occlusal adjustments in complete dentute

1. Dr. Jibi Sara Varghese
1st year PG

2. INTRODUCTION
REQUIREMENTS OF COMPLETE DENTURE OCCLUSION
THEORIES OF OCCLUSION
CLASSIFICATION OF OCCLUSAL SCHEMES
CAUSES OF OCCLUSAL DISHARMONY
OCCLUSAL ERRORS
INTRAORAL OCCLUSAL ADJUSTMENTS
EXTRAORAL OCCLUSAL ADJUSTMENT
CONCLUSION
REFERENCE

3. Occlusion is one major factor over which all prosthodontic
procedures revolve around. Regardless of the type of
modality of rehabilitation, prosthodontic procedures result
in or intend to establish (or) correct( or) modify the existing
or lost occlusal relationship.
All prosthodontic procedures aim to accomplish 3 main
goals:
• Optimum function
• Preservation of supporting tissues
• Equalization of functional loads
In order to attain the above mentioned objectives,
functional harmony of the prosthesis to the
components of stomatognathic systems becomes the
major requirement.

4. OCCLUSION is defined as………
The static and dynamic
relationship between the incising or
masticating surfaces of the
maxillary and mandibular teeth or
tooth analogues

5.  -Stability of occlusion at centric and an
area forward and lateral to it.
 -Balanced occlusion contacts bilaterally
for all eccentric mandibular movements.
 -Control of horizontal force by
buccolingual cusp height reduction
according to residual ridge resistance
form and interarch distance.
 -Functional lever balance by favourable
tooth-to-ridge crest position.
 -Masticatory efficiency.

6. THEORIES OF OCCLUSION

7. OCCLUSAL SCHEMES HAVE BEEN CLASSIFIED
INTO :
-NEUTROCENTRIC OCCLUSION
-LINGUALIZED OCCLUSION
-NON ANATOMIC OCCLUSION (MONOPLANE
OCCLUSION WITH BALANCE)
-LINEAR OCCLUSION
-BALANCED OCCLUSION

8. BALANCED OCCLUSION :
“The bilateral, simultaneous, anterior and posterior occlusal contact of teeth in
centric and eccentric positions .”
It is not seen in natural dentition.
Characteristic requirements of balanced occlusion:
• All the teeth of the working side (central incisor to second molar) should glide evenly against
the opposing teeth.
• No single tooth should produce any interference or disocclusion of the other teeth.
• There should be contacts in the balancing side, but they should not interfere with the smooth
gliding movements of the working side. There should be simultaneous contact during
protrusion

10. NEUTROCENTRIC OCCLUSION
1.
2.Neutrocentric occlusion is at the far right of the
occlusal spectrum and the exact opposite of the
anatomic occlusion, was developed by De van. De
Van coined the term neutrocentric to embody the two
key objectives of his occlusal scheme,
3.1. The neutralization of inclines.
4.2. The centralization of forces which act on the
basal seat when the mandible is in centric relation to
the maxilla

11. LINGUALIZED OCCLUSION
1.Concept was introduced by Alfred Gysi in 1927
2.“Lingualized occlusion can be defined as, the form of denture
occlusion that where the maxillary lingual cusps articulate with
the mandibular occlusal surfaces in centric working and non-
working mandibular positions.”
3. Lingualized occlusion should not be confused with placement
of the mandibular teeth lingual to the ridge crest
Indications :
- When patient places high priority on esthetics but oral
conditions indicate a non-anatomic occlusal scheme such as:
Severe alveolar resorption, Class II jaw relationship,Displaceable
supporting tissues.
-When a complete denture opposes a removable partial denture.
1.• When a more favorable stress distribution is desired in patients
with parafunctional habits.

12. MONOPLANE OCCLUSION
Sear introduced monoplane occlusion with
balancing ramps or tooth at the distal part of the
mandibular arch which comes in contact only in
eccentric excursions
De Van has used the same principle without the
balancing Ramp. According to this concept teeth
which are flat mesiodistally and buccolingually
are used, oriented as close as possible parallel to
the maxillary and mandibular mean foundation
plane.

