Classification of malocclusion

3. OCCLUSION,
MALOCCLUSION AND
ITS CLASSIFICATION
DR. GOLAM SOROAR
FCPS TRAINEE, DDCH

4. Introduction
The study of occlusion involves the entire
stomatognathic system, the understanding of
the inter relationship between the teeth,
periodontal tissues, bones, joints, muscles, and
nervous system during the full range of
mandibular movements as well as the normal
functional movements.
The study of occlusion is essential for the
proper undertsnding and for achieving the
objectives of orthodontic treatment.

5. Definitions
 Occlusion: Occlusion may be defined as the
contact relationship between maxillary and
mandibular teeth in function and parafunction.
 Normal occlusion: The ward “Normal” simply
implies a situation commonly found in the
absence of disease.
Normal occlusion usually involves occlusal
contact, alignment of teeth, overjet, overbite,
arrangement and relationship of teeth to
osseous structure.

6. Cont…
 Ideal occlusion: The structural and
functional relationship of maxilla and
mandible that include idealized
principles and characteristics that an
occlusion should have.
 Balanced occlusion: An occlusion in
which balanced and equal contacts are
maintained throughout the entire arch
during all excursions of the mandible.

7. Cont…
 Functional occlusion: It is defined as an
arrangement of teeth, which will provide
the highest efficacy during all the
excursive movements of the mandible,
which are necessary during function.
 Physiological occlusion: An occlusion
which has no signs of occlusion related
pathosis.
It may not be an ideal occlusion.

8. Cont…
Traumatic occlusion: It is an abnormal
occlusal relation that is capable of
producing or has produced an injury to
the periodontium.
Theraputic occlusion: An occlusion that
has been modified by appropriate
therapeutic modalities in order to
change a non-physiological occlusion to
that is at least physiologic if not ideal.

9. Cont…
 Centric relation: It may be defined as
the relation between maxilla and
mandible in which the mandibular
condyles are in the most superior and
retruded position in their glenoid fossa
with the articular discs properly
interposed.

10. Cont…
 Centric occlusion: The occlusion in
which maxillary and mandibular teeth
are in maximum intercuspal contact with
the centric relation of the mandible.
 Eccentric relation: Other than centric
relation is called eccentric relation. It
may be lateral, protruded or retruded
occlusion.

11. Cont…
 Canine guided or protected occlusion:
During lateral movement of mandible,
the opposing upper and lower canines
of the working side comes in contact
resulting in disocclusion of all posterior
teeth.
This type of occlusion is seen in young
adults with unworn dentition.

12. Cont…
 Mutually protected occlusion: The
occlusion in which the posterior teeth
prevent excessive contact of the
anterior teeth in maximum
intercuspation and the anterior teeth
disengage the posterior teeth in all
mandibular excursive movements.

13. Cont…
 Group function occlusion: It may be
defined as the multiple contact
relationship between the maxillary and
mandibular teeth, in lateral movements
of the working side; where by
simultaneous contacts of several teeth
is achieved and they act as a group to
distribute occlusal forces

14. Andrew’s six keys to normal
occlusion.
 Key 1: Molar
realtion- The mesio-
buccal cusp of
maxillary 1st
permanent molar
should occlude in the
anterior buccal
groove of mandibular
1st
permanent molar.

15. Cont…
 Key 2: Crown
angulation- The
gingival part of
the long axis of
the crown must
be distal to the
occlusal part.

16. Cont…
 Key 3: Crown inclination-
The crowns of the
maxillary incisors are so
placed that the incisal
portion of the labial
surface is labial to the
gingival portion of the
clinical crown. In all other
crowns, the occlusal
portion of the labial or
bucccal surface is lingual
to the gingival portion.

17. Cont…
 Key 4: Absence of rotation- All teeth
must be free from any undesirable
rotations.
 Key 5: Tight contacts- All teeth must
have tight contact points.
 Key 6: Flat curve of spee- Curve of
spee should flat.

18. Compensatory curvatures
 Curve of spee: It refers to the
antero-posterior corvature of the
occlusal surfaces, beginning at
the lower cuspid and following
cusp tip of the bicuspids and
molars continuing as an arc
through the condyle. If the curve
is extended it forms a circle of
about 4 inches diameter.

19. Compensatory curvatures
 It is measured from the most prominent
cusp of the lower 2nd
molar to the lower
central incisor. More than 1.5 mm deep
curvature in not acceptable.

20. Compensatory curvatures
 Curve of wilson: If a line is
drawn from the buccal cusp
tip to the lingual cusp tips of
mandibular posterior teeth
and extended to the
opposite side, it forms
another curvature, which is
termed as curve of wilson
This is due to inward
inclination of the posterior
teeth.

21. Compensatory curvatures
 Curve of monson: ?????????

23. Malocclusion and It’s
Classification
Malocclusion may be defined as appreciable deviations
from the ideal that may be considered aesthetically or
functionally.
Classification of malocclusion is the description of
dentofacial deviations according to a common
characteristic or norm

24. Types of Malocclusion
Intra arch Malocclusion
Inter arch Malocclusion
Skeletal Malocclusion

25. Intra-arch malocclusion
Includes individual tooth position, variations
and malocclusions affecting a group of
teeth within an arch.
 Inclinations-
mesial,distal,lingual
and buccal
 Displacements-
mesial, distal,lingual
and buccal.
 Infra occlusion
 Supra occlusion
 Rotations
 Transposition

26. Intra Arch Malocclusion

27. Intra Arch Malocclusion

28. Inter-arch malocclusion
Malrelation of dental arches to one
another upon skeletal bony basis that
may themselves be normally related.
 Sagittal plane malocclusions
 Vertical plane malocclusions
 Transverse plane malocclusions

29. Sagittal plane malocclusions
 Pre-normal
occlusion
Mandibular arch
anteriorly placed in
centric occlusion.
 Post-normal
occlusion
Mandibular arch
posteriorly placed in
centric occlusion.

