classifcation of malocclusion

all types of classification of malocclusion

1. Dr. Nagi Hussein Al-Awdi MSc. in clinical Orthodontics Classification of malocclusion Development of Problems

2. Malocclusion definition Malocclusion is a condition in which there is a departure from the normal relation of teeth to the other teeth in the same arch and/or to the teeth in the opposing arch (White TC, Gardiner JH and LeightonB ).

3. Definition of classification in orthodontics ➤ Classification in orthodontics is concerned with the recognition of deviation from a quantitative and qualitative biological norm . ➤ Classification is also defined as the orderly reduction of the database to a list of the patient’s problem (William R Proffit). Classification employs various diagnostic criteria like clinical examination , facial photographs, radiographs and diagnostic casts .

4. Need/purpose/uses of classification There are various purposes/uses of classification: ➤ Classification is used for grouping of orthodontic problems into a category . ➤ Such grouping helps in ease of reference . ➤ Useful in locating the problems which have to be treated . ➤ Classification helps in diagnosis and treatment plan . ➤ Classification is done for the purpose of comparison of different types of malocclusions.

5. Need/purpose/uses of classification There are various purposes/uses of classification: ➤ Classification is used for communication . ➤ Useful for documentation of the problem . ➤ Used for studying in the prevalence and severity of malocclusion in population groups . ➤ Used for epidemiological studies . ➤ Training of orthodontist. ➤ To assess treatment effects of orthodontic appliances.

6. Methods of recording and measuring malocclusion/various methods of classification of malocclusion

7. Methods of classification can be broadly divided into two types: quantitative and qualitative types of classification and ( ii) intraarch and interarch problems .

8. I . Classification of malocclusion: quantitative and qualitative methods

9. Methods of classification can be broadly divided into two types: II . Classification based on intraarch and interarch problems Malocclusion can also be classified depending upon the problems present in the same arch ( intraarch) and the problems present between maxillary and mandibular arches (interarch ).

10. II . Classification based on intraarch and interarch problems Malocclusion a . Malpositions of an individual tooth or groups of teeth in the same arch/intraarch problems. This has five types : i. Sagittal problems Labioversion Linguoversion Mesioversion Distoversion

11. II . Classification based on intraarch and interarch problems Malocclusion a . Malpositions of an individual tooth or groups of teeth in the same arch/intraarch problems. This has five types : ii . Transverse problems Crowding Spacing Buccoversion Linguoversion

12. a . Malpositions of an individual tooth or groups of teeth in the same arch/intraarch problems. This has five types : iii . Vertical problems Supraversion Infraversion iv. Rotated teeth v. Transposition of teeth

13. II . Classification based on intraarch and interarch problems Malocclusion b . Malrelationship between upper and lower arches or interarch problems i. Sagittal Class II malocclusion Class III malocclusion ii. Transverse Crossbites, scissor bite Midline shift

14. II . Classification based on intraarch and interarch problems Malocclusion b . Malrelationship between upper and lower arches or interarch problems ii . Transverse Crossbites, scissor bite Midline shift iii. Vertical Deep bite Open bite

15. Angle’s classification of malocclusion Introduction ➤ Angle’s system of classification is based on the anteroposterior relationship of the teeth with each other . ➤ Edward Hartley Angle introduced this classification with the concept of key of occlusion and line of occlusion. ➤ Maxillary first permanent molar is considered to be the key of occlusion and Angle stated that the position of the maxillary first permanent molar is relatively constant.

16. Angle’s classification Angle described three classes of malocclusion . The three classes of malocclusion are based on the permanent first molar relationship . Class II malocclusion has got two types, namely division 1 and 2 .

17. Angle’s class I malocclusion ( neutroclusion ) Molar relation : The mesiobuccal cusp of the upper first molar occludes with the mesiobuccal groove of the lower first molar. Canine relation : The mesial incline of the upper canine occludes with the distal incline of the lower canine whereas the distal incline of the upper canine occludes with mesial incline of lower first premolar.

18. Angle’s class I malocclusion ( neutroclusion ) Line of occlusion : Line of occlusion will be altered in the maxillary and mandibular arches: • Individual tooth irregularities , like crowding, spacing, rotations, absence of tooth, will be seen. • Interarch problems , like deep bite, open bite, proclination or increased overjet, crossbite will be present . Class I bimaxillary protrusion Class I bimaxillary malocclusion is a condition where both the key of occlusion and line of occlusion are not altered , but the upper and lower anteriors are proclined and exist usually in an edge–edge relationship.

