The document outlines the process and importance of occlusal equilibration, including causes of occlusal interference, recognition of stable and unstable occlusion, and treatment goals related to selective grinding. It details various technologies and techniques for diagnosing occlusal interferences and emphasizes the need for proper orthodontic knowledge in managing occlusal adjustments. The document also explores the significance of precise occlusal contact patterns and procedures for eliminating interferences during dental treatment.

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Occlusal Equilibration Dr. Mohammed Alruby
Occlusal equilibration
Prepared by:
Dr. Mohammed Alruby

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Occlusal Equilibration Dr. Mohammed Alruby
Aims of occlusal equilibration
Causes of occlusal interferences
How to recognize stable occlusion
How to recognize unstable occlusion
Parts of equilibration procedures
Aids of equilibration
Locating occlusal interferences
Eliminating interferences in centric relation
Eliminating interferences in lateral excursion
Eliminating interferences in protrusive movement
Treatment goals for selective grinding
Technology in diagnosis and locating occlusal interferences
- Transparent occlusal sheet
- Mylar paper
- Poly ether occlusal indicator
- Alginate impression material
- Foil
- Occlusal spray
- Pressure sensitive film
- T scan
- Photo occlusion
- Wax

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Occlusal Equilibration Dr. Mohammed Alruby
Definition:
Correction of stressful occlusal contact through selective grinding, it is not only involving
reshaping of the tooth but also restoration of tooth contour when indicated
Aims of occlusal equilibration:
1- Avoid interference between initial contact and centric occlusion which may causes
avoidance reflexes and deviation of the mandible
2- Eliminate discomfort, pain, and TMJ disorders
3- Allows free mandibular movements (free border movements)
4- Reinforce the occlusion by unconscious reflex swallowing
5- As preventive and interceptive measures during deciduous, mixed dentition to prevent
development of facial asymmetry
6- Enhance stability after orthodontic correction
7- Provides favorable environment for further developmental changes
Occlusal equilibration in orthodontics:
Every orthodontist should learn the principles and technique of OE, no one can be in better
situation to equilibrate the orthodontic patients than the orthodontist himself, his understanding
of growth changes may eliminate the need of reduction of inclines that tend to move with growth
into more favorable position. Also the orthodontics can adjust the minor discrepancy through
tooth movement when the alternative will be the reduction of tooth material
His knowledge of tooth rebound enable him to evaluate which inclines will move to favorable
position during retention period
OE is usually required after active treatment and before the destructive changes and allow
proper reorganization of tooth support.
Supine position:
the individual is lying on their back, with their face and abdomen facing upwards. During a
procedure, the back of their head typically rests on a pad or pillow, and their neck is in a neutral
position, as if in a sleeping position
upright sitting position:
sitting or standing with your back straight, rather than bending or lying down
Arc of closure:
Horizontal movement of lower incisal edge that sometimes can present an advantages in
treatment planning for anterior teeth
Line of closure:
Refer to primary interference that cause the mandible to deviate to the left or right from the 1st
point of contact in centric relation to the most closed position
Acceptable C R position developed when:
1- Equal and simultaneous contact occur between cusp tip and flat surface of all posterior
teeth
2- When the mandible is guided to C R and force is applied, no shift or slide occur (there is
no inclined to create a slide)

