92 R. F. SOGNNAES 



standing modern mans widespread dental ills) are spared from 

 destruction during life, subterranean saprophytes in search of food 

 are waiting in the ground to consume the buried dento-alveolar 

 organs bv a biological capacity to dissolve both the solid inorganic 

 salts, mainly calcium phosphate, and the proteinaceous organic 

 matrices, mainly collagen ("The houses of iyory shall perish . . . ," 

 Amos 3:15) (Sognnaes, 1960c). 



The Spectrum of Dento-Alveolar Destruction 



All told there are some thirty conditions, including those caused 

 by growth, aging, pathology, therapy, and experimental procedures, 

 in which the hard tissues of the dento-alyeolar apparatus can un- 

 dergo some form of biologically reyersible or irreyersible dissolution 

 (Table I). 



TABLE I. Dento-Alveolar Aspects of Hard Tissue Destruction 

 Bone destruction (maxillar}- and mandibular resorption processes) 



1. (a) Growth, eruption, and aging 



2. (6) Shedding mechanism 



3. (c) Traumatic occlusion 



4. (d) Orthodontic therapy 



5. (e) Periodontal disease 



6. (/) MetaVjolic bone disease 



7. ig) Jaw tumors, cysts, and infections 



8. (/i) Radiation injury 



Tooth destruction (enamel, dentin, and cementum) 



I. Dental attrition 



9. (a) Masticatory wear 



10. (b) Traumatic, general, and localized 



II. Dental resorption 



A. Internal pulpal (dentin) 



11. (a) Normal shedding 



12. (b) Pathologic granulations ("pink tooth") 



B. External periodontal (cementum) 



13. (a) Shedding and aging 



14. (b) Periodontal disease 



15. (f) Periapical tumors, cysts, and infections 



16. {d) Orthodontic therapy 



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