Principle of Occlusion
Mohammed Alfarsi
BDS, MDSc(Pros), PhD
www.DrMohdAlfarsi.com
www.!"$%&*)(+.com
Tuesday 3 December 13
Principle of Occlusion
Overview
Tuesday 3 December 13
Principle of Occlusion
Overview
Mutually protected occlusion
Vs
Unilaterally/Bilaterally balanced occlusion
Vs
Lingualized occlusion
Point centric
Vs
Long centric Functional movements
Vs Vs
Freedom in centric Parafunctional movements
Centric relation
Vs
Habitual relation
Vs
Centric occlusion
Vs
Maximum intercuspation
Normal occlusion Bennet angle
Vs Vs
Pathologic occlusion Bennet movement
Tuesday 3 December 13
Principle of Occlusion
Introduction
Tuesday 3 December 13
Principle of Occlusion
Introduction
Occlusal
Principles of Occlusion Optimal
correction/
occlusion analysis occlusion
rehabilitation
Tuesday 3 December 13
Principle of Occlusion
Introduction
Occlusal
Principles of Occlusion Optimal
correction/
occlusion analysis occlusion
rehabilitation
Patient adaptation
People will adapt to deviation in
occlusion as long as they are within
their adaptation limits
Tuesday 3 December 13
Principle of Occlusion
Introduction
Occlusal
Principles of Occlusion Optimal
correction/
occlusion analysis occlusion
rehabilitation
Patient adaptation
People will adapt to deviation in
occlusion as long as they are within
their adaptation limits
Occlusion and Tempromandibular
joint dysfunction syndrome (TMD)
There are NO studies proved that the occlusion
could cause TMD
Tuesday 3 December 13
Principles
of occlusion
Maxillo-Mandibular Relationship
Tuesday 3 December 13
Principles
of occlusion
Maxillo-Mandibular Relationship
Tuesday 3 December 13
Principles
of occlusion
Maxillo-Mandibular Relationship
Max-Mand relation where; 1- condyles are in their
most superior/anterior unstrained position, 2- Mand
Centric Relation
is most retruded, 3- Mand can do hinge movement,
and 4- Mand can do lateral movements.
Tuesday 3 December 13
Principles
of occlusion
Maxillo-Mandibular Relationship
Max-Mand relation where; 1- condyles are in their
most superior/anterior unstrained position, 2- Mand
Centric Relation
is most retruded, 3- Mand can do hinge movement,
and 4- Mand can do lateral movements.
Tuesday 3 December 13
Principles
of occlusion
Maxillo-Mandibular Relationship
Max-Mand relation where; 1- condyles are in their
most superior/anterior unstrained position, 2- Mand
Centric Relation
is most retruded, 3- Mand can do hinge movement,
and 4- Mand can do lateral movements.
Tuesday 3 December 13
Principles
of occlusion
Maxillo-Mandibular Relationship
Max-Mand relation where; 1- condyles are in their
most superior/anterior unstrained position, 2- Mand
Centric Relation
is most retruded, 3- Mand can do hinge movement,
and 4- Mand can do lateral movements.
Teeth contact (not intercuspation) in CR.
Centric Occlusion
Rarely MI coincides with CR.
Tuesday 3 December 13
Principles
of occlusion
Maxillo-Mandibular Relationship
Max-Mand relation where; 1- condyles are in their
most superior/anterior unstrained position, 2- Mand
Centric Relation
is most retruded, 3- Mand can do hinge movement,
and 4- Mand can do lateral movements.
Teeth contact (not intercuspation) in CR.
Centric Occlusion
Rarely MI coincides with CR.
Max-Mand relation where the opposing teeth
Maximum
Intercuspation cusps are in maximum integrations. Regardless
the condyles position.
Tuesday 3 December 13
Principles
of occlusion
Maxillo-Mandibular Relationship
Max-Mand relation where; 1- condyles are in their
most superior/anterior unstrained position, 2- Mand
Centric Relation
is most retruded, 3- Mand can do hinge movement,
and 4- Mand can do lateral movements.