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Occlusal Equilibration Dr. Mohammed Alruby
3- When patient closes and taps in centric, all posterior teeth are felt eventually
4- When this is accomplished orthopedic stability has been achieved
Developing an acceptable lateral and protrusive guidance:
1- Acceptable laterotrusive contacts occur between the buccal cusps and not the lingual
cusps
2- During straight protrusive movements, the mandibular incisors pass down the lingual
surface of maxillary incisors dis-occluding the posterior teeth
= during latroprotrusive movement, the lateral incisors can also be involved in the
guidance
= as the movement more lateral, the canine begins to contribute to the guidance
Causes of occlusal interference:
1- Tilting of teeth
2- Premature extraction of deciduous teeth
3- Pathologic condition of the teeth either deciduous or permanent
4- Periodontal problems that cause loss of bone support
5- TMJ disturbance
6- Improper orthodontic treatment
7- Improper prosthetic either fixed or removable
8- Improper filling of the teeth
9- Abnormal pressure habits
10-Muscular imbalance
How to recognize stable occlusion:
1- Stable stops on all teeth when condyle are in centric relation
2- Anterior guidance in harmony with the border movement of the envelop of function
3- Distocclusion of all posterior teeth in protrusive movements
4- Distocclusion of all posterior teeth in the non-working (balancing side)
5- Non-interference of all posterior teeth on the working side with either lateral anterior
guidance or the border movement of the condyle
How to recognize unstable occlusion:
1- Hypermobility of one or more teeth
2- Excessive wear
3- Migration of one or more teeth:
Horizontal shifting
Intrusion
Supra-eruption
Classification of tooth contact pattern:
1- Cuspid provided occlusion: contact of canines on the working side
2- Group function occlusion: contact of canines, premolars, and / or molars, or contact
premolars and molars on working side only
3- Full balanced occlusion tooth contact pattern with group of functions or cuspid protected
occlusion on the working side plus multiple tooth contacts of posterior teeth in non-
working side

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Occlusal Equilibration Dr. Mohammed Alruby
4- Others: occlusal pattern other than those described: contact of incisors teeth, if any were
included in this classification
Hellman described four ways in which teeth contacts:
- Surface
- Cusp tip and fossa
- Ridge and groove
- Ridge and embrasure
Equilibration procedures can be divided into four parts:
1- Reduction of all contacting tooth surface that interfere with completely seated condylar
position (centric relation)
2- Selective reduction of tooth structure that interfere with lateral excursion, this will vary
as the influences of the anterior guidance varies to accommodate to individual chewing
cycle. It will also vary, as necessary to minimize lateral stress on weak health
3- Elimination of all posterior teeth structure that interfere with protrusive excursion that
must be varied in arch – to arch relationship in which anterior teeth are not in a position
to disocclude the posterior teeth in protrusion
4- Harmonization of anterior guidance: it is most often necessary to do this in conjunction
with the correction of lateral and protrusive interferences
Aids of equilibration:
1- Study casts
2- Anatomic articulator
3- Stones for straight or contra angle hand piece
4- Pumice and rubber cups
5- Marking material such as ribbon, articulating papers, wax, pasts, or spray.
Locating occlusal interference:
Firstly:
Clinician should try OE on the cast, then after proper equilibration is achieved on the cast, he
should do the same in the patient’ mouth
a- Centric relation of the mandible should be located
b- Insert marking ribbons or waxes
c- Guide the mandible manually to the point of initial contact, which will be the first point
of interference
d- Holds for a seconds and lets the patient full the first point of interference
e- Squeeze to determine the degree and direction of slide
f- Remove ribbon to observe the point of initial contact
g- Grind carefully to fully eliminate this point
Eliminating interference to centric relation:
1- Interference to the arc closure, the cusp tip and incisal edge of lower teeth usually follows
an arc of closure in upward and forward direction
Any tooth structure that interferes with this arc should be ground, as a general rule, grind
the mesial inclines of upper teeth or distal inclines of lower teeth (MU or DL)
2- Interference to the line of closure: this is the primary interference that causes the
mandible to shift either to right or left from the initial point of contact to the most closed
position

