An oral interface (100, 400, 401, 402, 403, 404, 500, 600, 700, 800, 1000, 1400, 1500, 1501, 1700, 1800, 1900, 2100, 2200), comprising: a connecting tube (110, 410, 411, 412, 413, 414, 510, 610, 710, 810, 1010, 1410, 1510, 1511, 1710, 1810, 1910, 2110, 2210) having a first end and a second end, the first end being in communication with a negative pressure source (590, 592, 594, 1080, 1082, 1084, 2111); a collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220) having a third end and a forth end opposite the third end, the third end being in communication with the second end of the connecting tube and the forth end being open-ended; and a non-collapsible structure (130, 431, 432, 433, 434, 630, 730, 830, 1430, 1431, 1432, 1531, 1531', 1730, 1830, 1930, 2130) disposed on at least one internal wall of the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220); wherein when a negative pressure environment is generated inside the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220) via being pumped by the negative pressure source (590, 592, 594, 1080, 1082, 1084, 2111), the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220) is adapted to assume a collapsed condition, while the non-collapsible structure (130, 431, 432, 433, 434, 630, 730, 830, 1430, 1431, 1432, 1531, 1531', 1730, 1830, 1930, 2130) supports the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220) whereby there are fluid channels formed inside the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220), the non-collapsible structure (130, 431, 432, 433, 434, 630, 730, 830, 1430, 1431, 1432, 1531, 1531', 1730, 1830, 1930, 2130) has one or a plurality of first ribs (430, 1030, 1530) disposed on one internal wall of the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220), and characterized in that the non-collapsible structure (431, 432, 433, 434, 1531, 1531') has one or a plurality of second ribs (430', 1030', 1530') disposed on another internal wall of the collapsible chamber (420, 421, 422, 423, 424, 1020, 1520, 1521) opposite to the first ribs, the first ribs (430, 1030, 1530) and the second ribs (430', 1030', 1530') constituting a perpendicular or non-parallel stack configuration. a connecting tube (110, 410, 411, 412, 413, 414, 510, 610, 710, 810, 1010, 1410, 1510, 1511, 1710, 1810, 1910, 2110, 2210) having a first end and a second end, the first end being in communication with a negative pressure source (590, 592, 594, 1080, 1082, 1084, 2111); a collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220) having a third end and a forth end opposite the third end, the third end being in communication with the second end of the connecting tube and the forth end being open-ended; and a non-collapsible structure (130, 431, 432, 433, 434, 630, 730, 830, 1430, 1431, 1432, 1531, 1531', 1730, 1830, 1930, 2130) disposed on at least one internal wall of the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220); wherein when a negative pressure environment is generated inside the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220) via being pumped by the negative pressure source (590, 592, 594, 1080, 1082, 1084, 2111), the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220) is adapted to assume a collapsed condition, while the non-collapsible structure (130, 431, 432, 433, 434, 630, 730, 830, 1430, 1431, 1432, 1531, 1531', 1730, 1830, 1930, 2130) supports the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220) whereby there are fluid channels formed inside the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220), the non-collapsible structure (130, 431, 432, 433, 434, 630, 730, 830, 1430, 1431, 1432, 1531, 1531', 1730, 1830, 1930, 2130) has one or a plurality of first ribs (430, 1030, 1530) disposed on one internal wall of the collapsible chamber (120, 420, 421, 422, 423, 424, 520, 620, 720, 820, 1020, 1420, 1421, 1422, 1520, 1521, 1720, 1820, 1920, 2120, 2220), and characterized in that the non-collapsible structure (431, 432, 433, 434, 1531, 1531') has one or a plurality of second ribs (430', 1030', 1530') disposed on another internal wall of the collapsible chamber (420, 421, 422, 423, 424, 1020, 1520, 1521) opposite to the first ribs, the first ribs (430, 1030, 1530) and the second ribs (430', 1030', 1530') constituting a perpendicular or non-parallel stack configuration.