Prevalence of dehiscences and fenestrations in modern American skulls

Background: The purpose of this study was to examine the prevalence, distribution, and features of alveolar dehiscences and fenestrations in modern American skulls and correlate their presence with occlusal attrition, root prominence, and alveolar bone thickness. Methods: A representative sample of 146 dentate modern American skulls from a collection at the National Museum of Natural History were examined. Results: The skulls were from subjects ranging in age from 17 to 87 years old (mean 49.1 years). The mean number of teeth per skull was 22.7 and the mean number of either dehiscence or fenestration defects per skull was 3.0. Of the 3,315 individual teeth examined, 4.1% (135) had dehiscences and 9.0% (298) had fenestrations. A dehiscence was present in 40.4% of the skulls, and a fenestration was present in 61.6% of skulls. Mandibular canines were most often affected by dehiscences (12.9%), while maxillary first molars were most often affected by fenestrations (37.0%). Sixty-seven percent of dehiscences were found in the mandible, and 58% of fenestrations were found in the maxilla. Conclusions: The presence of dehiscences and fenestrations were positively correlated with thin alveolar bone and negatively correlated with occlusal attrition. African-American males and Caucasian females were significantly more likely to have dehiscences, while African-American females were significantly more likely to have fenestrations.