full mouth rehabilitation / Labial orthodontics

INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

Contents
Introduction
Occlusal disease
Determinants of occlusion
Temporomandibular joint
Masticatory musculature
Centric relation
Determining centric relation
Recording centric relation
Classification of occlusionswww.indiandentalacademy.com

Introduction
The defining philosophy that underlies an honest
concern for patients can be summarized in one word:
complete.
Embracing the concept of complete dentistry always
puts the patient first. It says that every patient is
entitled to a complete examination and a clear
understanding of every problem that should be
treated.

It is axiomatic that patients cannot perceive a need for
treatment if they do not clearly understand what
problems are present. That is the primary purpose of
the complete examination.
Patients cannot make a truly informed decision about
treatment unless they also understand the
implications of not treating each problem within a
reasonable time frame.

Practitioners cannot reliably predict implications if
they don't have a working knowledge of the total
masticatory system, which includes the
interrelationships of the teeth, the
temporomandibular joints (TMJs), the muscles, and
the supporting tissues, in addition to a clear picture of
the causes and effects of occlusal disease.

Types of implications
A. Immediate implications.
B. Deferrable implications.
C. Implications for optional treatment

Goals for complete dentistry
I. Freedom from disease in all masticatory system
structures
II. Maintainably healthy periodontium
III. Stable TMJs
IV. Stable occlusion
V. Maintainably healthy teeth
VI. Comfortable function
VII. Optimum esthetics

Occlusal disease
Most common destructive dental disorder.
Contributing factor to eventual loss of teeth.
Reason for needing extensive restorative dentistry.
Factor associated with discomfort within masticatory
system structures. This includes pain/discomfort in
the musculature, the teeth, and the region of the
temporomandibular joints (TMJs).

Factor in instability of orthodontic treatment.
Reason for tooth soreness and hypersensitivity.
Most commonly missed diagnosis leading to
unnecessary endodontics.
Most undiagnosed dental disorder until severe damage
becomes too obvious to ignore.

Attrition
Attrition is wear due to tooth-
to-tooth friction.
E.g. bruxism and empty
mouth parafunction.
In dentin, wear increases
seven times faster
Wear on the lower anterior
teeth is one of the most
common untreated problems.

Abrasion
Abrasion is wear due to
friction between a tooth and
an exogenous agent.
Chewing on a food bolus or
from tobacco chewing.
From overzealous
toothbrushing or improper
use of dental floss, toothpicks,
pencils, or any foreign object.

Erosion
Erosion is tooth surface loss due to chemical or
electrochemical action. It can be endogenous or
exogenous.
It does not include association with bacterial activity.
Endogenous erosion: Bulimia, Gastroesophageal reflux
disease (GERD) and Gingival crevicular fluid.

Exogenous erosion: Any food
or liquid with a pH of less
than 5.5 can demineralize
teeth.
"Coke swishers" and "fruit
mullers“
Evidence of erosion is obvious
because cupped-out dentin
areas cannot be contacted by
opposing teeth.www.indiandentalacademy.com

Splayed teeth
Mandibular deflection force the
upper anterior teeth forward.
Other signs are fremitus and
soreness of the anterior teeth.
Improperly contoured
restorations that are too thick
on the lingual of the upper
anterior teeth or overcontoured
lower restorations.

Destroyed
Dentition
Result of not intercepting
occlusal disease early.
Severe wear, fractured
teeth, and elongated
alveolar processes are
typical when treatment of
delta-stage bruxism is
delayed. www.indiandentalacademy.com

Advanced occlusal
disease
This disease results from a
combination of attritional
wear and moved teeth.

Anterior guidance
attrition
Occurs when anterior teeth
that either interfere with
centric relation closure or
interfere with functional
jaw movement patterns
(envelope of function).

Sensitive teeth
One of common cause of
hypersensitivity is occlusal
overload
Pulp may be vital.
Result from pulpal hyperemia
or from the effects of non-
carious cervical cracks.

Sore teeth
Compression of
periodontal ligaments and
pulpal hyperemia
If empty mouth clenching
causes any discomfort in a
tooth, it is an indication
that the sore tooth is in
occlusal interference.

Hypermobility
An early sign of occlusal
disease.
Result in widened
periodontal space and
greater susceptibility to
periodontal disease.
Deflective contact or occlusal
overload is a factor.

