Resorption of teeth

External and internal resorption

1. RESORPTION OF TEETH Dr VASANTHI V Senior Lecturer, Dept of Oral Pathology

2. Glossary of the American Association of Endodontists , Condition associated with either a physiologic or a pathologic process resulting in loss of dentin, cementum or bone RESORPTION OF TEETH Physiologic/Pathologic External/Internal Tooth- resorbing cells ( dentinoclasts , odontoclasts , cementoclasts )

3. External Resorption Internal Resorption Periodontal/ Pericoronal Tissue Pulpal Tissue Periapical inflammation Reimplantation of teeth Tumors & Cysts Excessive occlusal /mechanical forces Impaction of teeth Idiopathic Idiopathic RESORPTION OF TEETH

4. ODONTOCLASTS (tooth resorbing cells) Analogous to osteoclasts Similar enzymatic properties and resorption patterns Ruffled border, contain fewer nuclei than osteoclasts , and have smaller resorption lacunae than osteoclasts

5. Degradation of the inorganic mineral structure Acid phosphatase and carbonic anhydrase II The carbonic anhydrase II enzyme catalyses the intracellular conversion of CO  2  to H  2  CO  3  , which provides a readily available source of H  +  ions to be pumped into the subosteoclastic region via the proton pump associated with the ruffled border Cysteine proteinase , collagenase and matrix metalloproteinase enzymes. The cysteine proteinase enzymes act at an acidic pH closer to the ruffled border, while collagenase and matrix metalloproteinase enzymes are active at the resorbing bone surface where the pH is closer to neutral due to the buffering capacity of the dissolving bone salts. Disintegration of the organic matrix

6. PHYSIOLOGICAL RESORPTION Physiologic resorption Direct pressure Signals from dental follicle

7. EXTERNAL RESORPTION Associated with Periapical inflammation

8. Associated with reimplantation of tooth

9. Associated with cysts & tumors

10. Associated with Orthodontic movement

11. Associated with impacted tooth

12. Idiopathic resorption

13. INTERNAL RESORPTION Odontoclastoma , Pink tooth of mummery, Internal granuloma , Chronic perforating hyperplasia of pulp Inflammatory hyperplasia of pulp Begins centrally within the tooth Blood supply brings the clastic cells in the pulp chamber Carious exposure, pulp infection

14. INTERNAL RESORPTION Round/ovoid radiolucent area – center of the tooth Inflammatory & replacement resorption . C/f – No early clinical symptoms Fist evidence – pink hue – crown – due to hyperplastic vascular pulp filling the resorbed area

15. INTERNAL RESORPTION Histopathological features Resorption of pulpal surface of dentin Proliferation of pulp tissue filling the defect Irregular lacunar resorption by odontoclasts – “ Odontoclastoma ” Alternating resorption & repair – irregular lacuna-like areas in dentin Partially/completely filled with irregular/ osteodentin Progression of lesion – complete resorption of dentin Coronal – resorption of enamel also Radicular – resorption of cementum too-complete separation - internal/external??/