Contents Introduction Rationale for Establishing Tooth Contacts during Fixed Prosthodontics Concepts of Occlusion Occlusion in fixed dental prosthesis Occlusal treatment Conclusion References Introduction Maxillary and mandibular teeth should contact uniformly on closing to allow optimal function, minimize trauma to the supporting structures and allow for uniform load distribution throughout the dentition. Occlusion - The static relationship between the incising or masticating surfaces of the maxillary and mandibular teeth. GPT -9 Centric relation - a maxillomandibular relationship, independent of tooth contact, in which the condyles articulate in the anterior-superior position against the posterior slopes of the articular eminences; in this position, the mandible is restricted to a purely rotary movement; from this unstrained, physiologic, maxillomandibular relationship, the patient can make vertical, lateral or protrusive movements; it is a clinically useful, repeatable reference position. Centric Occlusion [CO] - the occlusion of opposing teeth when the mandible is in centric relation; this may or may not coincide with the maximal intercuspal position. Maximum Intercuspation [MI] - It is the maximum interdigitation of the maxillary teeth with the mandibular teeth independent of condylar position. GPT 9 Anatomy Temporomandibular joint

1. Occlusion in FPD
Guided by
Dr Sudheer Arunachalam
Presented by
Dr Megha Sahu
1

2. Contents
 Introduction
 Rationale for Establishing Tooth Contacts during Fixed
Prosthodontics
 Concepts of Occlusion
 Occlusion in fixed dental prosthesis
 Occlusal treatment
 Conclusion
 References
2

3. Introduction
 Maxillary and mandibular teeth should contact uniformly on closing to allow
optimal function, minimize trauma to the supporting structures and allow for
uniform load distribution throughout the dentition.
 Occlusion - The static relationship between the incising or masticating surfaces
of the maxillary and mandibular teeth. GPT -9
3

4.  Centric relation - a maxillomandibular relationship, independent of tooth
contact, in which the condyles articulate in the anterior-superior position against
the posterior slopes of the articular eminences; in this position, the mandible is
restricted to a purely rotary movement; from this unstrained, physiologic,
maxillomandibular relationship, the patient can make vertical, lateral or
protrusive movements; it is a clinically useful, repeatable reference position.
 Centric Occlusion [CO] - the occlusion of opposing teeth when the mandible
is in centric relation; this may or may not coincide with the maximal intercuspal
position.
 Maximum Intercuspation [MI] - It is the maximum interdigitation of the
maxillary teeth with the mandibular teeth independent of condylar position.
GPT 9
4

5. Anatomy
 Temporomandibular joint
5

6. 6

7. Muscles of mastication
7

8. 8

9. Mandibular movement
 Translation : all the points within a body have identical motion.
 Rotation : the body is turning around an axis.
9

10. Reference planes
10

11. Sagittal plane
 In Sagittal plane , mandible is capable of a purely
rotational movement, as well as translation.
 Rotational movement occurs around terminal hinge axis.
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12. 12

13. Horizontal plane
 In horizontal plane, the mandible is capable of rotation around several
vertical axes.
 e. g. – during lateral movement, rotation occurs around an axis situated in
working condylar process.
 Laterotrusion – A slight translation of rotating condyle.
 Lateroprotrusion - outward and forward movement.
13

14. 14

15. 15

16. Frontal plane
 Frontal plane-
In a lateral movement in frontal plane, the nonworking condyle moves
down and medially, whereas the working condyle rotates around the sagittal
axis.
 Laterosurtrusion – on working side, lateral and upward.
 Laterodetrusion – lateral and downward.
16

17. 17

18. Border movement
 Mandibular movements are limited by the TMJS and ligaments, the
neuromuscular system and the teeth.
 Posselt was the first to describe mandibular movement and he called it
Border movement.
 Starting from the maximum inter cuspation position, in the protrusive
pathway, the lower incisors are initially guided by the lingual concavities
of maxillary anterior teeth. As a result, posterior tooth contact is gradually
lost as the incisors reach to edge to edge contact position.
18

19. 19

20. RATIONALE FOR ESTABLISHING TOOTH
CONTACTS DURING FIXED
PROSTHODONTICS
 Occlusion is the dynamic interplay of various components, including the
teeth, their supporting tissues, the jaw muscles, the temporomandibular
joints (TMJs) and other associated interactions.
 1. Tooth Contacts
There has been debate regarding the number and position of contacts
required to maintain individual tooth stability. Contacts on natural teeth
occur on flat surfaces, marginal ridges, cusp tips, cusp inclines, and in
fossae.
Contacts between teeth result in vertical and lateral forces. The resilience
of the periodontal ligament dissipates some of this stress through
physiological tooth movement.
20