Split teeth and
fractured cusps
Fracture lines routinely
develop when a cusp incline
interferes with strong
occlusal forces.
Sign of occlusal disease that
precedes cusp fracture or
split tooth. www.indiandentalacademy.com

Painful musculature
Deflective occlusal
interferences that require the
jaw joints to displace to achieve
maximum intercuspation are a
potent cause for painful
masticatory musculature.
Excessive wear, hypermobility,
fractured cusps, and
hypersensitivity.

Determinants of occlusion
Determination of the correct physiologic jaw
relationship must always be determined before we can
determine the correct alignment and occlusal
relationship of the teeth.
The teeth must fit into the harmony of the jaw
relationship and not vice versa

Primary requirements for
successful occlusal therapy
I. Comfortable and stable TMJs:
Must be able to function and accept loading forces
with no discomfort.
Starting point for any dental treatment that involves
the occlusal surfaces of the teeth.
II. Anterior teeth in harmony with the envelope of
function and in proper relationship with the lips,
the tongue and the occlusal plane.www.indiandentalacademy.com

III. Non-interfering posterior
teeth: posterior occlusal
contacts should not interfere
with either the comfortable
TMJs in the back or the
anterior guidance in the
front.

Temporomandibular Joint
The first requirement for successful occlusal treatment
is stable, comfortable TMJs. The jaw joints must be
able to accept maximum loading by the elevator
muscles with no sign of discomfort.
The articulating surfaces: In opening-closing
movements the two condyles form a common axis and
act as one hinge joint.

The fact that the condyles are rarely symmetric, the axial
rotation occurs around a true hinge that is on a fixed
axis when the condyles are fully seated.

Each condyle is normally at about a 90-degree
angulation with the plane of the mandibular ramus,
which places their alignment at an obtuse angle to
each other.
The medial pole serve as a point of rotation. Its
triangular shape serves this mechanical function
very well.

The medial part of the
fossa is reinforced with
thick bone so it can also
serve as a stop for the
upward force of the
elevator muscles and the
inward force of the medial
pterygoid muscles.

The TMJ is designed as a load-bearing joint and must be
capable of resisting forces that measure into hundreds of
pounds.
The articular eminence forms the anterior part of the
articular fossa. Because of the slightly forward pull of the
elevator muscles, the condyles are always held firmly
against the eminence.
The importance of the biconcave articular disk that fits
between the two convex surfaces.

The disk divides the joint into an upper and a lower
compartment.
The lower compartment serves as the socket in which
the condyle rotates, whereas the upper compartment
allows the socket to slide up and down the eminence.
Thus the mandible can hinge freely as either one or
both condyles translate forward.
The disk itself is a classic example of design for
function.

It is composed of layers of collagen fibers oriented in
different directions to resist the shearing effect that
might occur in a sliding joint.
The bearing area is avascular, and so it is nourished by
synovial fluids that also lubricate the joint for smooth
gliding function.
The disk is firmly attached to the medial and lateral
poles of the condyle.

The diskal ligaments allow it to rotate from the front of
the condyle to the top and vice versa.
In normal function, the disk is always positioned so
that pressure from the condyle is directed through its
central bearing area.
Positioning of the disk is controlled by the
combination of elastic fibers attached to the back of
the disk and the superior lateral pterygoid muscle that
is attached to the front of the disk.

Condyle disk alignment
Medial and lateral diskal ligaments
The disk is designed to rotate on the condyle like a
bucket handle that attaches to the medial and lateral
poles of the condyle (collateral ligaments).

This allows the disk to
rotate from the top of the
condyle to the front and
back so it can stay aligned
with the direction of force
as the condyle moves up
and down the curved
eminentia.

Posterior ligament
The disk is tethered to the back
of the condyle by an inelastic
band of collagen fibers.
Prevents the disk from rotating
too far forward and being
displaced anteriorly.
To permit any forward
displacement it must be
stretched or torn.

Superior elastic
stratum
Elastic fibers bind the
disk to the temporal
bone behind it and
maintain constant
tension on the disk
toward the distal.

Superior lateral pterygoid
muscle
The only forward pulling force that
could anteriorly displace the disk
In combination with the elastic
fibers behind the disk controls the
position of the disk on the condyle so
it is always aligned with the direction
of force as the condyle moves down
the slope of the eminentia.

