OCCLUSION (PART III)
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

www.indiande...
Contents





Introduction
Posterior controlling factors
Anterior controlling factors
Understanding the controlling
fa...
Vertical determinants of occlusal
morphology (on cusp height)
Horizontal
determinants
of
occlusal morphology (on ridge a...
Introduction




The occlusal anatomy of the teeth must
function in harmony with the structures
controlling the movement...
Posterior controlling factors

www.indiandentalacademy.com
The angle at which the condyle moves
away from horizontal reference plane is
referred to as the condylar guidance
angle.
...
Anterior controlling factors
Vertical overlap and horizontal overlap
Variable factor (altered by dental
procedures)

www...
Understanding the controlling factors
If the criteria for optimum functional
occlusion has to be fulfilled, the
morpholog...
www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
Therefore, the significance of the
anterior and condylar guidances lies in
how they influence posterior tooth
shape.
www.i...
Occlusal surface of the posterior teeth can be
affected in 2 manners
1. Height
2. Width
 Factors that influence the heigh...
Vertical determinants of occlusal
morphology (on cusp height)
a) Effect of condylar guidance
b) Effect of anterior guidanc...
a) Effect of condylar guidance

www.indiandentalacademy.com
www.indiandentalacademy.com
b) Effect of anterior guidance
It is a function of the relationship
between the maxillary & mandibular
anterior teeth.
A...
www.indiandentalacademy.com
c) Effect of plane of occlusion
It is an imaginary line extending from
cusp tip of mandibular canine to
distobuccal cusp ...
www.indiandentalacademy.com
www.indiandentalacademy.com
As the plane of occlusion becomes
more nearly parallel to the angle of the
articular eminence, the posterior cusps
must be...
d) Effect of curve of Spee
3 components affecting the cusp
height are:
a) Length of the radius of the curve
b) Degree of c...
Length of the radius of the curve

www.indiandentalacademy.com
Degree of curvature of the curve of
Spee

www.indiandentalacademy.com
Orientation of curve of Spee

www.indiandentalacademy.com
e) Effect of mandibular lateral
translation movement
Bennett movement- A bodily side shift
of the mandible that occurs dur...
The degree of medial movement of
orbiting condyle depends on two
factors :
a. Morphology of medial wall of the
fossa.
b. I...
www.indiandentalacademy.com
Lateral translation movement has 3
attributes
1. Amount
2. Direction
3. Timing
 Amount and Timing are dependent on
medial...
www.indiandentalacademy.com
Effect of amount of lateral translation
movement on cusp height

Greater the amount of lateral translation
movement, short...
Effect of the direction of lateral
translation movement on cusp height
Determined by the morphology and
ligamentous attac...
www.indiandentalacademy.com
Effect of timing of lateral translation
movement on cusp height
Dependent on the medial wall of fossa
and TM ligament.
I...
www.indiandentalacademy.com
Horizontal determinants of occlusal
morphology
Influences the direction of ridges and
grooves on the occlusal surfaces
E...
www.indiandentalacademy.com
Horizontal determinants of occlusal
morphology (on ridge and groove
direction)
a) Effect of distance from rotating condyle...
a)Effect of distance from rotating
condyle

Greater the distance – wider the angle
www.indiandentalacademy.com
b) Effect of distance from midSagittal plane

More the distance – wider the angle
www.indiandentalacademy.com
c) Effect of distance from rotating
condyle and from mid-Sagittal plane
 The combination of the two positional
relationsh...
Therefore, the teeth toward the
anterior region (e.g. premolars) have
larger angles than posterior teeth
(e.g. molars).
ww...
d) Effect of mandibular lateral
translation movement
 influences the directions of ridges
and grooves
Movement depends on...
Effect of amount of lateral
translation movement on ridge and
groove direction

www.indiandentalacademy.com
Effect of direction of lateral
translation movement on ridge and
groove direction

www.indiandentalacademy.com
e) Effect of inter-condylar distance
 As inter condylar distance increases –
distance between the condyle and the
tooth i...
Increase in inter-condylar distance – decrease in
angle between mediotrusive and laterotrusive
pathways
www.indiandentalac...
Summary
Vertical determinants of occlusal
morphology (on cusp height and
fossa depth)
Horizontal
determinants
of
occlusa...
Factor

Condition

Effect

Condylar
guidance

Steeper

Taller

Anterior
guidance

More overbite
More Overjet

Taller
Short...
Factor

Condition

Effect

Distance from
rotating condyle

Greater

Wider the angle

Distance from
midsagittal plane

Grea...
References
 Occlusion series in BDJ, 2001;191:6-

7


Okeson
JP.
Management
of
Temporomandibular
Disorders and
Occlusion...
Santos JD. Occlusion Principles and
Concepts, ed. 2nd, 1999; Ishiyaku
EuroAmerica, Inc. U.S.A.
 Shillingburg HT. Fundame...
Thank you
For more details please visit
www.indiandentalacademy.com

www.indiandentalacademy.com
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Occlusion part(iii) /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078