21. 2. Functional movement :
is defined as all normal, proper or characterstic movements of the mandible
made during speech, mastication, yawning, swallowing and associated
activities.
I. Chewing
When incising food, adults open their mouth a comfortable distance and
move the mandible forward until they incise, with the anterior teeth
meeting approximately edge to edge.
The food is then transported to center of mouth as the mandible returns to
its starting position, with the incisal edges of the mandibular anterior
teeth tracking along the lingual concavities of the maxillary anterior
teeth.
The mouth opens slightly, tongue pushes the food onto the occlusal table,
and the mandible closes into the foods until the guiding teeth contact.
21

22.  Mastication usually involves an approximation, but not necessarily contact
between posterior teeth. It is possible to prepare a food bolus for
swallowing without tooth contact.
 The efficiency of comminution of the food bolus will be influenced by the
contour of the occlusal surfaces.
22

23. II. Speaking
 The teeth, tongue, lips, floor of the mouth and soft palate form the resonance
chamber that affects pronunciation.
 During speech, the teeth are generally not in contact, although the anterior
teeth may come very close together during “c” “ch” “s” and “z” sounds
forming the speaking space. (The space that occurs between the incisal
and/or occlusal surfaces of the maxillary and mandibular teeth during
speech).
III. Parafunctional movements
Parafunctional movements of the mandible may be described as sustained
activities that occur beyond the normal functions of mastication, swallowing
and speech.
Tooth clenching and grinding (bruxing) are common forms of parafunction
involving tooth contacts.
23

24.  Oral habits consisting of involuntary rhythmic or spasmotic nonfunctional
grinding or clenching of teeth, other than chewing movements of the
mandible, that may lead to occlusal trauma is known as bruxism.
 May be diurnal, nocturnal or both.
 Patients with bruxism can exert considerable forces on their teeth, and
much of this may have a lateral component. Posterior teeth do not tolerate
lateral forces as well as vertical forces in their long axes. Buccolingual
forces, cause rapid widening of the periodontal ligament space and
increased mobility.
24

25.  Clenching is defined as the pressing and clamping of the jaws and teeth
together frequently in association with acute nervous tension or physical
effort.
 The pressure thus created can be maintained over a considerable time with
short periods of relaxation in between.
 In contrast to bruxism, clenching does not necessarily result in damage to
the teeth because the concentration of pressure is directed more or less
through the long axes of posterior teeth without the involvement of
detrimental lateral forces.
 What is normal physiological activity and what is parafunctional activity?
Clenching during power activities, such as weight lifting, is more likely a
normal physiological action than parafunction.
25

26. Concepts of occlusion
 Broadly categorized
1. Bilaterally balanced occlusion
2. Unilaterlly balanced occlusion / group function
3. Mutually proteceted
26

27. Bilateral balanced occlusion
 The bilateral, simultaneous, anterior, and posterior occlusal contact of teeth
in centric and eccentric positions. GPT 9
27

28. Unilaterally balanced occlusion or
Group function occlusion
 Multiple contact between the maxillary and mandibular posterior teeth in
lateral movements on the working side.
 Widely accepted and used method of tooth arrangement in restorative
dental procedures.
 The group function of the teeth on working side distributes the occlusal
load. The absence of contact on the nonworking side prevents those teeth
from being subjected to destructive, obliquely directed forces found in
nonworking side.
28

29.  Its also saves the centric holding cusp from excessive wear.
 Advantage is maintenance of occlusion.
 Long centric:
As the concept of unilateral balance evolved, it was suggested that allowing
some freedom of movement in an anteroposterior direction is advantageous.
This concept is known as long centric.
Schuyler was one of the first to advocate such occlusal arrangement.
He thought that it was important for the posterior teeth to be in harmonious
gliding contact when the mandible translates from centric relation forward to
make anterior tooth contact.
29

30. Mutually protected occlusion
 Also kown as canine protected occlusion or organic occlusion.
 In 1963, Stuart and Stallard advocated this occlusal scheme.
 They observed that in many mouths with a healthy periodontium and
minimal wear, the teeth were arranged so the overlap of anterior teeth
prevented the posterior teeth from making any contact on either the
working or the non working side during the mandibular excursions.
 The anterior teeth protecting the posterior teeth in all mandibular
excursions and the posterior teeth protecting the anterior teeth at the
intercuspal position.
30

