This document discusses occlusion and its study. It begins by defining occlusion and centric relation. It describes studying occlusion by examining dental arch formation, compensatory curves, tooth angulations, functional tooth form, and tooth relationships in centric occlusion. Key points include the first permanent molars acting as the "key of occlusion," compensatory curves guiding mandibular movement, and Angle's classification of malocclusions. Studying occlusion is important for treating malocclusions and TMJ issues as well as constructing dental restorations.
3. Def.Def.
Contact relationship of the upper and
lower teeth during various activities of
the mandible (mastication, swallowing
and speech) .
4. •The relation of the upper and lower teeth
when they are in maximum intercuspation
during swallowing and the terminal position of
the masticatory stroke.
5.
6. •Is a position of the
mandibule in which the
condyles are resting in
the most retrusive
unstrained position in
the glenoid fossa and
related anteriorly to the
distal slope of the articular
eminence.
7. Why we study the occlusion?
The study of occlusion helps in the treatment
of malocclusion,
Temporomandibular Joint problems,
in proper construction of dentures and other
dental restorations (e.g., crown and bridge,
etc…).
8. To study the occlusion it must be include the following
items:
1. Dental arch formation.
2. Compensatory curves of dental arches.
3. Compensatory curves of individual teeth.
4. Angulations of individual teeth in relation to various planes.
5. Functional form of the teeth at their incisal and occlusal thirds.
6. Facial relation of each tooth in one arch to its antagonist in centric
occlusion.
7. Occlusal contact and intercuspation of all teeth of one arch with
those in the opposing arch in centric occlusion.
8. Occlusal contact and interaction of all teeth during various functional
movements.
1. Dental arch formation.
2. Compensatory curves of dental arches.
3. Compensatory curves of individual teeth.
4. Angulations of individual teeth in relation to various planes.
5. Functional form of the teeth at their incisal and occlusal thirds.
6. Facial relation of each tooth in one arch to its antagonist in centric
occlusion.
7. Occlusal contact and intercuspation of all teeth of one arch with
those in the opposing arch in centric occlusion.
8. Occlusal contact and interaction of all teeth during various functional
movements.
9. 1. Dental arch formation:
Outline of the maxillary arch is larger
than mandibular arch
• So, maxillary teeth overhang the
mandibular teeth when the teeth are in
centric occlusion
•Permits overbite and overjet relation
ship
10. OverbiteOverbite: vertical relation of the upper
teeth to the lower teeth in centric
occlusion .
(increase efficiency of ant. teeth in biting
Over jetOver jet: horizontal relation of the
upper teeth to the lower teeth in centric
occlusion .
(increase duration of occlusal contact in
protrusive and lateral movements in incision
and mastication )
Importance:Importance:
•Prevent soft tissue biting
•Guide the mandible through
various lateral movement
11. Overbite enables the disclusion of the
posterior teeth during food incision and
increases the efficiency of the anterior teeth
in biting well.
Overjet increases duration of occlusal
contact in protrusive and lateral
movements in incising and mastication.
12. From occlusal aspect the outline following
labial and lingual surfaces confirmed to a
parabolic curves.parabolic curves.
• the dental arches have three segments:the dental arches have three segments:
1.1.Anterior segmentAnterior segment : semicircularsemicircular line
passing along facial surfaces of anterior teeth.
2.2.Middle segmentMiddle segment : straightstraight line
continuous with semicircular segment , include
1st
, 2nd
, M half of 1st
molar.
3.3.Posterior segmentPosterior segment : straightstraight line which
is parallel to the median plane e including
distobuccal half of 1st
molar, B of 2nd
and
3rd
molars.
13. Phases in development of dental arches :
11stst
phasephase:: 6
•6 years
• 1st
permanent molar take place post. to 2nd
deciduous molar
•Due to jaw growth Lead to :
• 1- increase chewing efficiency
2- Serve to back up the deciduous teeth
Mandibular one erupt firstly and max. one to
established occlusion
•1st
permanent molar corner stonecorner stone
2nd phase:2nd phase: 1,2
•Central and lateral lingual to the deciduous
predecessors.
