lecture 7 abnormalitis of teeth not full

lecture 7 abnormalitis of teeth not full

1. POST-DEVELOPMENTAL LOSS OF TOOTH STRUCTURE

   • Internal resorption
     • after injury to pulpal tissues: physical trauma or caries, pulpitis.
       • resorption can continue as long as vital pulp tissue remains and may result in communication of the pulp with the PDL.
     • patterns
       • Inflammatory resorption
         • resorbed dentin is replaced by inflamed granulation tissue.
         • histo
           • the pulp tissue in the area of destruction is vascular
             • increased cellularity and collagenization
               • adjacent to the dentinal wall are numerous multinucleated dentinoclasts
                 • - An inflammatory infiltrate cells are common
       • Replacement or metaplastic resorption
         • involve any portion of the canal
           • cervical zone is the most affected
             • portions of the pulpal dentinal walls are resorbed and replaced with bone or cementum like bone.
               • destruction is less defined than that seen in inflammatory resorption
         • histo
           • pulp tissue is replaced by woven bone that fuses with the adjacent dentin
     • affected part
       • coronal pulp
         • crown can display a pink discoloration (pink tooth of Mummery)
       • root
         • he original outline of the canal is lost and a balloon-like radiographic dilation of the canal is seen.
   • External resorption
     • extremely common
     • Factors
       • 1. Periradicular inflammation 2. Excessive mechanical forces (e.g., orthodontic therapy) 3. Dental trauma 4. Excessive occlusal forces 5. Pressure from impacted teeth 6. Intracoronal bleaching of pulpless teeth 7. Periodontal treatment 8. Reimplantation of teeth 9. Grafting of alveolar clefts 10.Cysts 11.Tumors 12.Hormonal imbalances 13.Hyperparathyroidism 14.Local involvement by herpes zoster 15.-Paget disease of bone
     • Clinical and Radiographic
       • occur at any site that contacts vital soft tissue
         • Most cases involve the apical or midportions of the root
       • "moth-eaten” loss of tooth structure- less well defined
       • compressive forces appear more strongly related than tensile forces.
     • Idiopathic apical root resorption involving multiple teeth in maxillary and mandibular arches
     • histo
       • numerous multinucleated dentinoclasts located in the areas of structure loss
         • resorption area <<repaired by deposition of osteodentin.
           • large defect
             • inflamed granulation tissue
             • woven bone
             • Extensive bony replacement<<lead to Ankylosis.
     • treatment
       • Apically sites cannot be approached without significant damage
       • cervical areas can be treated by surgical exposure, removal of all soft tissue from the defects, and restoration of the lost structure o the tooth