She is not comfortable with intraoral X-ray.  So CBCT is taken.  The coronal section shows that the bone density is low in the coronal ridge (Fig.2 arrowheads).  It is difficult to determine the buccolingual width at crest; probably a 5.9x10 mm implant is appropriate (Fig.3). 

Atrophic Ridge

Xin Wei, DDS, PhD, MS 1st edition 04/15/2015, last revision 04/15/2015