Teeth contact (not intercuspation) in CR.
Centric Occlusion
Rarely MI coincides with CR.
Max-Mand relation where the opposing teeth
Maximum
Intercuspation cusps are in maximum integrations. Regardless
the condyles position.
Max-Mand relation where the patient is used
Habitual Relation to occlude. Most often coincide with CR
(muscular-driven).
Tuesday 3 December 13
Principles
of occlusion
Mandibular Movement
Tuesday 3 December 13
Principles
of occlusion
Mandibular Movement
Laterotrusive (working side) Mediotrusive (nonworking side)
Bennet movement (mand. side shift) Bennet angle
Tuesday 3 December 13
Principles
of occlusion
Mandibular Movement
Tuesday 3 December 13
Principles
of occlusion
Mandibular Movement
Rotation (hinge) Translation
Tuesday 3 December 13
Principles
of occlusion
Mandibular Movement
Condylar angle
Rotation (hinge) Translation
Tuesday 3 December 13
Principles
of occlusion
Mandibular Movement
Tuesday 3 December 13
Principles
of occlusion
Mandibular Movement
Posselts 3D
envelope of
mandibular border
movement
1- Mandibular incisors track along the lingual concavity of the maxillary incisors.
2- Edge-to-edge position.
3- Incisors move superiorly until posterior tooth contact recurs.
4- Protrusive path.
5- Most protrusive mandibular position.
Tuesday 3 December 13
Principles
of occlusion
Anatomic Determinants of Mandibular Movement
Tuesday 3 December 13
Principles
of occlusion
Anatomic Determinants of Mandibular Movement
Anterior
determinants of
occlusion
Tuesday 3 December 13
Principles
of occlusion
Anatomic Determinants of Mandibular Movement
Anterior
determinants of
occlusion
Posterior
determinants of
occlusion
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Natural dentition Artificial dentition
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Natural dentition Artificial dentition
Mutually protected
occlusion (canine guided
Bilaterally balanced
occlusion)
occlusion
Unilaterally balanced
Lingualized occlusion
occlusion (group function
occlusion)
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Natural dentition
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Natural dentition
Mutually protected occlusion (canine guided occlusion)
- Uniform contact of all teeth around the arch when the mandibular condylar processes are in their
most superior position.
- Centric relation coincident with maximum intercuspation (intercuspal position).
- Stable posterior tooth contacts with vertically directed resultant forces.
- No contact of posterior teeth in lateral or protrusive movements. Lateral contact only between
canines & protrusive contacts only between anteriors.
- Anterior tooth contacts harmonizing with functional jaw movements.
CONDITIONS:
1- Full set of teeth exists. 2- Healthy PDL. 3- No cross-bite. 4- Angle Class I occlusion.
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Natural dentition
Mutually protected occlusion (canine guided occlusion)
- Uniform contact of all teeth around the arch when the mandibular condylar processes are in their
most superior position.
- Centric relation coincident with maximum intercuspation (intercuspal position).
- Stable posterior tooth contacts with vertically directed resultant forces.
- No contact of posterior teeth in lateral or protrusive movements. Lateral contact only between
canines & protrusive contacts only between anteriors.
- Anterior tooth contacts harmonizing with functional jaw movements.
CONDITIONS:
1- Full set of teeth exists. 2- Healthy PDL. 3- No cross-bite. 4- Angle Class I occlusion.
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Natural dentition
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Natural dentition
Unilaterally balanced occlusion (group function occlusion)
- In case canine PDL is compromised.
- Laterotrusive (working side): contact between all posterior teeth
- Mediotrusive (nonworking side): No contacts.
- Protrusive: No contacts between posterior teeth.
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Artificial dentition
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Artificial dentition
Bilaterally balanced occlusion
- Maximum number of teeth in contact in maximum intercuspation and all excursive
positions.
- Works best with complete dentures to maximize stability.
- DOES NOT work with natural dentition.
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Artificial dentition
Bilaterally balanced occlusion
- Maximum number of teeth in contact in maximum intercuspation and all excursive
positions.
- Works best with complete dentures to maximize stability.
