Transcript Document
Introduction to Occlusion Ideal Anatomical Contacts B. Cleghorn DMD MSc Associate Professor Dalhousie University Which cusp of which tooth is represented by the black dot (red arrow)? The 22 black blackdots dots represent represent MI 36 contacts areas of contact in a Class of mandibular I occlusion teeth with teeth in the maxillary arch Guidelines for Learning Ideal Contacts Mandibular third molar Mandibular second molar Mandibular first molar Maxillary third molar Maxillary second molar Maxillary first molar The DB (distobuccal) cusps of the mandibular molars contact the central pit or fossa of their maxillary counterparts Guidelines for Learning Ideal Contacts Mandibular third molar Mandibular second molar Mandibular first molar 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 Guidelines for Learning Ideal Contacts Maxillary second premolar Mandibular second premolar Mandibular first premolar Maxillary first 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 Guidelines for Learning Ideal Contacts Maxillary canine Mandibular canine 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) Guidelines for Learning Ideal Contacts Maxillary lateral incisor Maxillary central incisor Mandibular lateral incisor Mandibular central incisor 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 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 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 Determinants of Occlusion Horizontal Determinants Ridge and Groove Direction B. Cleghorn DMD MSc Associate Professor Dalhousie University Working Balancing Working Working Protrusion QuickTime™ and a Animation decompressor are needed to see this picture. Balancing Working QuickTime™ and a Animation decompressor are needed to see this picture. Balancing Working Protrusion QuickTime™ and a Animation decompressor are needed to see this picture. Determinants of Occlusion Horizontal Determinants Ridge and Groove Direction Balancing Side Interferences B. Cleghorn DMD MSc Associate Professor Dalhousie University QuickTime™ and a Animation decompressor are needed to see this picture. Balancing Working Frontal View Balancing side Interference •Inner inclines of maxillary MLi cusp (CHC) •Inner inclines of mandibular DB cusp (CHC) Balancing Working Determinants of Occlusion Horizontal Determinants Ridge and Groove Direction Working Side Interferences B. Cleghorn DMD MSc Associate Professor Dalhousie University QuickTime™ and a Animation decompressor are needed to see this picture. Balancing Working Frontal View Working side Interference •Inner inclines of maxillary and mandibular cusps ( NonCHC cusps) •Outer inclines of maxillary and mandibular cusps (CHC cusps) Balancing Working Determinants of Occlusion Horizontal Determinants Ridge and Groove Direction Distance from the Condyles B. Cleghorn DMD MSc Associate Professor Dalhousie University QuickTime™ and a Animation decompressor are needed to see this picture. Balancing Working QuickTime™ and a Animation decompressor are needed to see this picture. Balancing Working Protrusion QuickTime™ and a Animation decompressor are needed to see this picture. The angle between the working and idling grooves becomes greater the further the tooth is from the condyles