1. Oregon Dental Assistants Association
Occlusion & Facial Profiles
where is your clue?

2. Oregon Dental Assistants Association Disclaimer
All diagrams are courtesy of the following websites:
dhonline.chattanoogastate.edu
quizlet.com/ /skeletal-and-occlusal-classifications-oral anatomy-flash-cards
Dentistry/Fall 2012

3. Oregon Dental Assistants Association
Prepared by:
Sheri Billetter CDA, EFDA, MADAA BS
There are 39 slides to view. For credits refer to the exam and answer sheet for instructions

4. Centric Occlusion
The relationship of the occlusal surfaces of one arch to those of the opposing arch.
posterior teeth are closed in a relaxed normal position.
anterior teeth have light contact.
each person has their own individual centric occlusion.

5. Angles Classification of Occlusion
Dr. Edward Angle developed classifications for occlusion in 1890.
he based his finding on the maxillary molar.
it is important to remember that the mesiobuccal cusp of the maxillary 1st molar is the key to occlusion.
exactly how does it interdigitate (“fit”) with the mandibular 1st molar?

6. Angle’s Classification of Occlusion
Class I – Normal
also known as neutro-occlusion
the MB cusp of maxillary 1st molar rests in the MB groove of mandibular 1st molar.

7. Class I
Look where mesiobuccal cusp of the maxillary 1st molar is located in comparison to the mandibular molar. Also look where the cuspids line up.

8. Angle’s Classification of Occlusion
Class II - Division 1
Distal Occlusion - Bucky Beaver appearance.
maxillary incisors tip outward from crowding.
MB cusp of the maxillary 1st molar is forward on the MB cusp of the mandibular 1st molar.

9. Class II
Notice the location of the MB cusp of the maxillary 1st molar.

10. Angle’s Classification of Occlusion
Class II - Division 2
Distal Occlusion - Bucky Beaver crowded.
maxillary laterals protrude (tip facially)
centrals retrude (tip lingually)
MB cusp of the maxillary 1st molar is forward of the MB cusp of the mandibular 1st molar.

11. Class II Division 2
Notice how far forward the MB cusp of the maxillary 1st molar is. Also the cuspid relationship and crowding in the anterior.

12. Angle’s Classification of Occlusion
Class III
Also known as Mesial Occlusion
Jay Leno, Carol Burnett - protruded jaw.
lower jaw appears longer - may have a bulldog appearance.
maxillary incisors are “inside” mandibular incisors when jaws are closed.
MB cusp of the maxillary 1st molar is posterior of the MB cusp of the mandibular 1st molar.

13. Class III
Location of the MB cusp of the maxillary 1st molar is distal on mandible. Cuspids and centrals are out of proper alignment.
A Bulldog appearance is common.

14. Types of Occlusion Ideal Occlusion RARE - Seldom Occurs
there is a complete harmonious balance in the relationship of the teeth and other structures.
all 32 teeth are present .
all 138 occlusal contacts are in a specific pattern.
uses the 1st molar relationship.
maxillary anteriors (slightly) overlap the mandibular anteriors by 1/3.

15. Types of Occlusion Normal Occlusion variations are minimal.
functional stability of alignment and occlusion are maintained.
1st molar relationship is the key.
molar relationship the same as ideal occlusion.

16. Types of Malocclusion What is malocclusion?
any deviation from the ideal.
can be minor, moderate or severe.
may involve several teeth .
can include jaw position.
1st molar relationship is not always involved.

17. Types of Malocclusion Openbite
there is an existing space between the mandibular and maxillary teeth.
may be anterior openbite.
may be posterior openbite.
may be unilateral (one side).
or bilateral (both sides).

18. Open Bite
anterior

19. Types of Malocclusion Overbite
very deep vertical overlap - incisal edges of maxillary incisors extend far over the mandibular central incisors - can extend to the gingiva in severe cases.
maxillary incisors are over the mandibular incisors far more than the 1/3 overlap.

20. Normal - Moderate - Severe Overbites

21. Types of Malocclusion Overjet
there is a horizontal overlap creating a protrusion or space.
between the labial surface of the mandibular incisors and the lingual surface of the maxillary incisors.

22. Types of Malocclusion
Severe Overjet
and posterior crossbite

23. Types of Malocclusion Crossbite
teeth are positioned to the facial, buccal or lingual in contrast to its antagonist (opposing tooth).
can be maxillary or mandibular teeth.
Can be anterior or posterior.

24. Malocclusion - Anterior Crossbite
Anterior crossbite before and after correction.

25. Malocclusion - Posterior Crossbite
Unilateral Posterior Crossbite - only on one side.

26. Malocclusion - Posterior Crossbite

27. Types of Malocclusion Edge to Edge occurs in the anterior teeth.
the incisal edges contact each other edge to edge.
a cross bite or pre-crossbite condition can exist.

28. Types of Malocclusion
Underbite

29. Types of Malocclusion End to End occurs in the molar areas
there is no interdigitation of cusps or fossas -
interdigitation is a natural fitting together.
a cross bite or pre-crossbite condition can exist.

30. Malocclusion
a malocclusion or deviation can be genetic or created by habits or muscular dysfunction such as:
thumbsucking or reverse swallowing
malocclusion classification depends on: the intensity, duration, how often it happens and the age it began.

31. Facial Profiles
Facial profiles are based on an imaginary line from the forehead, through the ala of the nose and to the chin.
Mesiognathic - considered a normal profile.
Prognathic the mandible protrudes outward.
Retrognathic - the mandible retrudes, is small or under developed.

32. Facial Profiles

33. Deviations in Tooth Position
Torsoversion
a tooth may be rotated ie: buccal wall may face the lingual.
Infraversion
tooth is not completely erupted.
Supraversion
super erupted (over erupted).
Transversion
tooth is in the wrong place in the arch.

34. Form and Function Curve of Spee
a curvature formed by the maxillary and mandibular arches in occlusion.
curvature of the occlusal plane from the posterior to the anterior.

35. Curve of Spee

36. Form and Function Curve of Spee Mandibular Arch
forms a slight curve inward
concave (like the inside of a bowl)
Maxillary Arch
forms a slight curve outward
convex (like the outside of a bowl)

37. Form and Function Curve of Wilson
cross arch curvature of the posterior occlusal plane
extends from the tip of the right molar
across the arch to the tip of the left molar
from the left to the right across the arch

38. Curve of Wilson

39. Form and Function
Functions of the Curve of Spee and the Curve of Wilson
accounts for strength and efficiency in chewing and the stability of teeth.
aids in defining occlusion.
aids in denture construction.
balances the arches for orthodontics.