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Occlusion part(iii) /certified fixed orthodontic courses by Indian dental academy

  1. 1. OCCLUSION (PART III) INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. Contents     Introduction Posterior controlling factors Anterior controlling factors Understanding the controlling factors www.indiandentalacademy.com
  3. 3. Vertical determinants of occlusal morphology (on cusp height) Horizontal determinants of occlusal morphology (on ridge and groove direction) Summary References www.indiandentalacademy.com
  4. 4. Introduction   The occlusal anatomy of the teeth must function in harmony with the structures controlling the movement patterns of the mandible. To maintain harmony of the occlusal condition, the posterior teeth must pass close to but must not contact their opposing teeth during mandibular movement www.indiandentalacademy.com
  5. 5. Posterior controlling factors www.indiandentalacademy.com
  6. 6. The angle at which the condyle moves away from horizontal reference plane is referred to as the condylar guidance angle. Two TMJ’s factors –posterior controlling Fixed factors www.indiandentalacademy.com
  7. 7. Anterior controlling factors Vertical overlap and horizontal overlap Variable factor (altered by dental procedures) www.indiandentalacademy.com
  8. 8. Understanding the controlling factors If the criteria for optimum functional occlusion has to be fulfilled, the morphologic characteristics of each posterior tooth must be in harmony with those of its opposing tooth or teeth during all eccentric mandibular movements. The relationship of a posterior tooth to the controlling factors influences the precise movement of that tooth. www.indiandentalacademy.com
  9. 9. www.indiandentalacademy.com
  10. 10. www.indiandentalacademy.com
  11. 11. www.indiandentalacademy.com
  12. 12. Therefore, the significance of the anterior and condylar guidances lies in how they influence posterior tooth shape. www.indiandentalacademy.com
  13. 13. Occlusal surface of the posterior teeth can be affected in 2 manners 1. Height 2. Width  Factors that influence the heights of cusps and depths of fossae are the vertical determinants of the occlusal morphology  Factors that influence the direction of ridges and grooves on the occlusal surfaces are considered the horizontal determinants of the occlusal morphology www.indiandentalacademy.com
  14. 14. Vertical determinants of occlusal morphology (on cusp height) a) Effect of condylar guidance b) Effect of anterior guidance c) Effect of plane of occlusion d) Effect of curve of Spee e) Effect of mandibular lateral translation movement www.indiandentalacademy.com
  15. 15. a) Effect of condylar guidance www.indiandentalacademy.com
  16. 16. www.indiandentalacademy.com
  17. 17. b) Effect of anterior guidance It is a function of the relationship between the maxillary & mandibular anterior teeth. Anterior guidance = Overjet X overbite www.indiandentalacademy.com
  18. 18. www.indiandentalacademy.com
  19. 19. c) Effect of plane of occlusion It is an imaginary line extending from cusp tip of mandibular canine to distobuccal cusp of lower second molar Relationship of this plane to the angle of articular eminence influences the steepness of the cusps. www.indiandentalacademy.com
  20. 20. www.indiandentalacademy.com
  21. 21. www.indiandentalacademy.com
  22. 22. As the plane of occlusion becomes more nearly parallel to the angle of the articular eminence, the posterior cusps must be made shorter. www.indiandentalacademy.com
  23. 23. d) Effect of curve of Spee 3 components affecting the cusp height are: a) Length of the radius of the curve b) Degree of curvature of the curve of Spee c) Orientation of curve of Spee www.indiandentalacademy.com
  24. 24. Length of the radius of the curve www.indiandentalacademy.com
  25. 25. Degree of curvature of the curve of Spee www.indiandentalacademy.com
  26. 26. Orientation of curve of Spee www.indiandentalacademy.com
  27. 27. e) Effect of mandibular lateral translation movement Bennett movement- A bodily side shift of the mandible that occurs during lateral movements. www.indiandentalacademy.com
  28. 28. The degree of medial movement of orbiting condyle depends on two factors : a. Morphology of medial wall of the fossa. b. Inner horizontal portion of the Temporomandibular ligament (which attaches to the lateral pole of the rotating condyle) www.indiandentalacademy.com
  29. 29. www.indiandentalacademy.com
  30. 30. Lateral translation movement has 3 attributes 1. Amount 2. Direction 3. Timing  Amount and Timing are dependent on medial wall of fossa and TM ligament.  Direction depends on the direction taken by the rotating condyle. www.indiandentalacademy.com
  31. 31. www.indiandentalacademy.com
