Fig. 2.

Diagrams for alveolar ridge and buccal undercut measurements. a. Alveolar height and width measurements. Line “a” represents the floor of nasal fossa. Green line represents the distance from alveolar crest to the floor of nasal fossa, and is designated as alveolar height. The alveolar height is divided into thirds (shown by the purple dots). In the middle of each third, a dotted purple line is drawn perpendicular to the long axis of the ridge and extends from buccal to palatal cortical plate. The distance between the two plates is designated as alveolar width at apical third, middle third, and coronal third, respectively. b. Buccal undercut location and depth measurements. Line “b” is the alveolar crest line perpendicular to the long axis of alveolar ridge. Blue dot is where buccal cortical plate starts dipping. The distance from the blue dot to line “b” is designated as buccal undercut location. Line “c” is tangent to buccal cortical plate and parallel to the long axis of alveolar ridge. The pink dot represents the deepest point on the buccal undercut. The green line representing the distance between the deepest point and tangent line is designated as the buccal undercut depth