Alveolar bone dehiscences and fenestrations: an anatomical study and review

To determine the prevalence and distribution of fenestrations and dehiscences of the jaw bones among the Caucasian population, to find if any correlations can be established between their occurrence and certain teeth characteristics and to discuss the clinical implications the defects of alveolar process could have.

138 skulls of specimens ranging from 21 to 54 years of age, having either complete dentition or reduced number of missing teeth were studied. Teeth found to have one of the two defects were examined for signs of faceting (attrition) that was considered an indicative for excessive occlusal forces and were submitted (except for the case of the third molars) to an analysis concerning their bucco-lingual inclination in the jaw.

High-prevalence rates for both osseous entities were found. Fenestrations were present in 69.565% of the skulls and dehiscences were present in 53.623% of the skulls. More fenestrations were found in the maxilla: 74.679% and more dehiscences were found in the mandible: 71.613%. No correlations could be established between the presence of dehiscences and fenestrations and the development of high-occlusal forces, whereas all teeth affected either by dehiscences or by fenestrations were found to have modifications of the normal bucco-lingual inclination angle's values (p<0.05).

The interest regarding the correlation between the alveolar processes morphology and the teeth dates back to 1963. The published studies are somewhat consistent with regard to prevalence and distribution of dehiscences and fenestrations, while opinions concerning their etiology are heterogenous. According to our study and the data provided by the specialized literature references, dehiscences and fenestrations are common findings related to the presence of the teeth.

The potential of developing fenestrations and dehiscences must be carefully evaluated through oral surgery procedures. With regard to implant placement, this study aims to help the clinician design and manage treatment, in order to clinically correct the conditions and identify the principles of bone augmentation, so that endo-osseous implants can be properly placed.