On the lingual surfaces of the individual, dry mandibles, the interalveolar medial and lateral foramina were examined close to the crest of alveolar ridge
[Figure 1].[sup] The interalveolar medial foramen is defined when the foramen is located between the central and lateral incisors, whereas the interalveolar lateral foramen is between the lateral incisors and the canines.
For the mandible, the primary stress-bearing area is buccal shelf area and relieving area is a sharp mylohyoid ridge and the crest of alveolar ridge
. Selective pressure can be achieved either by scraping of the primary impression in selected areas or by fabrication of a custom (special) tray with a proper spacer design and escape holes (relief).
Primary stress bearing areas of maxilla are crest of alveolar ridge
and the horizontal plate of palatine bone and in the mandible; it is the buccal shelf area.