Classification of malocclusion

for better and simple under standing

1. CLASSIFICATION OF MALOCCLUSION UNDER THE GUIDANCE OF : DR. D.K. JAIPURIA DR. JAIDEEP Singh DR. NEHA AGARWAL PRESENTED BY: MAUSAM TIWARI BDS 4 TH YR (10-11) BATCH

2. SYNOPSIS: INTRODUCTION DEFINITIONS: OCCLUSION IDEAL OCCLUSION NORMAL OCCLUSION MALOCCLUSION NEED OF CLASSIFICATION TYPES OF MALOCCLUSION CLASSIFICATION OF MALOCCLUSION

3. INTRODUCTION: In the specialty of orthodontics, the classification of malocclusion plays an important role. Classification aids in the diagnosis and treatment planning of malocclusions by orienting the clinician to the type and the magnitude of the problems and possible mechanical solutions to the problems.

4. Terminologies: Occlusion: The relation of maxillary and mandibular teeth when the jaws are closed in a centric relation without strain of musculature or displacement of condyles in their fossae. Ideal occlusion: It is a pre- conceived theoretical concept of occlusal structures and functional relationships that include idealized principles and characteristics that an occlusion should have.

5. 3) NORMAL OCCLUSION: It i s some deviation from that of ideal but is aesthetically acceptable and functionally stable for the individuals. - The upper and lower teeth fit nicely and evenly together with the least amount of destructive interferences.

6. ANDREWS 6 KEYS TO NORMAL OCCLUSION: Andrews in 1970s put forward the six keys to normal occlusion after studying models of 120 patients with ideal occlusion. The six keys to normal occlusion are considered under following headings.

7. Molar inter-arch relationship. Mesio -distal crown relationship. Labio -lingual crown inclination. Absence of rotation. Tight contacts. Curve of spee.

8. 4) malocclusion : Defined as a condition where there is departure from the normal relation of the teeth to the other teeth in the same dental arch or teeth in opposing arch. The term was coined by E dward H Angle , the father of modern orthodontics. It is a condition that reflects an expression of normal biologic variability in the way the maxilla and mandible teeth occlude - Bishara .

9. An occlusion in which there is a malrelationship between the arches in any of the planes of the spaces or in which there are anomalies in tooth position beyond the limit of normal- Walther and Huston .

10. Need for classification: Acquire a better understanding of the many deviates from normal occlusion. Divide the wide range into small groups. Describe the salient features. Helps in diagnosing and planning treatment for patient. Helps in visualizing and understanding the problem associated with that malocclusion.

11. 5) Helps in communicating the problem. 6) Comparison of the various malocclusions is made easy by classification. 7) Unify the communications.

12. Types of malocclusion: 1) Intra-arch malocclusion: It include variations in individual tooth position or a group of teeth within an arch. 2) Inter-arch malocclusions: I t compromise of mal relationship between two teeth or group of teeth of one arch to another arch. 3 ) Skeletal malocclusions: It involves the apical upper and lower bony bases.

13. Intra-arch malocclusions: It includes: Abnormal inclination. Abnormal displacement. Spacing and crowding within same arch.

14. Abnormal inclinations: 1)Mesial inclination: This is a condition where the crown of tooth is tilted or inclined mesially .

15. 2) Distal inclination: Refers to a condition where the crown is tilted or inclined distally.

16. 3 )Lingual inclination( Retroclination ): This is an abnormal lingual or palatal tilting of tooth.

17. 4 )Buccal inclination( Proclination ): This refers to labial or buccal inclination of tooth.

18. Abnormal displacement: 1) Mesial displacement : This refers to a tooth that is bodily moved in a mesial direction towards the midline.

19. 2) Distal displacement: T his refers to a tooth that is bodily moved in a distal direction away from the midline.

20. 3) Lingual displacement: This is a condition where the entire tooth is displaced in lingual direction.

21. 4) Buccal displacement: This is a condition where the tooth is displaced bodily in labial or buccal direction.

22. 5) extrusion(supra-version): this is a condition in which a tooth that has over erupted as compared to other teeth in the arch. 6) Intrusion(infra-version): Refers to a tooth that has not erupted enough as compared to other teeth in the arch.

23. 7) disto -lingual or mesio-buccal rotation: This describes a tooth that has rotated around its long axis so that the distal aspect is more lingually placed. 8) mesio -lingual or disto-buccal rotation: This is a condition where the tooth has rotated around its long axis so that the mesial aspect is more lingually placed.