13. LINEAR OCCLUSION
1.“ The occlusal arrangement of artificial teeth, as viewed in the horizontal plane,
where in the masticatory surfaces of the mandibular posterior artificial teeth have a
straight, long, narrow occlusal form resembling that of a line, usually articulating with
opposing monoplane teeth” – FRUSH (1996)
2.• Teeth are arranged on a flat plane, which extend from tip of maxillary incisors to
the 2/3rd of retromolar papilla.
3.• The anterior vertical overlap is absent leading to non-interception in eccentric
movements
4.• The posterior teeth used are non- anatomic with mandibular blade form of teeth.
They exhibit bilateral fulcrum of protrusive stability

14. Occlusal harmony in complete denture is
necessary so that the denture will be:
1- comfortable and functions efficiently.
2- preserve the supporting structures

15. Causes of Occlusal Disharmony
1- Undetected errors in registering jaw relations.
2- Errors in mounting the master casts on the articulator.
3- Processing errors.
4. Dimensional changes of acrylic denture base material
5- Differences in tissue adaptation between the processed
denture bases & the record bases that were used in recording
maxillo- mandibular relations.
6- Changes in the supporting structures since the impression is
made ( as pt .using ill-fitting denture )

16. METHODS TO CHECK OCCLUSAL ERRORS
1) EXTA ORAL EVALUATION IN ARTICULATOR:
There should be complete intercuspation of the denture teeth in
centric relation.

17. 2) INTRA ORAL OBSERVATION OF INTERCUSPATION
The patient is guided into centric relation by a thumb placed on the
antero inferior portion of the chin and the index fingers bilaterally on
the buccal flanges of the lower trial denture.

18. The patient pulls his lower jaw back as far as it
will go and closes just until the back teeth make a
“feather touch”. Then the patient closes tightly.
Any error in Centric Relation will be apparent
when the teeth slide over each other (TOUCH
AND SLIDE), especially if anatomical teeth are
used. A second closure made with the same
instructions and a stop at first tooth contact will
permit visual observation of any error.

19. OCCLUSAL ERRORS
The final correction of possible occlusal disharmony on dentures is carried out
with the procedure of selective grinding. Each occlusal error is corrected by
grinding of specific tooth surfaces, which preserves the desired tooth form and
type of occlusion.
On denture teeth, occlusal errors can include errors in centric occlusion, errors
during protrusive movements, and errors on the working and nonworking
(balancing) side.

20. There are three types of occlusal errors in centric
occlusion-
Any pair of antagonist teeth can be too long and thus keep
other teeth out of contact
To correct this error,
the fossae are deepened by grinding
so that teeth can telescope into each other.
The cusps are not reduced

21. Mandibular and maxillary teeth may be placed
almost edge to edge.
To correct this error,
the cusp inclines are ground.
The buccal inclines of the maxillary teeth and the lingual inclines of the mandibular
teeth are ground.
The central fossae are widened.
The maxillary palatal cusp is narrowed by grinding on the palatal side, and the
mandibular buccal cusp is narrowed by grinding on the buccal side.
The cusps are not reduced

22. Maxillary teeth can be placed too far buccally in relation to mandibular
teeth
To correct this error,
maxillary palatal cusp is narrowed by widening the central fossa, and the mandibular buccal cusp
is ground on the buccal side by widening the central fossa.
The palatal cusp is ground on the palatal side and the mandibular buccal cusp is ground buccally
so that the teeth telescope into each other.
The cusps are not reduced

23. Errors in the frontal plane can include:
The maxillary buccal cusp and the mandibular lingual cusp are
too long.
To correct this error,
the length of the cusps is reduced by grinding
to change the incline extending from the central fossa to the cusp tip.
The central fossa is not deepened,
but the maxillary buccal cusps and the mandibular lingual cusps are reduced

24. The lingual cusps are in contact, but the buccal cusps
are not
The mandibular lingual cusps are reduced
by grinding their buccal inclines.
The maxillary palatal cusp is not reduced, and the central
fossa is not deepened

25. The buccal cusps are in contact, but the lingual ones
are not.
The maxillary buccal cusps should be ground from the central fossa
to the cusp tip to reduce the cusp
change the lingual cusp incline to become less steep

26. Errors in the sagittal plane can include the
following:
The maxillary buccal or lingual cusps are placed mesially to
their maximal intercuspal position.
This error can occur along with any of the three errors already described.
To correct this,
the mesial inclines of the maxillary buccal cusps are ground distally as if they
were narrowed, and the distal inclines of the mandibular cusps are ground
mesially.
the same cuspal inclination is achieved

27. The maxillary buccal and lingual cusps are placed distally
to their maximal intercuspal position
This error can also occur along with the buccolingual errors.
To correct this,
grinding is performed on the maxillary cusps distally
and
on the mandibular cusps mesially

29. A. Articulating paper
It will not give an accurate indication of premature contacts because the resiliency of
the supporting tissues allows the denture to shift producing markings which are
frequently false
Articulator paper detects premature
occlusal contacts either on articulator or
in the pt’s mouth
Articulating paper of a different color must be
used to distinguish contacts marked in eccentric
positions from those marked in centric position

30. When selective grinding in lateral occlusions is completed ,
incisal pin usually stays in contact with incisal table during
lateral excursions
Marking & grinding procedure is repeated for both lateral
movements until markings indicate uniform contacts on
working & balancing sides
After completing selective grinding , marks made by movements in all directions must show uniform
contacts. Red marks show contacts made in centric position & blue marks show contacts made during
lateral and protrusive movements