19. Angle’s class II division 1 malocclusion ( distoclusion ) Molar relation : Lower dental arch is distally positioned in relation to upper arch. The distobuccal cusp of the upper first permanent molar occludes with the mesiobuccal groove of the lower first permanent molar. Class II canine relation : The distal incline of upper canine occludes with mesial incline of lower canine .

20. Angle’s class II division 1 malocclusion ( distoclusion ) Line of occlusion : Altered; other features of class II division 1 are: 1. V-shaped or constricted maxilla 2. Proclined maxillary incisors 3. Lip trap 4. Exaggerated curve of Spee 5. Deep bite

21. Angle’s class II division 1 malocclusion ( distoclusion ) Class II division 1 subdivision : Condition where the class II molar relationship is unilateral or present only on one side with normal class I molar occlusion on the other side.

22. Angle’s class II division 2 malocclusion Class II molar relation: Lower dental arch is distally positioned in relation to upper arch . The distobuccal cusp of the upper first molar occludes with the mesiobuccal groove of the lower first molar . Class II canine relation : The distal incline of the upper canine occludes with the mesial incline of the lower canine .

23. Angle’s class II division 2 malocclusion Line of occlusion: Altered . Other features: ➤ Characteristic lingual inclination of upper central incisor alone or central and lateral incisors together . ➤ Canine overlaps the retroclined incisors . ➤ Closed bite will be present. ➤ Square-shape d arch. ➤ Exaggerated curve of Spee.

24. Angle’s class III malocclusion ( mesiocclusion ) Class III molar relation : The lower dental arch is in anterior relation to the maxillary arch . Mesiobuccal cusp of the upper first permanent molar occludes with the interdental space between the lower first and second permanent molars. Class III canine relation : Upper canine occludes with the interdental space between the lower first and second premolars .

25. Angle’s class III malocclusion ( mesiocclusion ) Line of occlusion: May or may not be altered . Other features are: ➤ Reverse overjet or anterior crossbite ➤ Maxillary anterior crowding ➤ Posterior crossbite Class III subdivision: Condition in which class III molar relation is present only on one side with normal molar relation on the other side .

26. Angle’s class III malocclusion ( mesiocclusion ) True class III : This is a skeletal malocclusion . The reasons for skeletal class III malocclusion are ➤ Retrognathic maxilla ➤ Prognathic mandible ➤ Combination of both In this class III , molar relation exists both in centric occlusion and rest position.

27. Angle’s class III malocclusion ( mesiocclusion ) Pseudo-class III/habitual class III: 1. This is not a true class III malocclusion. Due to occlusal prematurities , when the mandible moves from rest position to occlusion , it slides forwards into a pseudo-class III position. 2. These patients show normal molar relationship in rest position. 3. In centric occlusion , they show class III relation. 4. Cephalogram in both rest position and occlusion helps to differentiate between true class III and pseudo-class III malocclusion.

28. Merits and demerits of angle’s classification/validity of angle’s classification Merits 1. Angle’s system of classification is the most traditional and oldest system still in use. 2. Most practical and easy to comprehend method of classification. 3. Most popular . 4. Easy to communicate. 5. Widely used for teaching purpose .

29. Merits and demerits of angle’s classification/validity of angle’s classification Demerits 1. Disregarded the relationship of the teeth to the face. 2. Malocclusion is a three-dimensional problem , but Angle considered only sagittal dimension. 3. The position of the maxillary first permanent molar is not stable as stated by Angle. 4. Muscle malfunction and growth of bones were overlooked. These factors influence the molar position. 5. Classification is not applicable when first permanent molars are missing .

30. Merits and demerits of angle’s classification/validity of angle’s classification Demerits 6 . Not applicable in deciduous dentition . 7. When there is migration of first molar, classification is not feasible. 8 . Aetiology of the malocclusion is not known. 9. Skeletal problems are not given consideration. 10. Differentiation between dentoalveolar and skeletal malocclusion is not possible. 11. The classification considers only static occlusion .

31. Modifications of angle’s classification There are two modifications of Angle’s classification: Lischer’s modification and Dewey’s modification .

