Introduction to Occlusion

1. Introduction to Occlusion Ideal Anatomical Contacts

2. Which cusp of which tooth is represented by the black dot (red arrow)? The black dots represent MI contacts in a Class I occlusion 22 black dots represent 36 areas of contact of mandibular teeth with teeth in the maxillary arch

3. Guidelines for Learning Ideal Contacts Maxillary third molar Maxillary second molar Maxillary first molar Mandibular third molar The DB (distobuccal) cusps of the mandibular molars contact the central pit or fossa of their maxillary counterparts Mandibular second molar Mandibular first molar

4. Guidelines for Learning Ideal Contacts Maxillary third molar Maxillary second molar Maxillary first molar The MB (mesiobuccal) cusps of the mandibular molars contact the MMR of their maxillary counterparts and the DMR of the tooth mesial to that Mandibular third molar Mandibular second molar Mandibular first molar

5. Guidelines for Learning Ideal Contacts Maxillary second premolar The B (buccal) cusps of the mandibular premolars contact the MMR of their maxillary counterparts and the DMR of the tooth mesial to that Maxillary first premolar Mandibular second premolar Mandibular first premolar

6. Guidelines for Learning Ideal Contacts The cusp tip of the mandibular canines contacts the MMR of their maxillary counterparts and the DMR of the tooth mesial to that (maxillary lateral incisor) Maxillary canine Mandibular canine

7. Guidelines for Learning Ideal Contacts The incisal ridges of the mandibular lateral incisors contact the MMR of their maxillary counterparts and the DMR of the tooth mesial to that (maxillary central incisor) The incisal ridges of the mandibular central incisors contact the MMR of their maxillary counterparts Maxillary lateral incisor Maxillary central incisor Mandibular lateral incisor Mandibular central incisor

8. Guidelines • Identify tooth shown • Dot represents cusp of opposing tooth • Mandibular teeth are 1/2 cusp mesial to the maxillary counterparts • Contacts same for all mandibular molars • DB cusp (Md) ->Central Fossa (Mx) • MB cusp (Md)-> MMR & DMR (Mx) • B cusps and canines (Md) contact MMR & DMR of teeth 1/2 cusp mesial to maxillary counterparts • Each tooth contacts two teeth • Except maxillary third molars • Except mandibular central incisors

9. Which cusp of which tooth is represented by the black dot (red arrow)? DB cusp of the mandibular left first molar B cusp of the mandibular right first premolar

10. Determinants of Occlusion Horizontal Determinants Ridge and Groove Direction

12. Working

13. Balancing Working Working

14. Protrusion

17. Balancing Working

18. Balancing Working

19. Protrusion

21. Determinants of Occlusion Horizontal Determinants Ridge and Groove Direction Balancing Side Interferences

22. Balancing Working

23. Balancing side • Interference • Inner inclines of maxillary MLi cusp (CHC) • Inner inclines of mandibular DB cusp (CHC) Frontal View Balancing Working

24. Determinants of Occlusion Horizontal Determinants Ridge and Groove Direction Working Side Interferences

25. Balancing Working

26. Working side • Interference • Inner inclines of maxillary and mandibular cusps ( Non- CHC cusps) • Outer inclines of maxillary and mandibular cusps (CHC cusps) Frontal View Balancing Working

27. Determinants of Occlusion Horizontal Determinants Ridge and Groove Direction Distance from the Condyles

30. Balancing Working

31. Balancing Working

32. Protrusion

33. The angle between the working and idling grooves becomes greater the further the tooth is from the condyles