  32. 32. Effect of amount of lateral translation movement on cusp height Greater the amount of lateral translation movement, shorter is the posterior cusp www.indiandentalacademy.com
  33. 33. Effect of the direction of lateral translation movement on cusp height Determined by the morphology and ligamentous attachments of the TMJ undergoing rotation. The movement occurs within a 60 degree cone whose apex is located at the axis of rotation. www.indiandentalacademy.com
  34. 34. www.indiandentalacademy.com
  35. 35. Effect of timing of lateral translation movement on cusp height Dependent on the medial wall of fossa and TM ligament. Immediate side shift – when the lateral translation movement occurs early Progressive side shift – if movement occurs in conjunction with an eccentric movement www.indiandentalacademy.com
  36. 36. www.indiandentalacademy.com
  37. 37. Horizontal determinants of occlusal morphology Influences the direction of ridges and grooves on the occlusal surfaces Each centric cusp tip generates both laterotrusive and mediotrusive pathways across its opposing tooth Each pathway represents a portion of the arc formed by the cusp rotating around the rotating condyle www.indiandentalacademy.com
  38. 38. www.indiandentalacademy.com
  39. 39. Horizontal determinants of occlusal morphology (on ridge and groove direction) a) Effect of distance from rotating condyle b) Effect of distance from mid-Sagittal plane c) Effect of distance from rotating condyle and from mid-Sagittal plane d) Effect of mandibular lateral translation movement e) Effect of inter-condylar distance www.indiandentalacademy.com
  40. 40. a)Effect of distance from rotating condyle Greater the distance – wider the angle www.indiandentalacademy.com
  41. 41. b) Effect of distance from midSagittal plane More the distance – wider the angle www.indiandentalacademy.com
  42. 42. c) Effect of distance from rotating condyle and from mid-Sagittal plane  The combination of the two positional relationships is what determines the exact pathways of the centric cusp tips  Because of the curvature of the dental arch; as the distance of tooth from rotating condyle increases – distance from midsagittal plane decreases, but distance from rotating condyles increases FASTER than decrease in distance from midsagittal plane. www.indiandentalacademy.com
  43. 43. Therefore, the teeth toward the anterior region (e.g. premolars) have larger angles than posterior teeth (e.g. molars). www.indiandentalacademy.com
  44. 44. d) Effect of mandibular lateral translation movement  influences the directions of ridges and grooves Movement depends on 2 factors: 1. Amount 2. Direction www.indiandentalacademy.com
  45. 45. Effect of amount of lateral translation movement on ridge and groove direction www.indiandentalacademy.com
  46. 46. Effect of direction of lateral translation movement on ridge and groove direction www.indiandentalacademy.com
  47. 47. e) Effect of inter-condylar distance  As inter condylar distance increases – distance between the condyle and the tooth increases – wider angles (in a given arch configuration)  As inter condylar distance increases – the tooth is placed nearer the mid-sagittal plane relative to the rotating condylemidsagittal plane distance – decrease in the angle generated www.indiandentalacademy.com
  48. 48. Increase in inter-condylar distance – decrease in angle between mediotrusive and laterotrusive pathways www.indiandentalacademy.com
  49. 49. Summary Vertical determinants of occlusal morphology (on cusp height and fossa depth) Horizontal determinants of occlusal morphology (on ridge and groove direction) www.indiandentalacademy.com
  50. 50. Factor Condition Effect Condylar guidance Steeper Taller Anterior guidance More overbite More Overjet Taller Shorter Plane of occlusion More parallel Shorter Curve of Spee More acute Shorter Lateral translation Greater movement Shorter More superior Shorter Greater immediate shift Shorter www.indiandentalacademy.com
  51. 51. Factor Condition Effect Distance from rotating condyle Greater Wider the angle Distance from midsagittal plane Greater Wider the angle Lateral translation Greater Wider the angle Intercondylar distance Greater Smaller the angle www.indiandentalacademy.com
  52. 52. References  Occlusion series in BDJ, 2001;191:6- 7  Okeson JP. Management of Temporomandibular Disorders and Occlusion, ed. 4th, 1998; Mosby  Ash MM and Ramfjord S. Occlusion, ed. 4th, 1966; WB Saunders Company, Michigan www.indiandentalacademy.com
  53. 53. Santos JD. Occlusion Principles and Concepts, ed. 2nd, 1999; Ishiyaku EuroAmerica, Inc. U.S.A.  Shillingburg HT. Fundamentals of Fixed Prosthodontics, ed.3rd, 1997;Quintessence www.indiandentalacademy.com
  54. 54. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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