How muscle controls disk
alignment
Opening
Condyle disk assembly is fully seated in centric
relation with disk positioned at the most forward
position that the posterior ligament allows.
Forces from condylar loading are directed up through
the medial third of the disk and forward through the
anterior surface of the condyle against the steepest
part of eminentia.www.indiandentalacademy.com

As the inferior lateral
pterygoid muscle (+)
starts to pull the condyle
forward the superior
lateral pterygoid muscle
(-) releases contraction to
allow the elastic to start
pulling the disk more to
the top of the condyle

Maximum opening
When the condyle reaches the
crest of the eminence, the disk
should be directly on top of the
condyle as forces are directed
upwardly against the flattest part
of the articular eminence.
Elastic fibers have rotated the disk
back because the superior lateral
pterygoid muscle is in controlled
release.

Closing
As the jaw closes, the condyle
starts to move back and up
steeper slope of the articular
eminence, so the disk must be
pulled back to the front of the
condyle.
Superior lateral pterygoid
muscle ( +) starts its contraction
as the inferior lateral pterygoid
muscle ( -) releases condyle to
the elevator muscles.

Closed
When the condyle reaches centric relation, the disk has been
pulled as far forward as the posterior ligament will allow.
If the ligament is intact the disk is stopped in perfect
alignment with the direction of loading through the condyle.
In the absence of occlusal interferences to centric relation, the
inferior lateral pterygoid muscle will stay passive, even if the
patient clenches.
The superior belly holds its contraction to maintain the disk in
its correct alignment.

Disk rotates to the top of the
condyle as it approaches the crest
of the eminentia, the inelastic
posterior ligament folds.
The functional aligning of the disk
is an example of the importance of
the coordinated contraction and
release of the neuromusculature
system in harmony with
mandibular function.

The temporomandibular ligament
Does not come into function until the jaw opens to 20
mm or more and reaches its limit of length and stops
the mandible from opening further in centric relation.
The attachment of the ligament to the posterior side
of the neck becomes a fulcrum that forces the condyle
to translate forward as the jaw opens further.
Not a factor in centric relation as it is not at its full
length when the condyle disk assemblies are fully
seated. www.indiandentalacademy.com

Misconception about joint physiology and
anatomy
Centric relation is not a physiologic position because "it is a
border position in which joints do not normally function."
All joints, including the TMJs, function in a fully seated
position in their sockets.
Fully loaded at an end point of compression, the condyles are
similarly loaded in centric relation by the elevator muscles.
Centric relation is not a ligament braced position, but rather it
is the physiologic end point that is achieved by coordinated
muscle function during jaw closure.

The arteriovenous shunt
As each condyle disk assembly moves down the
eminence it evacuates the space up in the fossa.
So the retrodiskal tissue must expand to fill the space
evacuated by the condyle and disk. It does this by a
rush of blood into a network of vessels that are spread
through the spongy retrodiskal tissues.
When the condyle and disk return to centric relation,
the blood flows out and the vessels contract in size.

It makes the retrodiskal tissue highly vascular and
richly innervated.
If the disk is displaced anteriorly, the condyle loads
onto this tissue and causes pain.
Inflammation and edema in these tissues are always
considerations when the joint is traumatically loaded

Masticatory musculature
When bone and muscle war; muscle never loses. (Harry
Sicher)
When teeth and muscle war; muscle never loses. (Peter E.
Dawson)
Muscle is the primary focus in vertical dimension, the neutral
zone, arch form, occlusal disease, orofacial pain, and even
smile design.
Incoordinated, hyperactive musculature can over time,
displace the disk from a condyle and cause a variety of
structural deformations to the TMJs.www.indiandentalacademy.com

Coordinated muscle
function during jaw
opening
Timely release of muscle or
group of muscles as
contraction of antagonistic
muscles takes place.
As the jaw opens, the depressor
muscles contract while the
elevator muscles release their
contraction.

Coordinated muscle
function during jaw closure
As the jaw closes, the elevator
muscles contract while the
depressor muscles release
contraction.
In the absence of deflective occlusal
interferences, inferior lateral
pterygoid muscle stays passive even
during firm clenching.www.indiandentalacademy.com

Coordinated muscle
function at maximum
intercuspation
Release of the inferior lateral
pterygoid muscle during
elevator muscle contraction is
the goal of occlusal harmony.
Condyle-disk assemblies can
completely seat up into their
respective fossae during closure
into maximum intercuspation.