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Occlusal Equilibration Dr. Mohammed Alruby
If the deviation is toward the cheek, grind the buccal inclines of upper teeth or the lingual
inclines of lower teeth or both (BU - LL)
If the deviation is toward the tongue, grind the lingual inclines of upper teeth or buccal
inclines of lower teeth or both (LU – BL)
Eliminating interference to lateral excursion:
1- After all interference to centric relation (CR) has eliminated, guides the mandible
manually with firm pressure by the forefinger into the position of initial contact, the
pressure on both working and balancing side should be directed to working condyle
2- Ask the patient to slide to the left or right side while holding the mandible with firm
pressure
3- One ribbon is used to mark interference on working side and two ribbons are used on the
balancing side
4- Mark the non-functional occlusal contact on balancing side and the interference to
lateral excursion on the working side
Rules for grinding:
 Interference on balancing side: BU – LL – or both
 Interference on working side: LU – BL – or both
Eliminating interference to protrusive movement:
When the mandible moves forward from centric occlusion to protrusive excursion, only the front
teeth should contact while posterior teeth should dis-occlude.
Ask the patient to protrude while holding the mandible by firm pressure, any non-functional
occlusal contact or interference to protrusive movement should be eliminated
Treatment goals of selective grinding:
1- With the condyles in musculoskeletal stable C R position and the articular disc properly
interposed, all possible posterior teeth contact eventually and simultaneously between
centric cusp tip and opposing flat surface
2- When the mandible moves laterally, latero-protrusive contact on the anterior teeth dis-
occlude the posterior teeth
3- When mandible is protruded, contact of the anterior teeth disocclude the posterior teeth
4- In the upright head position, the posterior teeth contact more heavily than anterior teeth
Grinding rules:
1- Narrow stamp cusps before reshaping fossa
2- Do not shorten stamp cusp
3- Adjust centric interference list
4- Eliminate all posterior teeth inclined contact, preserve cusp tip only
Rules for grinding protrusive interference:
BU – ML

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Occlusal Equilibration Dr. Mohammed Alruby
Technology in diagnosis and locating the occlusal interference:
Occlusal Sprays:
It can be challenging to mark an occlusal contact on glazed ceramic restorations. Untreated
articulating paper does not leave a mark, necessitating the need for an alternate technique.
Articulating ink ribbons leave smudge marks and inaccurate readings. Articulating sprays are
easier alternative in these cases.
They are easy to administer (Arti-Spray, Bausch articulating paper Inc, Nashua, NH, USA) and
leaves a thin colored film which can easily be removed with water, leaving no residues. They
are applied at a distance of 3-5 cm onto the occlusal surface.
When testing occlusion all contact points will be immediately visible. These are available in
colors: red, blue, green and white.
Wax:
As per authors articulating papers, particularly plastic strips and waxes, are the most commonly
used materials. Occlusal contacts can be recorded by placing the wax on the occlusal surfaces
of the maxillary posterior teeth and patient closing into maximum intercuspation. The wax
occlusal records were examined in front of a light screen. Disadvantages are inaccuracy and
problems of manipulation
Foil:
Foils are the thinnest indicator materials. Their marking capacity is less evident under reduced
pressure and on glossy surfaces, thus greater pressure must be applied for application of foils.
Authors studied the recording patterns of four foils, six paper materials, and four silk qualities
at different pressures and surface morphologies. They concluded that Foils are the thinnest
indicator materials and give more accurate
readings than paper and silk. However, under smaller loads their marking capacity is worse.
This means that higher pressures must be applied for the clinical use of foils. The drawbacks of
the more intensively marking papers and silk are their greater thickness and less flexible base
material. This leads to a greater number of pseudo contact markings.
Articulating paper:
Articulating papers are used to detect high spots, the width, thickness and dye type of the
articulating paper helps it to leave a mark. The color coating of many articulating papers
consists of waxes, oils and pigments, a hydrophobic mixture which repels saliva. High spots can
be detected easily as dark marks and contacts as light marks.
The disadvantages of articulating papers have been that they:
- Can be affected by saliva
- Thick and have a relatively inflexible base material
all of these factors contribute to greater number of pseudo contact markings.
In the in vitro part of the study, a test model (mounted in an articulator and in a universal
testing machine) was established with the use of maxillary and mandibular dentate casts.
Articulating papers, foils, silk strips, and the T Scan system were used to examine the loss of
sensitivity of the recording materials after 3 consecutive strokes.
The differences in the contact points of the test model determined by each of the recording
materials were evaluated both in the articulator and in a universal testing machine. Authors
concluded that multiple use of the recording materials tested may lead to inaccurate occlusal

