1. Is periodontal disease the primary cause of tooth extraction in adults?
2. (1985) Growth in the Ageing Craniofacial Skeleton. Monograph 17, Craniofacial Growth Series, Center for Growth and Development. Ann Arbor, Michigan: The University of Michigan, pp. 110–111.
3. Relative importance of periodontal disease for full mouth extractions in the Netherlands
4. , and (1976) Oral Microbiology and Infectious Disease. Baltimore: Williams and Wilkins, 4th ed., p. 244.