14. 3rd phase:3rd phase: 4,5
•1st
and 2nd
premolar take place of
deciduous molar.
•Primate space the size of premolars
are smaller than the larger teeth they replace.
(Leeway space)
4th phase: 3,7
The canines (Keystones) and 2nd
molars
emerge. The forcing of the canine bet.
Incisors & 1st
premolars in both jaw with
backing effect of 2nd
molar
5th phase:5th phase: 8
•3rd
molar distal to the 2nd
molar.
15. Leeway spaceLeeway space
• The erupting premolars are smaller in mesiodistal
dimension than the primary molars.
• The difference in sizes between the premolars and
primary molars as well as the deciduous canines called
“Leeway space’.
16. The average mesiodistal size of the deciduous
molars in that area is 47mm, which when
compared with the premolars dimension of
42.2 mm, indicates an average gain of 4.8 mm
in available space.
The leeway space must be utilized for
alignment of the lower incisors as these teeth
erupt with an average of 1.6 mm of crowding.
The remainder of the space will be utilized by
the mandibular molar.
17. This movement of the mandibular molars
may correct an end-to-end molar
relationship (normal for the mixed
dentition) into a normal molar relationship
in the permanent dentition, i.e., the
mesiolingual cusp of the maxillary first molar
occludes in the central fossa of the
mandibular molar. This relationship is
discussed later on.
18. 2- Compensatory Curvatures of the dental
arches (Curved Occlusal Planes):
The significant of these curve as guidance
for mandible Movement to
complement the condyle paths and
for balance of mandible
19. •Curve of Spee
• Sagittal planes.
• Incisal Ridges of the anterior teeth and the B cusps of the
posterior teeth follow a curve which end at the anterior surface of
the condyle.
• when the arches were observed from a point opposite 6.
20. Curve of Wilson
• Coronal plane.
• The occlusal surfaces of posterior teeth conform to a curved plane.
• The crowns of mandibular posterior teeth must incline to the lingual
while the crowns of maxillary posterior teeth must incline toward the
buccal.
• Deeper posteriorly molars inclination is greater than
that of the premolar .
21. Curve of Monson
• Combination of curve of Spee and the curve of Wilson.
• coronal and sagittal planes.
• concave for the mandibular arch and convex for the maxillary
arch.
• in centric occlusion form a segment of a sphere of 4 inches
radius with the center of the sphere at the glabella
22. Bonwill TriangleBonwill Triangle
• Describe the mandible and found
that the mandibular dental arch
adapts itself to an equilateral
triangle of 4 inches length.
• Apex at the mesial
contact area of the lower central
incisors
• Angles of the base
at the centers of each condyle
24. 3- Compensating curvatures of individual teeth :
long axis of post. Teeth are not
To a horizontal plane but show axial
curvature
importance :
1- stability of teeth to resist force
of mastication .
7, 8 distally inclined to
prevent any distal drift of the posterior teeth.
7,8 mesially inclined to
strike the maxillary molar
25. 3. Compensating curvatures of3. Compensating curvatures of
the individual teeth:the individual teeth:
When we observed theWhen we observed the
dissected human jawdissected human jaw
with their rootswith their roots
exposed prove thatexposed prove that
the long axis ofthe long axis of
posterior teeth areposterior teeth are
not perpendicular tonot perpendicular to
a horizontal planea horizontal plane
but show axialbut show axial
curvature. Thiscurvature. This
curvature iscurvature is
essential for stabilityessential for stability
of teeth in the dentalof teeth in the dental
arches to resistarches to resist
forces offorces of
26. The maxillary 2The maxillary 2ndnd
&3&3rdrd
molars havemolars have
distal inclinationdistal inclination
to prevent anyto prevent any
distal drift ofdistal drift of
posterior teethposterior teeth
while mandibularwhile mandibular
22ndnd
& 3& 3rdrd
molarmolar areare
inclined mesiallyinclined mesially
to strike theto strike the
maxillary molarsmaxillary molars
with a mesialwith a mesial
direction of forcedirection of force
27. 4- Angulations of individual teeth4- Angulations of individual teeth
in relation to various planesin relation to various planes
The inclination ofThe inclination of
a tooth from aa tooth from a
vertical axis invertical axis in
mesiodistal andmesiodistal and
faciolingualfaciolingual
directionsdirections
1- upper anterior:1- upper anterior:
FL inclinedFL inclined
linguallingual
MD 1&2 inclinedMD 1&2 inclined
slightly mesialslightly mesial
but caninebut canine
toward distaltoward distal
28. DefDef . Inclination of the tooth from a vertical axis in a MD
and FL direction.
