Edentulation alters material properties of cortical bone in the human mandible.

Article Outline

• Purpose
• Material and methods
• Results
• Conclusion
• Copyright

Back to Article Outline

Purpose 

Residual ridge reduction after tooth loss is well documented; however, the effect of tooth loss on the material properties of mandibular cortical bone have not been studied well. This study evaluated the variation in material properties of the mandibular cortical bone in edentulous mandibles and compared it with data from a previous study on dentate subjects.

Back to Article Outline

Material and methods 

Ten completely edentulous human mandibles were selected for dissection from unembalmed cadavers. Forty-four cortical specimens were taken from each mandible, and their cortical thickness and density were measured. Bone specimens were measured using a digital caliper, and apparent density calculations were made based on Archimedes’ principle of buoyancy. Principal axes of each specimen were identified by an ultrasonic technique. Data were obtained and compared with data previously obtained from dentate mandibles by the authors. The specimen location from the edentulous mandible was compared with the corresponding location from the dentate mandible. Minitab software (Minitab Software, Pittsburhg, Pa.) was used for statistical comparisons.

Back to Article Outline

Results 

Mandibular cortical bone from endentulous specimens and dental cortical bone from dentate mandibles in similar sites differed in cortical thickness, elastic and shear moduli, anisotrophy, and orientation of the axis of maximum stiffness.

Back to Article Outline

Conclusion 

Cortical microstructural changes occur when the mandible becomes completely edentulous. This study suggests the importance of considering the 3-dimensional aspects of cortical bone and material properties for studies evaluating patterns and mechanisms of bone adaptation to the edentulous state. 23 references–RP Renner.