| 摘要 |
An orthodontic screw system includes two rods connected to rotatable head members. The two rods are couplable to one or more of lower teeth or mandibular bones of a patient. The rotatable head members have threaded holes and pairs of the rotatable head members have opposite hand threads. The screw system also includes two twin screws that have threaded ends of opposite hand threads. Each of the two twin screws is engaged to threads of a pair of the rotatable head members. Rotation of one of the twin screws causes the pair of rotatable head members and the ends of the rods to either move together or move apart. The two twin screws are independently rotatable to cause independent expansion or contraction of different portions of the screw system. |
