The effects of face mask therapy with and without rapid maxillary expansion in adolescent patients

Objective: To examine the effects of face mask therapy with and without associated rapid maxillary expansion (RME) in adolescent patients presenting with skeletal Class III malocclusion characterised by maxillary retrognathism.Methods: Case records consisting of lateral cephalograms and hand-wrist films of 43 patients with hypoplastic maxillary Class III malocclusions treated using a face mask with and without an RME were analysed. The patients were divided into two groups; Group A (N = 27) were treated with a face mask coupled with rapid maxillary expansion and patients in Group B (N = 16) were treated with a face mask appliance only. Ten cephalometric linear and 9 angular variables were measured to assess the dentofacial changes. Within group and between groups comparisons were determined by a paired t-test and Student's t-test, respectively.Results: Forward displacement of the maxilla and a clockwise rotation of the mandible occurred in both groups. The maxillarymandibular relationship improved and soft-tissue changes resulted in a more convex profile. The maxillary incisors moved forward only in Group B subjects but the mandibular incisors moved backward in both groups.Conclusions: Face mask therapy with and without an associated RME improved skeletal Class III malocclusion by a combination of skeletal and dental changes. These results suggested that the use of an RME should be based on clinical criteria rather than assisting the Class III correction.