31.  Requirements for a mutually protected occlusion included that the cusps of
posterior teeth should close in centric occlusion with the mandible in centric
jaw relation, while, in lateral excursions only opposing canines should
contact and in protrusion only the anterior teeth should contact.
 In the presence of anterior bone loss or missing canine, the mouth should
probably be restored to group function.
31

32.  D’Amico in 1958 studied the significance of cuspid teeth and presented the
Concept of Canine Guidance (Canine disclusion) in which the maxillary
canine teeth serve to guide the mandible during eccentric movements and
when in functional contact with the lower canines and first premolars,
determine both lateral and protrusive movements of the mandible. Thus
preventing any force other than along the long axis to be applied to the
opposing incisors, premolars and molars.
 Canine protected occlusion refers to disclusion by the canines of all other
teeth in lateral excursions. It usually serves as corner stone of mutually
protected occlusion.
 So, In mutually protected occlusion posterior teeth contact in centric relation
only, the incisors are the only teeth contact in protrusion and the canine are
the only teeth contacting in lateral excursion.
32

33. Pathogenic occlusion
 Pathogenic occlusion is an occlusal relationship capable of producing
pathologic changes in stomatognathic system.
 In such occlusions, disharmony between the teeth and the TMJs is
sufficient to result in symptoms that necessitate intervention.
 Signs & symptoms :
1. Teeth – hypermobility, open proximal contacts or abnormal wear.
2. Periodontium – widened periodontal ligament space may indicate
premature occlusal contact and is often associated with tooth mobility.
3. Musculature – acute or chronic musculature pain on palpation can
indicate habits associated with tension, such as bruxism or clenching.
33

34. Christensen LV. Facial pain and
internal pressure of masseter
muscle in experimental bruxism in
man.
 In one study, subjects were instructed to grind their teeth for approximately
30min. They experienced muscle pain that typically peaked 2 hours after
parafunctioning and lasted as long as 7 days.
 Asymmetric muscle activity can be diagnosed by observing a patient’s
opening and closing movements in frontal plane.
34

35. 4. TMJ
Pain, clicking, or popping in the TMJ can indicate temporomandibular
joint disorders.
Patient may complain of TMJ pain that is actually of muscular origin and
is referred to the joints.
Clicking may also be associated with internal derangements of joints.
A patient with unilateral clicking during opening and closing in
conjunction with a midline deviation may have a displaced articular disk.
5. Myofascial pain dysfunction (MPD)
The MPD syndrome manifests as diffuse unilateral pain in the preauricular
area, with muscle tenderness, clicking, or popping noises in the
contralateral TMJ and limitation of mandibular function.
35

36. Occlusion in fixed dental prosthesis
 tooth supported
 implant supported
36

37.  Tooth supported :
 Similar as occlusion in natural dentition either mutually protected or group
function occlusion.
In the following cases, desirable occlusion should be group function –
1) Periodontally compromised supporting anterior teeth or ant. bone loss.
2) Missing canine
3) Angle class-II and class-III malocclusion
4) Crossbite
37

38. Occlusion in full mouth rehabilitation
 Indications for full mouth rehabilitation :
1. The restoration of multiple teeth which are missing, worn, broken down or
decayed.
2. To replace improperly designed and executed crown and bridge
framework.
3. Loss of vertical dimension.
4. TMJ disorders, etc.
 One of the most practical philosophies is the rationale of treatment that was
originally organized into a workable concept by Dr. L.D. Pankey utilizing the
principles of occlusion espoused by Dr. Clyde Schuyler.
 When it has been determined that restoration of all or most of posterior teeth
is necessary, the PMS tech. provides an excellent and practical method for
determining an occlusal plane that will fulfil all of the requirements of a
correct occlusion.
38

39. PMS philosophy:
1. Static co-ordinated occlusal contact of the maximum number of teeth when
the mandible is in centric relation.
2. An anterior guidance that is in harmony with function in lateral eccentric
position on the working side.
3. Disclusion by the anterior guidance of all posterior teeth in protrusion.
4. Group function of the working side inclines in lateral excursions.
39

40.  Shetty et al. PHILOSOPHIES IN FULL MOUTH REHABILITATION – A
SYSTEMATIC REVIEW Int J Dent Case Reports Nov-Dec 2013, Vol.3,
No. 3
 A healthy 18 year old female patient reported to the Department of
Prosthodontics with a chief complant of discolored teeth. On clinical
examination, chipping of enamel was seen with respect to most teeth with
exposure of dentine. Generalized attrition was observed with respect to all
the occlusal surfaces. Utilizing phonetics and esthetics as a guide, 2 mm
decrease in vertical dimension was observed.
 Full mouth rehabilitation pertaining to the principles and goals of Pankey
Mann Schuyler philosophy was planned.
 A splint was fabricated with an increase in vertical dimension of 2 mm to
be worn by the patient for 6 weeks
40

