| 摘要 |
<p>A safety device for orthodontic appliances using extraoral forces, including an extraoral bow (1) resiliently connected to a first magnetised plate (8) which is supported on a second magnetised plate of opposite polarity (10) carried by a holder (6, 7). The tensile strength of the magnetic connection is set so that the connection is broken when a given value is reached.</p> |