24. 9)Transposition: This term describes a condition where two teeth have exchanged places.

25. Inter-arch malocclusions: These inter-arch malocclusions can occur in the: Sagittal plane Vertical plane Transverse plane of space.

26. Sagittal plane malocclusions: This includes condition where the upper and lower arches are abnormally related to each other in a sagittal plane. 1)pre-normal occlusions: T his is a condition where the lower arch is more forwardly placed when the patient bites in centric occlusion. 2)Post-normal occlusions: T his is a condition where the lower arch is more distally placed when the patients bite in centric occlusion.

27. Vertical plane malocclusions: These malocclusions include deep bite and open bite where an abnormal vertical relation exists between the teeth of upper and lower arch. 1)Deep bite or increased overbite: It is a condition where there is excessive vertical overlap between the upper and lower anterior. 2)Open bite: This is a condition where there is no vertical overlap between upper and lower teeth. -thus a space may appear between the upper and lower arch when the patient bites in centric occlusion. -it can either be in anterior or posterior region.

28. Transverse plane malocclusions: It includes various types of crossbites i.e. the abnormal transverse relationship between the upper and lower arches.

29. Skeletal malocclusions: - They are the malrelations of apical bases of upper and lower arch. -It is due to: Abnormal size Abnormal shape Abnormal relation to the skull Abnormal relation to each other

30. SAGITTAL PLANE MALOCCLUSION: The forward placement of a jaw is called as prognathism while more backward placement of jaw is called as retrognathism. Vertical plane malocclusions: The abnormal variations in vertical measurement of jaws can affect the lower facial height. Transverse plane malocclusion: It is a result of narrowing or widening of jaws. -can be described as narrow maxilla, wide mandible etc.

31. Classifications: A ngle classification Dewey's modification of Angles classification Lischer's modification of Angles’ classification Simon’s classification Bennett's classification Ackerman-Profit system of classification Ballard's incisor classification Katz premolar classification Newly proposed system

32. Angle’s classification: -It was introduced by Edward H Angle in 1899. -based on mesio-distal relation of the teeth, dental arches and the jaws. -According to him, the maxillary 1 st permanent molar is the key to occlusion and considered these as fixed anatomical points within jaws. -classified into 3 classes-class I, class II, class III.

33. Angle’s class i: -The mesio-buccal cusp of maxillary 1 st molar occludes in buccal groove of mandibular 1 st molar. -malocclusion could be crowding, spacing, rotations, missing tooth etc. -another malocclusion that is most often categorized under class I is bimaxillary protrusion where the patient exhibit normal class I molar relationship but the dentition of both the upper and lower arches are forwardly placed in relation to facial plane.

34. Angle’s class II: -Here the distobuccal cusp of the maxillary 1 st molar lies within the buccal groove of mandibular 1 st molar. -Divided into: Division 1: - proclined upper incisors with a resultant increase in overjet. - A deep incisor overbite can occur in anterior region. - Presence of abnormal muscle activity.

35. - The upper lip is usually hypotonic, short and fails to form a lip seal. -The lower lip cushions the palatal surface of upper teeth called as “lip trap”. -the muscle imbalance is produced by a hyperactive buccianator and mentalis and an altered tongue that accentuates the narrowing of upper dental arch (V shape). DIVISION 2:- presence of lingually inclined upper central incisors and labially tipped lateral incisors overlapping the central incisors.

36. Division 1 Division 2 Lip trap

37. Class II subdivision: - When a class II molar relationship exists on one side and a class I relationship on other side it is referred as class II subdivision.

38. Angle’s class III: -In this the mesiobuccal cusp of maxillary 1 st molar occludes the interdental space between mandibular 1 st and 2 nd molars. -Classified into: 1) True class III(skeletal) 2) Pseudo class III(false or postural).

39. True class III: It is of genetic origin and is due to: Excessively large mandible Forwardly placed mandible Smaller than normal maxilla Retro positioned maxilla Combination of above causes - The lower incisor tend to be lingually inclined.

40. Pseudo class III: - It is produced by forward movement of mandible during jaw closure; thus it is also called postural or habitual class III malocclusion. - It is due to: Presence of occlusal prematurities may deflect the mandible forward. In case of premature loss of deciduous posteriors. A child with enlarged adenoids.

41. Class III subdivision: This is a condition characterized by a class III molar relationship on one side ad class I on other.

