maxilla expansion is a procedure that aims at increasing the maxillary dental arch to correct occlusal disharmony. largely used in children, its efficacy in adults, when craniofacial growth has attained bone maturity, is controversial. aim: the present study has the objective of evaluating cephalometric modifications resulting from maxilla expansion in adult patients, observing the following linear measurements: facial width, nasal width, nasal height, maxillary width, mandibular width and maxillary molar width. material e methods: the sample was composed of 24 frontal teleradiographs, taken before and immediately after the expansions, from 12 male and female patients aged between 18 years and two months and 37 years and eight months. all patients were submitted to slow expansion of the maxillary bones by means of an appliance used in the technique named "dynamic and functional maxillary rehabilitation". wilcoxon paired statistical test was used for related samples with a 5% significance level. results: there was a mean increase of 1.92 mm in nasal width and 2.5 mm in nasal height. as regards the linear measurements maxillary and mandibular width, the mean increase was 2.42 mm and 1.92 mm, respectively. a mean increase of 1.41 mm was found for facial width and 2.0 mm for maxillary molar width, alterations which were statistically significant, the mean time was 5.3 months. conclusion: based on the results obtained, it may be concluded that the use of maxillary expansion induces increase of the facial measurements studied in adults.