Disharmony between the
occlusion and the TMJs
If the condyles must be displaced
from centric relation to achieve
maximum intercuspation, the
inferior lateral pterygoid muscle
must contract
Condyles must be pulled down as
they are pulled forward.

Muscle response to occlusal
interference
Occlusal interference evokes a
response of hyperactivity and
incoordinated contraction
Interfering tooth becomes
sensitive and sore.
Prolonged hyperactivity of the
temporal muscles, tension
headaches in that region occur

Placement of a simple flat
interocclusal device on the
anterior teeth separates the
posterior teeth.
Lateral pterygoid muscles releases
contraction and return to
coordinated muscle function.
The relief of all symptoms is
almost immediate unless there is
an intracapsular structural
disorder.

Muscle response to posterior
disclusion
When the posterior teeth are separated in all eccentric jaw
movements by the combination of anterior guidance and
condylar guidance more than two-thirds of the elevator muscle
force is shut off.
i. It greatly reduces the horizontal forces against the anterior
teeth, which are the only teeth in contact during excursions.
ii. It reduces the compressive loading forces on the TMJs.
iii. It makes it impossible to overload or wear the posterior
teeth, even if the patient bruxes.www.indiandentalacademy.com

Causative factor in disk
derangements
In a healthy, intact TMJ, the disk
is self-centering.
Incoordinated muscle activity
pulls the disk forward while the
elevator muscles pull the condyle
up and back, applying tensile
force to the posterior ligament of
the disk.
The ligament must be stretched

The ligament must be
torn
The attachment of the
ligament must migrate.

Centric relation
Centric relation is the relationship of the mandible to the
maxilla when the properly aligned condyle-disk assemblies
are in the most superior position against the emineniae
irrespective of vertical dimension or tooth position.

At the most superior position, the condyle-disk
assemblies are braced medially, thus centric relation is
also the midmost position.

A properly aligned condyle-
disk assembly in centric
relation can resist
maximum loading by the
elevator muscles with no
sign of discomfort.

The mandible is in centric relation if five criteria are
fulfilled:
 The disk is properly aligned on both condyles.
 The condyle-disk assemblies are at the highest point
possible against the posterior slopes of the
eminentiae.
 The medial pole of each condyle-disk assembly is
braced by bone.

 The inferior lateral pterygoid muscles have released
contraction and are passive.
 The TMJs can accept firm compressive loading with
no sign of tenderness or tension

Using bilateral manipulation to find
and verify centric relation or adapted
centric posture
PROCEDURE:
Step one: Recline the
patient all the way back
Step two: Stabilize the
head.

 Step three: After the head is
stabilized, lift the patient's
chin again to slightly stretch
the neck
 Step four: Gently position the
four fingers of each hand on
the border of the mandible.

Step five: Bring the
thumbs together to form a
C with each hand
Ensure that the fingers are
properly positioned

Step six: With a very gentle
touch, manipulate the jaw so
it slowly hinges open and
closed
Step seven: After the mandible
feels like it is hingeing freely
and the condyles seem to be
fully seated up in their fossae,
the mandible is in centric
relation. www.indiandentalacademy.com

The position and alignment of
each condyle must be tested
by applying firm pressure
Load testing must be applied
in increments starting with
gentle upward pressure
through the condyles while
the thumbs keep the teeth
apart

If there is no response of
discomfort, proceed to
moderate pressure and then
firm pressure.
With correct manipulation,
there is a torque effect from
the thumbs and fingers that
loads the joints in an upward
and forward direction.

With proper hand
position, very firm upward
pressure be maintained
through the condyles,
while still allowing them
to rotate freely

Bilateral manipulation provides a quick verification of:
a. The correctness of the position.
b. The alignment of the condyle-disk assembly.
c. The integrity of the articular surfaces.

OTHER METHODS
Directly fabricated anterior
deprogramming device
Mandible is manipulated to
centric relation, or as close to
it as can be achieved. The jaw
is then closed so the lower
incisors indent the soft
acrylic, but closure is stopped
short of posterior contact.

