Only limited information is available con- cerning the alteration of the tissues that occur when the alveolar process (that houses and supports the teeth) is transformed to an edentulous ridge. Processes involved in the resolution of extraction sockets have been described in biopsy samples from both man and animal models (for review, see Trombelli et al. 2008). The human studies referred to, however, had rather short observation inter- vals and included few tissue samples. Hence, they provided no definitive information regarding the fully healed socket site. In a recent publication from this laboratory (Lind- he et al. 2012), the composition of the tissue (>5 months after tooth extraction) of the pos- terior edentulous maxilla in man was pre- sented. It was observed that in most biopsy sites, the hard tissue portion of the ridge was covered by a layer of compact, cortical bone while more central parts were comprised of cancellous bone including varying amounts of lamellar bone and marrow. In addition, >50% of the ridge was built up of mineral- ized bone, and the bone trabeculae had a ran- dom, apparently haphazard orientation.