Pre Maxilla Appliance
The P.M.A. appliance is designed to place pressure on the premaxilla advancing Point “A”, and in turn creating a skeletal overjet of the maxilla to the mandible. This orthopedic correction when compensating the skeletal Class three patient, and when treating a maxilla that is excessively retrognathic relative to the anterior cranial base (Factor #1 -4.0 degrees or greater).
The P.M.A. appliance is always used in the permanent dentition. The Reverse Pull Head Gear is the appliance of choice for advancing the maxilla in the younger patient.
The appliance is typically banded on the maxillary first bicuspids and first molars. It is bonded to the palatal surface of the four upper incisors and the cuspids. Niti open coil springs are loaded on the buccal drive bars using a lock to compress the springs. The springs are reloaded on a monthly basis until the desired skeletal over jet is obtained.