A brief overview of occlusal therapy

1. Coronoplasty
Dr. Vamsi Lavu
Department of Periodontics

2. Characteristics of
Normal/ Therapeutic occlusion
• Intercuspal position: [ICP]: Bilateral
simultaneous well distributed contacts on the
posterior teeth providing arch stability.
• Retruded contact position [RCP]: The RCP to
ICP relationship is less than 1 mm along a
forward symmetrical path measured at incisal
levels.

3. Characteristics of
Normal/ Therapeutic occlusion
• Vertical stops: Stable multiple contacts on the
posterior teeth providing tooth stability. No
buccal-lingual thrust in ICP or RCP
• Lateral excursions: Smooth movement with
discursion controlled by canine or premolar
on the working side and no contact on the
balancing side.

4. Characteristics of
Normal/ Therapeutic occlusion
• Protrusive excursion: Smooth movement with
multiple contacts bilaterally distributed on the
anterior teeth.
• Interferences: Freedom from lateral,
protrusive contacts in molar teeth.
• Free way space: 1-4 mm.

5. Occlusal Treatment Planning
Orthofunction Preserve existing
occlusion and
mandibular function
Dysfunction Partial or total occlusal
alteration is indicated
Extensive occlusal
reconstructiion for
reasons other than
traumatic occlusion
New ICP so that joints
and teeth receive less
stress

6. Terminology
Occlusal adjustment:
• Establishment of functional relationships
favorable to the periodontium by one or more
of the following procedures: reshaping of the
teeth by grinding, dental restoration, tooth
movement, tooth removal or orthognathic
surgery

7. Terminology
Coronoplasty:
• Selective reduction of occlusal areas with
primary purpose of influencing the mechanical
conditions in contact situations and neural
pattern of sensory input.
• It is direct, permanent, and irreversible
change in the occlusal scheme.

8. Indications
• Trauma from occlusion.
• Occlusal prematurities following restorations/
prosthesis.
• Following orthodontic correction of tooth
position.
• TMJ disorders due to occlusion changes.
• Pathologic migration resulting from
periodontal disease and unreplaced missing
tooth

9. Techniques for coronoplasty
• Intercuspal position adjustment:
– Functional movements made by patient.
– MCP same as ICP.
– Slightly anterior to RCP.
– Interocclusal stabilization splint.
– Based on patient neuromuscular control and
feedback

10. Techniques for coronoplasty
• Retruded contact position adjustment:
– Passive jaw manipulation.
– Done by dentist.
– Patient co-operation is essential.
– ICP will be established at RCP.
– Based on presumed TMJ stability and alignment

11. Techniques for coronoplasty
• Myo-monitor method:
– Transcutaneous neural stimulation
– Intermittent electrical stimulation- Myocentric
ocntact position.
– New ICP anterior to existing RCP and ICP.
– Not very ideal.

12. Objectives of coronoplasty
To establish:
1.A change in the pattern and degree of
different impulses.
2.A decrease in tooth mobility.
3.Create multiple simultaneous contacts spread
over the occlusal plane.
4.Change in chewing pattern if required.
5.Multidirectional mandibular movements.

13. Occlusal analysis
• Casts / Models articulated in a semiadjustable
articulator with face bow transfer mounted in
RCP.

14. Armamentarium

15. Armamentarium

16. Basic steps in Coronoplasty
 Grooving
 Spheroiding
 Pointing

17. Grooving
• Restoring the depth of developmental grooves
made shallow by occlusal wear.
• Use a tapered cutting bur.

18. Spheroiding
• It consists of reducing the prematurity and
restoring the original tooth contour. Starting 2
– 3 mm mesial or distal to the prematurity.
• Tooth is recontoured from occlusal margin to
a distance of 2-3 mm apical top the amrking.
• Paintbrush stroke.
• Narrow the occlusal surface esp in cases of
attrition.

19. Spheroiding

20. Pointing
• It involves restoring the cusp point contours. It
is done by reshaping the tooth with rotating
cutting tools.

21. STEPS IN CORONOPLASTY

22. Step 1 Explain: Create positive patient acceptance
Step 2 Remove retrusive prematurities and eliminate deflective
shift from RCP to ICP
Step 3 Adjust ICP to achieve stable simultaneous multi-pointed
contacts
Step 4 Test for excessive contact in incisor teeth (fremitus)
Step 5 Remove psoterior protrusive interferences and establish
contacts bilaterally
Step 6 Remove or lessen mediotrusive (balancing) interferences
Step 7 Reduce excessive cusp steepness on the laterotrusive
(working) contacts
Step 8 Elimiate gross occlusal disharmonies
Step 9 Recheck tooth contact relationships
Step 10 Polish all rough tooth surfaces

23. Step1: Create positive patient acceptance
• Patient concern: change of shape, tooth
sensitivity and decay .
• Only reshaping, done in areas not susceptible
to decay usually.
• Periodic recall required.

