Bone density in human dentate and edentulous mandibles using computed tomography

Mandibular bone density, vertebral density and resorption of the edentulous ridge were correlated in a group of 17 partially edentulous subjects. Bone density was quantified by Quantitative Computerized Tomography; resorption was evaluated on panoramic radiographs. Mean bone density in dentate areas was significantly higher than that in edentulous areas; mandibular bone density was not found to relate significantly to vertebral bone density, nor to ridge resorption. In programming osseointegrated implants in the partially edentulous mandible, CT may give a more accurate evaluation of trabecular bone. However, further studies are necessary to clarify its clinical utility.

[The effect of mandibular bone density assessed by orthopantomography on the bone resorption of the alveolar crests]

The present study aimed to determine the value of orthopantomography in evaluating mandibular bone density in edentulous subjects; the authors proposed to correlate bone density evaluated using this methods with residual ridge resorption, age, and time of edentulism in the subjects in question. Bone density was evaluated from panoramic X-rays in 70 completely edentulous subjects through the observation of characteristics of bone trabeculae in a constant site for all 70 OPT, in correspondence with the horizontal blade of the jawbone, and through the subdivision of panoramic X-rays into three classes according to the greater or lesser compactness of the trabeculae of the cancellous bone. The resorption of residual ridges was assessed from OPT using Wical and Swoope's method. Correlations between bone density and residual ridge resorption, expressed in both mm and %, was statistical not significant. Correlations between the age of subjects examined and bone density, and between time of edentulism and bone density were also statistically not significant. The results obtained however appear to have been influenced by the non-reliability of data provided by OPT and draw attention to the need, in fully edentulous subjects, when programming, for example, osseointegrated implants, to study the quality of mandibular bone using more accurate and precise methods.

[The extent of mandibular bone resorption in edentulous subjects in relation to their psychological profile]

The resorption of edentulous alveolar crests has been correlated to a variety of factors which may be briefly summarised as anatomic, metabolic, functional and prosthetic factors. With regard to functional factors, some researchers have found that some psychological aspects in edentulous subjects may be indicative of a parafunctional damaging habit leading to consequent alterations of the physical characteristics of forces applied to the bone. The aim of this study was to evaluate whether alveolar crest resorption in edentulous subjects was correlated to aspects of their psychological status, such as trait anxiety and the presence of psychosomatic symptoms. A group of 70 totally edentulous subjects were examined and trait anxiety and the presence of psychosomatic symptoms were evaluated. The orthopantomographies of the 70 subjects were then analysed in order to assess the degree of edentulous crest resorption. The present study showed the absence of statistically significant correlations between edentulous crest resorption and trait anxiety and between edentulous crest resorption and the presence of psychosomatic symptoms. These results appear to indicate that "anxious" subjects might not have parafunctional habits or that the latter play a minor role in the process of edentulous mandibular crest resorption.