Figure 22. (a) Oblique sagittal T1weighted spin echo image ofthe right side of the face, hemisecting the teeth of both jawsthrough their anteroposterior midline. There is loss of signal around the roots of the lower premolars (arrowed) compared with the surrounding medullary bone signal. There is a large overjet (arrowed) of the upper anteriors in relation to the lower anterior teeth, typical of a Class 2 Division 1 (Angles classification) jaw relationship for this subject. (b) Oblique short tau inversion recovery (STIR) sequence image at a position equivalent to (a) shows an area of high signal (arrowed) at the same site as the area of signal loss in (a). The high signal around the crowns (V) of the lower molars is saliva retained in the mouth.