthe occlusion to function optimally in relation to the forces of
masticationmastication
If you elect to use cusped teeth because you believe in their merits,If you elect to use cusped teeth because you believe in their merits,
be prepared to apply the necessary geometric controlls of balancedbe prepared to apply the necessary geometric controlls of balanced
occlusion on an adjustable articulatorocclusion on an adjustable articulator
Non anatomic teeth do not need all these exacting jaw records andNon anatomic teeth do not need all these exacting jaw records and
instrumentation, but only a common starting point for all artificialinstrumentation, but only a common starting point for all artificial
occlusion-the position of centric relationocclusion-the position of centric relation

REFERENCESREFERENCES
Sheldon Winkler: Essential of complete denture
prosthodontics, 2nd
Edition.
Zarb Bolender: Prosthodontic treatment for edentulous
patients, 12th
edition.
John J. Sherry: Complete denture prosthodontics, 3rd
edition.
Rudd and Marrow: Dental laboratory procedures-complete
denture, Vol.1, 2nd
edition.
Brein R. Lang: Dental clinics of North America, July 2004.
Hamish Thomson: Occlusion, 2nd
edition.
Finn Tengs Christensen: Effect of Bonwill’s triangle on
complete dentures. JPD 9: 791; 1959.www.indiandentalacademy.comwww.indiandentalacademy.com

Harold OrtmanHarold Ortman : Role of occlusion in preservation and prevention in: Role of occlusion in preservation and prevention in
complete denture prosthodontics, JPD 1971.complete denture prosthodontics, JPD 1971.
Arthur R. RoraffArthur R. Roraff : Arranging artificial teeth according to anatomic: Arranging artificial teeth according to anatomic
landmarks, JPD 38: 120; 1977.landmarks, JPD 38: 120; 1977.
Donald G. GronesDonald G. Grones : Lineal occlusal concepts for complete dentures, JPD: Lineal occlusal concepts for complete dentures, JPD
32: 122; 1974.32: 122; 1974.
B.K. Goyal, K. BhargavaB.K. Goyal, K. Bhargava : Arrangement of artificial teeth in abnormal: Arrangement of artificial teeth in abnormal
jaw relation – Maxillary protrusion and wider upper arch, JPD 32: 107;jaw relation – Maxillary protrusion and wider upper arch, JPD 32: 107;
1974.1974.
Julian V. Walpel, Christer M WinterJulian V. Walpel, Christer M Winter : 5 years cephalometric study of: 5 years cephalometric study of
mandibular ridge resorption with different posterior occlusal forms, JPD,mandibular ridge resorption with different posterior occlusal forms, JPD,
36: 602; 1976.36: 602; 1976.
Honarato Villa A.:Honarato Villa A.: Technique for arranging posterior teeth, JPD 9: 803;Technique for arranging posterior teeth, JPD 9: 803;
1959.1959.
Honarato Villa A.:Honarato Villa A.: Adaptability of posterior teeth, JPD 9: 810; 1959.Adaptability of posterior teeth, JPD 9: 810; 1959.

Julian B. Woelfel, Judson C. Hickey:Julian B. Woelfel, Judson C. Hickey: Effect of posterior toothEffect of posterior tooth
form on jaw and denture movement. JPD 12: 922; 1962.form on jaw and denture movement. JPD 12: 922; 1962.
Ben L. Faber:Ben L. Faber: Comparison of an anatomic versus physiologicComparison of an anatomic versus physiologic
method of posterior tooth placement for complete dentures, JPD 67;method of posterior tooth placement for complete dentures, JPD 67;
410: 1992.410: 1992.
M.A. Pleasure:M.A. Pleasure: Anatomic versus nonanatomic teeth, JPD 3: 747;Anatomic versus nonanatomic teeth, JPD 3: 747;
1953.1953.
SS.Howard Payne:.Howard Payne: Selective occlusion, JPD 5: 301; 1955.Selective occlusion, JPD 5: 301; 1955.
Brien R. Lang:Brien R. Lang: A practical approach to restoring occlusion forA practical approach to restoring occlusion for
edentulous patients – Part I, guiding principles of tooth selection, JPDedentulous patients – Part I, guiding principles of tooth selection, JPD
50; 455: 1983.50; 455: 1983.
Curtis M. Becker:Curtis M. Becker: Lingualized occlusion for removableLingualized occlusion for removable
prosthodontics, JPD 38: 601; 1977.prosthodontics, JPD 38: 601; 1977.
Wilbur Ojenson:Wilbur Ojenson: Occlusion for the Class II jaw relation patient, JPDOcclusion for the Class II jaw relation patient, JPD
64; 432: 1990.64; 432: 1990.
Wilbur Ojenson:Wilbur Ojenson: Occlusion for the Class III jaw relation patient, JPDOcclusion for the Class III jaw relation patient, JPD
64; 566: 1990.64; 566: 1990.

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