The effects of a modified protraction headgear on maxilla

Protraction headgears are commonly used in the treatment of Class III maloc clusion characterized by maxillary retrognathism. The upward and forward ro tation of the maxilla during protraction is a major unwanted side effect. T he aim of this study was to eliminate the upward and forward rotation of ma xilla while protracting. Seventeen patients with Class III malocclusion as a result of maxillary retrognathism were treated for 3 months; their averag e age was 12.81 years. A full coverage acrylic cap splint-type rapid maxill ary expansion appliance was cemented and activated twice a day for 5 days. After sutural separation, a maxillary modified protraction headgear was wor n and 750 g of force was applied. Wilcoxon signed rank test was carried out to evaluate 42 parameters measured on cephalometric radiographs. The maxil la was displaced anteriorly by downward and backward rotation. The mandible was displaced downward and backward due to anterior elongation of the maxi lla. Extrusion and lingual tipping of the upper incisors and intrusion of u pper molars and downward and backward rotation of functional occlusal plane were observed, The aim of our study was achieved, which was to avoid upwar d and forward rotation while protracting the maxilla. In conclusion, maxill ary modified protraction headgear (MMPH) can be used effectively in Class I II patients with retrognathic maxilla and anterior open bite tendency.