42. Drawbacks of angle’s classification: Angle considered malocclusion only in antero -posterior plane not in transverse and vertical plane. He considered the 1 st permanent molars as fixed points in skull which was not found so. The classification cannot be applied if 1 st permanent molars are extracted or missing. The classification cant be applied to deciduous dentition.

43. 5) The classification does not differentiate between skeletal and dental malocclusions. 6) The classifications does not highlight the etiology of malocclusion. 7) Individual tooth malpositions have not been considered by Angle.

44. Dewey’s modification of angle’s classification: Divided class I into 5 subtypes and class III into 3 subtypes. Class I modification: - Type 1: - class I malocclusion with bunched or crowded anterior teeth. Type 2:- class I with protrusive maxillary incisors. Type 3: -class I malocclusion with anterior crossbite. Type 4: class I molar relation with posterior crossbite.

45. Type 5: - The permanent molar has drifted mesially due to early extraction of second deciduous molar or second premolar. Class III modification: Type 1:- The upper and lower dental arches when viewed separately are in normal alignment. But when the arches are made to occlude the patient shows an edge to edge incisor alignment ,suggestive of forward movement of mandible.

46. Type 2:- The mandibular incisors are crowded and are in lingual relation to the maxillary incisors. Type 3:- The maxillary incisors are crowded and are in cross bite in relation to mandibular anteriors.

47. Lischer’s modification of angle’s classification: Neutrocclusion : A ngle’s class I malocclusion. Distocclusion : Angle’s class II malocclusion. Mesiocclusion : Angle’s class III malocclusion. Buccocclusion: Buccal placement of a tooth or group of teeth. Linguocclusion : lingual placement of tooth or group of teeth. Supraocclusion: When a tooth or group of teeth have erupted beyond the normal level.

48. Infraocclusion: when a tooth or group of teeth have erupted below the normal level. Mesioversion: mesial to normal position. Distoversion: Distal to normal position. Transversion: transposition of two teeth. Axiversion: Abnormal axial inclination of a tooth. Torsiversion: Rotation of a tooth around its long axis.

49. Bennet’s classification: - Based on etiology . - Class I:- Abnormal position of one or more teeth due to local causes. - Class II:- Abnormal formation of a part of or whole of either arch due to developmental defects of bone. - Class III:- Abnormal relationship between upper and lower arches, and between either arch and facial contour and correlated abnormal formation of either arch.

50. Simmon’s classification: -It is a craniometric classification. -made use of anthropometric planes i.e. the Frankfort horizontal plane, the orbital plane, the midsagittal plane. - Classification was based on abnormal deviations of dental arches form their normal position in relation to these three planes.

51. FRANKFORT HORIZONTAL PLANE: - - It connects the margin of the external auditory meatus to the infra-orbital margin. -This plane is used to classify malocclusions in vertical plane . - When the dental arch or part of it is closer than normal to Frankfort plane, it is called attraction . - When the dental arch or part of it is farther away from the Frankfort plane, it is called abstraction .

52. Orbital plane: -This plane is perpendicular to the Frankfort plane, dropped down from the bony orbital margins directly under the pupil of the eye. -According to Simon, this plane should pass through the distal third of upper canine called as Simon’s law of canine . -This plane is used to describe malocclusion in sagittal or antero-posterior direction . -When the dental arch or part of it is away from orbital plane, it is called as protraction . -When the dental arch is closer or placed more posteriorly to this plane, it is called as retraction .

53. Mid sagittal plane:- -it is used to describe malocclusion in transverse direction. -When a part or whole of arch is away from the this plane, it is called as distraction . - When the dental arch is near to this plane, it is called as contraction .

54. Ackerman- profitt system of classification: - Based on 5 characteristics: Alignment Profile Transverse relationship Class Bite depth -considered transverse and vertical discrepancies. -evaluated crowded and arch asymmetry. -incisor protrusion. -influence of dentition on profile.

55. Venn symbolic diagram

56. Ballard’s classification: -Incisor classification. -A classification of malocclusion based on incisor. -As treatment is often primarily aimed at correcting this relationship. -Three classes: class I incisor class II incisor class III incisor

57. Katz premolar relationship: Premolar class I- most anterior upper premolar fits exactly into the embrasure created by distal contact of most anterior lower premolar. Premolar class II:- the most anterior premolar is occluding mesial embrasure created by distal contact of most anterior lower premolar. Premolar class III:- the most anterior premolar is occluding distal of the embrasure created by the most anterior lower premolar .

58. Bibliography: Balajhi – book of orthodontics Wikipedia

59. THANKYOU