Objectives: The aims of this study are: 1) to assess the cephalometric variables of the oropharynx and soft palate with different anteroposterior jaw relationships treated with a RME; 2) to assess the cephalometric variables of the pharyngx in the control group; and 3) to compare the variables of both groups.

Materials and Methods: Seventy-one subjects with maxillary constriction are selected from records of the Department of Orthodontics of the LMU, Munich. The RME group is compared with a control group comprising of 47 subjects with normal transverse maxillary width. The average age of the control group at T0 is 9.94 ± 2.11 years while in the RME group is 10.15 ± 2.22 years. Orthodontic treatment among the 71 subjects is started with RME, followed by conventional orthodontic treatment, not combined with any other orthodontic device. Seven linears are determined and hand traced by one investigator.

Results: A change in the oropharyngx and soft palate following RME treatment in the RME group and with growth in the control group exists. There are statistically significant differences between the orthognathics of control group and subgroups of the RME group. No statistically significant differences are found between the RME and control groups according to the Mann Whitney U-test (P < 0.05).

Conclusion: The results suggest that airway dimension changes after RME treatment. In the control group, change is caused by normal growth. These changes are usually affected and compensated in time by natural growth. Thus, RME can assist nature to increase maxillary growth process.