Classification of malocclusion

The presentation features malocclusion, Angle's classification, dewey's modification and andrew's six keys of normal occlusion

1. Classification of malocclusion Made by :- Amit varma Inder pal singh muzalda B.D.S final yr Department of Pedodontics Govt. College of Dentistry, I ndore

2. NORMAL OCCLUSION The relation of the maxillary and mandibular teeth when the jaws are closed in centric relation without strain of musculature or displacement of condyles in their fossa .

3. SIX KEYS OF NORMAL OCCLUSION 1.Molar inter-arch relationship 2.Mesiodistal crown angulation 3.Labiolingual crown inclination 4.Absence of rotation 5.Tight contacts 6.Curve of spee

4. MALOCCLUSION Malposition and imperfect contact of the mandibular and maxillary teeth

5. Angle’s system of classification of malocclusion EDWARD HARTLEY ANGLE introduced a system of classifying malocclusion in the year 1899. ANGEL classification was based on mesio -distal relation of the teeth,dental arch and the jaws. According to ANGLE , the maxillary first permanent molar is the key to occlusion.

6. He consider these teeth as fixed anatomical points within the jaws. Based on the relation of the lower first permanent molar to the upper first permanent molar. He classified malocclusion into three main classes designated by the roman numerials I,II AND III.

7. ANGLE’S CLASS I ANGLE’S CLASS II CLASS II, DIVISION 1 CLASS II, DIVISION 2 ANGLE’S CLASS III TRUE CLASS III PSEUDO CLASS IIII

8. CLASS I MALOCCLUSION Class I molar relationship The mesio-buccal cusp of the maxillary first permanent molar occlude in the buccal groove of mandibular first permanent molar.

9. Class I malocclusion can be a discrepancy either within the arch and or in the transverse or vertical relationship between the arches The patient may exhibit dental irregularities such as crowding,spacing,rotations,missing tooth etc. These patients exhibit normal skeletal relation and also show normal muscle function. Another malocclusion that is most often categorized under class I is bimaxillary protrusion.

10. The patient exhibit a normal class I molar relationship but the dentition of both the upper and lower arches are forwardly placed in relation to the facial profile.

11. Extroral features:- shape of the head- mesocephalic Lips- competent facial profile- straight Nasolabial angle- normal

12. Intraoral features:- Class I molar relation Class I canine relation Class I incisor relation Cross bite Open bite/deep bite Proclination / retroclination Rotation Crowding/spacing Spacing in arch- may be present

13. DEWEY’S MODIFICATION He divide class I into 5 subtypes and class III into 3 subtypes.

14. Class I modification :- Type 1:- class I malocclusion with bunched or crowded anterior teeth.

15. Type 2:- class I with protrusive maxillary incisors.

16. Type 3:- class I malocclusion with anterior crossbite .

17. Type 4:- class I molar relation with posterior crossbite .

18. Type 5:- the permanent molar has drifted mesially due to early extraction of second deciduous molar or second premolar.

19. 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

20. Type 2:- the mandible incisors are crowded and are in lingual relation to the maxillary incisors.

21. Type 3:-the maxillary incisors are crowded in relation to the mandibular anteriors .

22. Thank you