31. Indicator Wax
1.Two strips of adhesive green occlusal indicator wax 6 mm. wide are placed on the
occlusal surfaces of the mandibular denture. The dentures are placed in the patient’ s
mouth & the patient’s is guided into retruded contact position.
Wax must be carefully adapted to occlusal surfaces of teeth
Mandible is gently guided so that teeth make contact with the lower jaw maximally
retruded

32. Central- bearing Devices
When a central bearing device
assembled, bearing is the pin is adjusted
to permit an evaluation of the occlusion

33. Abrasive Paste
• Should not be used to eliminate errors in occlusion
of cusp teeth.
• The shifting of the denture bases as a result of
premature contact may result in altering the
occlusion so that centric occlusion does not
correspond to centric relation

34. Extraoral adjustment of
occlusion is carried out by a procedure known
as remounting & selective grinding. It includes:
1- Laboratory Remounting
2- Clinical Remounting

35. Laboratory Remounting
Objectives:
1- Restore or re-establish the vertical dimension of
occlusion.
2- Perfect working and balancing occlusion
3- Establish protrusive balanced occlusion.

36. I- Restore the Vertical
Dimension of Occlusion (VDO)
Supporting or Centric Holding Cusps -The
vertical dimension of occlusion is maintained
by occlusion of the palatal cusps of the
maxillary teeth & the buccal cusps of the
mandibular teeth

37. Rules of adjustment
a- If the cusp is high in centric & eccentric positions. Reduce the cusp.
1.b- If the cusp is high in centric & not in eccentric positions. Deepen the
opposing fossa or marginal ridge.
1.After all interceptive contacts have been eliminated in centric &
eccentric positions:
2.a- Don’t reduce upper palatal cusps or lower buccal cusps
3.b- Don’t deepen the fossa or marginal ridge of any tooth

38. II- Occlusal Balance in Lateral Excursions
Rules of Adjustment
A- On the Working Side Adjust the buccal cusps of the upper teeth & the lingual cusps
of the lower teeth ( B.U.L.L. rule ) to eliminate deflective contacts.
B- On the Balancing side Reduce inner inclines of lower buccal cusps , don’t reduce
the cusp tip as it is a centric holding cusp

39. III- Selective Grinding for Protrusive Balance
In protrusive balance, the anterior teeth should make incisal edge
contact at the same time that the tips of the buccal & lingual cusps of the
posterior teeth contact

40. Rules of Adjustment
a- If anterior teeth have heavy contact with no posterior contact:
Reduce the labio-incisal surfaces of the lower teeth & the palatal
surfaces of the upper teeth.
b. If posterior teeth have heavy contact with no anterior teeth
contact. Reduce distal inclines of upper cusps & mesial inclines
of lower cusps

41. Clinical Remounting
It consists of remounting the finished denture on an
articulator by using interocclusal records in the patient’s
mouth The occlusion is then adjusted on the articulator to
remove discrepancies & interferences.
Step by Step Procedure

42. I- Preserve the orientation of the Maxillary cast to the Articulator:
A plaster remount index is an occlusal registration of the maxillary denture which
is recorded on a remount jig attached to the lower member of the articulator

43. II- Preparation of the Remount Casts
Casts should be constructed to facilitate the positioning of the complete denture on
articulator & the process of occlusal correction

44. III- Centric Interocclusal Record
1.The centric interocclusal record is used to mount the mandibular
denture on the articulator as a part of the clinical remount & selective
grinding procedure.

45. Advantages of Clinical Remounting
1- It reduces patient participation.
2- It permits the dentist to see better what he is doing.
3- It provides a stable working foundation; denture bases are not
shifting .
4- The absence of saliva makes possible more accurate markings
with the articulating paper.
5- Corrections can be made away from the patient

46. Remounting of finished complete dentures is an integral part of
prosthetic treatment.
 Occlusal errors can be corrected by selective grinding of denture
teeth.
The anterior/canine guided occlusal concept is the preferred option
for tooth arrangement.

47. In centric occlusion, only the posterior teeth are in uniform
and simultaneous contact, whereas a slight distance should be
kept between the anterior teeth.
During lateral movements, contacts on the balancing side are
considered as occlusal interferences. The arrangement of teeth
in such occlusion is simpler, esthetics are better, and patients
experience fewer parafunctional movements.

49. Boucher’s Prosthodontic Treatment for Edentulous Patients.
Dawson P. Evaluation, Diagnosis and Treatment of Occlusal Problems, ed 2.
Okeson JP: management of TMJ disorders and occlusion
Ramfjord S, Ash MM: Occlusion