(Considered root inclination so the crown inclined in
opposite direction ).
importance:importance: Proper occlusal function ( each tooth must be
placed at the angle that best withstand forces during function )
29. 2-Maxillary premolars
are slight lingual in
FL, Distal in MD
3-Maxillary Molars
roots have lingual
inclination with distal
inclination
30. 4-Mandibular4-Mandibular
anterior haveanterior have
greet lingualgreet lingual
root inclinationroot inclination
in FL. In MDin FL. In MD
incisors areincisors are
nearly straightnearly straight
or minor rootor minor root
inclinationinclination
while caninewhile canine
has distal roothas distal root
inclinationinclination
31. 5- Mandibular5- Mandibular
premolars In MDpremolars In MD
have distalhave distal
inclination but ininclination but in
FL 1FL 1stst
premolarpremolar
incline lingually.incline lingually.
But 2But 2ndnd
premolarspremolars
is offset buccallyis offset buccally
6-Mandibular molars6-Mandibular molars
moderate to greatmoderate to great
buccal and distalbuccal and distal
toot angulationstoot angulations
36. MD angulations
All teeth have
distally root
inclination except
the upper
incisors teeth
have slight
mesially root
inclination and
the lower
incisors have
slight mesial or
straight .
37. 5. Functional form of the teeth at their5. Functional form of the teeth at their
incisal and occlusal thirdsincisal and occlusal thirds
There are no flat planes on the incisal or occlusalThere are no flat planes on the incisal or occlusal
surface of any of the teeth unless they aresurface of any of the teeth unless they are
created by wear or accident.created by wear or accident.
The cusps and incisal ridges acts as cutting bladesThe cusps and incisal ridges acts as cutting blades
when they are come to contact in centricwhen they are come to contact in centric
occlusion, the concave surface opposing theocclusion, the concave surface opposing the
ridges in circumscribed points or areas andridges in circumscribed points or areas and
spaces appear all around this point which act asspaces appear all around this point which act as
spillways or escapement spacespillways or escapement space
So, this escapement space is provided in teeth bySo, this escapement space is provided in teeth by
the form of cusps, ridges, DG, ISthe form of cusps, ridges, DG, IS
38. • Provided in teeth by cusps, ridges, DG , interdental spaces .
• its location and form differ when occlousal relation is changed.
• less space in centric occlusion and large space in lateral
relation .
39. The location and form the escapement areThe location and form the escapement are
changed when the occlusal relation ischanged when the occlusal relation is
changeschanges
In centric occlusion with less escapementIn centric occlusion with less escapement
space available but in lateral relation thespace available but in lateral relation the
escapement is increased but the numberescapement is increased but the number
of contact point is decreasedof contact point is decreased
40. 6&7. The relation of each tooth in6&7. The relation of each tooth in
one arch to its antagonist in theone arch to its antagonist in the
opposing arch in centric occlusionopposing arch in centric occlusion
Centric occlusion It is
relation of the upper
and lower teeth when
they are intercuspated
together and the
condyle are in resting
in most retrusive
position in the glenoid
fossa.
41.
42. 11stst
permanent maxillary molar followed bypermanent maxillary molar followed by
mandibular one are a key of occlusion why??mandibular one are a key of occlusion why??