41. a) Pre operative photograph of Case to be treated by Pankey Mann Schuyler
technique
b) Broadrick’s occlusal plane analysis
c) Tooth preparation of lower anteriors completed
d) Provisionalization of lower anterior teeth.
41

42.  In order to maintain the increase in VD, the mandibular posterior also had
to be prepared in order to prevent posterior open bite. An impression was
made and temporization of the mandibular posterior teeth was done.
 This was followed by fabrication of porcelain fused to metal crowns for the
mandibular anteriors.
 Cementation of the crowns was done using glass ionomer cement.
 The maxillary anterior teeth were prepared next. Centric relation was
recorded at the proposed vertical dimension and casts were mounted in the
same relation. PFM crowns were cemented.
 The mandibular posterior teeth preparations were refined and impressions
made.
 The porcelain crowns fabricated were subject to occlusal plane verification
and then cemented.
42

43. a) Transfer of cusp to fossa relationship
b) Fabrication of fossa guide
c) Wax preparation of the mandibular posteriors using fossa guide
d) Re- establishment of occlusal plane with Broadrick’socclusal plane
analysis
43

44. Occlusion in full mouth rehabilitation
 T Bhawana et al. Occlusal Concepts in Full Mouth Rehabilitation: An
Overview. JIPS
 There has been a search for the ideal occlusal scheme to be followed during
full mouth rehabilitation that would provide optimal muscle and joint
function besides aiming at restoring the occlusal surfaces of teeth.
 An early concept of comprehensive dentistry originated from the
gnathologic society founded by McCollum in 1926. McCollum together
with Stuart published their classic ‘‘Research Report’’ in 1955 and gave the
Gnathological Concept.
44

45. 45

46. 46

47. 47

48.  An organized approach to oral rehabilitation was introduced by Pankey,
utilizing the principles of occlusion advocated by Schuyler , known as the
Pankey– Mann–Schuyler (PMS) Philosophy of Oral Rehabilitation.
 Their philosophy was pertinently based on the spherical theory of
occlusion, the ‘‘wax chew-in’’ technique described by Meyer and Brenner
and on the importance of cuspid teeth as discussed by D’Amico. As a
modification of canine disclusion, the PMS philosophy was to have
simultaneous contacts of the canine and posterior teeth in the working
excursion (group function), and only anterior teeth contact in the
protrusive excursive movement.
48

49. 49

50. Functionally generated path
 In natural articulation, the mandibular teeth move over the maxillary teeth
in a harmonious manner. The cusps move in the fossae and grooves
between the opposing cusps and normally, there is no interference during
the various mandibular movements.
 An alternative method to reproduce a precise occlusion that was developed
way back in the 1930s and is now becoming popular is the functionally
generated path (FGP) technique.
 The original technique was described by Meyer for obtaining the
‘functional occlusal path’ for complete dentures and fixed partial dentures
fabricated. Later, this technique was adapted for use in complete occlusal
rehabilitation by Mann and Pankey.
50

51.  E Prashanti et al.Fabrication of fixed partial dentures using functionally
generated path technique and double casting. Indian J Dent Res 2009 :
20(4) ; 492
 A 26-year-old male patient who required a three-unit fixed partial denture for
replacement of a missing first molar reported to the Department of
Prosthodontics. At the initial appointment, a preliminary impression was made
using irreversible hydrocolloid impression material and the diagnostic casts
were mounted on a semi-adjustable articulator.
 Protrusive records were made using polyether bite registration paste.
 The patient was trained to close in maximum intercuspation position (MIP) and
perform various eccentric movements (right lateral, left lateral, and protrusive).
This was carried out to accustom the patient to the various movements that
would have to be performed later for recording the FGP.
 The tooth preparation for the abutment teeth, gingival displacement, final
impression making, and master die preparation was done following the
principles given by Schillingburg.
51

52. Pre treatment appearance (a).
Fabrication of wax pattern with retentive beads for base casting (b)
These beads would aid in the retention of the pattern resin during
functional generation of the occlusal morphology in the next step
52

53. Base casting checked in the mouth (a). Completed functionally
generated path (b)
53
The occlusal morphology was generated using pattern resin
following the technique described by Dawson.