24. Step 2: Remove Retrusive Prematurities
• Aimed at eliminating the deflective shift from
RCP to ICP.

25. One hand and
Two hand
method for
guiding the
mandible into
Retrusive
Contact
Position
(RCP)-
Supine
position

26.  Place wax on occlusal
surface of teeth.
Tap mandibular teeth
against maxillary teeth
Mark perforations in
wax with marking pencil.
Remove prematurities
with spheroiding.
MUDL rule:
Mesial inclines of upper
teeth and Distal inclines
of lower

27. Usually done in Maxillary lingual cuspal
inclines
Do not do in cuspal tips/ marginal
ridges

28. Step 2:
• It should achieve the following
1. Contact pattern is bilateral with multipointed
contacts.
2. Deflective shift from RCP to ICP is eliminated.
3. RCP and ICP should have same vertical dimension
of occlusion.
4. RCP to ICP- path should be smooth and gliding.
5. repeated closure of teeth should produce
resonant sound

29. Step 3: Adjustment of ICP
• Progressive adjustment of supracontacts/
undesirable contacts during one more more
visits.
• Posterior teeth are adjusted first followed by
anterior teeth.
• Identify prematurities by asking patient to tap
the back teeth together both sides at the same
time slow and hard.

30. Step 3: Adjustment of ICP
• Place mylar occlusal indicator strips and pull
with tugging motion when closed. ICP contact
will be established.
• If conatct is located in an undesirable area,
adjust the contact. If supracontact, create
more fossa depth.

31. Normal
ICP

32. Step 4: Test for excessive contact in
incisors (Fremitus)
• Incisor teeth should be out of contact or in
light contact.
• No fremitus should be detectable in the
incisors on firm closure of the teeth.
• Check with mylar strips. Minimal resistance on
tugging.
• Remove any prematurities identified.

33. Step 5: Remove posterior protrusive
interferenes
• Protrusive excursion: refers to the path of the
mandible as it moves anteriorly or posteriorly
between the ICP and edge to edge
relationship of the anterior teeth..
• Edge to edge relation of the incisor is called as
Protrusive position.
• Protrusive position and protrusive excursion
are corrected separately.

34. Step 5: Correction of protrusive position
• Objective: to obtain bilateral well distributed
contact on the incisal edges of the maxillary
and mandibular incisor teeth.
• Steps:
1. From ICP ask patient to protrude the
mandible slowly.
2. Observe for any deviant shift in the
mandible during the glide.
3. If shift is present it is indicative of posterior
prematurity.

35. Step 5: Correction of protrusive position
4. Once protrusive position is reached, ask the
patient to open and close in the edge to edge
relation with marking paper between the
incisors
5. Contacts other than incisal edges should be
adjusted.
Grinding should be done in maxillary teeth.
Mandibular incisors should be adjusted only if
tooth is positioned facially, pain or sensitivity.

36. Step 5: Correction of protrusive excursion
• Protrusive interferences are on distal facing
inclines of the maxillary teeth and mesial
facing inclines of the mandibular teeth.
• Two color method should be followed.
• Red marking ribbon- protrusive glides- identify
the prematurities.
• Blue marking ribbon: ICP contacts.
• Eliminate the red marking contacts. Primarily
in the lingual cusp of the maxillary teeth.

37. Step 6: Remove the mediotrusive
(balancing side) interferences
• They are seen as oblique facets in the first and
second molar teeth (inner inclines of the
mandibular buccal cusps and inner inclines of
the maxillary lingual cusps).
• Excursion and passive manipulation of the
mandible should be used to identify the
mediotrusive interferences.
• Two color method should be used.
• Make fossa for the smooth passage of the
opposing cusps.

39. Step 7: Reduce interferences on the
laterotrusive side
• Lateral guidance is dominated by canine and
premolar teeth.
• Canine contributes for disclusion of teeth.
• If canine wears away, posterior single tooth contacts
will occur and present as prematurities.
• Canine disclusion angle should be high enough for
avoiding mediotrusive contact on opposite side.
• Grooving should be done to establish inclines.

41. Step 8: Eliminate gross occlusal
disharmonies
• Extruded teeth.
• Plunger cusp.
• Uneven adjacent marginal ridges.
• Rotated, malposed teeth.
• Facets, flat occlusal wear.

43. Step 9: Check Tooth contact
relationships
• Tooth contact should be bilateral multi-
pointed and equal.
• Trial carving of the articulated casts should be
done

44. Step 10:
• Polish all the rough tooth surfaces.

45. THANK YOU