-1-1stst
tooth permanent erupted in oral cavitytooth permanent erupted in oral cavity
-Largest in dental arch-Largest in dental arch
-Guided by its position the deciduous teeth-Guided by its position the deciduous teeth
-Have no predecessors-Have no predecessors
-Maxillary one more accurate than mandibular-Maxillary one more accurate than mandibular
because it attached to fixed in base of skullbecause it attached to fixed in base of skull
-In normal jaw relations and when teeth are of-In normal jaw relations and when teeth are of
normal size and in the correct position, thenormal size and in the correct position, the
mesiobuccal cusp of the maxillary first molarmesiobuccal cusp of the maxillary first molar
occludes in the mesiobuccal groove of theoccludes in the mesiobuccal groove of the
mandibular first molar. This normalmandibular first molar. This normal
relationship of these two teeth is called therelationship of these two teeth is called the
key of occlusionkey of occlusion ..
44. ANGLES CLASSIFICATION.Angle was a dentistANGLES CLASSIFICATION.Angle was a dentist
who developed a classification of normal andwho developed a classification of normal and
abnormal ways teeth meet into centric occlusion.abnormal ways teeth meet into centric occlusion.
Angle came up with threeAngle came up with three
classes, Class I, II and IIIclasses, Class I, II and III
1-Class I patient's profile is1-Class I patient's profile is
characterized as normal.characterized as normal.
2-Class II patient's profile is2-Class II patient's profile is
deficient in chin length anddeficient in chin length and
characterized as a retrudedcharacterized as a retruded
(retrognathic) profile.(retrognathic) profile.
3-Class III patient's profile is3-Class III patient's profile is
excessive in chin length andexcessive in chin length and
characterized as protrudedcharacterized as protruded
(prognathic) profile.(prognathic) profile.
46. The centric relation of the teeth inThe centric relation of the teeth in
centric occlusion :centric occlusion :Permanent toothPermanent tooth
The median plane isThe median plane is
coincident in two jawscoincident in two jaws
Upper tooth has labialUpper tooth has labial
relation to lower incisor inrelation to lower incisor in
centriccentric
- Incisal ridges is free of- Incisal ridges is free of
contact and has labial relationcontact and has labial relation
to labioincisal portion of lowerto labioincisal portion of lower
central incisorcentral incisor
- Cingulum above the lingual- Cingulum above the lingual
embrasure of 1&2 lowerembrasure of 1&2 lower
incisorincisor
- Mesial outline is in line with- Mesial outline is in line with
the mesial outline of lowerthe mesial outline of lower
laterral incisorlaterral incisor
The distal outline is centeredThe distal outline is centered
47. 6- Facial and lingual Relations of Each Tooth in6- Facial and lingual Relations of Each Tooth in
One Arch to Its Antagonist in the Opposing Arch inOne Arch to Its Antagonist in the Opposing Arch in
Centric Occlusion.Centric Occlusion.
•In centric occlusion, each tooth occludes
with two teeth in the opposing arch,
except the mandibular central incisors and
the maxillary third molars.
•Importance:Importance:
1.Prevent the over eruption of the teeth of
the opposing arch.
2.prevent the mesial migration of the
teeth in the same arch.
3.Distribute occlusal forces to several
teeth.
mesial
migration
48.
