Functional Demands Change Bone Mineral Density at Different Tooth Locations

Objectives: Each tooth has a different functional demand for mastication. As such, the bone surrounding the teeth should bear different levels of masticatory force to maintain a healthy dentition. The objective of the study was to examine how the masticatory functional demands can affect the local bone densities that play an important role in determining the stability of teeth.
Methods: Following the approved IRB, 61 clinical cone beam computerized tomography (CBCT) images were obtained from 34 female and 27 male patients (age range of 40 to 60 years). The alveolar bone (AB) regions of the incisors and left first premolar in the mandibular arch were isolated within 1mm outside the root surface. The basal cortical bone (CB) regions of the identical dentition were measured at 0.6 mm inside the mandibular bone borders. The mean gray level, which is proportional to the bone mineral density (BMD), was measured for each bone region. A paired t-test and Pearson's correlation were performed to compare and correlate the AB and CB gray levels of the incisor and premolar regions of the same patient.
Results: The gray levels of AB were significantly higher around the incisors than the premolar (p<0.001) while those of CB were the opposite (p=0.04). The gray levels of AB and CB around the incisors have weak but significant correlations with those around the premolar (r<0.17, p<0.001).
Conclusions: The result collected suggests that higher BMD of AB can provide more stability to resist a stronger unit force of mastication transmitted to the incisors than to the premolar. The significant correlations of BMD between the incisors and the premolar regions indicate that the oral bones develop interactively between the oral anatomical sites of the same individual. These results provide a heterogeneous BMD information to help the diagnosis of site-specific oral bone disease.