A comparison of maxillary and mandibular bone mineral densities.

STATEMENT OF PROBLEM: The success rate of implant osseointegration is dependent on many factors such as bone mineral density, volume and vascularity of bone, implant design, ridge shape, and patient selection criteria among others.
PURPOSE: This study examined whether a technique to measure differences in bone mineral density in the maxilla and mandible might be useful to predict the likelihood of successful osseointegration.
MATERIAL AND METHODS: Bone densitometry of the jaws was performed with a densitometer, and bone mineral density was calculated at three regions of the maxilla and one site in the mandibular body in 39 edentulous subjects.
RESULTS: Significant differences were found between the mean bone mineral density of each site when compared with the three other locations. The mean bone mineral density for the mandible (mean = 1.11 g.cm-2), was twice that of the anterior maxilla (mean = 0.55 g.cm-2). Both were significantly greater than the bone mineral density of the posterior maxilla (mean = 0.31 g.cm-2; including the hard palate, mean = 0.45 g.cm-2). The bone mineral densities at the three maxillary sites were all highly correlated (r > or = 0.78, p < 0.001).
CONCLUSION: The dissimilarity in bone mineral density at different mandibular and maxillary sites may partly explain some variation in previously reported osseointegration rates. The posterior maxilla had the lowest bone mineral density and in certain circumstances before implant insertion, bone augmentation, or guided tissue regeneration may be advisable to improve the rate of osseointegration. Because the radiation dose is low, dual energy x-ray absorptiometry may be a useful noninvasive technique for determining the bone mineral density before implant insertion.