1. Fundamentals of occlusion include the anatomy of the temporomandibular joints, dentition, and muscles. Centric relation is the reliable reference position with condyles seated in the glenoid fossae. 2. Mandibular movements include rotation around the sagittal, frontal, and horizontal axes as well as border movements. Anatomic determinants like condylar guidance and anterior guidance affect occlusion. 3. Organizations of occlusion include bilaterally balanced, unilaterally balanced, and mutually protected occlusions. Criteria for normal occlusion include stable posterior contacts and centric relation coinciding with maximum intercuspation.

1. Fundamentals of occlusion
Ashwini Narayankar
Reader, Department of Prosthodontics
S B Patil Dental college, Bidar

2. Fundamentals of
occlusion
Anatomy
Centric
relation
Mandibular
movement
Organization
of occlusion
Anatomic
determinants

3. Anatomy
• Temporomandibular Joints :

5. Ligaments

7. Musculature

10. Dentition
• Maximum intercuspation and condylar disc
• Angles class I relationship
• Malocclusion

11. Centric relation
• Anterosuperior position
• Bilateral condyle-disk assemblies are fully seated in their
corresponding glenoid fossae, with the condyles
positioned along the anterior slope of the articular
eminence.
• Reliable and reproducible reference position.
• Intercuspal position coinciding with the centric relation
position

12. Mandibular movement

13. Reference planes
• Sagittal axis
• Anteroposterior axis passing through other condyle
• Condyle moves to one side, opposite side condyle travels
forward
• Frontal plane – downward arc

14. Horizontal axis
• Sagittal plane
• Purely rotational opening and closing movement around
transverse hinge axis

15. Vertical axis
• Horizontal plane
• Lateral excursion movements
• Working side condyle

16. Border movements

17. MP
MO
ICP
RCP
HA
MP = Maximal protrusion
ICP = Intercuspal position
RCP= Retruded Contact position
HA = Hinge axis
MO = Maximum opening
Posselt’s Figure

18. Posterior and anterior determinants

20. Effects of anatomic determinants
Condylar Guidance
• Average – 30.4 degrees
• Shallow – short cusps
• Steep – longer cusps

21. Anterior Guidance
• Protrusive incisal path inclination
• Vertical overlap
• Pronounced vertical overlap – longer cusps
• Minimum anterior overlap – shorter cusps

22. • Horizontal overlap
• Pronounced horizontal overlap – short cusps
• Minimum horizontal overlap – longer cusps

23. • Molar disocclusion
– MB cusp tips of mandibular 1st molar
– Working – 0.5mm
– Non working – 1mm
– Protrusive – 1.1mm

24. Organization of occlusion
• Bilaterally balanced occlusion
• Von Spee and Monson
• Maximum number of teeth in maximum intercuspation
• Complete dentures
• Wear, forces

25. Unilaterally balanced occlusion
(group function)
• Schuyler
• Functionally generated path technique – Meyer
• Mann and Pankey et al – complete mouth occlusal
reconstruction

26. Mutually protected occlusion
• Stuart, and Stellard
• CR coincides with maximum ICP

27. 1. Uniform contact of all teeth around the arch when the
mandibular condylar processes are in their most superior
position
2. Stable posterior tooth contacts with vertically directed
resultant forces
3. Centric relation coincident with maximum intercuspation
(CR = MI)
4. No contact of posterior teeth in lateral or protrusive
movements

28. • A full complement of teeth exists
• The supporting tissues are healthy
• There is no cross bite
• The occlusion is angle class I

30. Occlusal interferences
– Undesirable occlusal contacts
• Centric interference

31. • Working interference

32. • Non working interference

33. • Protrusive interference

34. Normal versus pathologic occlusion
• 10% population

36. Criteria for normal occlusion
• In closure, the condyles are in most superoanterior
position against discs on the posterior slopes of the
eminences of the glenoid fossae, posterior teeth in firm
contact and anterior light contact
• Occlusal forces are in the long axes of the teeth
• Lateral excursions, working side contacts disoccludes
nonworking teeth
• Protrusive excursions, anterior teeth contact will
disoccludes posterior teeth

37. • Teeth
– Hypermobility, open contacts wear, migration,
cusp fracture
• Periodontium
– Widened PDL space, bone loss
• Musculature
– Tenderness, trismus

38. Occlusal treatment
• Occlusal device therapy

39. References
• Shillingburg et al, Fundamentals of fixed prosthodontics,
3rd edition, 2002, Quintessence publishers, India, pp 11-
24
• Rosenstiel, Land and Fujimoto, Contemporary Fixed
Prosthodontics, 3rd edition, 2002, Harcourt Publishers,
India, pp 83 – 107
• Tylman’s Theory and practice of fixed prosthodontics, 8th
edition,1997, ishiyaku euroamerica publishers, India, pp
301-324

40. • Dawson P.E , Evaluation, diagnosis, and treatment of
occlusal problems, 2nd edition,1989, Mosby publishers ,
U.S.A.
• Klinebarg I, Jagger R, occlusion and clinical practice an
evidence based approach, 3rd edition, 2006Elsevier
publications, London, pp 3 – 22
• www.egydental.com