49. Tooth Alignment and OcclusionTooth Alignment and Occlusion
Normal Interarch RelationshipsNormal Interarch Relationships
The mandibular first molar is positionedThe mandibular first molar is positioned
mesial to the maxillary first molarmesial to the maxillary first molar
Interarch relationship of
opposing teeth Modified after
Okeson Fig. 3-21
Contact Relationships-Contact Relationships- OcclusalOcclusal
contacts of posterior teethcontacts of posterior teeth
The mesiobuccal cusp of theThe mesiobuccal cusp of the
mandibular first molar occludes in themandibular first molar occludes in the
embrasure between the maxillaryembrasure between the maxillary
second premolar and the first molarsecond premolar and the first molar
The mesiobuccal cusp of the maxillaryThe mesiobuccal cusp of the maxillary
first molar is opposite the mesiobuccalfirst molar is opposite the mesiobuccal
(buccal) groove of the mandibular first(buccal) groove of the mandibular first
molarmolar
The mesiolingual cusp of the maxillaryThe mesiolingual cusp of the maxillary
first molar occludes in the central fossafirst molar occludes in the central fossa
of the mandibular first molarof the mandibular first molar
50. Tooth Alignment and OcclusionTooth Alignment and Occlusion
Normal Interarch RelationshipsNormal Interarch Relationships
Normal buccolingual
relationship of the molars
Modified after Okeson Fig. 3-
12
Normal buccolingual relationshipNormal buccolingual relationship
allows forallows for
efficient use of musculature in chewingefficient use of musculature in chewing
Minimizing trauma from cheek or tongue-Minimizing trauma from cheek or tongue-
bitingbiting
Functional cuspsFunctional cusps
buccal cusps of Mandibularbuccal cusps of Mandibular
posterior teethposterior teeth
lingual cusps of Maxillarylingual cusps of Maxillary
posterior teethposterior teeth
Centric cuspsCentric cusps
Centric holding cuspsCentric holding cusps
Stamp cuspsStamp cusps
Maintain vertical dimension or distanceMaintain vertical dimension or distance
between the maxilla and mandiblebetween the maxilla and mandible
51. Tooth Alignment and OcclusionTooth Alignment and Occlusion
Normal Interarch RelationshipsNormal Interarch Relationships
Normal contacts in a Class I
occlusion Modified after
Okeson Fig. 3-23
Contact Relationships-Contact Relationships- MesiodistalMesiodistal
• Occlusal contacts result from functioningOcclusal contacts result from functioning
cusps contacting the opposing CF linecusps contacting the opposing CF line
• Contacts will occur inContacts will occur in
• Central fossaeCentral fossae
• Comparable to a mortar and pestleComparable to a mortar and pestle (臼(臼
杵)杵)
• Two dissimilar shaped surfaces meetTwo dissimilar shaped surfaces meet
result in a spillway being produced andresult in a spillway being produced and
masticatory efficiencymasticatory efficiency
SUMMARY STATEMENTSSUMMARY STATEMENTS
• Mesiolingual cusp of eachMesiolingual cusp of each
maxillary molar occludes in themaxillary molar occludes in the
central fossa of the opposingcentral fossa of the opposing
mandibular molarmandibular molar
• Mesiobuccal cusp of eachMesiobuccal cusp of each
mandibular molar occludes on themandibular molar occludes on the
mesial marginal ridge of themesial marginal ridge of the
52. Tooth Alignment and OcclusionTooth Alignment and Occlusion
Normal Interarch RelationshipsNormal Interarch Relationships
Normal contacts in a Class I occlusion Modified
after Okeson Fig. 3-23
Contact Relationships-Contact Relationships- MesiodistalMesiodistal
• Occlusal contacts result from centricOcclusal contacts result from centric
cusps contacting the opposing CF linecusps contacting the opposing CF line
• Contacts will occur inContacts will occur in
• Central fossaeCentral fossae
• Comparable to a mortar and pestleComparable to a mortar and pestle
• Two dissimilar shaped surfaces meetTwo dissimilar shaped surfaces meet
result in a spillway being producedresult in a spillway being produced
