Vertical control is the key to successful orthodontic treatment of Class II malocclusion. The control of the horizontal movement of the dentition depends on how the vertical dimension of the maxillomandibular complex is controlled. Vertical control can make horizontal correction possible. This might be the single most important mechanical consideration that has to be accomplished during the treatment of the patient with a high angle Class II malocclusion. Successful correction of various orthodontic problems depends on the control of the horizontal planes, particularly the occlusal plane. The occlusal plane is the key to counterclockwise rotation of the horizontal planes. The clinician should control extrusion of the maxillary and mandibular posterior teeth, and control anterior vertical dimension, particularly the maxillary anterior segment during mechanotherapy to maintain or close the occlusal plane. A large increase in horizontal mandibular response for Class II correction, chin enhancement, and Z-angle improvement can be achieved by vertical control. Micro-implant anchorage (MIA) is very effective in maintaining or closing the occlusal plane and mandibular plane with counterclockwise movement of the chin by vertical control of maxillomandibular complex.
Define and identify the characteristics of Class II malocclusion.
Describe and explain the importance of the vertical control using Tweed-Merrifield directional force technology in Class II treatment.
Demonstrate and distinguish the efficiency of the Micro-implant anchorage (MIA) for vertical control in Class II treatment.