Anterior overbites, whether they result from alveolar discrepancies or skeletal ones, such as sever rotation during anterior growth, and open bites can both interfere with vertical mandibular movement( Figs3-3 and3-4).

• 前牙区过度垂直覆盖不论是来自齿槽或骨骼上的差异，如在前区生长期间之分离旋转，与可能是两者（槽或骨骼）有干扰的开咬有下颚垂直运动，图3-3与3-4。