32. Modifications of angle’s classification Lischer’s modifications 1. Lischer introduced the following names to Angle’s classification. Neutroclusion – class I Distoclusion – class II Mesiocclusion – class III 2. Lischer also introduced nomenclature to describe malpositions of individual tooth. It consists of adding the suffix ‘ version’ to the word. These indicate the direction of deviation from the normal position.

33. Modifications of angle’s classification Lischer’s modifications • Mesioversion – mesial to the normal position. • Distoversion – distal to the normal position. • Linguoversion – lingual to the normal position. • Labioversion / buccoversion – towards the lip or cheek. • Infraversion – away from the line of occlusion. • Supraversion – crossing the line of occlusion. • Axiversion – wrong axial inclination. • Torsiversion – rotated on its long axis. • Transversion – transposition – wrong position in the arch .

34. Modifications of angle’s classification Dewey’s modification Martin Dewey divided Angle’s classes I and III into further types: ➤ Class I is divided into five types. ➤ Class III is divided into three types. ➤ Class II has no types . Class I ➤ Type 1: Crowded maxillary anterior teeth; canines may be abnormally positioned; other individual tooth irregularities present. ➤ Type 2 : Proclined or labioversion of maxillary incisors.

35. Modifications of angle’s classification Dewey’s modification Class I ➤ Type 3: Linguoversion of maxillary incisors; anterior crossbite present . ➤ Type 4 : Incisors and canines are normally positioned . Molars and premolars are in buccoversion . Posterior crossbites are seen. ➤ Type 5: Mesioversion of molars; molars have moved mesially due to premature loss of teeth anterior to molar .

36. Modifications of angle’s classification Dewey’s modification

37. Modifications of angle’s classification Dewey’s modification

38. Modifications of angle’s classification Dewey’s modification Class III ➤ Type1 : Well-aligned teeth and dental arches; edge–edge relationship exists. ➤ Type 2 : Crowded mandibular incisors; normally placed lower incisors behind the upper incisors. ➤ Type 3 : Crowded maxillary incisors; underdeveloped maxilla; anterior crossbite present.

39. Simon’s classification ➤ In Simon’s classification , the dental arches are related to three anthropologic planes. ➤ Since malocclusion is a three-dimensional problem, Simon devised this method of classification orienting dental arch to three different planes . ➤ It is a craniometric form of classification.

40. Simon’s classification Planes used 1. Frankfort horizontal plane or eye–ear plane (E–E–P) • This plane is obtained by drawing a line through the margin of inferior orbit below the eyeball and upper margin of auditory meatus . • This plane helps to detect deviatio ns in the vertical plane. • Height of the dental arches and teeth is related to the cranium. • Dental arch closer to the plane is called attraction and farther away from the plane is called abstraction

41. Simon’s classification Planes used 2 . Orbital plane (O–P) • This plane is obtained by drawing a line perpendicular to the Frankfort horizontal plane at the margin of the bony orbit below the pupil. • This plane helps to detect deviations in the sagittal plane . • Anteroposterior relationship of the dental arches and axial inclinations of the teeth are related to cranium . • Dental arch more anteriorly placed is called protraction and posteriorly placed dental arch is called retraction .

42. Simon’s classification Planes used 3 . Raphe median plane (R–M–P) or midsagittal plane • This plane is obtained by drawing lines through midpalatal raphe at right angle to Frankfort plane. • This plane helps to detect deviations in the transverse plane . • Mediolateral relationship of the dental arches and axial inclination of teeth are related to midline of the head. • Dental arch closer to midsagittal plane is called contraction and farther away from midsagittal Plane is called distraction .

43. Simon’s classification Law of canines According to Simon, in a normal arch relationship , the orbital plane passes through the distal aspect of canine. This is called ‘law of canines’.

44. Simon’s classification Interpretations of Simon’s classification of malocclusion

45. Incisor classification/British standard classification of incisor relationship ➤ British Standards Institute’s incisor relationship classification ( 1983) is used commonly nowadays . ➤ This classification is used without considering the molar relationship in some cases. ➤ Incisor classification is prone for interexaminer errors .

46. Incisor classification/British standard classification of incisor relationship Class I. The lower incisor edges occlude with or lie immediately below the cingulum of the upper central incisors. Class II . The lower incisor edges lie posterior to the cingulum prominence of the upper incisors .

