In vitro experimental evaluation of mandibular bone quality using ultrasound measurement of speed of sound

Abstract AR

Background & Objective : Ultrasound quantitative measurements of speed of sound (SOS) represent an established means of skeletal status assessment.

Our study is the first attempt to use SOS as a new ultrasonic diagnostic tool for bone quality assessment before oral implant treatment.

The goal of this paper is to demonstrate the in vitro feasibility of local SOS measurement at the mandible, and to investigate the relationships between mandibular SOS and local bone mineral density (BMD) and the ratio between the trabecular and cortical thickness ( Tb.

Th/Cort.

Th).

Methoh: 14 excised human mandibles were measured in transmission with a pair of flat 1.6-MHz central frequency transducers.

Three regions of interest (ROls) were selected in the specimens: incisor, premolar and molar regions.

Ten measurements with repositioning were performed on each ROI to determine the short-term precision.

Dual X-ray absorptiometry scans were performed on the samples for local BMD measurements.

Computed Tomography (CT) was used with dentaScan software to determine mandibular cross-sectional morphological measurements.

Results: The coefficient of variation for SOS was found to be around 2%.

SOS measurements at different sites were significantly different, reflecting the heterogeneity between the different sites.

A strong linear relationship was found between SOS and BMD (r2=0.68, P<0.0001) while a non-linear relationship was found between SOS and Tb.Th/Cort.Th (r2= 0.5, P<0.0001).

Conclusion: Our study demonstrates in vitro the feasibility of SOS measurement at the mandible.

In vitro mandibular SOS reflects local bone quality before implant placement, which is important in obtaining a good result.