OBJECTIVE To test the hypothesis that maxillary development may be affected by occlusal support. METHODS The sample was composed by Wistar rats (5 weeks old) divided into three groups: Control (n = 10), extraction of mandibular molar teeth - left side (n = 10), extraction mandibular molar teeth - left and right sides (n = 10). The rats were sacrificed 8 weeks postextraction. Cone beam computed tomography scan images were taken for posterior measurement of maxillary length and width. Data were analyzed by one-way analysis of variance (Tukey test as post-hoc test). RESULTS Maxillary length was significantly shorter (P < 0.005) in both groups after tooth extraction. No difference was observed regarding maxillary width and body weight. CONCLUSIONS Reduced occlusal support may impair the development of the maxilla in rats.