In this case report, a 19-year-old male patient with maxillary transverse deficiency, concave profile, and facial asymmetry is presented. In the case of transversal insufficiency, nonsurgical maxillary expansion was performed with the miniscrew-assisted rapid palatal expansion (MARPE) appliance to reduce the number of surgeries and provide both dentoalveolar and skeletal expansion. The periodontal soundness and short-term stability of the maxillary expansion were confirmed both clinically and radiologically. Mandibular prognathism was later corrected with orthognathic surgery. MARPE is an effective approach to the treatment of maxillary transverse deficiencies in adult patients.