- DOES NOT work with natural dentition.
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Artificial dentition
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Artificial dentition
Lingualized occlusion
- Only contacts are between maxillary molars palatal cusps and mandibular molar
CENTRAL fossae in ALL maxillo-mandibular positions.
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Artificial dentition
Lingualized occlusion
- Only contacts are between maxillary molars palatal cusps and mandibular molar
CENTRAL fossae in ALL maxillo-mandibular positions.
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
CUSP
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
CUSP
Marginal ridge
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
CUSP
Marginal ridge
Fossa
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
CUSP
Cusp tip
Marginal ridge
Fossa
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
CUSP
Cusp tip
Cusp slope
Marginal ridge
Fossa
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
CUSP
Cusp tip
Cusp slope
Marginal ridge
Fossa
Too much horizontal force
NO
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
Point centric
CR = MI
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
Point centric Long centric
Anteroposterior
CR = MI CR 0.5-1.5mm MI
Tuesday 3 December 13
Principles
of occlusion
Concepts of Occlusion
Centric contacts
Freedom in centric
Point centric Long centric Anteroposterior
Anteroposterior 0.5-1.5
CR = MI CR 0.5-1.5mm MI +
Buccolingual 0.5-1
Tuesday 3 December 13
Principles
of occlusion
Parafunctional Movements
Tuesday 3 December 13
Principles
of occlusion
Parafunctional Movements
- Parafunctional movements of the mandible may be described as sustained activities
that occur beyond the normal functions of mastication, swallowing, and speech.
- E.g. Bruxism, clenching, nail biting and pencil chewing.
- Long periods of increased muscle contraction and hyperactivity.
- Excessive occlusal pressure and prolonged tooth contact, which is inconsistent with
normal chewing cycle.
- Over time this can result in excessive wear, widening of the periodontal ligament,
mobility, migration or fracture of the tooth.
- In some cases muscle dysfunction such as myospasms, myostitis, myalgia and referred
pain (headaches) from trigger point tenderness may also occur. MOST common cause
for seeking professional help.
- Increased radiographic bone density and wear facets are often seen in patients with
sustained parafunctional activity.
Tuesday 3 December 13
Principles
of occlusion
Parafunctional Movements
Tuesday 3 December 13
Principles
of occlusion
Parafunctional Movements
Bruxism
- Bruxism is defined as the oral habits consisting of involuntary rhythmic or spasmodic
nonfunctional gnashing, grinding, or clenching of teeth that may lead to occlusal
trauma. It occurs at the subconscious level during day (diurnal) or at sleep (nocturnal).
- Altered mastication has been observed in subjects who brux and may result from an
attempt to avoid premature occlusal contacts (occlusal interferences). There may also
be a neuromuscular attempts to rub out an interfering cusp.
- Bruxism can exert considerable lateral forces on the posterior teeth, leading to
widening of the PDL and mobility.
- The causes of bruxism are difficult to determine. One theory states that bruxism is
performed on a subconscious reflex-controlled level and is related to emotional
responses and occlusal interferences.
- The relationship, if any, between bruxism and temporomandibular disorders is still
unclear.
Tuesday 3 December 13
Principles
of occlusion
Parafunctional Movements
Tuesday 3 December 13
Principles
of occlusion
Parafunctional Movements
Clenching
- Clenching is defined as the pressing and clamping of the jaws and teeth together
frequently associated with acute nervous tension or physical effort.
- The pressure created can be maintained over a long time with short periods of
relaxation.
- The pressure is concentrated more through the long axis of the the posterior teeth
without lateral forces (UNLIKE bruxism).
- Abfractures, cervical defects at the cementoenamel junction, may result from
sustained clenching.
Tuesday 3 December 13
Principles
of occlusion
Parafunctional Movements
Clenching
- Clenching is defined as the pressing and clamping of the jaws and teeth together
frequently associated with acute nervous tension or physical effort.
- The pressure created can be maintained over a long time with short periods of
relaxation.
- The pressure is concentrated more through the long axis of the the posterior teeth
without lateral forces (UNLIKE bruxism).