54. The pattern, along with the base casting, was invested
and double casted, Completed double casting (a).
Double casting with functionally generated path
cemented (b)
54

55. Functionally generated path prosthesis in occlusion
55

56.  Implant supported
1) Full-arch fixed prosthesis –
1) Bilateral balanced occlusion with opposing complete denture
2) Group function occlusion or mutually protected occlusion with shallow
anterior guidance when opposing natural dentition.
2) Overdenture –
1) Bilateral balanced occlusion using lingualized occlusion
2) Monoplane occlusion on a severely resorbed ridge
56

57. 3. Posterior fixed prosthesis –
1) Anterior guidance with natural dentition
2) Group function occlusion with compromised canines
3) Cross bite posterior occlusion when necessary
4) Single implant prosthesis
1) Anterior or lateral guidance with natural dentition
2) Light contact at heavy bite and no contact at light bite
57

58. V Mahesh et al. Principles of occlusion in implant dentistry
Journal of the International Clinical Dental Research
Organization.
 The occlusal rehabilitation schemes for implant-supported prostheses are
derivatives of the occlusal scheme for natural dentition. The implant-
protected occlusion (IPO) scheme has been designed to ensure the
longevity of both prosthesis and implant. The article reviews the concepts
of IPO and their applicability in different clinical scenarios.
 Due to ridge resorption, the direction of the remaining ridge shifts lingually
and the implant body is most often not under the buccal cusp tip position of
natural teeth. In fact, it may be either under or near the central fossa or
more lingual under the lingual cusp of a natural tooth, depending on the
resulting position of the remaining ridge due to resorption.
 All attempts should be made to provide a narrow occlusal table with
reduced buccal contour, improving axial loading, and reducing the risk of
porcelain fracture.
58

59. maxillary natural tooth vs mandibular implant-supported prosthesis
in division a bone
59

60. maxillary implant-supported prosthesis vs mandibular
natural tooth in division a bone
60

61. maxillary implant-supported prosthesis vs mandibular
implant-supported prosthesis in division a bone
61

62. maxillary implant-supported prosthesis vs mandibular
natural tooth in division b-d bone, might require cross-
arch relation of teeth
62

63. Occlusal treatment
 When a patient exhibits signs and symptoms that appear to be associated
with occlusal interference, occlusal treatment should be considered.
 Treatment can be done by:
Tooth movement through orthodontic treatment, elimination of deflective
occlusal contacts through selective reshaping of occlusal surfaces of teeth
or missing teeth restoration and replacement that result in more favourable
distribution of occlusal forces.
63

64.  Objective of occlusal treatment:
1. To direct the occlusal forces along the long axes of the teeth.
2. To attain simultaneous contact of all teeth in centric relation
3. To eliminate any occlusal contact on inclined planes to enhance the
positional stability of teeth.
4. To have centric relation coincide with the maximum intercuspation
position.
5. To arrive at the occlusal scheme selected for the patient.
In the short term, these objectives can be accomplished with a removable
occlusal device.
64

65. Occlusal device therapy:
 Occlusal splints, Occlusal appliances are used extensively in the
management of TMJ disorders and bruxism.
 From a fixed prosthodontic perspective, occlusal devices are particularly
helpful in determining whether a proposed change in a patients occlusal
scheme will be tolerated.
 The anticipate occlusal scheme is mimicked in an acrylic resin overlay,
which allows testing the patients acceptance through reversible means,
although a slightly increased vertical dimension.
 If a patient responds favourably to an occlusal device, it is reasonable to
assume that the response to restorative treatment will be positive as well.
65

66. Conclusion
 Occlusion of FPD with the antagonist should be achieved favourably in
order to fulfil the requirements of mastication, aesthetics, speech and
prevention of TMJs dysfunction.
66

67. References
 Shillingburg. Fundamentals of Fixed prosthodontics. 4th ed.
 Tylman’s Theory and practice of fixed prosthodontics. 8th ed.
 Rosenstiel, Land, Fujimoto. Contemporary Fixed prosthodontics. 3rd ed.
 Christensen LV. Facial pain and internal pressure of masseter muscle in experimental
bruxism in man
 V Mahesh et al. Principles of occlusion in implant dentistry
Journal of the International Clinical Dental Research Organization.
 T Bhawana et al. Occlusal Concepts in Full Mouth Rehabilitation: An Overview. JIPS
 E Prashanti et al.Fabrication of fixed partial dentures using functionally generated path
technique and double casting. Indian J Dent Res 2009 : 20(4) ; 492
67

68. 68