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Occlusal Equilibration Dr. Mohammed Alruby
analysis results. It is recommended that the recording materials be used only once and that the
teeth be dry during occlusal analysis.
Transparent Acetate Sheet:
It is based on occlusal sketch technique that aimed to provide a simple and reliable means of
recording and transferring information about the location of marked occlusal contacts.
The authors marked static occlusal contacts of 20 sets of models were recorded in a pseudo-
clinical situation, by three dentists and in addition by one dentist on two occasions using a
schematic representation of the dental arch - the 'occlusal sketch'. As per Daves et al. the
occlusal sketch is a simple, inexpensive and easy way of recording the results of an occlusal
examination using marking papers.
Polyether occlusal indicator:
Durbin and Sadowsky described a silicone impression material method for examining occlusal
contact patterns. The locations of the contacts were then transferred to study models
Pressure Sensitive Films:
This device records the location and force of occlusal contacts with the force sensitive film. An
occlusal diagnostic system dental pre-scale system, Fuji photo film, Tokyo has recently been
developed in japan. This system uses improved pressure sensitive sheets and a computer for
analysis to make simple measurements of occlusal contact areas and occlusal pressures
Mylar Paper / Shim-stock films:
The shim stock was positioned over the tooth evaluated. When the participants close in Inter-
cuspal Position, teeth holding the shim-stock were considered to have occlusal contact with
their antagonists. Anderson et al reported on the reliability of dentists’ ability to evaluate
occlusal contacts in the inter-cuspal position. Shim stock and an articulating film were
compared in the evaluation of occlusal contacts of 337 antagonist occlusal pairs in 24 young
adults by two examiners.
Shim stock displayed better reliability than articulating film and appeared suitable for clinical
measurement of occlusal contacts in inter-cuspal position.
Alginate Impression Material:
Number and location of perforations were registered as occlusal tooth contacts for each
subject. The observed perforations were analyzed according to the frequency of occlusal
contacts. Most subjects had asymmetric distribution in number and location of occlusal contacts
Photo-occlusion: (Arcan)
It is more sensitive method for locating the very minute premature contact through the
measurements of strain induced in aplastic wafer, that is called memory sheet, by using special
optical instrument.
This method is of great value not only as a diagnostic measure but also as a pretreatment record
of the occlusal relationship
The patient bite on 98mm thick film (memory sheet) for 10 -20 seconds and then the film layer
is inspected and the variation in strain can be analyzed under a Polariscope light to obtain the
relative tooth contact intensity, the results can transfer to graphic occlusal scheme

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Occlusal Equilibration Dr. Mohammed Alruby
Authors designed the study to test clinically the reproducibility of techniques by comparing two
consecutive occlusal records and records made at 1-month intervals and to test the
reproducibility of a color-marking technique under the same conditions, and to compare the
location of occlusal contacts as registered by these two techniques.
Computer assisted dynamic occlusal analysis: (T-scan system) (Maness):
1987, T-scan analysis system manufactured by Tek-scan and developed by William L Maness
This system is composed of thin sensor unit, that record the occlusal relationship in the patient’
mouth and relay information to computer, where they analyzed using a special software
program
When the patient bite on sensor, the electrical resistance of conductive sensor is lessened since
the force applied compress the particles together, there is recorded as quantitative force data
It records the sequence of occlusal contact from 1st
point of contact to maximum inter-cuspation
MIP
The occlusion is scanned in time increment of 0.01 seconds to record the relative force among
the occlusal contact. Printout of the patient pre and post treatment occlusal analysis can be
added to his permanent records
Occlusion Sonography:
It detects tooth contact by the sounds generated during mouth closure. The relationship between
graphic records of sounds of occlusion and the types of tooth contact which produced them was
investigated by the authors by filming various types of occlusal contacts with a Fastax rotating
prism camera at approximately 1,000 frames per second the sliging of the teeth over each other
was seen on the films as low amplitude vibrations and the tooth impacts as high amplitude one.
Advantages of computerized occlusal analysis technology:
1- Quantify occlusal contact timing and forces
2- Alternative to conventional occlusal registration method due to its ability to record
dynamic tooth contact relationship
3- Can display the relative occlusal force variance from the 1st
point of contact to maximum
inter-cuspation MIP
4- Improve the treatment outcome of the occlusal adjustment procedures
Limitation of computerized occlusal analysis:
1- Does not have the ability to measure absolute bite force
2- Highly compressible capacity of sensor also provides bilateral interference during
mandibular movements
3- Increase chair time during computerized occlusal adjustment
4- Need more clinical trials to recommended the computerized method superior to the
conventional occlusal indicators

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Occlusal Equilibration Dr. Mohammed Alruby