30. Vertical plane malocclusions
 Deep bite
Excessive vertical
overlap between
maxillary and
mandibular anteriors.
 Open bite
No vertical overlap.
- Anterior region
- Posterior region

31. Transverse plane
malocclusions
Includes various types of cross bites.
Poterior cross biteAnterior cross bite

32. Skeletal malocclusion
 Includes defects in underlying skeletal structure.
 Due to abnormalities in maxilla or mandible in size,
position or relationship between jaws.
 Sagittal abnormalities

Prognathism

Retrognathism

Combinations
 Transverse abnormalities

Narrowing and widening of jaws causes crossbites
 Vertical abnormalities

Variation affects lower facial height.

33. Systems of Classification of
Malocclusion
1. Angle’s classification
2. Dewey’s modification of Angle’s
classification
3. Lischer’s modification of Angle’s
classification
4. Bennet’s classification
5. Simon’s classification
6. Ackermann-Profitt classification
7. Incisor classification

34. Angle’s classification
 It was introduced by Edward Angle in 1899.
 Based on mesiodistal relationship of teeth, dental arches
and jaws.
 Maxillary 1st
molar is taken as key to occlusion.
Three classes :
 Class I
 Class II

Class II division I

Class II division II

Class II subdivision
 Class II division I subdivision
 Class II division II subdivision
 Class III

True Class III

Pseudo Class III

Class III subdivision

35. Class I
 Normal inter-arch molar relation
 The anterior buccal grove of mandibular 1st
permanent
molar occlude with the anterior buccal cusp of the
maxillary 1st
permanent molar.
 Dental irregularities

Crowding

Spacing

Rotations

Missing teeth
 Normal skeletal retaionships.
 Normal muscle function.
 Includes bimaxillary proclination – normal Class I molar
relationship but the dentitions of both arches are forwardly
placed in relation to the facial profile.

36. Class-I Malocclusion

37. Class II
 The lower arch occlude at least half a cusp
distal than normal in relation to the upper
arch.
Class II division I
 Characterized by proclined upper
incisors,therefore, increased overjet.
 Lip trap and abnormal muscle activity like
hypotonic upper lip or hypertonic mentalis
and buccinator may be associated.

38. Class II division II
 Characterized by lingually inclined upper
central incisors and labially tipped upper
lateral incisors overlapping the centrals.
Class II subdivision
 Class II molar relation exist on one side
and Class I molar relation on the other
side.
 Class II division I subdivision
 Class II division II subdivision

39. Division 1
Class-ІІ Malocclusion
Division 2

40. Class III
 The lower dental arch occlude at least half a cusp
mesial than normal in relation to the upper dental
arch.

True Class III

Pseudo Class III

Class III subdivision
 True Class III – Skeletal Class III malocclusion of
genetic origin. Characterized by -
 Excessively large mandible
 Forwardly placed mandible
 Maxilla is smaller than normal
 Combinations

41.  Pseudo Class III – Produced by forward
movement of mandible during jaw closure
 Also called postural/habitual Class III
 Due to

Occlusal prematurities

Premature loss of posterior deciduous.
 Class III subdivision – Class III molar
relation on one side and Class I on the
other.

42. Class-III Malocclusion

43. Advantages of Angle’s
Classification
 First comprehensive classification.
 Most widely accepted.
 Simple
 Easy to use
 Conveys precisely the relationship of
mandibular teeth with the maxillary 1st
permanent molar.

44. Drawbacks of Angle’s
Classification
 Considers malocclusion only in the
anteroposterior plane and not in transverse/
vertical planes.
 Considered 1st
permanent molar as fixed
points in the skull, not found to be so.
 Cannot be applied if 1st
permanent molar is
missing or to deciduous dentition.
 Doesn’t distinguish between skeletal/dental
malocclusion.
 Doesn’t highlight etiology.

45. Dewey’s modification of Angle’s
classification
Angle’s Class I
 Type I – Class I with crowded anteriors.
 Type II – Class I with protrusive maxillary
incisors.
 Type III – Class I with anterior cross bite.
 Type IV – Class I with posterior cross bite.
 Type V – Mesially drifted permanent molars
due to early extraction of deciduous.

46. Incisor classification
 Class I
 Class II

Division I

Division II
 Class III
Class II
div 1
Class I Class II
div 2
Class III

47.  Class I
Mandibular incisor edges occlude with or
lie immediately below the cingulum
plateau of the maxillary central incisors.
 Class II
Mandibular incisor edges lie posterior to
the cingulum plateau of the maxillary
central incisors.

Division I

Division II

48. Division I
Maxillary central incisors are proclined or of
average inclination and there is an increased
overjet.
Division II
Maxillary central incisors are retroclined; the
overjet is normally decreased, but maybe
increased.
 Class III
Mandibular incisor edges lie anterior to the
cingulum plateau of the upper central incisors;
the overjet is decreased or reversed.

49. Incisor Classification
Class-I Class-II Class-III

50. Conclusion
Normal alignment of teeth not only
contributes to the oral health but also goes a
long way in the overall well-being and
personality. Correct tooth position is an
important factor for esthetics, function and for
overall preservation of dental health. So
malocclusion should be considered as a
factor that may affect a person’s physical and
mental health as well as his social status.