The tooth contact surface is ground to a smooth flat
surface that permits full horizontal movement of the
mandible.
If the TMJs are intact and the lateral pterygoid muscles
are completely released and passive, the patient can
squeeze firmly to hold the condyles in centric relation
as a fast setting bite material is injected between the
posterior teeth.

The Pankey Jig.
The Best-bite
Appliance: A kit is
available with an
injection material for
stabilizing the appliance.

The Lucia jig
NTI (Nociceptive
trigeminal Inhibition)

Leaf Gauge: consists of
layers of flexible mylar
that can be adjusted to
varying thicknesses.
The material is smooth
and slick, so it allows the
mandible to move
horizontally as the
condyles seat up.

Disadvantages of anterior
bite stops
During equilibration procedures, marking occlusal
interferences with an anterior bite stop in place.
Even with an anterior bite stop in place, load testing to
verify centric relation is the only sure way to ensure
accuracy.
Combining bilateral manipulation with an anterior
deprogrammer appliance if helpful to the operator,
should be used.

Recording of centric relation
Reasons for error:
Improper manipulation (chin point guidance or
forcing)
No guidance or verification of centric relation
Flimsy bite-recording materials. Rubbery materials
are consistently inaccurate because there is no stable
position for seating the casts in the record.

Too-deep indentations into the bite material causing
the compression of soft tissue in the mouth.
Use of soft waxes that are easily distorted when casts
are seated into the record.
Too shallow or nonexistent indentations into part of a
bite record so there is no verifiable position for the
casts to seat into the record
Unstable bite-recording materials that warp or distort
after the recording is made

Criteria for accuracy
The bite record must not cause any movement of teeth or
displacement of soft tissue.
It must be possible to verify the accuracy of the interocclusal
record in the mouth
The bite record must fit the casts as accurately as it fits in the
mouth
Must be possible to verify the accuracy of the bite record on
the casts.
The bite record must not distort during storage or
transportation to the laboratory.

Wax bite record
Delar wax: brittle-hard
wax supplied in sheets
that are thicker at the
front for more even
penetration teeth from
back to front.

Anterior stop techniques

Dawson's classification
Type I: Maximal
intercuspation is in harmony
with centric relation.
Implications for type I
 Centric relation is verifiable
with the teeth separated.
 No discomfort in the TMJ region
even when loaded.

Jaw can close to maximal intercuspation without pre
mature tooth contacts or deflections .
Occlusal equilibration is not needed except for
possible excursive interferences.
Patient can clench with no sign of discomfort.
An occlusal splint is not indicated.
Type I occlusion can occur with any Angle's
classification.

Type I A: Maximal intercuspation
occurs in hamony with adapted
centric posture.
Implications for Type I A
 Inter capsular structures have
deformation but have adapted
 TMJs can accept loading with no
discomfort.
 Treatment for TMD is not needed.
 Occlusal correction is not needed
because there is no occlusion
disharmony.

Type II: Condyles must
displace from a verifiable
centric relation for
maximum intercuspation to
occur.
Type IIA: Condyles must
displace from an adapted
centric posture for
maximum intercuspation to
occur.

Implications for Type II or IIA
Centric relation or adapted centric posture has been
verified so discomfort from an intracapsular disorder
has been ruled out.
Prognosis is excellent if all occlusal interferences are
eliminated.
TMJ surgery, arthroscopy, joint injections, or lavage are
contraindicated.
The occlusal therapy goal is to achieve type I or IA.

Type III: Centric relation cannot be verified.
Implications for Type III
Need for Piper classification of TMJs.
Focus on correcting the TMD before occlusal
treatment
Treatment vary from a simple permissive occlusal
device to relieve muscle spasm, to surgical correction
of intracapsular disorders.
The treatment goal is Type I or IA.

Type IV: The occlusal relationship is in an active stage
of progressive disorder because of pathologically
unstable TMJs.
Implications for Type IV
An actively progressive disorder of the TMJs
Impossible to establish a stable TMJ/occlusion relationship
Typical signs of type IV are:
 Progressive anterior open bite
 Progressive asymmetry
 Progressive mandibular retrusion

Stop the progression of the
TMJ deformation until
manageable stability of the
TMJs can be confirmed.
Occlusal treatment is
contraindicated at this
stage

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