| 摘要 |
<p>A maxillary protraction device (12) characterized with a chin-cup (1); one or more front hook-levers (2) on the front section of said chin-cup (1) to exert a force horizontally and forwards to the chin; at least two lateral linear hooks (5) located at the sides of the chin-cup (1) to exert an upwards force to the chin orthogonally; a stationary or movable anchorage unit (13) placed on the upper palate; a head-cap (11) to be placed on the head; front recesses (6) and lateral recesses (7) to be used for engaging the hooks (2 and 5) to the chin-cup (1), in the same number as that of hooks; and fixing members (9) in the same number as that of hooks.</p> |
