Dentoskeletal Effect of Using Hyrax Expander and Protraction Facemask in Early Treatment of Class III Malocclusion

Objective: To evaluate dento-skeletal effect of maxillary expansion appliance and protraction Facemask in early treatment of skeletal Class III malocclusion Materials and Method: 18 patients with an age range of (6-12) years with skeletal Class III malocclusions due to maxillary deficiency were selected. Patients received banded hyrax expander for 1 week then attached with face mask(FM) until a positive overjet was achieved. Cephalometric and cast variables were measured before and after treatment to evaluate the dento-skeletal changes produced by treatment. Results:Maxillary advancement with increased SNA, ANB (p<0.001) and (Co-A). Downward and backward rotation of the mandible with decreased SNB and FHN-Pg (p=0.02). An increase in total anterior facial height (p=0.04). Significant increase in both (PP/MP) and (FMA), (p=0.001). Lower incisors retroclination with decreased (L1-NB) measurement (p=0.04). A significant difference in both overjet and overbite (p<0.001). A significant increase in both arch length (p=0.006) and intermolar width (p=0.001). Conclusion:Maxillary expansion and protraction using hyrax appliance and Face mask therapy was effective in early management of skeletal Class III maxillary deficiency. Skeletal changes were primarily due to maxillary advancement, mandibular backward and downward rotation with an increase in the vertical facial dimensions.