This work is motivated by the lack of current imaging modalities to accurately predict the mechanical properties and defects in jawbone. Ultrasonic guided waves are sensitive to changes in microstructural properties and thus have been widely used for non-invasive material characterization. Guided waves propagating along the mandibles may exhibit dispersion behavior which depends on material properties, geometry and embedded cavities. In this work, we present the first theoretical and experimental study for the analysis of guided wave propagation in jawbone. Semi-analytical finite-element (SAFE) method is employed to analyze dispersion behavior of guided waves propagating in human mandibles. The cross section of the mandible is divided in two regions representing the cortical and trabecular bones. The experimental set-up for the guided waves experiment is described. Gabor Wavelet is used to calculate the experimental dispersion behavior from the ultrasound radio frequency (RF) signals. Results from both numerical analysis and guided waves experiment exhibit variations in the group velocity of the first arrival signal and also in the dispersion behavior of healthy and defected mandibles. These results shall provide a means to non-invasively characterize the jawbone and assess the bone mechanical properties.