and masticatory efficiencyand masticatory efficiency
• Marginal ridges andMarginal ridges and
embrasuresembrasures
• Cusp tip is very convexCusp tip is very convex
• Marginal ridge is slightly convex (flatMarginal ridge is slightly convex (flat
by comparison)by comparison)
• Actual contact is not cusp tip butActual contact is not cusp tip but
0.5mm area around it0.5mm area around it
53. Facial relation of the upper and lowerFacial relation of the upper and lower
teeth in centric occlusionteeth in centric occlusion
54. lingual relation of the upper and lowerlingual relation of the upper and lower
teeth in centric occlusionteeth in centric occlusion
55. Facial relation of the upper and lowerFacial relation of the upper and lower
teeth in centric occlusionteeth in centric occlusion
56. lingual relation of the upper andlingual relation of the upper and
lower teeth in centric occlusionlower teeth in centric occlusion
57. Centric occlusion relation of theCentric occlusion relation of the
deciduous teethdeciduous teeth
At age 3 years, the
child has centric
occlusion similar
to permanent
teeth
58. Centric occlusion relation of the deciduous teeth:Centric occlusion relation of the deciduous teeth:
At age 3 years the child has centric
occlusion similar to permanent teeth
59. Tooth Alignment and OcclusionTooth Alignment and Occlusion
Contacts during Mandibular MovementsContacts during Mandibular Movements
Anterior guidance Okeson Fig. 3-30
Contact Relationships-Contact Relationships-
PROTRUSIONPROTRUSION
• Potential posterior contacts in aPotential posterior contacts in a
protrusive movement are theprotrusive movement are the
• mesial inclines of mandibularmesial inclines of mandibular
teeth (fossae and marginalteeth (fossae and marginal
ridges)ridges)
• distal inclines of the maxillarydistal inclines of the maxillary
teeth (lingual cusps)teeth (lingual cusps)
• These contacts are undesirable andThese contacts are undesirable and
are calledare called ProtrusiveProtrusive
interferencesinterferences
60. Tooth Alignment and OcclusionTooth Alignment and Occlusion
Contacts during Mandibular MovementsContacts during Mandibular Movements
Left laterotrusive movement (and right
mediotrusive movement) Okeson Fig. 3-31
Contact Relationships-Contact Relationships-
LATEROTRUSIVELATEROTRUSIVE
MANDIBULAR MOVEMENTMANDIBULAR MOVEMENT
• Desirable contacts in a leftDesirable contacts in a left
laterotrusive movement arelaterotrusive movement are
maxillary buccal cusps inmaxillary buccal cusps in
contact with mandibularcontact with mandibular
buccal cuspsbuccal cusps
Working
Side
Non-
working
Side
61. Tooth Alignment and OcclusionTooth Alignment and Occlusion
Contacts during Mandibular MovementsContacts during Mandibular Movements
Left laterotrusive movement (and right
mediotrusive movement) Okeson Fig. 3-31
Contact Relationships-Contact Relationships-
LATEROTRUSIVELATEROTRUSIVE
MANDIBULAR MOVEMENTMANDIBULAR MOVEMENT
• Other contacts that mayOther contacts that may
occur includeoccur include
• WORKING SIDEWORKING SIDE
(LATEROTRUSIVE)(LATEROTRUSIVE)
INTERFERENCESINTERFERENCES
• Outer inclines of maxillaryOuter inclines of maxillary
lingual cuspslingual cusps
• Inner inclines of mandibularInner inclines of mandibular
lingual cuspslingual cusps
• NON-WORKINGNON-WORKING
(MEDIOTRUSIVE)(MEDIOTRUSIVE)
INTERFERENCESINTERFERENCES
• Inner inclines of maxillaryInner inclines of maxillary
lingual cuspslingual cusps
• Inner inclines of mandibularInner inclines of mandibular
buccal cuspsbuccal cusps
Working
Side
Non-
working
Side
62. 8-The Occlusal Contact and Intercusp8-The Occlusal Contact and Intercusp
Relations of all the Teeth During the VariousRelations of all the Teeth During the Various
Functional mandibular movements.Functional mandibular movements.
Mandibular movements are: (rotating movement )
A.Symmetrical bilateral movements:A.Symmetrical bilateral movements:
•Depression.
•Elevation.
•Protrusion.
•Retrusion.
B.Asymmetrical bilateral movements:B.Asymmetrical bilateral movements:
•Right lateral movements.