47. Incisor classification/British standard classification of incisor relationship Class II . The lower incisor edges lie posterior to the cingulum prominence of the upper incisors. Division 1 : The upper central incisors are proclined or of average inclination . There is an increase in overjet . Division 2 : The upper central incisors are retroclined. The overjet is usually minimal but may be increased . Class III. The lower incisor edges lie anterior to the cingulum prominence of the upper incisor. The overjet is reduced or reversed .

48. Ackerman– proffit classification ➤ Ackerman and Proffit introduced a new method of classification to overcome the drawbacks of traditional Angle’s classification. It is based on Venn-Diagrams . It has got 9 groups . Ackerman and Profit gave an all-inclusive method of diagramming and categorizing malocclusions to overcome the limitations of the Angle’s classification system in which five characteristics and their interrelationships are assessed, using a modified Venn diagram .

49. Ackerman– proffit classification Five characteristics assessed are: 1 . Alignment 2. Profile 3. Type 4. Class 5. Bite depth. ➤ In this classification a set theory is used where sets or groups represent malocclusions. A group contained within a larger enveloping group is a subset of the latter (enveloping group). A subset has the characteristics of its outer group also along with its own characteristics .

50. Ackerman– proffit classification Since the degree of alignment and symmetry is common to all dentitions , this is presented as the outer envelope or universe (Group 1 ). The profile is affected by many malocclusions, so it becomes a major set within the universe (Group 2 ). Deviations in three planes are presented by Group 3–9 which include the overlapping or interlocking subsets.

51. Ackerman– proffit classification GROUPS AND SETS Group 1 Group 1 is the outer all enveloping group/universe, which represents alignment of teeth, since the degree of alignment and symmetry are common to all directions. Group 2 Group 2, representing the facial profile, becomes a major set within the universe (group 1), as the profile is affected by many malocclusions .

52. Ackerman– proffit classification GROUPS AND SETS Groups 3, 4 and 5 Groups 3, 4 and 5 represent deviations in three planes of space that is transverse (lateral), sagittal ( anteroposterior) and vertical plane, respectively. Groups 6, 7 and 8 The overlapping groups 6, 7 and 8 at the center of the Venn diagram represent more severe problems, with characteristics from their enveloping groups .

53. Ackerman– proffit classification GROUPS AND SETS Group 9 The group 9 at the exact center would be the most severe, with involvement of criteria from all the groups that is alignment , profile, transverse, anteroposterior and vertical problems .

54. Advantages of Ackerman-Profit Classification ➤ The advantages of Ackerman-Profit classification are as follows : 1. The complexities of malocclusion are explained . 2. All three planes or dimensional problems are included. 3. Profile of the patient is given due consideration 4. This classification helps in complete diagnosis and differential treatment planning. 5. Differentiation between skeletal and dental problem is made easily with this system of classifying malocclusions .

55. Advantages of Ackerman-Profit Classification ➤ The advantages of Ackerman-Profit classification are as follows : 6 . Arch length problems are evaluated. 7. Ackerman: Profit introduced a new method of classification to overcome the drawbacks of traditional Angle’s classification. 8. Readily adaptable to the computer processing .

56. Disadvantages of Ackerman-Profit Classification Disadvantages of Ackerman-Profit Classification 1. Etiological considerations are not included in the classification. 2. This system of classifying malocclusion is based only on static occlusion . Functional occlusion not included.

57. Skeletal classification Skeletal classification considers both the facial skeletal pattern and also the relationship of the teeth . Skeletal class I ➤ The bones of the face, maxilla and mandible are in normal relation to each other . ➤ Maxilla and mandible are in normal relation to the cranium also. ➤ Profile is orthognathic. Division 1 : Malpositions of incisors, canines o premolars . Division 2: Proclined maxillary incisors . Division 3: Linguoversion of maxillary incisors . Division 4: Bimaxillary protrusion .

58. Skeletal classification Skeletal class II ➤ Mandibular development retarded when compared to maxilla. ➤ Distal relationship of mandible to maxilla. Division 1 : Protrusion of maxillary anterior teeth. Narrow maxillary arch. Crowding in canine region. Posterior crossbite. Retrognathic profile. Division 2: Retroclined maxillary central incisors. Lateral incisors normal or labially placed .

59. Skeletal classification Skeletal class III ➤ Increased growth of mandible ➤ Prognathic profile ➤ Increased mandibular angle .

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