- Abfractures, cervical defects at the cementoenamel junction, may result from
sustained clenching.
Tuesday 3 December 13
Principles
of occlusion
Pathologic Occlusion
Tuesday 3 December 13
Principles
of occlusion
Pathologic Occlusion
Definition: It is the occlusal relationship that is capable of producing pathologic changes in the
stomatognathic system. Also known as traumatic occlusion.
Signs & symptoms:
1- Teeth: Wear,, mobility, migration or fracture of the tooth/teeth.
2- Periodontium: Widening of the periodontal ligament, isolated or circumferential periodontal
pockets.
3- Muscles: Muscle aches, asymmetric muscle activity in mouth opening/closing, restricted
opening (trismus).
4- TMJ: Pain, clicking, popping.
Tuesday 3 December 13
Principles
of occlusion
Pathologic Occlusion
Definition: It is the occlusal relationship that is capable of producing pathologic changes in the
stomatognathic system. Also known as traumatic occlusion.
Signs & symptoms:
1- Teeth: Wear,, mobility, migration or fracture of the tooth/teeth.
2- Periodontium: Widening of the periodontal ligament, isolated or circumferential periodontal
pockets.
3- Muscles: Muscle aches, asymmetric muscle activity in mouth opening/closing, restricted
opening (trismus).
4- TMJ: Pain, clicking, popping.
Tuesday 3 December 13
Principles
of occlusion
Pathologic Occlusion
Definition: It is the occlusal relationship that is capable of producing pathologic changes in the
stomatognathic system. Also known as traumatic occlusion.
Signs & symptoms:
1- Teeth: Wear,, mobility, migration or fracture of the tooth/teeth.
2- Periodontium: Widening of the periodontal ligament, isolated or circumferential periodontal
pockets.
3- Muscles: Muscle aches, asymmetric muscle activity in mouth opening/closing, restricted
opening (trismus).
4- TMJ: Pain, clicking, popping.
Tuesday 3 December 13
Principle of Occlusion
Overview
Tuesday 3 December 13
Principle of Occlusion
Overview
Tuesday 3 December 13
Principle of Occlusion
Overview
Centric relation
Vs
Habitual relation
Vs
Centric occlusion
Vs
Maximum intercuspation
Tuesday 3 December 13
Principle of Occlusion
Overview
Centric relation
Vs
Habitual relation
Vs
Centric occlusion
Vs
Maximum intercuspation
Bennet angle
Vs
Bennet movement
Tuesday 3 December 13
Principle of Occlusion
Overview
Point centric
Vs
Long centric
Vs
Freedom in centric
Centric relation
Vs
Habitual relation
Vs
Centric occlusion
Vs
Maximum intercuspation
Bennet angle
Vs
Bennet movement
Tuesday 3 December 13
Principle of Occlusion
Overview
Point centric
Vs
Long centric
Vs
Freedom in centric
Centric relation
Vs
Habitual relation
Vs
Centric occlusion
Vs
Maximum intercuspation
Normal occlusion Bennet angle
Vs Vs
Pathologic occlusion Bennet movement
Tuesday 3 December 13
Principle of Occlusion
Overview
Point centric
Vs
Long centric Functional movements
Vs Vs
Freedom in centric Parafunctional movements
Centric relation
Vs
Habitual relation
Vs
Centric occlusion
Vs
Maximum intercuspation
Normal occlusion Bennet angle
Vs Vs
Pathologic occlusion Bennet movement
Tuesday 3 December 13
Principle of Occlusion
Overview
Mutually protected occlusion
Vs
Unilaterally/Bilaterally balanced occlusion
Vs
Lingualized occlusion
Point centric
Vs
Long centric Functional movements
Vs Vs
Freedom in centric Parafunctional movements
Centric relation
Vs
Habitual relation
Vs
Centric occlusion
Vs
Maximum intercuspation
Normal occlusion Bennet angle
Vs Vs
Pathologic occlusion Bennet movement
Tuesday 3 December 13
The End
Tuesday 3 December 13
The End
References
Tuesday 3 December 13
