Microscopic anatomy of edentulous residual alveolar ridges

The histologic tissue changes of the residual alveolar ridges were studied in five edentulous patients ranging from 55 to 80 years of age. The material studied was obtained from cadavers. The following observations were made: (1) The epithelium was hornified. Acanthosis was found in all specimens. (2) In four of the specimens, the collagen fibers covering the residual bone crest showed a hyalinized area. (3) Mucoid collagen degeneration was seen in all specimens. (4) The most striking finding, common to all specimens, was the epithelial remnants. Resting and proliferating types were identified. (5) Chronic inflammation was found in all specimens. (6) Both osteoid and necrotic bone types were observed. (7) An outstanding characteristic of the residual alveolar ridge was the reinforcement of the internal structure of the bone by endosteal apposition.