•Left lateral movements.
63.
64. 8-the Occlusal Contact And Intercusp Relation8-the Occlusal Contact And Intercusp Relation
Of All Teeth During The Various FunctionalOf All Teeth During The Various Functional
Mandibular MovemMandibular Movem6464entent
The mandibular movement are:The mandibular movement are:
A) Symmetrical bilateral movement:A) Symmetrical bilateral movement:
-Depression-Depression
-Elevation-Elevation
-Protrusion-Protrusion
-Retrusion-Retrusion
B) Asymmetrical bilateral movement:B) Asymmetrical bilateral movement:
-Right lateral movement-Right lateral movement
-Left lateral movement-Left lateral movement
65. Rest position of the mandible :Rest position of the mandible :
•When the mandible is at rest lower teeth are not
in contact with the upper teeth as there is a space
of 2 mm in-between the two arches freeway
space .
•Not a functional relation.
functional relations offunctional relations of
mandibular movements:mandibular movements:
1.Protrusive occlusal relation.
2.Retrusive occlusal relation.
3.Right occlusal relation.
4.Left occlusal relation
66. •The mandibular arch
bears a forward,
anterioranterior relation to its
centric relationcentric relation with the
maxillary arch.
•Biting or shearing food
material
1)1) Protrusive occlusal relation:Protrusive occlusal relation:
67. •Retrusion of the mandible,
•the mandibular teeth will
have posteriorposterior relation to
centric occlusioncentric occlusion with the
maxillary arch.
•Very limited and non
functional movement.
2)Retrusive occlusal relation:2)Retrusive occlusal relation:
68. •The mandibular dental arch is placed in a right orright or
leftleft lateral relation to centric occlusioncentric occlusion with the
maxillary arch.
3) Right and left lateral occlusal relation:3) Right and left lateral occlusal relation:
69.
70. The masticatory cycle of posteriorThe masticatory cycle of posterior
teeth:teeth:
•The working side shows the buccal cusps
of maxillary and mandibular teeth to be in
contact.
•The balancing side shows contact of
lingual cusps of the maxillary teeth with
the buccal cusps of mandibular teeth.
•Then both sides move to centric occlusion.
72. The masticatory cycle of anterior teeth:The masticatory cycle of anterior teeth:
• In bitting
• the functioning side is located at the
anterior teeth
• the balancing side at the posterior teeth.
73. When the two jaw are not in occlusion, thereWhen the two jaw are not in occlusion, there
is a space of 2mm (freeway space)is a space of 2mm (freeway space)
inbetween the two arches called Restinbetween the two arches called Rest
positionposition
1- Protrusive occlusal relation:1- Protrusive occlusal relation:
Mandible arch bear a forward relation to itsMandible arch bear a forward relation to its
centric relation with maxillary arch. (bitingcentric relation with maxillary arch. (biting
or sheering food material)or sheering food material)
2-Retrusive occlusal relation:2-Retrusive occlusal relation:
Mandible will have posterior relation toMandible will have posterior relation to
centric occlusion with upper arch. (limitedcentric occlusion with upper arch. (limited
and non functional movement)and non functional movement)
74.
75. Right and left lateral movement: achieved byRight and left lateral movement: achieved by
lateral movement of mandible where is placed Rlateral movement of mandible where is placed R
or L to centric occlusionor L to centric occlusion
Musticatory cycle of posterior teeth: duringMusticatory cycle of posterior teeth: during
movement, the posterior teeth are not in contact.movement, the posterior teeth are not in contact.
SoSo the working sidethe working side shows buccal cusps of max.shows buccal cusps of max.
and mandibular to be in contactand mandibular to be in contact
InIn balanced sidebalanced side shows contact of lingual cusps ofshows contact of lingual cusps of
max. with buccal cusp of mandibular teeth thenmax. with buccal cusp of mandibular teeth then
come to centric occlusion. These movement iscome to centric occlusion. These movement is
calledcalled musticatory movementmusticatory movement