Figure 8.

Example artifacts and challenges encountered during this investigation. Panel A shows a midfacial sonogram of an incisor. Crown and root are collinear. The blue dashed box indicates reverberation from the gel pad and within the crown. Panel B shows a midfacial sonogram of a premolar where the crown, neck and root are not collinear. Panel C shows the shadowing effect of a ligature on the crown. Panel D shows the E₁’s annotation (solid line) and prediction (dashed line) masks of the crown. Proximal refers to the side closer to the transducer.